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IntroductionWe previously reported the initial results of a phase II multicenter transplant trial using haploidentical parental donors for children and aolescents with high-risk sickle cell disease achieving excellent survival with exceptionally low rates of graft-versus-host disease and resolution of sickle cell disease symptoms. To investigate human leukocyte antigen (HLA) sensitization, graft characteristics, donor chimerism, and immune reconstitution in these recipients.MethodsCD34 cells were enriched using the CliniMACS® system with a target dose of 10 x 106 CD34+ cells/kg with a peripheral blood mononuclear cell (PBMNC) addback dose of 2x105 CD3/kg in the final product. Pre-transplant HLA antibodies were characterized. Donor chimerism was monitored 1-24 months post-transplant. Comprehensive assessment of immune reconstitution included lymphocyte subsets, plasma cytokines, complement levels, anti-viral T-cell responses, activation markers, and cytokine production. Infections were monitored.ResultsHLA antibodies were detected in 7 of 11 (64%) evaluable patients but rarely were against donor antigens. Myeloid engraftment was rapid (100%) at a median of 9 days. At 30 days, donor chimerism was 93-99% and natural killer cell levels were restored. By 60 days, CD19 B cells were normal. CD8 and CD4 T-cells levels were normal by 279 and 365 days, respectively. Activated CD4 and CD8 T-cells were elevated at 100-365 days post-transplant while naïve cells remained below baseline. Tregs were elevated at 100-270 days post-transplant, returning to baseline levels at one year. At one year, C3 and C4 levels were above baseline and CH50 levels were near baseline. At one year, cytokine levels were not significantly different from baseline.DiscussionThese results suggest that haploidentical transplantation with CD34-enriched cells and peripheral blood mononuclear cell addback results in rapid engraftment, sustained donor chimerism and broad-based immune reconstitution.

Abstract Objective This study aimed to build and validate a nomogram model to predict the risk of incomplete immune reconstitution in people living with HIV (PLWH). Methods Totally 3783 individuals with a confirmed diagnosis of HIV/AIDS were included. A predictive model was developed based on a retrospective set (N = 2678) and was validated using the remaining cases (N = 1105). Univariate and multivariate logistic regression analyses were performed to determine valuable predictors among the collected clinical and laboratory variables. The predictive model is presented in the form of a nomogram, which is internally and externally validated with two independent datasets. The discrimination of nomograms was assessed by calculating the area under the curve (AUC). Besides, calibration curve and decision curve (DCA) analyses were performed in the training and validation sets. Results The final model comprised 5 predictors, including baseline CD4, age at ART initiation, BMI, HZ and TBIL. The AUC of the nomogram model was 0.902, 0.926, 0.851 in the training cohort, internal validation and external cohorts. The calibration accuracy and diagnostic performance were satisfactory in both the training and validation sets. Conclusions This predictive model based on a retrospective study was externally validated using 5 readily available clinical indicators. It showed high performance in predicting the risk of incomplete immune reconstitution in people living with HIV.

Ziwei Zhou, Xuan Liu, Xuejun Zhang, Shupeng Wen, Huan Hua, Zhenzhen Wang, Zheng Xu, Yu Lu, Fuxu Wang Department of Hematology, The Second Hospital of Hebei Medical University, Hebei Key Laboratory of Hematology, Shijiazhuang, Hebei 050000, People’s Republic of ChinaCorrespondence: Fuxu Wang, Department of Hematology, The Second Hospital of Hebei Medical University, Hebei Key Laboratory of Hematology, No. 215 West Heping Road, Shijiazhuang, Hebei, 050000, People’s Republic of China, Tel +86 13931100360, Fax +86 031166003936, Email wfxhebmu@163.comBackground: Early immune reconstitution is crucial to successful outcomes after allogeneic stem cell transplantation (allo-HSCT). However, in T cell-replete HSCT, the impact of natural killer (NK) cells on transplantation outcome and the factors influencing early NK cell reconstitution remain unclear.Methods: In this retrospective study, we analyzed 128 patients with hematological malignancies who received the first T cell-replete allo-HSCT between May 2019 and September 2021. After application of a conditioning regimen, prophylaxis for graft versus host disease (GVHD), and engraftment, the patients received prevention and treatment procedures for cytomegalovirus (CMV) reactivation. NK cells, T lymphocytes and B lymphocytes in peripheral blood were collected and analyzed at 30, 60, 90, 135 and 180 days after transplantation to observe immune cell reconstitution. Overall survival (OS), relapse-free survival (RFS), minimal residual disease (MRD), relapse, and non-relapse mortality (NRM) were evaluated. SPSS 25.0 and R version 4.2.1 were used for statistical analysis.Results: In patients with rapid NK recovery (NK cell count at 30 days post-HSCT [NK30] > 165/μL and 60 days post-HSCT [NK60] > 265/μL), we observed lower rates of NRM, CMV reactivation and acute GVHD (aGVHD). Multivariate analysis indicated that a lower NK30 (≤ 165/μL) was an independent factor associated with inferior OS and RFS. The NK30 and NK60 in patients with CMV reactivation and aGVHD after transplantation were significantly lower than those in patients without these complications. In addition, CD107a expression in NK cells was also significantly lower in patients who experienced aGVHD. Correlation analysis did not find an inhibitory effect of T-lymphocyte subset reconstitution on NK cells in the early stage after transplantation.Conclusion: Rapid NK cell reconstitution early after allo-HSCT had protective effects on NRM and survival. Promoting early NK cell reconstitution represents a new approach to improving the outcomes of allo-HSCT.Keywords: allogeneic hematopoietic stem cell transplantation, immune reconstitution, natural killer cells, T-cell replete, non-relapse mortality

Non-Hodgkin lymphoma (NHL) is among the five most common pediatric cancer diagnoses in children and adolescents and consists of a heterogeneous group of lymphoid tissue malignancies –with B-cell-derived NHL accounting for nearly 80% of cases. Novel and high-throughput diagnostic tools have significantly increased our understanding of B-NHL biology and molecular pathogenesis, leading to new NHL classifications and treatment options. This retrospective cohort study investigated 17 cases of both mature B-cell NHL (Burkitt lymphoma or BL; Diffuse large B-cell lymphoma or DLBCL; Primary mediastinal large B-cell lymphoma or PMBCL; Follicular lymphoma or FL) and immature B-cell progenitor NHL (B-lymphoblastic lymphoma or BLL) that were treated in a tertiary Pediatric Hematology-Oncology Department during the last 20 years. Modern NHL protocols for children, adolescents, and young adults, along with the addition of rituximab, are safe and efficient (100% overall survival; one relapse). Elevated ESR was more prevalent than elevated LDH. Analyses have focused on immune reconstitution (grade ≥3 infections, lymphocyte and immunoglobulin levels recovery) and body-mass-index changes post-treatment, late effects (in 53% of patients), and the presence of histology markers BCL2, BCL6, CD30, cMYC, and Ki-67%. One patient was diagnosed with a second malignant neoplasm (papillary thyroid cancer).

Triple-negative breast cancer (TNBC) in humans is the most aggressive and deadly form of BC. Although TNBCs are about 15 percent of the total number of BC cases, they are associated with the highest mortalities. Current treatment options are limited, and most modalities are toxic and have not increased the 5-year survival rates of TNBC. Many oncolytic viruses are emerging as potential therapies for TNBC. In this study, two Tanapoxvirus (TPV) recombinants, one expressing FliC and the other expressing mouse interleukin-2 (mIL-2), were assessed for their efficacy in an immuno-competent xenograft mouse model. MDA-MB-231 tumors were planted in BALB/c nude mice, treated, made immuno-competent via adoptive transfer of splenocytes from healthy BALB/c donors, and then monitored for 40 days. TPV/Δ2L/66R/FliC and TPV/Δ66R/mIL-2 demonstrated significant tumor reduction (p = 0.01602 and p = 0.03890, respectively) compared to the reconstituted control (RC), whereas wtTPV did not. Pathological analyses of treated tumors revealed cells consistent with lymphocyte and plasma cell morphology in reconstituted mice treated with TPV recombinants. Anti-viral plaque reduction assays conducted using harvested serum from treated animals indicated the presence of anti-TPV antibodies in mice reconstituted and treated with TPV that were missing from immune-deficient nude mice, including those exposed to TPV and of statistically equivalent serum concentrations to normal BALB/c mice immunized against TPV. The results suggest immuno-deficient BALB/c nude mice can become immuno-competent via adoptive transfer of splenocytes from genetically identical donors and allow for testing of tumor xenografts in a competent model system. The TPV recombinants tested should be further studied for the potential treatment of human TNBC.

Introduction: The immune reconstitution (IR) after the allogenic hematopoietic stem cell transplantation (allo-HSCT) is a progressive process intrinsically correlated to the therapeutic success. It is essential to understand the interfering factors in IR to prevent the HSCT-related mortality. Methods: We retrospectively evaluated the clinical outcomes, absolute lymphocyte counts (ALCs) and lymphocyte subtypes at different time-points of 111 pediatric patients with allogeneic HSCT for malignant and non-malignant diseases from 2013 to 2018. Results: The ALCs gradually increased on D+30, D+100, and D+180 (medians 634/μL, 1022/μL and 1541/μL, respectively). On D+100, the CD3+CD8+ achieved the highest recovery rate (68%), followed by the CD16+CD56+ (47%), CD3+CD4+ (39%) and CD19+ (8%). The adequate ALC recovery was associated with age < 8 years, bone marrow grafts, myeloablative conditioning, non-use of serotherapy and non-haploidentical donors. The ALC and CD3+CD8+ on D+100 counts were higher in patients with the cytomegalovirus infection. The CD3+CD4+ recovery was associated with an age < 8 years, a non-malignant disease and a lower incidence of acute graft-versus-host disease ≥ grade 2. Furthermore, the ALC recovery on D+100 resulted in a higher overall survival, regardless of the disease type (HR 3.65, 1.05 - 12.71, p = 0.04). Conclusion: Several factors influenced the IR after the allo-HSCT. The ALC ≥ 500/μL on D+100 was a simple IR predictor of survival, easily available to resource-limited centers.

ABSTRACTWe aimed to explore the impact of sexual transmission modes on immune reconstitution after combined antiretroviral therapy (cART). We have retrospectively analyzed longitudinal samples from 1557 treated male patients with virological suppression (HIV-1 RNA

Alemtuzumab is a monoclonal antibody targeting CD52 on the surface of immune cells, approved for the treatment of active relapsing-remitting multiple sclerosis (RRMS). The purpose of this study was to analyze the repopulation of peripheral lymphocytes following alemtuzumab-induced lymphocyte depletion and investigate associations with disease activity and development of secondary autoimmunity. For this, blood samples were collected two years after initiation of alemtuzumab treatment and lymphocytes were subjected to a comprehensive flow cytometry analysis. Included in the study were 40 patients treated with alemtuzumab and 40 treatment-naïve patients with RRMS. Disease activity and development of secondary autoimmune disease was evaluated after three years of treatment. Our study confirms that alemtuzumab treatment profoundly alters the circulating lymphocyte phenotype and describes a reconstituted immune system characterized by T cell activation/exhaustion, an increased regulatory control of IL-17 producing effector T cells and CD20+ T cells, and a reduced control of B cells. There were no obvious associations between immune cell subsets and disease activity or development of secondary autoimmune disease during treatment with alemtuzumab. Our results indicate that the reconstituted immune response is skewed towards a more effective regulatory control of MS-associated proinflammatory T cell responses. Also, the enlarged pool of naïve B cells together with the apparent decrease in control of B cell activity may explain why alemtuzumab-treated patients retain the ability to mount a humoral immune response towards new antigens. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to build and validate a nomogram model to predict the risk of incomplete immune reconstitution in people living with HIV (PLWH). Methods: Totally 3783 individuals with a confirmed diagnosis of HIV/AIDS were included. A predictive model was developed based on a retrospective set (N = 2678) and was validated using the remaining cases (N = 1105). Univariate and multivariate logistic regression analyses were performed to determine valuable predictors among the collected clinical and laboratory variables. The predictive model is presented in the form of a nomogram, which is internally and externally validated with two independent datasets. The discrimination of nomograms was assessed by calculating the area under the curve (AUC). Besides, calibration curve and decision curve (DCA) analyses were performed in the training and validation sets. Results: The final model comprised 5 predictors, including baseline CD4, age at ART initiation, BMI, HZ and TBIL. The AUC of the nomogram model was 0.902, 0.926, 0.851 in the training cohort, internal validation and external cohorts. The calibration accuracy and diagnostic performance were satisfactory in both the training and validation sets. Conclusions: This predictive model based on a retrospective study was externally validated using 5 readily available clinical indicators. It showed high performance in predicting the risk of incomplete immune reconstitution in people living with HIV. [ABSTRACT FROM AUTHOR]

Combination antiretroviral therapy has demonstrated proved effectiveness in suppressing viral replication and significantly recovering CD4+ T cell count in HIV type-1 (HIV-1)-infected patients, contributing to a dramatic reduction in AIDS morbidity and mortality. However, the factors affecting immune reconstitution are extremely complex. Demographic factors, co-infection, baseline CD4 cell level, abnormal immune activation, and cytokine dysregulation may all affect immune reconstitution. According to report, 10-40% of HIV-1-infected patients fail to restore the normalization of CD4+ T cell count and function. They are referred to as immunological non-responders (INRs) who fail to achieve complete immune reconstitution and have a higher mortality rate and higher risk of developing other non-AIDS diseases compared with those who achieve complete immune reconstitution. Heretofore, the mechanisms underlying incomplete immune reconstitution in HIV remain elusive, and INRs are not effectively treated or mitigated. This review discusses the recent progress of mechanisms and factors responsible for incomplete immune reconstitution in AIDS and summarizes the corresponding therapeutic strategies according to different mechanisms to improve the individual therapy. [ABSTRACT FROM AUTHOR]

Background: Haploidentical hematopoietic stem cell transplantation (HSCT) with depletion of αβ+ T cells and CD19+ B cells has emerged as a viable alternative to traditional donors for treating acute leukemia in children. As the use of this innovative approach continues to grow and more experience is gained, it is essential to identify and comprehend the key factors that contribute to successful transplantation and improved outcomes. Methods: We conducted a retrospective analysis of single‐center data from 27 children with acute lymphoblastic leukemia and 11 children with acute myeloid leukemia who underwent haploidentical HSCT with depletion of αβ+ T cells and CD19+ B cells between the years 2013 and 2020. Results: Engraftment was successful in 34 out of 38 patients (90%). The 5‐year overall survival and event‐free survival rates were 51% and 42%, respectively. There were no cases of grade III–IV acute graft‐versus‐host disease, and only two patients developed chronic graft‐versus‐host disease. Patients with a higher content of γδ+ T cells in the graft demonstrated a longer event‐free survival. Conclusions: αβ+/CD19+‐depleted haploidentical hematopoietic stem cell transplantation can offer long‐term remission for children with acute leukemia with minimal graft‐versus‐host disease. [ABSTRACT FROM AUTHOR]

Human melanoma is the most aggressive form of skin cancer and is responsible for the most deaths of all skin cancers. Localized tumors, and those which have limited spread, have 5-year survival rates of over 90%, with those numbers steadily rising over the past decade. However, metastatic melanomas have a sharp decrease in 5-year survival rates and are still an area of need for new, successful therapies. Immuno-oncolytic viruses (OVs) have emerged as a promising class of immunovirotherapy that can potentially address this disease. The Food and Drug Administration in the United States has approved one oncolytic herpes simplex virus expressing granulocyte-macrophage colony-stimulating factor (Talimogene Laherparepvec) for the treatment of metastatic melanoma, and others could soon follow for this and other cancers. In previous studies, Tanapoxvirus (TPV) recombinants expressing mouse interleukin-2 (mIL-2) and another expressing bacterial flagellin from Salmonella typhimurium (FliC) have demonstrated anti-tumor efficacy in nude mouse models. TPV replicates only in humans and monkeys, including tumor cells, which makes the use of syngeneic tumor models impossible for the study of this OV in a standard immunocompetent system. In this study, TPV/Δ66R/mIL-2 and TPV/Δ2L/Δ66R/FliC were tested for their ability to treat human melanoma xenografts (SK-MEL3) in a BALB/c nude mouse model reconstituted with splenocytes from genetically compatible, normal BALB/c donor mice. Two SK-MEL3 tumors were transplanted into each flank of BALB/c nude mice, and the larger tumor was treated intratumorally (IT) with virus or mock injection. In one set of animals, mice received adoptive transfers of splenocytes from BALB/c mice on day 4 to reconstitute their immune systems and allow for adaptive immune responses to occur in a xenograft model. Direct IT injection of TPV/Δ66R/mIL-2 led to significantly greater rates of tumor regression compared to reconstituted control (RC) mice in the primary and distant tumor sites, whereas TPV/Δ2L/Δ66R/FliC treatment led to significantly greater rates of tumor regression in distant tumor sites only. A second experiment used TPV/Δ66R/mIL-2 to test whether TPV could be administered intravenously (IV), intramuscularly (IM), or both routes simultaneously to exert similar anti-tumor effects in an indirectly treated tumor. A single SK-MEL3 tumor was transplanted into one flank of BALB/c nude mice and was treated either into the tail vein, the nearest rear leg to the tumor, or both. All mice then received adoptive transfers of splenocytes in the same way as previously described on day 4 and received an additional TPV treatment on day 14. The results demonstrated that TPV/Δ66R/mIL-2 treatment IV or IM had significantly greater rates of tumor regression than RC-treated mice but failed to exert this effect when both routes were used simultaneously. Data obtained through these experiments support the continued development of Tanapoxvirus for the treatment of human melanoma and using immune reconstitution to create intact adaptive immunity in a xenograft context, which can allow other tropism-limited OVs to be studied against human cancers. [ABSTRACT FROM AUTHOR]

Hematopoietic stem cell (HSC) transplantation's success lies in its ability to induce immune reconstitution. To date, there is no review published to compare the immune reconstitution among the three sources of HSC: umbilical cord blood (UCB), bone marrow (BM), and peripheral blood (PB). The review aims to analyze the kinetic of immune reconstitution among UCB, PB, and BM in HSC transplant patients by focusing on natural killer (NK) cells, B and T lymphocytes, and neutrophils. A systematic review was conducted through five databases, searching for clinical trials and randomized control trials (RCTs) which analyze the kinetics of immune reconstitution in at least two sources. Selected studies were assessed with Cochrane RoB 2.0. This review included 14 studies, with a total of 2539 subjects. The PB group achieved the fastest time to neutrophil recovery, while the B‐cell count was the highest in the UCB group. The T‐cell count is the lowest in the BM group, and the NK‐cell count does not differ significantly among the three HSC sources. Among the three sources of HSC, there is no superior HSC source for any immune reconstitution parameter. More studies must be conducted to compare the immune reconstitution and clinical outcomes of all HSC sources in specific diseases. [ABSTRACT FROM AUTHOR]

Objectives: Immune recovery following haematopoietic cell transplantation (HCT) functions as a dynamical system. Reducing the duration of intense immune suppression and augmenting antigen presentation has the potential to optimise T‐cell reconstitution, potentially influencing long‐term outcomes. Methods: Based on donor‐derived T‐cell recovery, 26 patients were adaptively randomised between mycophenolate mofetil (MMF) administered for 30‐day post‐transplant with filgrastim for cytokine support (MMF30 arm, N = 11), or MMF given for 15 days with sargramostim (MMF15 arm, N = 15). All patients underwent in vivo T‐cell depletion with 5.1 mg kg−1 antithymocyte globulin (administered over 3 days, Day −9 through to Day −7) and received reduced intensity 450 cGy total body irradiation (3 fractions on Day −1 and Day 0). Patients underwent HLA‐matched related and unrelated donor haematopoietic cell transplantation (HCT). Results: Clinical outcomes were equivalent between the two groups. The MMF15 arm demonstrated superior T‐cell, as well as T‐cell subset recovery and a trend towards superior T‐cell receptor (TCR) diversity in the first month with this difference persisting through the first year. T‐cell repertoire recovery was more rapid and sustained, as well as more diverse in the MMF15 arm. Conclusion: The long‐term superior immune recovery in the MMF15 arm, administered GMCSF, is consistent with a disproportionate impact of early interventions in HCT. Modifying the 'immune‐milieu' following allogeneic HCT is feasible and may influence long‐term T‐cell recovery. [ABSTRACT FROM AUTHOR]

The failure of autologous hematopoietic stem cell transplantation (HSCT) has been associated with a profound immunodeficiency that follows shortly after treatment, which renders patients susceptible to opportunistic infections and/or cancer relapse. Thus, given the additional immunosuppressive pathways involved in immune evasion in cancer, strategies that induce a faster reconstitution of key immune effector cells are needed. Natural killer (NK) cells mediate potent anti-tumor effector functions and are the first immune cells to repopulate after HSCT. TGF-β is a potent immunosuppressive cytokine that can impede both the development and function of immune cells. Here, we evaluated the use of an immunotherapeutic regimen that combines low dose of IL-2, an NK cell stimulatory signal, with TGF-β neutralization, in order to accelerate NK cell reconstitution following congenic HSCT in mice by providing stimulatory signals yet also abrogating inhibitory ones. This therapy led to a marked expansion of NK cells and accelerated NK cell maturation. Following HSCT, mature NK cells from the treated recipients displayed an activated phenotype and enhanced anti-tumor responses both in vitro and in vivo. No overt toxicities or adverse effects were observed in the treated recipients. However, these stimulatory effects on NK cell recovery were predicated upon continuous treatment as cessation of treatment led to return to baseline levels and to no improvement of overall immune recovery when assessed at later time-points, indicating strict regulatory control of the NK cell compartment. Overall, this study still demonstrates that therapies that combine positive and negative signals can be plausible strategies to accelerate NK cell reconstitution following HSCT and augment anti-tumor efficacy.

BackgroundIn Botswana, nearly two-thirds of cervical cancer patients are HIV-positive. This study examined the relationship between CD4 count and chemoradiation therapy outcomes among cervical cancer patients with HIV.SettingA prospective cohort study of 231 HIV-positive women with locally invasive cervical cancer was conducted in Gaborone, Botswana from January 2015 to February 2018.MethodsPrimary outcome was survival, defined as time from scheduled end of chemoradiation therapy to death or last contact with patient. Nadir CD4 count was defined as lowest CD4 available before cancer diagnosis. Delta CD4 count was defined as improvement from nadir CD4 to CD4 at cancer diagnosis. Hazard ratio (HR) analyses were adjusted for presenting variables (age, baseline hemoglobin, cancer stage, and performance status) and treatment variables (chemotherapy cycles and radiation dose).ResultsTwo hundred thirty-one patients were included in nadir CD4 analysis; 139 were included in delta CD4 analysis. Higher delta CD4 was significantly associated with reduced mortality after adjusting for presenting and treatment variables (CD4 100-249: HR 0.45, 95% CI: 0.21 to 0.95; CD4 ≥250: HR 0.45, 95% CI: 0.20 to 1.02). Higher nadir CD4 showed a trend toward reduced mortality after adjusting for presenting and treatment variables (HR 0.94, 95% CI: 0.84 to 1.06).ConclusionsHigher delta CD4 (greater improvement from nadir CD4 to CD4 at cervical cancer diagnosis) is significantly associated with lower mortality. Although not statistically significant, data suggest that higher nadir CD4 may reduce mortality. These results reinforce the importance of early HIV diagnosis and antiretroviral therapy initiation, as their effects influence cervical cancer outcomes years later.

Severe combined immunodeficient (SCID) mice serve as a critical model for human xenotransplantation studies, yet they often suffer from low engraftment rates and susceptibility to graft-versus-host disease (GVHD). Moreover, certain SCID strains demonstrate ‘immune leakage’, underscoring the need for novel model development. Here, we introduce an SCID mouse model with a targeted disruption of the dclre1c gene, encoding Artemis, which is essential for V(D)J recombination and DNA repair during T cell receptor (TCR) and B cell receptor (BCR) assembly. Artemis deficiency precipitates a profound immunodeficiency syndrome, marked by radiosensitivity and compromised T and B lymphocyte functionality. Utilizing CRISPR/Cas9-mediated gene editing, we generated dclre1c-deficient mice with an NOD genetic background. These mice exhibited a radiosensitive SCID phenotype, with pronounced DNA damage and defective thymic, splenic and lymph node development, culminating in reduced T and B lymphocyte populations. Notably, both cell lines and patient-derived tumor xenografts were successfully engrafted into these mice. Furthermore, the human immune system was effectively rebuilt following peripheral blood mononuclear cells (PBMCs) transplantation. The dclre1c-knockout NOD mice described herein represent a promising addition to the armamentarium of models for xenotransplantation, offering a valuable platform for advancing human immunobiological research.

Alemtuzumab is a monoclonal antibody targeting CD52 on the surface of immune cells, approved for the treatment of active relapsing-remitting multiple sclerosis (RRMS). The purpose of this study was to analyze the repopulation of peripheral lymphocytes following alemtuzumab-induced lymphocyte depletion and investigate associations with disease activity and development of secondary autoimmunity. For this, blood samples were collected two years after initiation of alemtuzumab treatment and lymphocytes were subjected to a comprehensive flow cytometry analysis. Included in the study were 40 patients treated with alemtuzumab and 40 treatment-naïve patients with RRMS. Disease activity and development of secondary autoimmune disease was evaluated after three years of treatment. Our study confirms that alemtuzumab treatment profoundly alters the circulating lymphocyte phenotype and describes a reconstituted immune system characterized by T cell activation/exhaustion, an increased regulatory control of IL-17 producing effector T cells and CD20+ T cells, and a reduced control of B cells. There were no obvious associations between immune cell subsets and disease activity or development of secondary autoimmune disease during treatment with alemtuzumab. Our results indicate that the reconstituted immune response is skewed towards a more effective regulatory control of MS-associated proinflammatory T cell responses. Also, the enlarged pool of naïve B cells together with the apparent decrease in control of B cell activity may explain why alemtuzumab-treated patients retain the ability to mount a humoral immune response towards new antigens.

Summary: To validate the efficacy and safety of haematopoietic stem cell transplantation (HSCT) in hepatitis‐associated aplastic anaemia (HAAA) patients, we reviewed 260 patients who underwent HSCT for acquired aplastic anaemia and eventually included 30 HAAA patients and 90 non‐HAAA patients using propensity score matching. In the HAAA group, the estimated 5‐year overall survival rate (75.8% vs. 86.5%, p = 0.409), failure‐free survival (FFS) rate (74.0% vs. 83.2%, p = 0.485), graft‐versus‐host disease (GVHD)‐free FFS rate (61.2% vs. 67.6%, p = 0.669) after HSCT were slightly lower but not statistically significant than those in the non‐HAAA group. Both groups did not significantly differ in engraftment, post‐transplant severe infection, cytomegalovirus (CMV) or Epstein‐Barr virus viraemia, or GVHD incidences. The patterns of immune reconstitution were broadly consistent between the two groups. When stratifying HAAA patients according to donor type, no significant differences in survival, transplant‐related mortality, or GVHD cumulative incidences were observed. CMV viraemia (68.7% vs 8.3%, p = 0.009) occurred more commonly in haploidentical donor (HID) transplants than in matched sibling donor transplants. However, early CMV disease incidence (5.6% vs. 0.0%, p = 1.000) was low. Overall, the post‐transplant outcomes of HAAA patients were comparable to those of non‐HAAA patients after balancing potential confounders, and HID‐HSCT can offer an alternative curative option for HAAA. [ABSTRACT FROM AUTHOR]

Background: Bictegravir/emtricitabine/tenofovir alafenamide fumarate (BIC/FTC/TAF) is a recommended once-daily single-tablet regimen for the treatment of people living with HIV (PLWH). We aimed to assess efficacy, safety, and tolerability of BIC/FTC/TAF among PLWH, with a specific focus on people older than 55 years. Methods: We recruited an observational retrospective real-life cohort, including all PLWH who underwent a therapeutic switch to BIC/FTC/TAF, independently from the previous treatment regimen (the BICTEL cohort). Longitudinal nonparametric analyses and linear models were built. Results: After 96 weeks of follow-up, 164 PLWH were included, with 106 older than 55. Both the intention-to-treat and the per-protocol analysis showed low rates of virologic failure, independent of the pre-switch anchor drug. At week 96, a significant increase in CD4+ T cell count and in CD4+/CD8+ ratio was observed, inversely correlated with baseline immune status. Fasting serum lipid profile, total body weight, BMI, and hepatic function were not affected by the switch, without new onset of metabolic syndrome or weight gain. Compared to baseline, we observed a renal function worsening which is worthy of further follow-up. Conclusion: BIC/FTC/TAF is an effective, safe, and well-tolerated switching strategy for PLWH, especially among those older than 55. [ABSTRACT FROM AUTHOR]

A patient diagnosed with late-presenting HIV infection [CD4 count 86 cells/mm3, viral load (VL) 95 000 copies RNA/mL], treated with DRV/c 800/150 mg (Rezolsta®) and TDF/FTC 200/245 mg, was hospitalized with ischemic brain stroke, confirmed by CT scan and MRI. Motor functions quickly recovered, but nausea, abdominal heaviness, ascites, and hepatosplenomegaly appeared. Laboratory investigations revealed anaemia, thrombocytopenia, normal transaminases, increased GGT and negative serological tests for HBV and HCV and she was diagnosed with Gastroenterologists diagnosed liver cirrhosis. After 20 days of hospital treatment, the patient recovered from the stroke and ascites but with persisting anaemia and thrombocytopenia. Liver cirrhosis had been confirmed, and relevant treatment had been administered. Six months later, an MRI of the brain revealed an improved image. Follow-up showed stabilized somatic and neurologic status, improved laboratory parameters, stable T-helper count and undetectable viral load (VL). ART regimen continued with Raltegravir 400 mg (Isentress®) 2×1 tablet/24 h, TDF/FTC 200/245 mg 1 tablet/24 h. Three months later, the patient continued her treatment continued abroad. The increased access to precise diagnosis and treatment with improved adherence has transformed the HIV-infection into a manageable chronic health condition, even in complicated cases. [ABSTRACT FROM AUTHOR]

Background: HIV DNA mirrors the number of infected cells and the size of the HIV viral reservoir. The aim of this study was to evaluate the effect of pre-cART HIV DNA levels as a predictive marker of immune reconstitution and on the post-cART CD4 counts trends. Methods: HIV DNA was isolated from PBMCs and quantified by real-time PCR. Immune reconstitution was assessed up to four years. Piecewise-linear mixed models were used to describe CD4 count changes. Results: 148 people living with HIV (PLWH) were included. The highest rate of immune reconstitution was observed during the first trimester. There was a trend showing that high HIV RNA level resulted in greater increase in CD4 count, especially during the first trimester of cART (difference above vs. below median 15.1 cells/μL/month; 95% CI −1.4–31.5; p = 0.073). Likewise, higher HIV DNA level would predict greater CD4 increases, especially after the first trimester (difference above vs. below median 1.2 cells/μL/month; 95% CI −0.1–2.6; p = 0.071). Higher DNA and RNA levels combined were significantly associated with greater CD4 increase past the first trimester (difference high/high vs. low/low 2.1 cells/μL/month; 95% CI 0.3–4.0; p = 0.024). In multivariable analysis, lower baseline CD4 counts predicted a greater CD4 rise. Conclusions: In successfully treated PLWH, pre-cART HIV DNA and HIV RNA levels are predictors of immune reconstitution. [ABSTRACT FROM AUTHOR]

Background Toxoplasmic encephalitis (TE) is a life-threatening complication of people with human immunodeficiency virus (PWH) with severe immunodeficiency, especially those with a CD4+ T-cell count <100 cells/µL. Following a clinical response to anti- Toxoplasma therapy, and immune reconstitution after initiation of combination antiretroviral therapy (ART), anti- Toxoplasma therapy can be discontinued with a low risk of relapse. Methods To better understand the evolution of magnetic resonance imaging (MRI)–defined TE lesions in PWH receiving ART, we undertook a retrospective study of PWH initially seen at the National Institutes of Health between 2001 and 2012, who had at least 2 serial MRI scans. Lesion size and change over time were calculated and correlated with clinical parameters. Results Among 24 PWH with TE and serial MRI scans, only 4 had complete clearance of lesions at the last MRI (follow-up, 0.09–5.8 years). Of 10 PWH off all anti- Toxoplasma therapy (median, 3.2 years after TE diagnosis), 6 had persistent MRI enhancement. In contrast, all 5 PWH seen in a pre–ART era study who were followed for >6 months had complete clearance of lesions. TE lesion area at diagnosis was associated with the absolute change in area (P <.0001). Conclusions Contrast enhancement can persist even when TE has been successfully treated and anti- Toxoplasma therapy has been stopped, highlighting the need to consider diagnostic alternatives in successfully treated patients with immune reconstitution presenting with new neurologic symptoms. [ABSTRACT FROM AUTHOR]

BackgroundIt is unclear whether human immunodeficiency virus (HIV) infection results in permanent loss of T-cell memory or if it affects preexisting antibodies to childhood vaccinations or infections.MethodsWe conducted a matched cohort study involving 50 pairs of HIV-infected and HIV-uninfected women. Total memory T-cell responses were measured after anti-CD3 or vaccinia virus (VV) stimulation to measure T cells elicited after childhood smallpox vaccination. VV-specific antibodies were measured by means of enzyme-linked immunosorbent assay (ELISA).ResultsThere was no difference between HIV-infected and HIV-uninfected study participants in terms of CD4+ T-cell responses after anti-CD3 stimulation (P = .19) although HIV-infected participants had significantly higher CD8+ T-cell responses (P = .03). In contrast, there was a significant loss in VV-specific CD4+ T-cell memory among HIV-infected participants (P = .04) whereas antiviral CD8+ T-cell memory remained intact (P > .99). VV-specific antibodies were maintained indefinitely among HIV-uninfected participants (half-life, infinity; 95% confidence interval, 309 years to infinity) but declined rapidly among HIV-infected participants (half-life; 39 years; 24-108 years; P = .001).ConclusionsDespite antiretroviral therapy-associated improvement in CD4+ T-cell counts (nadir, 350/μL after antiretroviral therapy), antigen-specific CD4+ T-cell memory to vaccinations or infections that occurred before HIV infection did not recover after immune reconstitution, and a previously unrealized decline in preexisting antibody responses was observed.

Introduction: Severe Combined Immunodeficiency (SCID) is a life-threatening immunodeficiency caused by several pathogenic genetic variants, and it is characterized by profound defects in T-cell numbers and immune function. First performed in the late 1960's, hematopoietic stem cell transplantation remains the standard treatment for most cases of SCID. There is a growing number of post-transplant SCID patients, and it is imperative to assess the long-term outcomes of these patients. We have reported here the longest follow-up of a post-transplant SCID patient who, to our knowledge, bears the first gamma chain (γc) variant to show intact IL-21 signaling. Case Presentation: The patient presented at 5 months of age with recurrent thrush and Pneumocystis jiroveci pneumonia. In 1971, at the age of 11 months, he received an unconditioned, matched, related donor transplant comprising whole, unprocessed bone marrow. He is now 48 years old without significant illness and has never required immunoglobulin replacement. He exhibits T-dependent vaccine responses. He does suffer from chronic warts and bacterial infections that have worsened in recent years. We confirmed a known pathogenic variant in the IL2RG gene showing a hemizygous variant NM_000206.2:c.675C>A, resulting in p.Ser225Arg. His chimerism studies revealed donor T cells, host B cells, host myeloid cells, and mixed NK cells. Lymphocyte enumeration revealed normal numbers and distribution of B cells. The host B cells carry the pathogenic variant in IL2RG, but, when stimulated with IL-21, they demonstrated intact, γc-dependent signaling. Conclusions: Even with host B cells, reconstitution with donor T cells can be sufficient to allow over four decades of survival when B-cell function is intact. Our case demonstrates that satisfactory B-cell function can arise as a consequence of both intact IL-21 signaling due to a hypomorphic γc variant, and close HLA matching with the donor to allow for effective T-cell help.

BACKGROUND:We aimed to characterize the impact of ART initiation on GALT at various sites along the gastrointestinal site. METHODOLOGY:Peripheral blood and duodenal and rectal biopsies were obtained from 12 HIV and 33 treatment-naïve HIV subjects at baseline and after 9-months ART. Tissue was digested for immunophenotyping. Inflammatory, bacterial translocation and intestinal damage markers were measured in plasma. RESULTS:Twenty-six HIV subjects completed follow-up. The lowest reconstitution of CD4 T-cells and the lowest CD4/CD8 ratio during ART compared to blood were observed in the duodenum with the rectum being either intermediate or approaching blood levels. Regulatory T-cells (Treg) were in higher proportions in the duodenum than the rectum and neither declined significantly during ART. Several correlations with biomarkers of microbial translocation were observed including increases in LTA levels, which reflects gram-positive bacterial translocation, correlated with increases in %CD4 T-cells in duodenum (Rho 0.773, P = 0.033), and with decreases duodenal Treg populations (Rho -0.40, P = 0.045). CONCLUSIONS:HIV-mediated immunological disruption is greater in the duodenum than rectum and blood before and during ART. Small intestine damage may represent a unique environment for T-cell depletion, which might be attenuated by interaction with gram positive bacteria.

Objective To observe the effect of Tonifying deficiency and Zhengqi porridge on immune function reconstruction of HIV/AIDS patients with Qi deficiency. Methods Sixty (Human Immunodeficiency Virus/ Acquired Immunodeficiency Syndrome)HIV/AIDS patients admitted to the center for Disease Control and prevention in Huichuan District of Zunyi City were randomly divided into control group and treatment group by random number table. All patients received the highly active anti-retroviral therapy, and those in the treatment group were given Tonifying deficiency and Zhengqi porridge. The CD4+ T-cell count was measured before, 3 months and 6 months after intervention. The Effective reconstitution of immune function was analyzed. Results After 3 and 6 months of treatment, the immune reconstitution in the treatment group was better than that in the control group for patients with CD4+ T-cell count of 100-500/mm3 (P＜0. 05). Conclusion Tonifying deficiency and Zhengqi porridge can promote the reconstruction of immune function in HIV / AIDS patients with Qi deficiency and help to restore immune function. (目的 探讨补虚正气粥对人类免疫缺陷病毒(HIV)感染及艾滋病(AIDS)气虚型患者的免疫功能恢复作用。方法 选择遵义市汇川区疾病预防控制中心60名HIV/AIDS患者, 随机将患者分为治疗组和对照组, 各30例。对照组按传统方法进行HAART(高效抗反转录病毒)治疗, 治疗组则在对照组治疗的基础上加用补虚正气粥。于干预前、干预后3个月和干预后6个月比较两组患者CD4+T淋巴细胞计数值和免疫功能重建有效率。结果 对于干预前CD4+T淋巴细胞计数100～500个/mm3的患者, 在介入3个月和6个月, 治疗组免疫功能的恢复较对照组好(P＜0. 05)。结论 补虚正气粥对HIV/AIDS气虚型患者免疫功能重建有促进作用, 有助于免疫功能的重建。)

Abstract Background Highly active anti-retroviral therapy (HAART) can successfully suppress human immunodeficiency virus (HIV) viral replication and reconstruct immune function reconstruction in HIV-1-infected patients. However, about 15–30% of HIV-1-infected patients still fail to recover their CD4+ T cell counts after HAART treatment, which means immune reconstruction failure. Pyroptosis plays an important role in the death of CD4+ T cells in HIV-1- infected patients. The study aims to explore the association between the expression of pyroptosis in peripheral blood and immune function reconstruction in HIV-1- infected patients. Methods One hundred thirty-five HIV-1-infected patients including immunological non-responders (INR) group, immunological responders (IR) group and normal immune function control (NC) group were analyzed. The expression of GSDMD and Caspase-1 in peripheral blood of HIV-1-infected patients were measured by qPCR. The concentrations of GSDMD, Caspase-1, IL-1β and IL-18 in the peripheral serum were quantified by ELISA. The associations between the expression of pyroptosis in peripheral blood and immune function reconstruction were analyzed using multivariate logistic models. Results The relative expression of GSDMD mRNA and caspase-1 mRNA in peripheral blood, as well as the expression of IL-18 cytokine in the INR, were significantly higher than those in the IR and NC (P 0.05). Multivariate logistic analysis showed that the patients with baseline CD4+ T cell counts less than 100 cells/μL (aOR 7.051, 95% CI 1.115–44.592, P = 0.038), high level of expression of Caspase-1mRNA (aOR 2.803, 95% CI 1.065–7.377, P = 0.037) and IL-18 cytokine (aOR 10.131, 95% CI 1.616–63.505, P = 0.013) had significant poor CD4+ T cell recovery. Conclusions The baseline CD4+ T cell counts less than 100 cells/μL, high relative expression of Caspase-1 mRNA, and high expression of IL-18 cytokine are associated factors that affect the reconstruction of immune function.

Abstract Background Although combined antiretroviral therapy (cART) has decreased the mortality associated with HIV infection, complete immune reconstitution is not achieved despite viral suppression. Alterations of CD8+ T cells and some of their subpopulations, such as interleukin (IL)-17-producing cells, are evidenced in treated individuals and are associated with systemic inflammation and adverse disease outcomes. We sought to evaluate if different CD8+ T cell subsets are differentially normalized during a clinical follow-up of people living with HIV (PLWH) receiving suppressive cART. Methods We explored the changes in the frequencies, activation/exhaustion phenotypes (HLA-DR, CD38, PD-1, and TIM-3), and function (total and HIV-specific cells expressing CD107a, perforin, granzyme B, interferon [IFN]-γ and IL-17) of CD8+ T cells from early-treated PLWH receiving cART in a 1-year follow-up, using a multidimensional flow cytometry approach. Results Despite continuous cART-induced viral suppression and recovery of CD4+ T cells, after a 1-year follow-up, the CD8+ T cell counts, CD4:CD8 ratio, PD-1 expression, and IL-17 production by CD8+ T cells exhibited incomplete normalization compared with seronegative controls. However, the proportion of CD8+ T cells with an exhausted phenotype (co-expressing PD-1 andTIM-3), and cells co-expressing cytotoxic molecules (Perforin and Granzyme B), reached normalization. Conclusions Although suppressive cART achieves normalization of CD4+ T cell counts, only particular subsets of CD8+ T cells are more rapidly normalized in PLWH receiving cART, which could be routinely used as biomarkers for therapy efficiency in these patients.

Serum neurofilament light chain (sNfL) is an intensely investigated biomarker in multiple sclerosis (MS). The aim of this study was to explore the impact of cladribine (CLAD) on sNfL and the potential of sNfL as a predictor of long-term treatment response. Data were gathered from a prospective, real-world CLAD cohort. We measured sNfL at baseline (BL-sNfL) and 12 months (12Mo-sNfL) after CLAD start by SIMOA. Clinical and radiological assessments determined fulfilment of "no evidence of disease activity" (NEDA-3). We evaluated BL-sNfL, 12M-sNfL and BL/12M sNfL ratio (sNfL-ratio) as predictors for treatment response. We followed 14 patients for a median of 41.5 months (range 24.0–50.0). NEDA-3 was fulfilled by 71%, 57% and 36% for a period of 12, 24 and 36 months, respectively. We observed clinical relapses in four (29%), MRI activity in six (43%) and EDSS progression in five (36%) patients. CLAD significantly reduced sNfL (BL-sNfL: mean 24.7 pg/mL (SD ± 23.8); 12Mo-sNfL: mean 8.8 pg/mL (SD ± 6.2); p = 0.0008). We found no correlation between BL-sNfL, 12Mo-sNfL and ratio-sNfL and the time until loss of NEDA-3, the occurrence of relapses, MRI activity, EDSS progression, treatment switch or sustained NEDA-3. We corroborate that CLAD decreases neuroaxonal damage in MS patients as determined by sNfL. However, sNfL at baseline and at 12 months failed to predict clinical and radiological treatment response in our real-world cohort. Long-term sNfL assessments in larger studies are essential to explore the predictive utility of sNfL in patients treated with immune reconstitution therapies. [ABSTRACT FROM AUTHOR]

Background: The impact of donor age on the immune reconstitution of patients with hematological malignancies who underwent hematopoietic cell transplantation (HCT) is unclear. Method: We retrospectively compared the outcomes of 381 patients who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) from 308 donors under 50 years of age and 73 donors over 50 years of age. IVIG was regularly supplemented for patients in the first 3 months post‐HCT. Results: The counts of CD8+CD45RA+ naïve T cells were significantly lower in patients of the older donor group than in the younger donor group in the first year after PBSCT (190.6 cells/μl vs. 239.6 cells/μl, p =.018). Patients in the older donor group had significantly fewer CD19+ B cells on day +270 (123.4 cells/μl vs. 183.5 cells/μl, p =.021) and day +365 (169 cells/μl vs. 271.1 cells/μl, p =.01) after PBSCT. Serum IgA (.76 g/L vs..97 g/L, p <.001) and IgM levels (.75 g/L vs. 1.04 g/L, p <.001) were significantly lower in patients in the older donor group from day +60 to +365 after PBSCT. The EBV reactivation rate within the first 3 months after PBSCT was significantly higher in patients in the older donor group (48.6% vs. 38.3%, p =.034). However, the incidences of CMV reactivation, II‐IV acute graft‐versus‐host disease (aGvHD), chronic GvHD (cGvHD), 3‐year relapse rate, 3‐year transplant‐related mortality (TRM) and 3‐year overall survival (OS) were not significantly different between the two groups. Conclusion: In conclusion, donors ≥50 years old were associated with inferior immune reconstitution and higher EBV reactivation in patients after PBSCT, but no change in OS. [ABSTRACT FROM AUTHOR]

Delayed immune reconstitution is a major challenge after matched unrelated donor (MUD) stem cell transplant (SCT). In this randomized phase 2 multi-center trial, Adoptive Immunotherapy with CD25/71 allodepleted donor T cells to improve immunity after unrelated donor stem cell transplant (NCT01827579), the authors tested whether allodepleted donor T cells (ADTs) can safely be used to improve immune reconstitution after alemtuzumab-based MUD SCT for hematological malignancies. Patients received standard of care or up to three escalating doses of ADTs generated through CD25+/CD71+ immunomagnetic depletion. The primary endpoint of the study was circulating CD3+ T-cell count at 4 months post-SCT. Twenty-one patients were treated, 13 in the ADT arm and eight in the control arm. The authors observed a trend toward improved CD3+ T-cell count at 4 months in the ADT arm versus the control arm (230/µL versus 145/µL, P = 0.18), and three ADT patients achieved normal CD3+ T-cell count at 4 months (>700/µL). The rates of significant graft-versus-host disease (GVHD) were comparable in both cohorts, with grade ≥2 acute GVHD in seven of 13 and four of eight patients and chronic GVHD in three of 13 and three of eight patients in the ADT and control arms, respectively. These data suggest that adoptive transfer of ADTs is safe, but that in the MUD setting the benefit in terms of T-cell reconstitution is limited. This approach may be of more use in the context of more rigorous T-cell depletion. [ABSTRACT FROM AUTHOR]

Cord blood (CB) transplantation is a promising treatment for hematologic malignancies due to its strong graft-versus-leukemia effect and a low incidence of graft-versus-host disease. However, the risk of infection caused by delayed engraftment has limited its clinical application. In this study, we compared the single-cell RNA-seq of CB, bone marrow (BM), and granulocyte colony-stimulating factor primed BM to understand the differences between these grafts from a comprehensive view, and verified some differences in our clinical data of patients receiving transplantation. We focused on the biological features of key cell types involving the hematopoietic reconstitution and immune reconstitution. Based on the comparison of homing signal and differentiation potential of hematopoietic stem/progenitor cells (HSPCs), CB exhibited a lower content of HSPCs with weaker homing ability but higher stemness than BM. In addition, CB had a higher proportion of naïve T cells, while BM had a higher abundance of effector and memory T cells. Notably, the CD4+ naïve T cells in CB were prone to differentiate into Tregs. In response to neoantigens, the immune activation interactions between T cells and antigen-presenting cells were strong in CB, including CD40_CD40LG, IL16_CD4, and so on. In our clinical data, the subpopulation variations of T cells and the status of monocytes after transplantation were consistent with the results of the single-cell RNA-seq study above. CB, as a new birth system, is immature and active; several mechanisms contribute to its good anti-tumor effect, which can be introduced to other grafts. These findings provide insights into the development of new strategies for hematologic malignancies treatment. [ABSTRACT FROM AUTHOR]

Background & Aims: Antivirals represent the mainstay of chronic hepatitis B treatment given their efficacy and tolerability, but rates of functional cure remain low during long-term therapy. Treatment discontinuation has emerged as a strategy to maintain partial cure and achieve functional cure in select patient groups. We aimed to evaluate how data from treatment discontinuation studies exploring novel viral and/or immune markers could be applied to the functional cure program. Methods: Treatment discontinuation studies evaluating novel viral and/or immune markers were identified by a systematic search of the PubMed database through to October 30, 2022. Data extraction focused on information regarding novel markers, including identified cut-off levels, timing of measurement, and associated effect on study outcomes of virological relapse, clinical relapse, and HBsAg seroclearance. Results: From a search of 4,492 citations, 33 studies comprising a minimum of 2,986 unique patients met the inclusion criteria. Novel viral markers, HBcrAg and HBV RNA, were demonstrated across most studies to be helpful in predicting off-therapy partial cure, with emerging evidence to support a link with functional cure. From novel immune marker studies, we observed that treatment discontinuation has the potential to trigger immune restoration, which may be associated with a transient virological relapse. To this end, these studies support the combination of virus-directing agents with immunomodulator therapies to induce two key steps underlying functional cure: viral antigen load reduction and restoration of the host immune response. Conclusions: Patients with a favourable profile of novel viral and immune markers stand to benefit from a trial of antiviral treatment discontinuation alongside novel virus-directing agents with the aim of achieving functional cure without excessive risk of severe clinical relapse. Impact and implications: Select patients with chronic hepatitis B undergoing nucleoside analogue therapy may benefit from a trial of treatment discontinuation, aiming to maintain partial cure and/or achieve functional cure. We propose a profile of novel viral and immune markers to identify patients who are likely to achieve these goals without excessive risk of hepatic decompensation. Furthermore, treatment discontinuation may also be considered as a therapeutic strategy to trigger immune restoration, which may increase the chance of functional cure when used in conjunction with novel virus-directing agents.

HIV-1 infection causes T cell dysfunction that cannot be fully restored by anti-retroviral therapy (ART). Myeloid-derived suppressor cells (MDSCs) expand and suppress T cell function during viral infection. In this study, we evaluated the dynamics of phenotypes and function of T cells and MDSCs and the effects of their interaction on CD4+ T cell reconstitution in people with acute HIV-1 infection (PWAH) with early ART. Flow cytometry was used to detect the phenotypic dynamics and function of T cells and MDSCs at pre-ART, 4, 24, 48, and 96 weeks of ART. We observed that T cells were hyper-activated and hyper-proliferative in PWAH at pre-ART. Early ART normalized T cell activation but not their proliferation. T cell proliferation, enriched in PD-1+ T cells, was persisted and negatively associated with CD4+ T-cell counts after ART. Moreover, M-MDSCs frequency was increased and positively correlated with T cell proliferation after 96 weeks of ART. M-MDSCs persisted and inhibited T cell proliferation ex vivo, which could be partially reversed by PD-L1 blockade. Further, we found higher frequencies of proliferative CD4+ T cells and M-MDSCs in PWAH with lower CD4+ T cell numbers (600 cells/μL) after 96 weeks of ART. Our findings indicate that persistent T cell proliferation, MDSCs expansion, and their interaction may affect CD4+ T-cell recovery in PWAH with early ART.

IRIS is a common complication in HIV-infected patients treated for tuberculosis (TB) and cART. Our aim was to evaluate NK cell reconstitution in HIV-infected patients with TB-IRIS compared to those without IRIS. 147 HIV-infected patients with TB from the CAMELIA trial were enrolled. HIV+TB+ patients were followed for 32 weeks. The NK cell repertoire was assessed in whole blood at different time points. As CAMELIA has two arms (early and late cART initiation), we analysed them separately. At enrolment, individuals had low CD4 cell counts (27 cells/mm3) and high plasma viral loads (5.76 and 5.50 log/mL for IRIS and non-IRIS individuals, respectively). Thirty-seven people developed IRIS (in the early and late arms). In the early and late arms, we observed similar proportions of total NK and NK cell subsets in TB-IRIS and non-IRIS individuals during follow-up, except for the CD56dimCD16pos (both arms) and CD56dimCD16neg (late arm only) subsets, which were higher in TB-IRIS and non-IRIS individuals, respectively, after cART. Regarding the repertoire and markers of NK cells, significant differences (lower expression of NKp30, NKG2A (CD159a), NKG2D (CD314) were observed in TB-IRIS compared to non-IRIS individuals after the start of cART. In the late arm, some changes (increased expression of CD69, NKG2C, CD158i) were observed in TB-IRIS compared to non-IRIS individuals, but only before cART initiation (during TB treatment). KIR expression by NK cells (CD158a and CD158i) was similar in both groups. CD69 expression by NK cells decreased in all groups. Expression of the NCR repertoire (NKp30, NKp44, NKp46) has similar kinetics in TB-IRIS subjects compared to non-IRIS subjects regardless of the arm analysed. NK cell reconstitution appeared to be better in TB-IRIS subjects. Although NK cell reconstitution is impaired in HIV infection after cART, as previously reported, it does not appear to be affected by the development of IRIS in HIV and TB-infected individuals.

ObjectivesAutologous stem cell transplantation following high-dose chemotherapy (HDC/ASCT) is the prime model to study the impact of HDC in HIV-1-infected participants. We analyzed the impact of HDC/ASCT on the resurgent reservoir composition and origin.DesignWe included retrospectively a homogenous group of HIV-1-infected patients treated for high-risk lymphoma in a reference center with similar chemotherapy regimens.MethodsThirteen participants treated with HDC/ASCT from 2012 to 2015 were included. A median seven longitudinal blood samples per participant were available. Total HIV-1 DNA levels in peripheral blood mononuclear cells (PBMCs) were quantified by quantitative PCR. In six participants with sustained viral suppression, the highly variable C2V3 viral region was subjected to next-generation sequencing. Maximum-likelihood phylogeny trees were generated from the reconstructed viral haplotypes. Lymphocyte subsets were studied by flow cytometry.ResultsPBMC-associated HIV-1 DNA levels were stable over time. Viral diversity decreased along lymphoma treatment, but increased promptly back to prechemotherapy numbers after HDC/ASCT. Blood viral populations from all time-points were intermingled in phylogeny trees: the resurgent reservoir was similar to pre-HDC circulating proviruses. Memory subsets were the main contributor to the early restoration of the CD4+ T-cell pool, with a delayed increase in naïve cell counts.ConclusionsThe characterization of HIV-1 reservoir in blood revealed a fast and consistent replenishment from memory CD4+ T cells after HDC/ASCT. As HDC/ASCT is increasingly involved in HIV cure trials with gene-modified hematopoietic stem cells, the management of infected T cells in HIV-positive autologous transplants will be critical.

Abstract Background Mucosal-associated invariant T (MAIT) cells are systemically depleted in human immunodeficiency virus type 1 (HIV-1) infected patients and are not replenished even after successful combined antiretroviral therapy (cART). This study aimed to identify the mechanism underlying MAIT cell depletion. Methods In the present study, we applied flow cytometry, single-cell RNA sequencing and immunohistochemical staining to evaluate the characteristics of pyroptotic MAIT cells in a total of 127 HIV-1 infected individuals, including 69 treatment-naive patients, 28 complete responders, 15 immunological non-responders, and 15 elite controllers, at the Fifth Medical Center of Chinese PLA General Hospital, Beijing, China. Results Single-cell transcriptomic profiles revealed that circulating MAIT cells from HIV-1 infected subjects were highly activated, with upregulation of pyroptosis-related genes. Further analysis revealed that increased frequencies of pyroptotic MAIT cells correlated with markers of systemic T-cell activation, microbial translocation, and intestinal damage in cART-naive patients and poor CD4+ T-cell recovery in long-term cART patients. Immunohistochemical staining revealed that MAIT cells in the gut mucosa of HIV-1 infected patients exhibited a strong active gasdermin-D (GSDMD, marker of pyroptosis) signal near the cavity side, suggesting that these MAIT cells underwent active pyroptosis in the colorectal mucosa. Increased levels of the proinflammatory cytokines interleukin-12 (IL-12) and IL-18 were observed in HIV-1 infected patients. In addition, activated MAIT cells exhibited an increased pyroptotic phenotype after being triggered by HIV-1 virions, T-cell receptor signals, IL-12 plus IL-18, and combinations of these factors, in vitro. Conclusions Activation-induced MAIT cell pyroptosis contributes to the loss of MAIT cells in HIV-1 infected patients, which could potentiate disease progression and poor immune reconstitution.

Feng Qian,1– 3,&ast; Song Hu,4,&ast; Yueping Zhu,2,3 Yinling Wang,2,3 Jin Liu,2,3 Jialu Qiao,4 Xiji Shu,4 Yong Gao,5 Binlian Sun,4 Chuanwu Zhu1– 3 1Department of Infectious Diseases, The Second Affiliated Hospital of Soochow University, Suzhou, 215004, People’s Republic of China; 2Department of Infectious Diseases, The Affiliated Infectious Disease Hospital of Soochow University, Suzhou, 215131, People’s Republic of China; 3Department of Infectious Diseases, The Fifth People’s Hospital of Suzhou, Suzhou, 215131, People’s Republic of China; 4Wuhan Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, People’s Republic of China; 5The First Affiliated Hospital, Department of Life Science and Medicine, University of Science and Technology of China, Hefei, 230001, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Chuanwu Zhu; Binlian Sun, Tel/Fax +86 512 87806206 ; +86 27 84225149, Email zhuchw@126.com; binlian17@jhun.edu.cnPurpose: To investigate factors involved in T-cell depletion in combination antiretroviral therapy (cART)-treated human immunodeficiency virus 1 (HIV-1)-positive patients.Patients and Methods: 29 HIV-1-positive patients were enrolled. The CD4+, CD8+ T cell subsets and CD56dim NK cells were detected by flow cytometry. The concentrations of cytokines were measured by enzyme-linked immunosorbent assay. Extraction, amplification, and viral load quantification of specimens were performed using the Roche Cobas Ampliprep/Cobas TaqMan HIV-1 test.Results: Compared with IR group, the total number of red blood cells (RBCs) and lymphocytes (LCs) in INR group was significantly reduced, and there was a significant positive correlation between the number of RBCs and that of LCs. The overall production rates of T cells-related cytokines were lower in INR group. However, the cell-surface expression of programmed death-1 (PD-1) on CD4+ T and CD8+ T cells were markedly elevated in INR group. Moreover, it was found that the proportion and the killing ability of CD56dim NK cells significantly increased in INR patients, and significantly correlated with apoptosis of T lymphocytes.Conclusion: A poor immune reconstitution in HIV-positive patients might result from multiple factors, including bone marrow suppression, high PD-1 expression on the surface of CD4+ T cells, and over-activation of T and NK cells. Besides, the activity of NK cells and RBCs count might be important auxiliary indicators for immune reconstitution and provided a reliable guidance for developing strategies to improve immune reconstitution.Keywords: AIDS, T-cells, CD56dim NK cells, antiretroviral therapy, immune reconstitution

Abstract Despite the increased usage of post-transplant cyclophosphamide (PTCy) in allogeneic hematopoietic stem cell transplantation (allo-HSCT), our knowledge of immune reconstitution post-allo-HSCT in the setting of PTCy is limited. Adequate immune reconstitution is the key to a successful transplant. In this study, we aim to investigate the effect of PTCy on the reconstitution of each immune component; more focus was placed on the immunophenotype and functions of T cells. Using blood samples from patients who underwent allo-HSCT under regimens containing PTCy (n = 23) versus those who received no PTCy (n = 14), we examined the impact of PTCy on the post-transplant immune response. We demonstrated a distinct T cell immune signature between PTCy versus non-PTCy group. PTCy significantly delayed T cell reconstitution and affected the T cell subsets by increasing regulatory T cells (Treg) while reducing naïve T cells. In addition, we observed remarkable enhancement of multiple inhibitory receptors (TIGIT, PD-1, TIM-3, CD38, CD39) on both CD4+ and CD8+ T cells on day 30 post-transplantation in patients who received PTCy. Importantly, upregulation of PD-1 on CD8 T cells was persistent through day 180 and these T cells were less functional, manifested by reduced cytokine production upon anti-CD3/CD28 stimulation. Furthermore, we found a significant correlation of T cell immune phenotypes to clinical outcome (disease relapse and GVHD) in patients who received PTCy. Our novel findings provide critical information to understand the mechanism of how PTCy impacts immune reconstitution in allo-HSCT and may subsequently lead to optimization of our clinical practice using this treatment.

Posttransplant cyclophosphamide (PTCy) has been found to be effective in ameliorating acute graft-versus-host disease (GVHD) in patients following allogeneic hematopoietic stem cell transplantation (aHSCT). Adoptive transfer of high numbers of donor Tregs in experimental aHSCT has shown promise as a therapeutic modality for GVHD regulation. We recently described a strategy for in vivo Treg expansion targeting two receptors: TNFRSF25 and CD25. To date, there have been no direct comparisons between the use of PTCy and Tregs regarding outcome and immune reconstitution within identical groups of transplanted mice. Here, we assessed these two strategies and found both decreased clinical GVHD and improved survival long term. However, recipients transplanted with Treg-expanded donor cells (TrED) exhibited less weight loss early after HSCT. Additionally, TrED recipients demonstrated less thymic damage, significantly more recent thymic emigrants, and more rapid lymphoid engraftment. Three months after HSCT, PTCy-treated and TrED recipients showed tolerance to F1 skin allografts and comparable immune function. Overall, TrED was found superior to PTCy with regard to weight loss early after transplant and initial lymphoid engraftment. Based on these findings, we speculate that morbidity and mortality after transplant could be diminished following TrED transplant into aHSCT recipients, and, therefore, that TrED could provide a promising clinical strategy for GVHD prophylaxis.

In allogeneic hematopoietic cell transplantation (allo-HSCT), both virus-specific T cells and leukemia-specific T cells need to be reconstituted to protect patients from virus infections and primary disease relapse. Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality after allo-HSCT. Emerging data indicate that CMV reactivation is associated with reduced risk of leukemia relapse in patients with acute myeloid leukemia (AML) undergoing allo-HSCT. In a cohort of 24 WT1+ AML patients during the first year following HSCT, CMV specific CD8+ T cells (CMV-CTL) reconstituted much faster than WT1-specific CD8+ T cell (WT1-CTL) after allo-SCT. Moreover, CMV-CTL expressed lower levels of exhaustion markers and were more functional as identified by production of IFN-γ/TNF-α and expression of Eomes/T-bet. Interestingly, our patients with CMV reactivation presented higher frequency of CMV-CTL, lower levels of Eomes+T-bet- and higher levels of Eomes+T-bet+ expression in response to WT1 and CMV pp65 antigen during the first year after transplantation as compared to patients without CMV reactivation. Kinetics of CMV-CTL and WT1-CTL after transplantation might be associated with measurable residual disease and later leukemia relapse. Our results support that CMV reactivation, aside from the CMV-CTL reconstitution, could influence WT1-CTL reconstitution after allo-HSCT, thus potentially contributing to the remission/relapse of AML.

Abstract Objectives Immune recovery following haematopoietic cell transplantation (HCT) functions as a dynamical system. Reducing the duration of intense immune suppression and augmenting antigen presentation has the potential to optimise T‐cell reconstitution, potentially influencing long‐term outcomes. Methods Based on donor‐derived T‐cell recovery, 26 patients were adaptively randomised between mycophenolate mofetil (MMF) administered for 30‐day post‐transplant with filgrastim for cytokine support (MMF30 arm, N = 11), or MMF given for 15 days with sargramostim (MMF15 arm, N = 15). All patients underwent in vivo T‐cell depletion with 5.1 mg kg−1 antithymocyte globulin (administered over 3 days, Day −9 through to Day −7) and received reduced intensity 450 cGy total body irradiation (3 fractions on Day −1 and Day 0). Patients underwent HLA‐matched related and unrelated donor haematopoietic cell transplantation (HCT). Results Clinical outcomes were equivalent between the two groups. The MMF15 arm demonstrated superior T‐cell, as well as T‐cell subset recovery and a trend towards superior T‐cell receptor (TCR) diversity in the first month with this difference persisting through the first year. T‐cell repertoire recovery was more rapid and sustained, as well as more diverse in the MMF15 arm. Conclusion The long‐term superior immune recovery in the MMF15 arm, administered GMCSF, is consistent with a disproportionate impact of early interventions in HCT. Modifying the ‘immune‐milieu’ following allogeneic HCT is feasible and may influence long‐term T‐cell recovery.

We present a case of a 57-year-old man with newly diagnosed acquired immunodeficiency syndrome (AIDS) infection who initially sought care for progressive dysarthria and gait instability. Neuroimaging and CSF studies revealed a diagnosis of progressive multifocal leukoencephalopathy (PML). Although the patient’s human immunodeficiency virus (HIV) decreased considerably in response to anti-retroviral therapy, he continued to deteriorate clinically. Ultimately, the central nervous system (CNS) lesions, which were once centered in the cerebellum, became expansile throughout his posterior fossa. There are few reported cases of cerebellar PML in patients with AIDS.

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) haploinsufficiency is a T-cell hyperactivation disorder that can manifest with both immunodeficiency and immune dysregulation. Approximately one-third of patients may present mild symptoms and remain stable under supportive care. The remaining patients may develop severe multiorgan autoimmunity requiring lifelong immunosuppressive treatment. Hematopoietic stem cell transplantation (HSCT) is potentially curable for patients with treatment-resistant immune dysregulation. Nevertheless, little experience is reported regarding the management of complications post-HSCT. We present case 1 (CTLA-4 haploinsufficiency) and case 2 (CTLA-4 insufficiency-like phenotype) manifesting with severe autoimmunity including cytopenia and involvement of the central nervous system (CNS), lung, and gut and variable impairment of humoral responses. Both patients underwent HSCT for which the main complications were persistent mixed chimerism, infections, and immune-mediated complications [graft-versus-host disease (GVHD) and nodular lung disease]. Detailed management and outcomes of therapeutic interventions post-HSCT are discussed. Concretely, post-HSCT abatacept and human leukocyte antigen (HLA)-matched sibling donor lymphocyte infusions may be used to increase T-cell donor chimerism with the aim of correcting the immune phenotype of CTLA-4 haploinsufficiency. [ABSTRACT FROM AUTHOR]

Thymic stromal lymphopoietin (TSLP) is an immunoregulatory, Th2-polarizing cytokine produced by epithelial cells. We hypothesized that TSLP affects immune reconstitution after hematopoietic stem cell transplantation (HSCT) leading to increased alloreactivity. We measured plasma TSLP by ELISA in 38 patients and assessed the immune reconstitution by flow cytometry. TSLP levels rose after initiation of the conditioning to peak at day +21 after HSCT (p =.03), where TSLP levels correlated with counts of neutrophils (rho = 0.36, p =.04), monocytes (rho = 0.58, p =.006), and lymphocytes (rho = 0.59, p =.02). Overall absolute TSLP levels were not associated with acute or chronic graft-vs-host disease (a/cGvHD). However, patients mounting a sustained increase in TSLP levels at day +90 had a higher risk of cGvHD compared to patients who had returned to pre-conditioning levels at that stage (cumulative incidence: 77% vs. 38%, p =.01). In conclusion, this study suggests a role of TSLP in immune reconstitution and alloreactivity post-HSCT. lymphopoietin (TSLP) is an immunoregulatory, Th2-polarizing cytokine produced by epithelial cells. We hypothesized that TSLP affects immune reconstitution after hematopoietic stem cell transplantation (HSCT) leading to increased alloreactivity. We measured plasma TSLP by ELISA in 38 patients and assessed the immune reconstitution by flow cytometry. [ABSTRACT FROM AUTHOR]

Background: Highly active anti-retroviral therapy (HAART) can successfully suppress human immunodeficiency virus (HIV) viral replication and reconstruct immune function reconstruction in HIV-1-infected patients. However, about 15-30% of HIV-1-infected patients still fail to recover their CD4+ T cell counts after HAART treatment, which means immune reconstruction failure. Pyroptosis plays an important role in the death of CD4+ T cells in HIV-1- infected patients. The study aims to explore the association between the expression of pyroptosis in peripheral blood and immune function reconstruction in HIV-1- infected patients.Methods: One hundred thirty-five HIV-1-infected patients including immunological non-responders (INR) group, immunological responders (IR) group and normal immune function control (NC) group were analyzed. The expression of GSDMD and Caspase-1 in peripheral blood of HIV-1-infected patients were measured by qPCR. The concentrations of GSDMD, Caspase-1, IL-1β and IL-18 in the peripheral serum were quantified by ELISA. The associations between the expression of pyroptosis in peripheral blood and immune function reconstruction were analyzed using multivariate logistic models.Results: The relative expression of GSDMD mRNA and caspase-1 mRNA in peripheral blood, as well as the expression of IL-18 cytokine in the INR, were significantly higher than those in the IR and NC (P < 0.05). There was no significant difference in the expression of IL-1β cytokine (P > 0.05). Multivariate logistic analysis showed that the patients with baseline CD4+ T cell counts less than 100 cells/μL (aOR 7.051, 95% CI 1.115-44.592, P = 0.038), high level of expression of Caspase-1mRNA (aOR 2.803, 95% CI 1.065-7.377, P = 0.037) and IL-18 cytokine (aOR 10.131, 95% CI 1.616-63.505, P = 0.013) had significant poor CD4+ T cell recovery.Conclusions: The baseline CD4+ T cell counts less than 100 cells/μL, high relative expression of Caspase-1 mRNA, and high expression of IL-18 cytokine are associated factors that affect the reconstruction of immune function. [ABSTRACT FROM AUTHOR]