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Methotrexate (MTX) is an anti-folate chemotherapeutic agent that is considered to be a gold standard in Acute Lymphoblastic Leukemia (ALL) therapy. Nevertheless, toxicities induced mainly due to high doses of MTX are still a challenge for clinical practice. MTX pharmacogenetics implicate various genes as predictors of MTX toxicity, especially those that participate in MTX intake like solute carrier family 19 member 1 (SLC19A1). The aim of the present study was to evaluate the association between SLC19A1 polymorphisms and its regulatory miRNAs with MTX toxicity in children with ALL. A total of 86 children with ALL were included in this study and were all genotyped for rs2838958, rs1051266 and rs1131596 SLC19A1 polymorphisms as well as the rs56292801 polymorphism of miR-5189. Patients were followed up (48, 72 and 96 h) after treatment with MTX in order to evaluate the presence of MTX-associated adverse events. Our results indicate that there is a statistically significant correlation between the rs1131596 SLC19A1 polymorphism and the development of MTX-induced hepatotoxicity (p = 0.03), but there is no significant association between any of the studied polymorphisms and mucositis or other side effects, such as nausea, emesis, diarrhea, neutropenia, skin rash and infections. In addition, when genotype TT of rs1131596 and genotype AA of rs56292801 are both present in a patient then there is a higher risk of developing severe hepatotoxicity (p = 0.0104).

Background: Bacterial infections frequently occur in haematological patients, especially during prolonged neutropenia after intensive chemotherapy, often leading to bloodstream infections and pneumonia. Objective: Routine antimicrobial prophylaxis (AMP) for high-risk haematology patients is still debated while prevalence of multi-drug resistant (MDR) Gram-negative bacteria (GNB) is rising globally. We aimed to assess the current practice of AMP in this population. Design: Cross-sectional observational survey study. Methods: Haematologists and infectious diseases physicians Europewide were invited to an online survey including questions on routine screening for GNB, incidence of MDR-GNB colonization, antimicrobial prophylaxis practices, rates of bloodstream infections (BSI), ICU admission and mortality differentiated by infections due to GNB versus MDR-GNB. Results: 120 haematology centres from 28 countries participated. Screening for MDR-GNB is performed in 86.7% of centres, mostly via rectal swabs (58.3%). In 39.2% of routine AMP is used, mostly with fluoroquinolones. Estimates of GNB-BSI yielded higher rates in patients not receiving anti-GNB prophylaxis than in those who do for E. coli (10% vs 7%) Klebsiella spp. (10% vs 5%), and Pseudomonas spp. (5% vs 4%). Rates for MDR-GNB infection were estimated lower in centres that administer AMP for MDR E. coli (5% vs 3%) Klebsiella spp. (5% vs 3%), and Pseudomonas spp. (2% vs 1%). In an exploratory analysis, Southern and Eastern European countries expected higher rates of MDR-GNB infections with lower ICU admission and mortality rates which may be subject to estimation bias. Conclusion: Screening for MDR-GNB is frequently performed. AMP against GNB infections is still often implemented. Estimated BSI rates are rather low, while the rate of MDR-GNB infections rises. Tailored prophylaxis including antimicrobial stewardship becomes more important.

IntroductionImmune checkpoint blockade (ICB) immunotherapy has revolutionized cancer treatment, demonstrating exceptional clinical responses in a wide range of cancers. Despite the success, a significant proportion of patients still fail to respond, highlighting the existence of unappreciated mechanisms of immunotherapy resistance. Delineating such mechanisms is paramount to minimize immunotherapy failures and optimize the clinical benefit.MethodsIn this study, we treated tumour-bearing mice with PD-L1 blockage antibody (aPD-L1) immunotherapy, to investigate its effects on cancer-induced emergency myelopoiesis, focusing on bone marrow (BM) hematopoietic stem and progenitor cells (HSPCs). We examined the impact of aPD-L1 treatment on HSPC quiescence, proliferation, transcriptomic profile, and functionality.ResultsHerein, we reveal that aPD-L1 in tumour-bearing mice targets the HSPCs in the BM, mediating their exit from quiescence and promoting their proliferation. Notably, disruption of the PDL1/PD1 axis induces transcriptomic reprogramming in HSPCs, observed in both individuals with Hodgkin lymphoma (HL) and tumour-bearing mice, shifting towards an inflammatory state. Furthermore, HSPCs from aPDL1-treated mice demonstrated resistance to cancer-induced emergency myelopoiesis, evidenced by a lower generation of MDSCs compared to control-treated mice.DiscussionOur findings shed light on unrecognized mechanisms of action of ICB immunotherapy in cancer, which involves targeting of BM-driven HSPCs and reprogramming of cancer-induced emergency myelopoiesis.

Hematopoietic stem cell transplantation (HSCT) and chimeric antigen receptor-T (CAR-T) immunotherapy are widely used for the management of hematological malignancies. HSCT can be complicated by endothelial injury syndromes, such as HSCT-thrombotic microangiopathy (HSCT-TMA) and sinusoidal obstructive syndrome/veno-occlusive disease (SOS/VOD), which are life-threatening. Moreover, venous thromboembolic events (VTEs) are common in HSCT recipients due to endothelial injury, use of central venous catheters, prolonged hospitalization, and the development of a procoagulant state. VTEs have also been reported post-CAR-T infusion. The management of thrombotic events in these patients is challenging, due to the high risk of bleeding that is present. CAR-T immunotherapy might be followed by toxicities, such as cytokine release syndrome (CRS) and immune effector cell-associated neuro-toxicity syndrome (ICANS). Endothelial dysfunction is implicated in the pathogenesis of these syndromes. Early recognition and management of the above complications are crucial for better patient outcomes.

Acquired hemophilia A (AHA) is a bleeding disorder characterized by the immunological inhibition of factor VIII (FVIII) of the hemostatic pathway leading to hemorrhagic events. Different domains of FVIII are the target of autoantibodies (mainly immunoglobulin (Ig) G) leading to the deficiency of FVIII. Several factors have been associated with the activation of the auto-immunity towards FVIII. Emerging evidence implicates CD4+ T cell activation in mediating this autoimmune response, with their involvement like that observed in congenital hemophilia A. Several genes such as HLA II DRB*16, DQB1*0502, and CTLA-4 + 49 are responsible for the pathogenesis of AHA. Epigenetic modifications and mainly long-coding RNAS (lncRNAs) are potentially contributing to the pathogenesis of AHA. The treatment approach of AHA includes the management of acute bleeding events and the administration of immunosuppressive medications. This review aimed to summarize the published data on the genetics and epigenetics of AHA. The severity and the mortality of this disease are creating an emerging need for further research in the field of the genetics and epigenetics of acquired hemorrhagic disorder.

Hematopoietic stem cell transplantation (HSCT) remains a cornerstone in the management of patients with hematological malignancies. Endothelial injury syndromes, such as HSCT-associated thrombotic microangiopathy (HSCT-TMA), veno-occlusive disease/sinusoidal obstruction syndrome (SOS/VOD), and capillary leak syndrome (CLS), constitute complications after HSCT. Moreover, endothelial damage is prevalent after immunotherapy with chimeric antigen receptor-T (CAR-T) and can be manifested with cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). Our literature review aims to investigate the genetic susceptibility in endothelial injury syndromes after HSCT and CAR-T cell therapy. Variations in complement pathway- and endothelial function-related genes have been associated with the development of HSCT-TMA. In these genes, CFHR5, CFHR1, CFHR3, CFI, ADAMTS13, CFB, C3, C4, C5, and MASP1 are included. Thus, patients with these variations might have a predisposition to complement activation, which is also exaggerated by other factors (such as acute graft-versus-host disease, infections, and calcineurin inhibitors). Few studies have examined the genetic susceptibility to SOS/VOD syndrome, and the implicated genes include CFH, methylenetetrahydrofolate reductase, and heparinase. Finally, specific mutations have been associated with the onset of CRS (PFKFB4, CX3CR1) and ICANS (PPM1D, DNMT3A, TE2, ASXL1). More research is essential in this field to achieve better outcomes for our patients.

Thrombotic microangiopathies during pregnancy are rare but may be life-threatening diseases for both the mother and the fetus. Thrombotic thrombocytopenic purpura (TTP) patients present with hemolytic anemia and thrombocytopenia associated with low ADAMTS-13 activity, a cleaving von Willebrand factor protein. Pregnancy has been described not only as a trigger of TTP but also as a phenotype modifier. In addition, hormonal changes induced by assisted reproduction technology (ART) swift the thrombotic – thrombolytic state towards coagulation, while increasing the pregnancy complications’ rate. We present a case of a 34-year-old pregnant woman, who conceived via ART and diagnosed with TTP at 13 weeks of gestation. She was initially treated with corticosteroids and daily plasmapheresis. Due to gradual unresponsiveness to treatment, rituximab was also added. After 3 doses, she was diagnosed with mild ovarian hyperstimulation syndrome, which resolved spontaneously after several weeks. She delivered a healthy neonate at 39+1 weeks via emergency cesarean section due to fetal distress, while the postpartum follow-up was uneventful. In conclusion, TTP should be suspected to a pregnant woman with raised hemorrhagic risk presenting with hematuria, anemia and thrombocytopenia.

Objectives: Elderly patients with hematologic malignancies face the highest risk of severe COVID-19 outcomes. The infection's impact on different age groups remains unstudied in detail. Methods: We analyzed elderly patients (age groups: 65-70, 71-75, 76-80, and >80 years old) with hematologic malignancies included in the EPICOVIDEHA registry between January 2020 and July 2022. Univariable and multivariable Cox regression models were conducted to identify factors influencing death in COVID-19 patients with hematological malignancy. Results: The study included data from 3,603 elderly patients (aged 65 or older) with hematological malignancy, with a majority being male (58.1%) and a significant proportion having comorbidities. The patients were divided into four age groups, and the analysis assessed COVID-19 outcomes, vaccination status, and other variables in relation to age and pandemic waves. The 90-day survival rate for patients with COVID-19 was 71.2%, with significant differences between groups. The pandemic waves had varying impacts, with the first wave affecting patients over 80 years old, the second being more severe in 65-70, and the third being the least severe in all age groups. Factors contributing to 90-day mortality included age, comorbidities, lymphopenia, active malignancy, acute leukemia, less than three vaccine doses, severe COVID-19, and using only corticosteroids as treatment. Conclusion: These data underscore the heterogeneity of elderly hematological patients, highlight the different impacts of COVID-19 waves and the pivotal importance of vaccination, and may help in planning future healthcare efforts.

Background/Objectives: Despite novel biological agents, steroid-dependent or -refractory graft-versus-host disease (GvHD) remains a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT). Extracorporeal photopheresis (ECP) is an alternative, non-immunosuppressive treatment for patients with acute (aGvHD) or chronic (cGvHD) GvHD. The aim of this study was to investigate the safety and efficacy of ECP in the treatment of acute and chronic GvHD; Methods: We prospectively studied 112 patients with cGvHD who received one or more previous lines of treatment and 28 patients with steroid-dependent or refractory grade II-IV aGvHD post-alloHSCT. Results: In terms of severe aGvHD, most of the patients (19/28) responded to ECP treatment, while the five-year overall survival (OS) was 34%. After adjustment for several confounder factors, the reduction in immunosuppression (p = 0.026) and number of ECP sessions (p < 0.001) were associated with improved OS. Regarding chronic GvHD, only 19 patients failed to respond to ECP treatment; though significantly lower rates of response were presented in patients with visceral involvement (p = 0.037) and earlier post-transplant GVHD diagnosis (p = 0.001). Over a follow-up period of 45.2 [interquartile range (IQR): 5.6–345.1] months, the 5-year cumulative incidence (CI) of cGvHD-related mortality was 21.2% and was significantly reduced in patients with ECP response (p < 0.001), while the 5-year OS was 65.3%. Conclusions: Our results confirm the safety and efficacy of ECP in patients with GvHD and provide sufficient data for further investigation and the best combination drugs needed such that GvHD will not be the major barrier of allo-HCT in the near future.

Summary: Background: The COVID-19 pandemic heightened risks for individuals with hematological malignancies due to compromised immune systems, leading to more severe outcomes and increased mortality. While interventions like vaccines, targeted antivirals, and monoclonal antibodies have been effective for the general population, their benefits for these patients may not be as pronounced. Methods: The EPICOVIDEHA registry (National Clinical Trials Identifier, NCT04733729) gathers COVID-19 data from hematological malignancy patients since the pandemic's start worldwide. It spans various global locations, allowing comprehensive analysis over the first three years (2020–2022). Findings: The EPICOVIDEHA registry collected data from January 2020 to December 2022, involving 8767 COVID-19 cases in hematological malignancy patients from 152 centers across 41 countries, with 42% being female. Over this period, there was a significant reduction in critical infections and an overall decrease in mortality from 29% to 4%. However, hospitalization, particularly in the ICU, remained associated with higher mortality rates. Factors contributing to increased mortality included age, multiple comorbidities, active malignancy at COVID-19 onset, pulmonary symptoms, and hospitalization. On the positive side, vaccination with one to two doses or three or more doses, as well as encountering COVID-19 in 2022, were associated with improved survival. Interpretation: Patients with hematological malignancies still face elevated risks, despite reductions in critical infections and overall mortality rates over time. Hospitalization, especially in ICUs, remains a significant concern. The study underscores the importance of vaccination and the timing of COVID-19 exposure in 2022 for enhanced survival in this patient group. Ongoing monitoring and targeted interventions are essential to support this vulnerable population, emphasizing the critical role of timely diagnosis and prompt treatment in preventing severe COVID-19 cases. Funding: Not applicable.

IntroductionExtracorporal Photophoresis (ECP) is in clinical use for steroid-refractory and steroid-dependent acute GVHD (SR-aGVHD). Based on recent Phase-III study results, ruxolitinib has become the new standard of care for SR-aGVHD. Our aim was to collect comparative data between ruxolitinib and ECP in SR-aGVHD in order to improve the evidence base for clinical decision making. MethodsWe asked EBMT centers if they were willing to participate in this study by completing a data form (Med-C) with detailed information on GVHD grading, -therapy, -dosing, -response and complications for each included patient.Results31 centers responded positively (14%) and we included all patients receiving alloSCT between 1/2017-7/2019 and treated with ECP or ruxolitinib for SR-aGVHD grades II-IV from these centers. We identified 53 and 40 patients with grades II-IV SR-aGVHD who were treated with ECP and ruxolitinib, respectively. We performed multivariate analyses adjusted on grading and type of SR-aGVHD (steroid dependent vs. refractory). At day+90 after initiation of treatment for SR-aGVHD we found no statistically significant differences in overall response. The odds ratio in the ruxolitinib group to achieve overall response vs. the ECP group was 1.13 (95% CI = [0.41; 3.22], p = 0.81). In line, we detected no statistically significant differences in overall survival, progression-free survival, non-relapse mortality and relapse incidence.DiscussionThe clinical significance is limited by the retrospective study design and the current data can’t replace prospective studies on ECP in SR-aGVHD. However, the present results contribute to the accumulating evidence on ECP as an effective treatment option in SR-aGVHD.

Haemophilia presents a significant challenge to the quality of life of affected individuals. Evaluating the health-related quality of life (HRQoL) of people with haemophilia (PwH) provides a valuable mean of assessing their perception of overall care outcomes, while also identifying influential factors across various age and condition severity demographics. This observational retrospective study determined the HRQoL of 100 adult PwH in Northern Greece through comprehensive analysis and interpretation of their HRQoL levels, particularly in domains concerning their physical, emotional, and mental well-being, obtained through the Haem-A-QoL index questionnaire. Disease severity and young age were significantly associated with the administration of prophylactic treatment (84.2% of patients with severe haemophilia and 65.2% of patients aged 18–30). The mean Haem-A-QoL score was 40.11 ± 17.38, with the lowest HRQoL observed in the 46–60 age group (46.16), and the highest in the ≥61 age groups (35.16). Notably, the ‘Sports/Leisure’ and ‘Physical Health’ domains exhibited the highest scores, in contrast to ‘Family Planning’ and ‘Relationships/Sexuality’. Individuals with mild haemophilia recorded the lowest mean score (39.38), while those with a severe condition exhibited the highest (41.23). Age, disease severity, and physical activity emerged as primary determinants significantly affecting HRQoL outcomes.

Immunotherapy with chimeric antigen receptor T (CAR-T) cell therapies has brought substantial improvement in clinical outcomes in patients with relapsed/refractory B cell neoplasms. However, complications such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) limit the therapeutic efficacy of this treatment approach. ICANS can have a broad range of clinical manifestations, while various scoring systems have been developed for its grading. Cognitive decline is prevalent in CAR-T therapy recipients including impaired attention, difficulty in item naming, and writing, agraphia, and executive dysfunction. In this review, we aim to present the diagnostic methods and tests that have been used for the recognition of cognitive impairment in these patients. Moreover, up-to-date data about the duration of cognitive impairment symptoms after the infusion are presented. More research on the risk factors, pathogenesis, preventive measures, and therapy of neurocognitive impairment is crucial for better outcomes for our patients.

Given the limited real-world data of caplacizumab, our multicenter real-world study was designed to assess the safety and efficacy of caplacizumab in immune thrombotic thrombocytopenic pupura (iTTP), compared to historic controls. We have studied 70 patients: 23 in the caplacizumab and 47 in the historic control group. Plasma exchange was applied in all episodes except for two patients that denied plasma exchange. Rituximab as first-line treatment was more common in the caplacizumab group compared to historic control. Caplacizumab (10 mg daily) was given at a median on day 7 (1–43) from initial diagnosis for 32 (6–47) dosages. In the caplacizumab group, a median of 12 (8–23) patients required plasma exchange sessions versus 14 (6–32) in the control group. Caplacizumab administration did not produce any grade 3 complications or major hemorrhagic events. After a median of 19.0 (2.6–320) months since the iTTP diagnosis, 5 deaths occurred (4 in the control group and 1 in the caplacizumab group, p = 0.310). Caplacizumab patients achieved early platelet normalization and ADAMTS13 activity normalization at the end of treatment. Relapse was observed only in 2/23 (9%) caplacizumab patients, compared to 29/47 (62%) historic controls (p

A crucial complication after allogeneic hematopoietic cell transplantation (alloHCT), namely, acute graft-versus-host disease (aGVHD), occurs in about 50% of transplant recipients, leading to high morbidity and mortality. Thus far, the diagnosis of GVHD has been mainly established through clinical features and histologic or laboratory evidence of periductal lymphocyte infiltration, fibroplasia, and mixed lymphocytic and plasmocytic inflammation. Intensive research is focused on identifying biomarkers for the early diagnosis, prediction of disease, response to treatment, prognosis, and risk stratification of patients. The serum biomolecules that have been investigated are reported and summarized. Moreover, oral tissue involvement in GVHD is described, and other biomarkers that have been proposed, such as saliva, are analyzed. Future research is highlighted as a necessity in order for these biomarkers to be validated and quantified for use in clinical practice.

Complement dysregulation has been documented in adults with COVID-19 and implicated in relevant pediatric inflammatory responses against SARS-CoV-2. We propose that signatures of complement missense coding SNPs associated with dysregulation could also be identified in children with multisystem inflammatory syndrome (MIS-C). We investigated 71 pediatric patients with RT-PCR validated SARS-CoV-2 hospitalized in pediatric COVID-19 care units (November 2020–March 2021) in three major groups. Seven (7) patients suffered from MIS-C (MIS-C group), 32 suffered from COVID-19 and were hospitalized (admitted group), whereas 32 suffered from COVID-19, but were sent home. All patients survived and were genotyped for variations in the C3, C5, CFB, CFD, CFH, CFHR1, CFI, CD46, CD55, MASP1, MASP2, MBL2, COLEC11, FCN1, and FCN3 genes. Upon evaluation of the missense coding SNP distribution patterns along the three study groups, we noticed similarities, but also considerably increased frequencies of the alternative pathway (AP) associated with SNPs rs12614 CFB, rs1061170, and rs1065489 CFH in the MIS-C patients. Our analysis suggests that the corresponding substitutions potentially reduce the C3b-inactivation efficiency and promote slower and weaker AP C3bBb pre-convertase assembly on virions. Under these circumstances, the complement AP opsonization capacity may be impaired, leading to compromised immune clearance and systemic inflammation in the MIS-C syndrome.

Summary: Background: Nirmatrelvir/ritonavir treatment decreases the hospitalisation rate in immunocompetent patients with COVID-19, but data on efficacy in patients with haematological malignancy are scarce. Here, we describe the outcome of nirmatrelvir/ritonavir treatment in a large cohort of the latter patients. Methods: This is a retrospective cohort study from the multicentre EPICOVIDEHA registry (NCT04733729) on patients with haematological malignancy, who were diagnosed with COVID-19 between January and September 2022. Patients receiving nirmatrelvir/ritonavir were compared to those who did not. A logistic regression was run to determine factors associated with nirmatrelvir/ritonavir administration in our sample. Mortality between treatment groups was assessed with Kaplan–Meier survival plots after matching all the patients with a propensity score. Additionally, a Cox regression was modelled to detect factors associated with mortality in patients receiving nirmatrelvir/ritonavir. Findings: A total of 1859 patients were analysed, 117 (6%) were treated with nirmatrelvir/ritonavir, 1742 (94%) were treated otherwise. Of 117 patients receiving nirmatrelvir/ritonavir, 80% had received ≥1 anti-SARS-CoV-2 vaccine dose before COVID-19 onset, 13% of which received a 2nd vaccine booster. 5% were admitted to ICU. Nirmatrelvir/ritonavir treatment was associated with the presence of extrapulmonary symptoms at COVID-19 onset, for example anosmia, fever, rhinitis, or sinusitis (aOR 2.509, 95%CI 1.448–4.347) and 2nd vaccine booster (aOR 3.624, 95%CI 1.619–8.109). Chronic pulmonary disease (aOR 0.261, 95%CI 0.093–0.732) and obesity (aOR 0.105, 95%CI 0.014–0.776) were not associated with nirmatrelvir/ritonavir use. After propensity score matching, day-30 mortality rate in patients treated with nirmatrelvir/ritonavir was 2%, significantly lower than in patients with SARS-CoV-2 directed treatment other than nirmatrelvir/ritonavir (11%, p = 0.036). No factor was observed explaining the mortality difference in patients after nirmatrelvir/ritonavir administration. Interpretation: Haematological malignancy patients were more likely to receive nirmatrelvir/ritonavir when reporting extrapulmonary symptoms or 2nd vaccine booster at COVID-19 onset, as opposed to chronic pulmonary disease and obesity. The mortality rate in patients treated with nirmatrelvir/ritonavir was lower than in patients with targeted drugs other than nirmatrelvir/ritonavir. Funding: EPICOVIDEHA has received funds from Optics COMMIT (COVID-19 Unmet Medical Needs and Associated Research Extension) COVID-19 RFP program by GILEAD Science, United States (Project 2020-8223).

BackgroundThe outcome of COVID-19 in allogeneic hematopoietic stem cell transplantation (HSCT) recipients is almost uniformely considered poor. The aim of present study was to retrospectively analyse the outcome and risk factors for mortality in a large series of patients who developed COVID-19 infection after an allogeneic HSCT.MethodsThis multicenter retrospective study promoted by the European Hematology Association – Infections in Hematology Study Working Group, included 326 adult HSCT patients who had COVID-19 between January 2020 and March 2022.ResultsThe median time from HSCT to the diagnosis of COVID-19 was 268 days (IQR 86-713; range 0-185 days). COVID-19 severity was mild in 21% of the patients, severe in 39% and critical in 16% of the patients. In multivariable analysis factors associated with a higher risk of mortality were, age above 50 years, presence of 3 or more comorbidities, active hematologic disease at time of COVID-19 infection, development of COVID-19 within 12 months of HSCT, and severe/critical infections. Overall mortality rate was 21% (n=68): COVID-19 was the main or secondary cause of death in 16% of the patients (n=53).ConclusionsMortality in HSCT recipients who develop COVID-19 is high and largely dependent on age, comorbidities, active hematologic disease, timing from transplant and severity of the infection.

Abstract Hematopoietic stem cell transplantation-associated thrombotic microangiopathy (HSCT-TMA) is a life-threatening syndrome that occurs in adult and pediatric patients after hematopoietic stem cell transplantation. Nonspecific symptoms, heterogeneity within study populations, and variability among current diagnostic criteria contribute to misdiagnosis and underdiagnosis of this syndrome. Hematopoietic stem cell transplantation and associated risk factors precipitate endothelial injury, leading to HSCT-TMA and other endothelial injury syndromes such as hepatic veno-occlusive disease/sinusoidal obstruction syndrome, idiopathic pneumonia syndrome, diffuse alveolar hemorrhage, capillary leak syndrome, and graft-versus-host disease. Endothelial injury can trigger activation of the complement system, promoting inflammation and the development of endothelial injury syndromes, ultimately leading to organ damage and failure. In particular, the lectin pathway of complement is activated by damage-associated molecular patterns (DAMPs) on the surface of injured endothelial cells. Pattern-recognition molecules such as mannose-binding lectin (MBL), collectins, and ficolins—collectively termed lectins—bind to DAMPs on injured host cells, forming activation complexes with MBL-associated serine proteases 1, 2, and 3 (MASP-1, MASP-2, and MASP-3). Activation of the lectin pathway may also trigger the coagulation cascade via MASP-2 cleavage of prothrombin to thrombin. Together, activation of complement and the coagulation cascade lead to a procoagulant state that may result in development of HSCT-TMA. Several complement inhibitors targeting various complement pathways are in clinical trials for the treatment of HSCT-TMA. In this article, we review the role of the complement system in HSCT-TMA pathogenesis, with a focus on the lectin pathway.

Bone marrow failure (BMF) syndromes are a group of various hematological diseases with cytopenia as a main common characteristic. Given their rarity and continuous progress in the field, we aim to provide data considering the efficiency and safety of the therapeutic methods, focusing on the treatment of aplastic anemia(AA) and paroxysmal nocturnal hemoglobinuria (PNH). We enrolled consecutive patients diagnosed with BMF in two referral centers of Northern Greece from 2008 to 2020. We studied 43 patients with AA (37 adults and 6 children/adolescents) and 6 with classical PNH. Regarding classical PNH, 4 patients have received eculizumab treatment with 1/4 presenting extravascular hemolysis. Among 43 patients with aplastic anemia, PNH clones were detected in 11. Regarding patients that did not receive alloHCT (n=15), 14/15 were treated with ATG and cyclosporine as first line, with the addition of eltrombopag in patients treated after its approval (n=9). With a median follow-up of 16.7 (1.8-56.2) months from diagnosis, 12/14 (85.7%) are alive (4-year OS: 85.1%). AlloHCT was performed in 28 patients. Five patients developed TA-TMA which did not resolve in 3/5 (all with a pre-transplant PNH clone). With the follow-up among survivors reaching 86.3 (6.3-262.4) months, 10-year OS was 56.9%, independently associated with PNH clones after adjusting for age (p=0.024). In conclusion, our real-world experience confirms that novel treatments are changing the field of BMF syndromes. Nevertheless, there is still an unmet need to personalize algorithms in this field.

Background: A robust efficiency of mRNA vaccines against coronavirus disease-2019 has been demonstrated, however, the intended long-term protection against SARS-CoV-2 has been challenged by the waning humoral and cellular immunity over time, leading to a third vaccination dose recommendation for immunocompetent individuals, six months after completion of primary mRNA vaccination. Methods: We here measured humoral responses via an immunoassay measuring SARS-CoV-2 neutralizing antibodies and T-cell responses using Elispot for interferon-γ 1- and 8- months post full BNT162b2 vaccination, in 10 health-care professionals. To explore whether the declining abundance of coronavirus-specific T-cells (CoV-2-STs) truly reflects decreased capacity for viral control, rather than the attenuating viral stimulus over time, we modeled ex vivo the T-cellular response upon viral challenge in fully vaccinated immunocompetent individuals, 1- and 8-months post BNT162b2. Findings.: Notwithstanding the declining CoV-2-neutralizing antibodies and CoV-2-STs, re-challenged CoV-2-STs, 1- and 8-months post vaccination, presented similar functional characteristics including high cytotoxicity against both the unmutated virus and the delta variant. Interpretation.: These findings suggest robust and sustained cellular immune response upon SARS-CοV-2 antigen exposure, 8 months post mRNA vaccination, despite declining CοV-2-STs over time in the presence of an attenuating viral stimulus.

Abstract Background Polycythemia vera (PV) is characterized by red cell mass expansion in the peripheral blood and can be complicated with thrombosis, bleeding, evolution to acute myeloid leukemia (AML) or a fibrotic phase. Paroxysmal nocturnal hemoglobinuria (PNH) in an acquired clonal haematopoietic stem cell disorder associated with chronic intravascular hemolysis, venous thrombosis, defective hematopoiesis, frequent episodes of infection and, rarely, leukemic transformation. Herein, we report an interesting case of a patient with coexistence of PNH clones and a JAK2V617F positive PV, with unusual thromboses without hemolysis. Case presentation A 51-year-old woman presented with increased levels of hematocrit, multiple liver, spleen, and left kidney infarctions and ascites; further investigation revealed a JAK2V617F-positive polycythemia vera and the presence of a significant PNH population (more than 90% CD55– CD59– cells among both granulocytes and red blood cells). Interestingly, the patient has experienced severe thrombotic events without any signs or symptoms of hemolysis. Conclusions This case raises questions over uncharted aspects of the PNH etiopathogenesis and its potential association with myeloproliferative neoplasms (MPN) and highlights the difficulty of diagnosing and managing patients with more than one potentially thrombophilic conditions, especially with established and severe thromboses.

Abstract Background Increased urinary albumin excretion (UAE) in diabetes is a sensitive marker of microvascular injury and a reliable predictor of cardiovascular outcomes. Hypertension-induced hemodynamic pressure load, diabetes-related metabolic processes and large artery stiffening have all been implicated in the development of microalbuminuria. We investigated whether hyperglycemia per se, or rather increased blood pressure (BP) and macrovascular dysfunction, is a stronger predictor of UAE at the earliest stages of diabetes. Methods Consecutive newly diagnosed patients with diabetes type 2, who were normoglycemic within a year’s time prior to diagnosis, were enrolled. UAE was estimated in 24-h urine samples. Both office and 24-h ambulatory BP was recorded. Arterial stiffness was evaluated by measurement of carotid-femoral pulse wave velocity (PWV) with applanation tonometry. Results Among 71 newly diagnosed patients with median diabetes duration of just 1 month, 15.5% presented microalbuminuria. UAE did not differ between hypertensive and normotensive diabetics; however, newly diagnosed patients for both hypertension and diabetes exhibited significantly higher levels of UAE, compared to diabetic patients with long-standing hypertension. UAE strongly and significantly correlated with office systolic BP, HbA1c, PWV and estimated glomerular filtration rate. However, in the multivariate analysis adjusting for these factors, only HbA1c was independently associated with UAE (beta = 0.278, p = 0.049). Conclusions Hyperglycemic state emerges as a powerful predictor of increased UAE even at the earliest stages of diabetes. The relative contribution of hypertension and macrovascular dysfunction to the development of microalbuminuria seems to be obscured by hyperglycemia, even in patients whose diabetes onset does not exceed a few months’ time.

Thrombotic microangiopathies (TMAs) represent a heterogeneous group of entities characterized by the same phenotype: microangiopathic hemolytic anemia, thrombocytopenia, and organ damage. Over the last decades, two major syndromes with distinct pathophysiology have been recognized: thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). A severe deficiency of the ADAMTS13 (A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motifs, member 13) enzyme has been established as the key feature for TTP. When ultra-large Von Willebrand factor (UL-VWF) multimers are allowed to accumulate due to the lack of ADAMTS13, uncontrolled platelet aggregation and adhesion can occur forming disseminated microthrombi resulting in clinical the clinical syndrome. TTP can be fatal without prompt recognition and treatment. Over time, increasing awareness, improvements in diagnostic techniques, and advances in therapeutics have increased survival rates substantially. Once previously thought to be only an acute illness, long-term complications in survivorship are being described with increasing frequency. As our understanding of this devastating condition has evolved, a need for updates has emerged in this increasingly complex setting. In this review, we summarize novel data regarding the pathophysiology, clinical diagnosis, acute management, long-term follow up and emerging therapies for TTP.

Abstract Objective Neurologic adverse events remain challenging complications with poor morbidity and mortality post adult allogeneic hematopoietic cell transplantation (allo‐HCT) for hematologic diseases. We conducted a systematic review and meta‐analysis to determine their spectrum, incidence, and impact on survival. Methods We searched MEDLINE, COCHRANE, EMBASE through March 2019 for all types of primary studies. Two independent reviewers screened, extracted data, and assessed risk of bias (RoB). Results We identified 552 eligible studies describing 57.972 patients; one randomized controlled trial, two case–control, 17 prospective, 86 retrospective cohort studies, 21 case series, and 425 case reports. RoB ranged from fair to high although case series were low‐risk. The majority of studies traced infectious or drug‐related neurologic manifestations. Infectious complications were present in 2.7% (95% CI 1.9–3.6) and 3.3% (95% CI 0.8–7.1) of patients in retrospective and prospective cohort studies, respectively. In retrospective studies, 3.4% (95% CI 2.1–4.9) of patients suffered from drug‐related neurologic events. In prospective cohorts the equivalent incidence was 13% (95% CI 4.2–24.8). Neurologic complications had a detrimental impact on survival. Interpretation Our study highlights the wide spectrum and significant impact of neurologic complications on survival post allo‐HCT. This systematic review summarizes existing data and provides the necessary background information for every physician involved in the management of these patients.

ADAMTS13 (A Disintegrin and Metalloprotease with ThromboSpondin type 1 motifs) activity is a key tool in differential diagnosis of thrombotic microangiopathies (TMAs). Due to the lack of availability of ADAMTS13 testing, PLASMIC/PLASIC scores have been suggested to predict ADAMTS13 deficiency. The importance of differentiating TTP from other complement-mediated TMAs is highlighted by the need to urgently start plasma exchange and utility of treatments such as caplacizumab or eculuzimab. Therefore, we aimed to evaluate ADAMTS13 activity, PLASMIC/PLASIC scores, and complement testing in guiding management of a real-world TMA cohort. We enrolled consecutive TMA patients with samples referred to our Center (01/2018–2020). If ADAMTS13 ​> ​10%, soluble C5b-9 was measured. Among 80 TMA patients, ADAMTS13 activity was ≤10% in 50 patients, while 28 had a relapsing disease. PLASMIC/PLASIC were excellent predictors of ADAMTS13 deficiency, especially in patients without secondary causes. Soluble C5b-9 levels were elevated (median 525 ​ng/ml, range 313–913 ​ng/ml) in 7 patients without secondary causes and ADAMTS13 ​> ​10% (hemolytic uremic syndrome/HUS). Two were shiga-toxin associated; while 5 atypical HUS. Only 1/5 patients received eculizumab and achieved TMA resolution implemented by guidance based on soluble C5b-9 levels. In transplant-associated TMA, 8/16 patients not responding to first-line treatment received eculizumab due to elevated C5b-9 levels (median 353 ​ng/ml, range 281–1252 ​ng/ml) and achieved TMA resolution. In conclusion, our real-world data confirm that ADAMTS13, complement testing, and PLASMIC/PLASIC are valuable tools in diagnosis and management of TMAs, but also highlight the unmet need of using available markers and treatments in clinical practice.

Objectives:Klebsiella pneumoniae carbapenemase (KPC)–producing K. pneumoniae (KPC-Kp) emerge as a major healthcare concern worldwide. Despite the significance of infections before and after allogeneic hematopoietic cell transplantation (alloHCT), the burden of KP infections has not been extensively evaluated.Methods: We studied the incidence, risk factors, and outcomes of consecutive alloHCT recipients with Kp isolates before and after alloHCT.Results: Among 424 patients who underwent alloHCT in 2008–2018, we studied two groups: those with Kp isolates before (group 1, 52 patients) and those with Kp isolates after alloHCT (group 2, 66 patients). prE-transplant infections were associated with post-transplant infections (p = 0.010), despite secondary prophylaxis. KPC-Kp was isolated in 29% of group 1, and 80% of group 2. Both groups were characterized by a significant burden of moderate–severe acute graft- vs.-host disease (GVHD) [cumulative incidence (CI) of 44.5 and 61.9%, respectively] and severe chronic (CI of 56.7 and 61.9%). Kp infections and GVHD were independent predictive factors of treatment-related mortality (TRM) in both groups.Conclusions: Our study highlights the significant impact of Kp infections on TRM, with GVHD consisting an important underlying factor. As prophylactic measures did not improve rates of post-transplant infections, innovative interventions need to be further investigated to address this major healthcare concern.

Purpose/Background/Objectives: Cardiovascular risk is increased in patients with autoimmune rheumatic disorders [1]. Endothelial and platelet MVs (EMVs, PMVs) are small vesicles (0.1–1 μm) released from plasma membrane and represent novel markers of endothelial dysfunction and thrombosis. Their levels increase substantially in patients with cardiovascular diseases [2,3]. We tested whether EMVs and PMVs are increased in patients with autoimmune rheumatic disorders in the absence of cardiovascular comorbidities. Methods: Consecutive patients with rheumatoid arthritis or systemic lupus erythematosus were studied, provided they were free from cardiovascular comorbidities (hypertension, diabetes, heart disease, history of cardiovascular or cerebrovascular events). We additionally used (a) a control group consisting of healthy volunteers and (b) a reference group including patients with stable coronary artery disease (CAD). MVs were measured by a standardized flow cytometry protocol [2,3]. Results: We studied 74 participants: 17 patients with autoimmune rheumatic diseases; 34 healthy volunteers, and 23 stable CAD patients. Patients with rheumatic diseases presented increased levels of both EMVs (283.3 ± 195.0/μL vs 168.5 ± 54.8/μL, p = 0.029) and PMVs (374.0 ± 275.3/μL vs 225.7 ± 101.1/μL, p = 0.046) compared to controls. In addition, they presented similar levels of EMVs compared to CAD patients (283.3 ± 195.0/μL vs 297.0 ± 211.8/μL, p = 0.846), whereas PMVs were substantially elevated in the latter (374.0 ± 275.3/μL vs 1034.8 ± 374.0/μL, p = 0.029). Conclusions: Endothelial dysfunction and thrombotic predisposition, shown by increased levels of EMVs and PMVs, respectively, may be evidenced in patients with autoimmune rheumatic diseases, even in the absence of cardiovascular comorbidities and before the establishment of clinically evident cardiovascular complications. In these patients, levels of EMVs appear to be comparable with those of stable CAD patients. Acknowledgements: This research is co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning 2014–2020” in the context of the project “Evaluation of novel markers of endothelial dysfunction and thrombotic microenvironment in patients with rheumatoid arthritis: association with markers of subclinical inflammation and cardiovascular damage (MIS 5047870)”.

Background/Objectives: Skin microcirculation represents an easily accessible window reflecting generalized microvascular dysfunction. It has been correlated with alterations in several microvascular beds, though evidence regarding its association with macrovascular damage is scarce. Carotid artery stiffening is a surrogate marker of macrovascular damage that has been significantly associated with incident stroke and cardiovascular mortality. In this study, we investigated the association between skin microcirculation and carotid stiffness in a mixed population of hypertensive and normotensive individuals. Methods: Untreated newly-hypertensive and normotensive individuals without major cardiovascular comorbidities were included in the study. Blood pressure (BP) parameters were recorded with the Mobil-O-Graph NG (IEM, Stolberg, Germany) device. Carotid measurements were performed using a high-resolution echo-tracking system (Prosound Alpha 7, Aloka, Japan). The beta index (β) was automatically calculated and averaged for the right and left common carotid artery values. Skin microcirculation was assessed under standardized conditions using laser speckle contrast analysis (PeriCam PSI NR, Perimed, Sweden) in conjunction with post-occlusive reactive hyperemia protocol. Results are expressed as a percentage increase between baseline and peak perfusion (%). Results: We studied 101 individuals including 70 newly diagnosed, untreated essential hypertensives aged 49.6 ± 9.4 and 31 healthy normotensive individuals. The β index demonstrated a significant negative correlation with the percentage increase between baseline and peak skin microvascular perfusion (r = −0.251, p = 0.01). Conclusion: In a population of newly-diagnosed, untreated essential hypertensive and normotensive individuals, endothelial function of skin microcirculation is inversely associated with carotid stiffness, an emerging tool in cardiovascular risk prediction.