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The CD4 + T-cell population plays a vital role in the adaptive immune system by coordinating the immune response against different pathogens. A significant transformation occurs in CD4 + cells during an immune response, as they shift from a dormant state to an active state. This transformation leads to extensive proliferation, differentiation, and cytokine production, which contribute to regulating and coordinating the immune response. Th17 and Treg cells are among the most intriguing CD4 + T-cell subpopulations in terms of genetics and metabolism. Gene expression modulation processes rely on and are linked to metabolic changes in cells. Lactylation is a new model that combines metabolism and gene modulation to drive Th17/Treg differentiation and functional processes. The focus of this review is on the metabolic pathways that impact lymphocyte gene modulation in a functionally relevant manner., (© 2024 Scandinavian Societies for Pathology, Medical Microbiology and Immunology.)

An open prospective, multicenter study enrolled 48 selected patients with chronic immune thrombocytopenia who achieved complete response for 1 year on thrombopoietin receptor agonists, half of the patients maintained a sustained response off treatment 4 years after treatment discontinuation. NCT03119974., (Copyright © 2024 American Society of Hematology.)

Objectives: Vacuoles, E1 enzyme, X-linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease associated with somatic ubiquitin-like modifier-activating enzyme 1 (UBA1) mutations. We aimed to evaluate the efficacy and safety of targeted therapies., Methods: Multicentre retrospective study including patients with genetically proven VEXAS syndrome who had received at least one targeted therapy. Complete response (CR) was defined by a clinical remission, C-reactive protein (CRP) ≤10 mg/L and a ≤10 mg/day of prednisone-equivalent therapy, and partial response (PR) was defined by a clinical remission and a 50% reduction in CRP levels and glucocorticoid dose., Results: 110 patients (median age 71 (68-79) years) who received 194 targeted therapies were included: 78 (40%) received Janus kinase (JAK) inhibitors (JAKi), 51 (26%) interleukin (IL)-6 inhibitors, 33 (17%) IL-1 inhibitors, 20 (10%) tumour necrosis factor (TNFα) blockers and 12 (6%) other targeted therapies. At 3 months, the overall response (CR and PR) rate was 24% with JAKi, 32% with IL-6 inhibitors, 9% with anti-IL-1 and 0% with TNFα blockers or other targeted therapies. At 6 months, the overall response rate was 30% with JAKi and 26% with IL-6 inhibitors. Survival without treatment discontinuation was significantly longer with JAKi than with the other targeted therapies. Among patients who discontinued treatment, causes were primary failure, secondary failure, serious adverse event or death in 43%, 14%, 19% and 19%, respectively, with JAKi and 46%, 11%, 31% and 9%, respectively, with IL-6 inhibitors., Conclusions: This study shows the benefit of JAKi and IL-6 inhibitors, whereas other therapies have lower efficacy. These results need to be confirmed in prospective trials., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ on behalf of EULAR.)

Introduction: Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are frequently overlapping conditions. Unlike in GCA, vascular inflammation is absent in PMR. Therefore, serum biomarkers reflecting vascular remodelling could be used to identify GCA in cases of apparently isolated PMR., Materials and Methods: 45 patients with isolated PMR and 29 patients with PMR/GCA overlap were included. Blood samples were collected before starting glucocorticoids for all patients. Serum biomarkers reflecting systemic inflammation (interleukin-6 (IL-6), CXCL9), vascular remodelling (MMP-2, MMP-3, MMP-9) and endothelial function (sCD141, sCD146, ICAM-1, VCAM-1, vWFA2) were measured by Luminex assays., Results: Patients with GCA had higher serum levels of sCD141 (p=0.002) and CXCL9 (p=0.002) than isolated PMR. By contrast, serum levels of MMP-3 (p=0.01) and IL-6 (p=0.004) were lower in GCA than isolated PMR. The area under the curve (AUC) was calculated for sCD141, CXCL9, IL-6 and MMP-3. Separately, none of them were >0.7, but combinations revealed higher diagnostic accuracy. The CXCL9/IL-6 ratio was significantly increased in patients with GCA (p=0.0001; cut-off >32.8, AUC 0.76), while the MMP-3/sCD141 ratio was significantly lower in patients with GCA (p<0.0001; cut-off <5.3, AUC 0.79). In patients with subclinical GCA, which is the most difficult to diagnose, sCD141 and MMP-3/sCD141 ratio demonstrated high diagnostic accuracy with AUC of 0.81 and 0.77, respectively., Conclusion: Combined serum biomarkers such as CXCL9/IL-6 and MMP-3/sCD141 could help identify GCA in patients with isolated PMR. It could allow to select patients with PMR in whom complementary examinations are needed., Competing Interests: Competing interests: MS: AbbVie consulting, Argenx consulting, Boehringer Ingelheim consulting, GSK consulting, Novartis consulting and research grant, Roche–Chugai consulting, CSL Vifor consulting, Fresenius consulting. BB: Roche–Chugai personal fees for consulting, Boehringer Ingelheim consulting. AR: Novartis research grant, Novartis consulting, AbbVie consulting, Boehringer Ingelheim consulting, Chugai consulting., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Acquired hemophilia A (AHA) is a rare autoimmune disorder due to autoantibodies against Factor VIII, with a high mortality risk. Treatments aim to control bleeding and eradicate antibodies by immunosuppression. International recommendations rely on registers and international expert panels., Methods: CREHA, an open-label randomized trial, compared the efficacy and safety of cyclophosphamide and rituximab in association with steroids in patients with newly diagnosed AHA. Participants were treated with 1 mg/kg prednisone daily and randomly assigned to receive either 1.5-2 mg/kg/day cyclophosphamide orally for 6 weeks, or 375 mg/m 2 rituximab once weekly for 4 weeks. The primary endpoint was complete remission over 18 months. Secondary endpoints included time to achieve complete remission, relapse occurrence, mortality, infections and bleeding, and severe adverse events., Results: Recruitment was interrupted because of new treatment recommendations after 108 patients included (58 cyclophosphamide, 50 rituximab). After 18 months, 39 cyclophosphamide patients (67.2 %) and 31 rituximab patients (62.0 %) were in complete remission (OR 1.26; 95 % CI, 0.57 to 2.78). In the poor prognosis group (FVIII < 1 IU/dL, inhibitor titer > 20 BU mL -1 ), significantly more remissions were observed with cyclophosphamide (22 patients, 78.6 %) than with rituximab (12 patients, 48.0 %; p = 0.02). Relapse rates, deaths, severe infections, and bleeding were similar in the 2 groups. In patients with severe infection, cumulative doses of steroids were significantly higher than in patients without infection (p = 0.03)., Conclusion: Cyclophosphamide and rituximab showed similar efficacy and safety. As first line, cyclophosphamide seems preferable, especially in poor prognosis patients, as administered orally and less expensive., Funding: French Ministry of Health., Clinicaltrials: gov number: NCT01808911., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The aim of this study was to assess the prevalence and the burden of difficult-to-treat primary ITP (pITP), defined by the need for another ITP treatment after romiplostim and eltrombopag. Adult patients were selected in the prospective, real-world CARMEN-France registry up to December 2021. Out of 821 adult patients with pITP, 29 had difficult-to-treat ITP (3.5%; 95% confidence interval [CI]: 2.3%-4.8% in total; 7.6%; 95% CI: 4.9%-10.2% of patients needing ≥2nd line treatment). The 3-year cumulative incidence of bleeding, infection and thrombosis was 100%, 24.1% and 13.8% respectively. The median cumulative duration of hospital stays was 31 days (median follow-up: 30.3 months)., (© 2024 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Warm autoimmune hemolytic anemia (wAIHA) is a rare acquired autoimmune disease mediated by antibodies targeting red blood cells. The involvement of CD4 T-helper cells has been scarcely explored, with most findings extrapolated from animal models. Here, we performed quantification of both effector T lymphocytes (Teff) and regulatory T cells (Treg), associated with functional and transcriptomic analyses of Treg in human wAIHA. We observed a shift of Teff toward a Th17 polarization concordant with an increase in serum interleukin-17 concentration that correlates with red blood cell destruction parameters, namely lactate dehydrogenase and bilirubin levels. A decrease in circulating Treg, notably effector Treg, associated with a functional deficiency, as represented by their decrease capability to inhibit Teff proliferation, were also observed. Treg deficiency was associated with a reduced expression of Foxp3, the master transcription factor known to maintain the Treg phenotype stability and suppressive functions. Transcriptomic profiling of Treg revealed activation of the tumor necrosis facto (TNF)-α pathway, which was linked to increased serum TNF-α concentrations that were twice as high as in controls. Treg transcriptomic profiling also suggested that post-translational mechanisms possibly accounted for Foxp3 downregulation and Treg dysfunctions. Since TNF-α participates in the rupture of immune tolerance during wAIHA, its inhibition could be of interest. To this end, the effects of fostamatinib, a SYK inhibitor, were investigated in vitro, and we showed that besides the inhibition of erythrocyte phagocytosis by monocytes, fostamatinib is also able to dampen TNF-α production, thus appearing as a promising multitargeting therapy in wAIHA (clinicaltrials gov. Identifier: NCT02158195).

Vascular smooth muscle cells (VSMCs) have been shown to play a role in the pathogenesis of giant cell arteritis (GCA) through their capacity to produce chemokines recruiting T cells and monocytes in the arterial wall and their ability to migrate and proliferate in the neointima where they acquire a myofibroblast (MF) phenotype, leading to vascular stenosis. This study aimed to investigate if MFs could also impact T-cell polarization. Confocal microscopy was used to analyze fresh fragments of temporal artery biopsies (TABs). Healthy TAB sections were cultured to obtain MFs, which were then treated or not with interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) and analyzed by immunofluorescence and RT-PCR. After peripheral blood mononuclear cells and MFs were co-cultured for seven days, T-cell polarization was analyzed by flow cytometry. In the neointima of GCA arteries, we observed a phenotypic heterogeneity among VSMCs that was consistent with a MF phenotype (α-SMA + CD90 + desmin + MYH11 + ) with a high level of STAT1 phosphorylation. Co-culture experiments showed that MFs sustain Th1/Tc1 and Th17/Tc17 polarizations. The increased Th1 and Tc1 polarization was further enhanced following the stimulation of MFs with IFN-γ and TNF-α, which induced STAT1 phosphorylation in MFs. These findings correlated with increases in the production of IL-1β, IL-6, IL-12 and IL-23 by MFs. Our study showed that MFs play an additional role in the pathogenesis of GCA through their ability to maintain Th17/Tc17 and Th1/Tc1 polarizations, the latter being further enhanced in case of stimulation of MF with IFN-γ and TNF-α., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia. Its pathogenesis is complex relying in large part on destruction of platelets recognized by autoantibodies within the spleen. However, other mechanisms, such as platelet desialylation, may play a role in platelet reduction by accelerating their clearance in the liver. In their study, Mendoza and colleagues reported on platelet scintigraphy performed in 51 ITP patients, showing a response in 87.5% when the sequestration occurred in the spleen versus 45% in case of non-splenic destruction. Platelet desialylation was also measured after splenectomy and found to be higher in non-responder patients. These latter results, while requiring confirmation prior to splenectomy, support platelet desialylation may also be a potential biomarker of non-response to splenectomy. Commentary on: Mendoza et al. Study of platelet kinetics in immune thrombocytopenia to predict splenectomy response. Br J Haematol 2024;204:315-323., (© 2023 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Hereditary hemorrhagic telangiectasia (HHT) is a rare inherited disease due to heterozygous loss-of-function mutations on the BMP9/10 pathway ( ENG, ACVRL1 or MADH4 mainly). HHT endothelial cells are prone to lose their quiescence, leading to progressive appearance of numerous telangiectases on skin and mucosa (complicated by epistaxis and anemia), and to larger arteriovenous malformations in lungs, liver and brain. HHT is also associated with T lymphocyte abnormalities, which are currently poorly understood. We quantified by flow-cytometry the main T lymphocyte circulating subsets in 40 HHT patients and 20 matched healthy controls. Immunostaining was done on 2 HHT skin telangiectases. Disruptions in T lymphocyte homeostasis was observed, characterized by increases in subsets known to promote angiogenesis: Th2 (1.38% vs 1.15%, p=0.021), Th17 (0.32% vs 0.22%, p=0.019 2) and Treg (4.94% vs 3.51%, p= 0.027). T angiogenic lymphocytes (Tang), defined as CD3+CD31+CXCR4+ T cells, were at similar levels in both groups, but the proportion of VEGF-A+ Tang after stimulation was higher in the HHT group compared to controls (68.2% vs 44.9%, p=0.012). The global HHT T lymphopenia predominantly affected the effector memory T-helper cells (200 vs 270 cells/mm 3 , p=0.017), and the lymphocytic infiltrate around HHT telangiectases consisted of memory T-helper cells. The Th17 circulating subset was positively correlated with the monthly epistaxis duration (r coefficient: +0,431, p=0.042), prospectively assessed. HHT T-helper lymphocytes are affected by several pro-angiogenic changes, potentially resulting from their recruitment by abnormal endothelial cells. They could constitute a biologically relevant source of VEGF-A and a valuable therapeutic target in HHT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Guilhem, Ciudad, Aubriot-Lorton, Greigert, Cladière, Leguy-Seguin, Audia, Samson and Bonnotte.)

The emergence of rituximab biosimilars offers the prospect of significant savings to the healthcare system. However, these drugs have never been evaluated for treating immune thrombocytopenia (ITP). This was an observational, matched study. We included adults who received a rituximab biosimilar for ITP. Each rituximab-naïve biosimilar patient was matched with two controls from the historic ITP-ritux registry. For non-naïve patients, we compared the response to the biosimilar with that observed with the reference product. Response status was defined according to international criteria. We included 107 patients; 55 receiving Rixathon™ and 52 Truxima™. Three months after the first infusion of rituximab biosimilars, the overall response rate was 47/74 (63.5%) versus 76/142 (53.5%) for the matched controls receiving the reference product ( p  = .13). The 3-month overall response rate was 76.5% for Rixathon™ versus 51.5% for the matched control group ( p  = .01) and 21/40 (52.5%) for Truxima™ versus 41/74 (55.4%) for the matched controls ( p  = .81). For non-naïve patients, the response pattern was similar to that observed previously with the reference product. Safety was analogous to that observed with the reference product. Rituximab biosimilars seemed safe and effective for ITP treatment.

Diagnosis of neuro-histiocytosis is challenging and relies on clinical presentation, imaging, and cerebrospinal fluid (CSF) analysis to exclude differential diagnoses. Brain biopsy remains the gold standard for accurate diagnosis, but it is rarely performed because of the risk of the procedure and the low rentability in neurodegenerative presentation. Therefore, there is an unmet need to identify a specific biomarker for diagnosing neurohistiocytosis in adults. Because microglia (brain macrophages) is involved in the pathogenesis of neurohistiocytosis and produces neopterin secondary to aggression, the purpose of our study was to evaluate the value of the CSF neopterin levels for the diagnosis of active neurohistiocytosis. Of the 21 adult patients with histiocytosis, four patients had clinical symptoms compatible with neurohistiocytosis. In the two patients with a confirmed diagnosis of neurohistiocytosis, CSF neopterin levels were elevated as well as IL-6 and IL-10 levels. In contrast, the two other patients in whom the diagnosis of neurohistiocytosis was infirmed and all other patients with histiocytosis without active neurological disease involvement had normal CSF neopterin levels. In summary, increased CSF neopterin concentration represented a valuable tool for diagnosing active neuro-histiocytosis in adults with histiocytic neoplasms in this preliminary study., (© 2023 John Wiley & Sons Ltd.)

Histiocytoses encompass a wide spectrum of diseases, all characterized by tissue infiltration by CD68+ histiocytes. Most adult histiocytoses are considered clonal diseases because they highlight recurrent somatic mutations in the MAP-kinase pathway gene, primarily BRAF . The presence of BRAF mutation is associated with widespread disease in children with Langerhans cell histiocytosis (LCH) or cardiovascular/neurological involvement in Erdheim-Chester disease (ECD). Nevertheless, few data are available on adult clonal histiocytosis. This is why we have conducted a retrospective study of all patients with clonal histiocytosis in our institution and present the data according to the presence of BRAF mutation. Among 27 adult patients (10 ECD, 10 LCH, 5 Rosai-Dorfman disease (RDD), and 3 mixed ECD/LCH), 11 (39%) have BRAF mutation with gain of function (n = 9) and deletion (n = 2). Those patients had frequent multicentric disease with risk organ involvement, especially the brain and cardiovascular system. They had frequent associated myeloid neoplasms (mostly chronic myelomonocytic leukemia) and received more frequently targeted therapy as the front-line therapy. Nevertheless, its presence did not affect the overall survival or relapse-free survival probably due to the emergence of efficient therapies. To conclude, rapid and accurate molecular establishment in adult clonal histiocytoses is crucial because BRAF V600E mutation correlates with multicentric disease with organ involvement and incomplete metabolic response., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Razanamahery, Godot, Leguy-Seguin, Samson, Audia and Bonnotte.)

Objectives: Mediation analyses were conducted to measure the extent to which musculoskeletal (MSK) flares and depression affected physical health through excessive fatigue., Methods: Mediation analyses were performed in a large multicentre cohort of SLE patients. Domains of the LupusQoL and SLEQOL questionnaires were selected as outcomes, MSK flares according to the SELENA-SLEDAI flare index (SFI-R) score and depression defined by Center for Epidemiologic Studies-Depression scale (CES-D) scale as exposures and different fatigue domains from MFI-20 and LupusQoL questionnaires as mediators. For each model, total, direct, indirect effects and proportion of effect mediated by fatigue (i.e. proportion of change in health-related quality of life) were determined., Results: Of the 336 patients, 94 (28%) had MSK flares at inclusion and 99 (29.5%) were considered with depression. The proportion of the total effect of MSK flares on physical health impairment explained by fatigue ranged from 59.6% to 78% using the LupusQOL 'Physical health' domain and from 51.1% to 73.7% using the SLEQOL 'Physical functioning' domain, depending on the fatigue domain selected. The proportion of the total effect of depression on physical health impairment explained by fatigue ranged from 68.8% to 87.6% using the LupusQOL 'Physical health' domain and from 79.3% to 103.2% using the SLEQOL 'Physical functioning' domain, depending on the fatigue domain selected., Conclusions: The effect of MSK flares and depression on physical health impairment is largely mediated by fatigue. Thus, the patient's perception of disease activity as measured by physical health is largely influenced by fatigue. In addition, fatigue has a significant negative impact on quality of lifeof SLE patients with depression., Trial Registration: ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904812., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Combining drugs could be an effective option for treating multirefractory ITP, that is, patients not responding to rituximab, thrombopoietin receptor agonists (TPO-RA) and splenectomy. We conducted a retrospective, multicenter, observational study including multirefractory ITP patients who received a combination of a TPO-RA and an immunosuppressive drug. We included 39 patients (67% women, median age 59 years [range 21-96]), with a median ITP duration of 57 months [3-393] and a median platelet count at initiation of 10 × 10 9 /L [1-35]. The combination regimen was given for a median duration of 12 months [1-103] and included eltrombopag (51%) or romiplostim (49%), associated with mycophenolate mofetil (54%), azathioprine (36%), cyclophosphamide (5%), cyclosporin (3%) or everolimus (3%). Overall, 30 patients (77%) achieved at least a response (platelet count ≥30 × 10 9 /L and at least doubling baseline during at least 3 months), including 24 complete responses (platelet count >100 × 10 9 /L during at least 3 months) with a median time to response of 30 days [7-270] and a median duration of response of 15 months [4-63]. Severe adverse event related to ITP treatment was observed in 31%. In conclusion, this study confirms that some patients with multirefractory ITP can achieve long lasting response with this combination., (© 2023 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by an isolated thrombocytopenia. The pathophysiology is complex but involves platelet-autoantibodies and/or cytotoxic T cells, with the spleen playing an important regulatory role. Accessory spleen (AcS) may possibly contribute to ITP relapse following splenectomy; however, the microenvironment of AcS has not been directly compared to the main spleen. Pizzi et al. conducted a histological study of adult ITP patients where they compared eight matched AcS to main spleens, and they observed a similar immunological composition in both groups. This supports the possibility of AcS-mediated ITP relapse post splenectomy. Commentary on: Pizzi et al. Accessory spleens recapitulate the immune microenvironment of the main spleen in immune thrombocytopenia. Br J Haematol 2023;202:147-152., (© 2023 British Society for Haematology and John Wiley & Sons Ltd.)

The Th17 + arrangement is critical for orchestrating both innate and acquired immune responses. In this context, the serum and glucocorticoid regulated kinase 1 (SGK1) exerts a key role in the governance of IL-23R-dependent Th17 + maturation, through the phosphorylation-dependent control of FOXO1 localization. Our previous work has shown that some of the SGK1-key functions are dependent on RAN-binding protein 1 (RANBP1), a terminal gene in the nuclear transport regulation. Here, we show that RANBP1, similarly to SGK1, is modulated during Th17 + differentiation and that RANBP1 fluctuations mediate the SGK1-dependent effects on Th17 + maturation. RANBP1, as the final effector of the SGK1 pathway, affects FOXO1 transport from the nucleus to the cytoplasm, thus enabling RORγt activation. In this light, RANBP1 represents the missing piece, in an essential and rate-limiting manner, underlying the Th17 + immune asset., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Brescia, Dattilo, D’Antona, Chiarella, Tallerico, Audia, Rocca, Iuliano, Trapasso, Perrotti and Amato.)

Sustained response off treatment (SROT) after thrombopoietin receptor agonist (TPO-RA) discontinuation has been reported in immune thrombocytopenia (ITP). This prospective multicenter interventional study enrolled adults with persistent or chronic primary ITP and complete response (CR) on TPO-RAs. The primary end point was the proportion of patients achieving SROT (platelet count >30 × 109/L and no bleeding) at week 24 (W24) with no other ITP-specific medications. Secondary end points included the proportion of sustained CR off-treatment (SCROT, platelet count >100 × 109/L and no bleeding) and SROT at W52, bleeding events, and pattern of response to a new course of TPO-RAs. We included 48 patients with a median age of 58.5 years; 30 of 48 had chronic ITP at TPO-RA initiation. In the intention-to-treat analysis, 27 of 48 achieved SROT, 15 of 48 achieved SCROT at W24; 25 of 48 achieved SROT, and 14 of 48 achieved SCROT at W52. No severe bleeding episode occurred in patients who relapsed. Among patients rechallenged with TPO-RA, 11 of 12 achieved CR. We found no significant clinical predictors of SROT at W24. Single-cell RNA sequencing revealed enrichment of a tumor necrosis factor α signaling via NF-κB signature in CD8+ T cells of patients with no sustained response after TPO-RA discontinuation, which was further confirmed by a significant overexpression of CD69 on CD8+ T cells at baseline in these patients as compared with those achieving SCROT/SROT. Our results strongly support a strategy based on progressive tapering and discontinuation of TPO-RAs for patients with chronic ITP who achieved a stable CR on treatment. This trial was registered at www.clinicaltrials.gov as #NCT03119974., (© 2023 by The American Society of Hematology.)

Objectives: To investigate the performance of cranial PET/CT for the diagnosis of GCA., Methods: All patients with a suspected diagnosis of GCA were prospectively enrolled in this study and had a digital PET/CT with evaluation of cranial arteries if they had not started glucocorticoids >72 h previously. The diagnosis of GCA was retained after at least 6 months of follow-up if no other diagnosis was considered by the clinician and the patient went into remission after at least 6 consecutive months of treatment. Cranial PET/CT was considered positive if at least one arterial segment showed hypermetabolism similar to or greater than liver uptake., Results: For cranial PET/CT, sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) were 73.3%, 97.2%, 91.7% and 89.7%, respectively. For extracranial PET/CT, diagnostic performance was lower (Se = 66.7%, Sp = 80.6%, PPV = 58.8%, NPV = 85.3%). The combination of cranial and extracranial PET/CT improved overall sensitivity (Se = 80%) and NPV (NPV = 90.3%) while decreasing overall specificity (Sp = 77.8%) and PPV (PPV = 60%)., Conclusion: Cranial PET/CT can be easily combined with extracranial PET/CT with a limited increase in examination time. Combined cranial and extracranial PET/CT showed very high diagnostic accuracy for the diagnosis of GCA., Trial Registration: ClinicalTrials.gov, https://clinicaltrials.gov, NCT05246540., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Competing Interests: Conflicts of interest None disclosed.

Introduction: The pathogenesis of Giant Cell Arteritis (GCA) relies on vascular inflammation and vascular remodeling, the latter being poorly controlled by current treatments., Methods: This study aimed to evaluate the effect of a novel cell therapy, Human Monocyte-derived Suppressor Cells (HuMoSC), on inflammation and vascular remodeling to improve GCA treatment. Fragments of temporal arteries (TAs) from GCA patients were cultured alone or in the presence of HuMoSCs or their supernatant. After five days, mRNA expression was measured in the TAs and proteins were measured in culture supernatant. The proliferation and migration capacity of vascular smooth muscle cells (VSMCs) were also analyzed with or without HuMoSC supernatant., Results: Transcripts of genes implicated in vascular inflammation ( CCL2 , CCR2 , CXCR3 , HLADR ), vascular remodeling ( PDGF , PDGFR ), angiogenesis (VEGF) and extracellular matrix composition ( COL1A1 , COL3A1 and FN1 ) were decreased in arteries treated with HuMoSCs or their supernatant. Likewise, concentrations of collagen-1 and VEGF were lower in the supernatants of TAs cultivated with HuMoSCs. In the presence of PDGF, the proliferation and migration of VSMCs were both decreased after treatment with HuMoSC supernatant. Study of the PDGF pathway suggests that HuMoSCs act through inhibition of mTOR activity. Finally, we show that HuMoSCs could be recruited in the arterial wall through the implication of CCR5 and its ligands., Conclusion: Altogether, our results suggest that HuMoSCs or their supernatant could be useful to decrease vascular in flammation and remodeling in GCA, the latter being an unmet need in GCA treatment., Competing Interests: MS: Roche–Chugai consulting, AbbVie consulting, Boehringer Ingelheim consulting, Novartis consulting and research grant, VIFOR Pharma consulting; BB: Roche–Chugai personal fees for consulting, Boehringer Ingelheim consulting; CC-G: Horus and Bayer grant, Novartis and Bayer honoraria and Novartis, Bayer, Thea, Horus, Alcon and Allergan medical advisory board; P-HG: Allergan, Bayer and Novartis travel expenses, Novartis and Bayer honoraria; MCC: GlaxoSmithKline consulting, CSL Vifor consulting, AbbVie consulting, Janssen consulting, Astrazeneca consulting, Kiniksa Pharmaceuticals research grant; GE-F: GlaxoSmithKline consulting, Janssen consulting. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Samson, Genet, Corbera-Bellalta, Greigert, Espígol-Frigolé, Gérard, Cladière, Alba-Rovira, Ciudad, Gabrielle, Creuzot-Garcher, Tarris, Martin, Saas, Audia, Bonnotte and Cid.)

RANBP1 encoded by RANBP1 or HTF9A (Hpall Tiny Fragments Locus 9A), plays regulatory functions of the RAN-network, belonging to the RAS superfamily of small GTPases. Through this function, RANBP1 regulates the RANGAP1 activity and, thus, the fluctuations between GTP-RAN and GDP-RAN. In the light of this, RANBP1 take actions in maintaining the nucleus-cytoplasmic gradient, thus making nuclear import-export functional. RANBP1 has been implicated in the inter-nuclear transport of proteins, nucleic acids and microRNAs, fully contributing to cellular epigenomic signature. Recently, a RANBP1 diriment role in spindle checkpoint formation and nucleation has emerged, thus constituting an essential element in the control of mitotic stability. Over time, RANBP1 has been demonstrated to be variously involved in human cancers both for the role in controlling nuclear transport and RAN activity and for its ability to determine the efficiency of the mitotic process. RANBP1 also appears to be implicated in chemo-hormone and radio-resistance. A key role of this small-GTPases related protein has also been demonstrated in alterations of axonal flow and neuronal plasticity, as well as in viral and bacterial metabolism and in embryological maturation. In conclusion, RANBP1 appears not only to be an interesting factor in several pathological conditions but also a putative target of clinical interest.

The risk of immune thrombocytopenia (ITP) worsening during pregnancy and neonatal ITP (NITP) have never been prospectively studied. We included 180 pregnant and 168 nonpregnant women with ITP in a prospective, multicenter, observational cohort study. A total of 131 pregnant women with ITP were matched to 131 nonpregnant women with ITP by history of splenectomy, ITP status (no response, response, complete response), and duration. Groups were followed for 15 months. The primary outcome was the first occurrence of ITP worsening defined by a composite end point including bleeding events and/or severe thrombocytopenia (<30 × 109/L) and/or ITP treatment modification. We also studied the recurrence of ITP worsening and the incidence of NITP and risk factors. The first occurrence of ITP worsening did not differ between pregnant and nonpregnant women with ITP (53.4 per 100 person-years [95% confidence interval {CI}, 40.8-69.9] vs 37.1 [95% CI, 27.5-50.0]; hazard ratio {HR}, 1.35 [95% CI, 0.89-2.03], P = .16). Pregnant women with ITP were more likely to have recurrence of severe thrombocytopenia and treatment modification (HR, 2.71 [95% CI, 1.41-5.23], P = .003; HR, 2.01 [95% CI, 1.14-3.57], P = .017, respectively). However, recurrence of severe bleeding events was not different between groups (P = .4). Nineteen (14%) neonates showed NITP <50 × 109/L. By multivariable analysis, NITP was associated with a previous offspring with NITP and maternal platelet count <50 × 109/L within 3 months before delivery (adjusted odds ratio, 5.55 [95% CI, 1.72-17.89], P = .004 and 4.07 [95% CI, 1.41-11.73], P = .009). To conclude, women with ITP do not increase their risk of severe bleeding during pregnancy. NITP is associated with NITP history and the severity of maternal ITP during pregnancy. These results will be useful for counseling women with ITP., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Objectives: To describe the characteristics, treatment and outcome of patients with immune thrombocytopenia with clinical significance (ITPCS) associated with SLE., Methods: This retrospective multicentre study included SLE patients who experienced ≥1 ITPCS (defined as ITP with attributable bleeding disorders and/or a platelet count <30×109/l). Other causes of secondary thrombocytopenia were excluded. Major bleeding event (MBG) was defined as Khellaf score >8 and/or WHO score >2., Results: A total of 90 patients were included, the median (range) follow-up duration was 80 (6-446) months. ITP was diagnosed before SLE in 25 patients. They presented a high rate of autoimmune haemolytic anaemia (15%), antiphospholipid antibody (62%) and antiphospholipid syndrome (19%). The 25 (28%) patients who experienced MBG had significantly more bleedings at ITP diagnosis and higher bleeding scores, and serositis and thrombosis during follow-up. They required significantly more treatment lines, transfusions and hospitalizations. The 11 (12%) patients who experienced no bleeding event presented a significantly more restricted SLE phenotype (cutaneous and/or articular). Patients received a mean (range) of 4.2 (1-11) treatment lines. Corticosteroids and HCQ allowed ITPCS overall response in one-third of patients. The median relapse-free survival of rituximab (n = 34), AZA (n = 19), MMF (n = 8), thrombopoietin-receptor agonists (n = 16) and splenectomy (n = 19) were 53, 31.5, 61, 24.5 and 78 months, respectively. Four patients experienced thrombotic events after splenectomy and one occurred under thrombopoietin-receptor agonist treatment., Conclusion: SLE-ITCS patients displayed a high rate of haematological abnormalities and MBG patients exhibited higher morbidity. Management of thrombocytopenia was highly heterogeneous and many options seem viable., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: This study aimed to identify markers of disease worsening in patients hospitalized for SARS-Cov2 infection., Patients and Methods: Patients hospitalized for severe recent-onset (<1 week) SARS-Cov2 infection were prospectively included. The percentage of T-cell subsets and plasma IL-6 at admission (before any steroid therapy) were compared between patients who progressed to a critical infection and those who did not., Results: Thirty-seven patients (18 men, 19 women) were included; 11 (30%) progressed to critical infection. At admission, the critical infection patients were older (P = 0.021), had higher creatinine levels (P = 0.003), and decreased percentages of circulating B cells (P = 0.04), T cells (P = 0.009), and CD4+ T cells (P = 0.004) than those with a favorable course. Among T cell subsets, there was no significant difference between the two groups except for the percentage of Th17 cells, which was two-fold higher in patients who progressed to critical infection (P = 0.028). Plasma IL-6 at admission was also higher in this group (P = 0.018). In multivariate analysis, the percentage of circulating Th17 cells at admission was the only variable associated with higher risk of progression to critical SARS-Cov2 infection (P = 0.021)., Conclusion: This study suggests that an elevated percentage of Th17 cells in patients hospitalized for SARS-Cov2 infection is associated with an increased risk of progression to critical disease. If these data are confirmed in a larger study, this marker could be used to better target the population of patients in whom tocilizumab could decrease the risk of progression to critical COVID-19., (Copyright © 2022. Published by Elsevier B.V.)

Erdheim-Chester disease (ECD) is a rare condition with underestimated neurological involvement. Mild psychiatric symptoms such as mood swings have been rarely described in the clinical spectrum of neuro-ECD. We here describe the first patient with psychiatric manifestations of delirium revealing ECD with neurological involvement with favorable evolution under interferon followed by BRAF inhibitor monotherapy. An 81-year-old woman was referred to the hospital because of delirium and severe cognitive impairment associated with a cerebellar syndrome. Brain magnetic resonance imaging showed "FLAIR-changes" lesions in the pons and upper cerebellum peduncles. Blood and cerebrospinal fluid (CSF) analyses showed normal results except for an elevated neopterin level in the CSF. Whole-body CT scan ( 18 FDG-PET) showed peri-nephric fat infiltration and aorta adventitia sheathing with radiotracer uptake in the pons, vessels, peri-nephric fat, and bone lesions, which was characteristic of ECD. The diagnosis was confirmed on perirenal tissue biopsy, which also showed a BRAF V600E mutation. Treatment with interferon resulted in the resolution of delirium, and treatment with BRAF inhibitor subsequently resulted in a partial remission of all active sites. This case highlights that delirium can be the first manifestation of neurodegenerative ECD. ECD should be screened in unexplained psychiatric features as interferon and targeted therapy appear to be effective in this situation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Razanamahery, Abdallahoui, Chabridon, Fromont, Tarris, Idbaih, Comby, Godard, Haroche, Audia and Bonnotte.)

Objective: A new adult-onset autoinflammatory syndrome has been described, named VEXAS (Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic). We aimed to compare the clinical characteristics, the laboratory features and the outcomes between idiopathic-relapsing polychondritis (I-RP) and VEXAS-relapsing polychondritis (VEXAS-RP)., Methods: Patients from French retrospective multicentre cohort of RP were separated into two groups: a VEXAS-RP and an I-RP., Results: Compared with patients with I-RP (n=40), patients with VEXAS-RP (n=55) were men (96% vs 30%, p<0.001) and were older at diagnosis (66 vs 44 years, p<0.001). They had a greater prevalence of fever (60% vs 10%, p<0.001), of skin lesions (82% vs 20%, p<0.001), of ocular involvement (57% vs 28%, p=0.01), of pulmonary infiltrates (46% vs 0%, p<0.001), of heart involvement (11% vs 0%, p=0.0336) and with higher median C-reactive protein levels (64 mg/L vs 10 mg/L, p<0.001). Seventy-five per cent of the patients with VEXAS-RP had myelodysplastic syndrome (MDS) versus none in I-RP group. The glucocorticoids use, and the number of steroid sparing agents were similar in both groups, but patients with VEXAS-RP had more frequent refractory disease (remission obtained in 27% vs 90%, p<0001). VEXAS-RP was associated with higher risk of death: six patients (11%) died in the VEXAS-RP group after a median follow-up of 37 months and none in the I-RP group after a median follow-up of 92 months (p<0.05)., Conclusion: We report the largest cohort of VEXAS-RP, characterised by high prevalence of male sex, fever, skin lesion, ocular involvement, pulmonary infiltration, heart involvement, older age and MDS association., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: While QuantiFERON-TB gold (QFT) is frequently used, little attention is paid to the mitogen response. How it could be impacted and associated with outcomes is poorly known., Methods: Retrospective, case-control study in hospitalized patients who underwent QFT testing in two hospitals between 2016 and 2019. We defined two groups of cases with either negative [interferon (IFN)-γ ≤ 0.5 IU/ml, official threshold] or weak (0.5-2 IU/ml) mitogen response, and one group of controls with normal (>2 IU/ml) mitogen response., Results: A total of 872 patients were included. An ongoing infection was independently associated with both a negative (RR = 4.34; 95% CI = 2.94-6.41) and a weak mitogen response (RR = 2.44; 95% CI = 1.66-3.58). Among tuberculosis patients, a weak mitogen response was associated with a false-negative QFT result (75%) compared to a normal response (20%). Decreasing mitogen response (normal, weak and negative, respectively) was associated with increasing length of hospital stay [median (interquartile range) 5 (3-13), 11 (5-21) and 15 (10-30) days; p < 0.001] and increasing hospital mortality (3, 7, and 15%; p < 0.001)., Conclusion: Clinicians should take notice of the mitogen response since IFN-γ concentrations lower than <2 IU/ml were associated with false-negative QFT results in tuberculosis patients, independently associated with ongoing infections, and could be associated with worse prognosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Jacquier, Binquet, Manoha, Audia, Simonet-Lamm, Casenaz, Sow, Piroth and Blot.)

Recently developed cell-based therapies have shown potential for graft-versus-host disease (GvHD) mitigation. Our team previously developed a protocol to generate human monocyte-derived suppressor Cells (HuMoSC), a subpopulation of CD33+ suppressor cells of monocytic origin. CD33+HuMoSC successfully reduced xenoGvHD severity in NOD/SCID/IL-2Rγc -/- (NSG) mice. While CD33+ HuMoSC culture supernatant inhibits T cell activation and proliferation, the recovery of CD33+ HuMoSC immunosuppressive cells and the subsequent production of their supernatant is limited. An attractive solution would be to use both the CD33+ and the large number of CD14+ cells derived from our protocol. Here, we assessed the immunoregulatory properties of the CD14+HuMoSC supernatant and demonstrated that it inhibited both CD4 and CD8 T cell proliferation and decreased CD8 cytotoxicity. In vivo , injection of CD14+HuMoSC supernatant reduced xenoGvHD in NSG mice. Furthermore, CD14+HuMoSC supernatant maintained its immunoregulatory properties in an inflammatory environment. Proteomic and multiplex analyses revealed the presence of immunosuppressive proteins such as GPNMB, galectin-3 and IL-1R(A) Finally, CD14+HuMoSC supernatant can be produced using good manufacturing practices and be used as complement to current immunosuppressive drugs. CD14+HuMoSC supernatant is thus a promising therapy for preventing GvHD. ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gérard, Thébault, Lamarthée, Genet, Cattin, Brazdova, Janikashvili, Cladière, Ciudad, Ouandji, Ghesquière, Greigert, Tinel, Adotevi, Saas, Samson, Audia and Bonnotte.)

Background: A new autoinflammatory syndrome related to somatic mutations of UBA1 was recently described and called VEXAS syndrome ('Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic syndrome')., Objectives: To describe clinical characteristics, laboratory findings and outcomes of VEXAS syndrome., Methods: One hundred and sixteen patients with VEXAS syndrome were referred to a French multicentre registry between November 2020 and May 2021. The frequency and median of parameters and vital status, from diagnosis to the end of the follow-up, were recorded., Results: The main clinical features of VEXAS syndrome were found to be skin lesions (83%), noninfectious fever (64%), weight loss (62%), lung involvement (50%), ocular symptoms (39%), relapsing chondritis (36%), venous thrombosis (35%), lymph nodes (34%) and arthralgia (27%). Haematological disease was present in 58 cases (50%): myelodysplastic syndrome (MDS; n = 58) and monoclonal gammopathy of unknown significance (n = 12; all patients with MGUS also have a MDS). UBA1 mutations included p.M41T (45%), p.M41V (30%), p.M41L (18%) and splice mutations (7%). After a median follow-up of 3 years, 18 patients died (15·5%; nine of infection and three due to MDS progression). Unsupervised analysis identified three clusters: cluster 1 (47%; mild-to-moderate disease); cluster 2 (16%; underlying MDS and higher mortality rates); and cluster 3 (37%; constitutional manifestations, higher C-reactive protein levels and less frequent chondritis). The 5-year probability of survival was 84·2% in cluster 1, 50·5% in cluster 2 and 89·6% in cluster 3. The UBA1 p.Met41Leu mutation was associated with a better prognosis., Conclusions: VEXAS syndrome has a large spectrum of organ manifestations and shows different clinical and prognostic profiles. It also raises a potential impact of the identified UBA1 mutation., (© 2021 British Association of Dermatologists.)