Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides, particularly granulomatosis with polyangiitis and microscopic polyangiitis, are rare but severe systemic diseases frequently requiring intensive care unit (ICU) admission due to life-threatening renal and pulmonary involvement. Despite advances in immunosuppressive therapy, these patients remain at high risk of mortality and end-stage kidney disease, with prognosis driven by organ failure (notably diffuse alveolar haemorrhage [DAH]) and treatment-related complications such as infection. ICU management is complex and relies on rapid diagnosis, aggressive induction therapy, and tailored organ support. Current remission-induction strategies centre on high-dose glucocorticoids combined with cyclophosphamide or rituximab, with growing emphasis on minimizing steroid exposure. Plasma exchange (PLEX), once widely used for severe renal disease and DAH, remains debated, although selected high-risk subgroups may still derive benefit. Optimal management in the ICU requires a multidisciplinary approach, including careful selection of immunosuppressive regimens, individualized use of adjunctive therapies such as PLEX and the management of infectious complications. Advances in supportive care, including lung-protective ventilation, renal replacement therapy, and extracorporeal support, have improved short-term outcomes. However, significant uncertainty persists regarding optimal therapeutic strategies in the critically ill populations, highlighting the need for further research and phenotype-driven approaches.

ABSTRACT:Congenital thrombotic thrombocytopenic purpura (cTTP) is caused by a severe inherited ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motif, member 13) deficiency. Although acute episodes are life-threatening, long-term burden of ischemic complications, and effectiveness of prophylactic strategies remain underexplored. We conducted a 25-year national, multicenter study of 88 patients with cTTP enrolled in the French Thrombotic Microangiopathy registry. Patients were stratified by age and clinical context at disease onset: pediatric (n = 42), pregnancy (n = 33), and adult onset (n = 13). Clinical features, genotypes, treatment regimens, and long-term ischemic outcomes were analyzed. Pediatric patients exhibited early-onset disease (median age at diagnosis, 2 years [interquartile range, 0-13]) with recurrent episodes and a high burden of neurological complications. In patients with pregnancy-onset disease, no relapses were observed outside pregnancy. Adult-onset patients, typically diagnosed aged >50 years, showed prevalent cardiovascular disease, stroke, and kidney injury. Mental health disorders were common across all groups. Despite long-term plasma prophylaxis, organ dysfunction persisted, particularly in pediatric- and adult-onset groups. In pregnancy-onset cTTP, tailored midterm prophylaxis during pregnancy reduced maternal and fetal complications. Thirty-nine patients received recombinant human ADAMTS13 (rhADAMTS13) prophylaxis (median follow-up, 5 months [interquartile range, 6-17]). Prophylactic treatment significantly improved relapse-free survival, with a comparable outcome using intensive plasma-derived products and rhADAMTS13 in pediatric-onset cases, although adverse events were more prevalent using plasma therapy. Our findings highlight the clinical and genetic heterogeneity of cTTP and the burden of organ dysfunction. Intensive prophylaxis improves relapse-free survival. rhADAMTS13 represents a safe and promising first-line option that should help reduce long-term organ damage and improve quality of life.

OBJECTIVE:VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is a recently identified adult-onset autoinflammatory disorder caused by somatic mutations in UBA1. It is characterized by heterogeneous inflammatory and haematological manifestations, making diagnosis challenging. 18F-FDG-PET/CT imaging, which identifies metabolic activity associated with inflammation and malignancy, is often performed during the diagnostic work-up. However, its utility in VEXAS syndrome remains unclear. METHODS:We conducted a multicentre retrospective observational study of patients with genetically-confirmed VEXAS syndrome who underwent 18F-FDG-PET/CT imaging. Clinical, laboratory and imaging data were collected, and 18F-FDG-PET/CT findings were analysed according to disease activity, myelodysplastic syndrome status and mortality. Qualitative 18F-FDG-PET/CT interpretations were based on local nuclear medicine reports. RESULTS:A total of 125 18F-FDG-PET/CT scans were analysed in 66 patients. Bone marrow (83%) and lymph nodes (53%) were the most frequent sites of abnormal FDG uptake, with combinations of bone marrow, lungs, lymph nodes and spleen being the most common patterns. Pulmonary (38%) and vascular involvement (11%) were also observed. The number of organs with abnormal FDG uptake was significantly higher in patients with active disease compared with remission (median 2 vs 1 abnormal sites, P < 0.001). However, 90% of scans performed during presumed clinical remission showed persistent abnormalities, especially in the bone marrow (57%). CONCLUSION:18F-FDG-PET/CT imaging reveals frequent but non-specific abnormalities in VEXAS syndrome, with persistent bone marrow hypermetabolism suggesting subclinical disease activity. While 18F-FDG-PET/CT may have limited diagnostic utility, it holds potential for disease monitoring.

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is caused by a severe, antibody-mediated deficiency of ADAMTS13 activity. The B-cell depleting agent rituximab is effective in restoring ADAMTS13 activity and therefore preventing relapses. However, the risk of relapse appears heterogeneous among patients, although the underlying causes are elusive. Preliminary reports suggested that African ancestry could be associated with decreased relapse-free survival (RFS). Data from the registry of the French National Thrombotic Microangiopathy Reference Center were used to further address the role of ethnicity on response and RFS after rituximab administration in the acute as well as in the preemptive setting. A total of 790 patients (134 patients of African ancestry and 656 patients of European ancestry) were included in the study. Time from rituximab administration to ADAMTS13 recovery was comparable between the two cohorts. Patients of African ancestry had inferior 3-year RFS after the first rituximab-treated episode compared to patients of European ancestry (P<0.05). In multivariate analyses, African ancestry was identified as an independent risk factor for relapse (hazard ratio [HR]=1.36; P<0.05), as well as male sex (HR=1.21; P<0.05) and type of index episode treated by rituximab (relapsed disease vs. initial episode, HR=1.62; P<0.05). Moreover, time to relapse shortened progressively after consecutive courses of rituximab, regardless of ethnicity (P<0.05). These results indicate that ethnicity affects RFS with patients of African ancestry relapsing earlier, suggesting that a closer ADAMTS13 monitoring might be necessary in high-risk patients.

Introduction:The identification of prognostic factors for renal failure in antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) remains a challenge. The benefit of plasma exchange (PLEX) has been questioned, and the target population remains to be defined. We investigated the outcome of patients requiring renal replacement therapy (RRT) at baseline and factors associated with their prognosis at 1 year. Methods:This retrospective multicenter study evaluated the 1-year composite end point of death or end-stage kidney disease (ESKD) in patients with biopsy-proven renal AAV involvement. Results:Of the 394 patients included, 105 (26.6%) were on dialysis at baseline. Of these, 60 (57.1%) reached the composite end point compared with 29 patients (10.0%) who were not on RRT at baseline (P < 0.001). On multivariate analysis, age and sex were not associated with the composite outcome (P = 0.945 and P = 0.154, respectively); however, myeloperoxidase (MPO)-ANCA was (odds ratio [OR]: 3.60; 95% confidence interval [CI]: 1.79-7.60), as was a high baseline histologic renal risk score (OR: 1.29; 95% CI 1.17-1.44). The most strongly associated factor remained the need for dialysis at baseline (OR: 10.91; 95% CI: 5.52-22.70). Of the 91 patients surviving after requiring dialysis at baseline, 45 were weaned from RRT (49.5%) at 1 year, and PLEX was independently associated with a reduced risk of the composite outcome (OR: 0.23, 95% CI: 0.05-0.80). Conclusion:MPO-ANCA, need for dialysis, and high histological renal risk score at baseline were associated with the 1-year composite end point of death or ESKD. Almost half of the patients on dialysis at baseline were off dialysis at 1 year, with a better prognosis in those who had received PLEX.

Durable responses with front-line rituximab in autoimmune cytopenias associated with indolent B-Cell clones.

CONTEXT:Pulmonary arterial hypertension (PAH) is one of the leading causes of mortality in patients with systemic sclerosis (SSc). Cardiopulmonary exercise testing (CPET) has been studied to detect SSc-associated PAH. OBJECTIVES:To evaluate the diagnostic value of the ventilatory equivalent for CO2 at anaerobic or ventilatory threshold [VE/VCO2(VeT)] and peak oxygen uptake (peak VO2) for SSc-associated PAH obtained by CPET. METHODS:A systematic database search from 1993 to 2024 and meta-analyses were performed according to PRISMA guidelines to include original studies relating to SSc and CPET reporting VE/VCO2(VeT) and peak VO2. The random-effects model was chosen for the meta-analyses studying VE/VCO2(VeT), indexed and predicted percentage (%pred.) peak VO2, respectively. Meta-regression was only performed for VE/VCO2(VeT) with covariates defined as the percentage of limited cutaneous disease, percentage of interstitial lung disease, and %pred. of peak VO2. RESULTS:Out of 206 studies, 941 SSc patients from 15 studies were included. VE/VCO2(VeT) (11 studies, n = 850) was statistically lower in patients without PAH (32.68 ± 5.42 vs. 39.81 ± 9.32) with a mean effect size of -1.182 (95 %CI, -1.691 to -0.672; p < 0.001) (I2 = 86 %). The mean effect size for weight-indexed peak VO2 (11 studies, n = 848) was 0.713 (95 %CI, 0.371 to 1.054; p < 0.001) with higher values in patients without PAH (16.47 ± 4.62 vs. 13.61 ± 4.16 mL/kg/mn) (I2 = 70 %). Similarly, the mean effect size for %pred. Peak VO2 (12 studies, n = 850) was 0.659 (95 %CI, 0.425 to 0.894; p < 0.001) reflecting higher values in patients without PAH (74.00 ± 17.50 vs. 54.84 ± 18.14 %pred.) (I2 = 37 %). Meta-regression analysis of data from 7 studies did not yield significant p values for the covariates. CONCLUSIONS:The effect size of each meta-analysis indicates that higher VE/VCO2(VeT) and lower peak VO2 may be considered as independent CPET markers of PAH in patients with SSc. CPET is a non-invasive and safe procedure for exploring dyspnoea in patients with SSc and, in association with conventional imaging techniques, may provide a reliable assessment of the presence of PAH.

BACKGROUND:The FIP1L1-PDFGRA (F/P)-associated hypereosinophilic syndrome (HES) is a rare condition. The F/P fusion gene testing is one of the first-line investigations in patients with unexplained eosinophilia and yields poor diagnostic performance. OBJECTIVE:To build and validate the factor interacting with PAPOLA and CPSF1 (FIP) score: a set of weighted criteria warranting testing for the F/P fusion gene. METHODS:We merged data from 151 patients with F/P-associated HES and 320 patients with either F/P-negative HES (n = 279) or hypereosinophilia of undetermined significance (n = 41). Training and validation cohorts (comprising, respectively, 90% and 10% of all patients) were randomly dichotomized. Variables with a P value less than .20 in univariate analysis were included in the multivariable forward-backward logistic regression model to assess their independent contribution to testing positive for the F/P fusion gene. Beta coefficients from multivariable logistic regression were used to assign points for the construction of the score. RESULTS:Age younger than 66 years, male sex, splenomegaly, lymphomatoid papulosis, absence of gastrointestinal involvement, high serum vitamin B12, high serum tryptase, and normal serum immunoglobulin E levels were the 8 variables retained in the model. The best cutoff value was greater than 48. The model yielded a sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve, respectively, of 88.3%, 93.7%, 87.1%, 94.4%, and 0.962 in the training dataset and of 85.7%, 97.0%, 85.7%, and 97.0%, 0.986 in the validation dataset. CONCLUSIONS:The FIP score highlights the need for closely selecting patients with hypereosinophilia for whom F/P fusion gene testing should be performed, resulting in medical time reduction and substantial cost-savings.

Current triplet regimens associating therapeutic plasma exchange (TPE), immunosuppression with corticosteroids and rituximab, and caplacizumab have dramatically improved the outcome of immune-mediated thrombotic thrombocytopenic purpura (iTTP). However, nearly half of the patients require extended caplacizumab treatment (i.e., > 30 days) due to persistent ADAMTS13 deficiency, raising cost and tolerance concerns. Therefore, we investigated whether anti-ADAMTS13 antibodies titer and their trajectory during the acute phase of the disease could predict ADAMTS13 improvement (i.e., activity ≥ 20% before day-30 post-TPE). From a cohort of 286 patients receiving the triplet regimen, we identified on diagnosis a cut-off value for anti-ADAMTS13 IgG antibodies of 90.5 U/mL, with a modest discriminating ability (AUC: 0.57) for predicting long-term response, precluding its use to guide therapeutic strategies. Nonetheless, the analysis of anti-ADAMTS13 IgG antibodies titer trajectory from diagnosis revealed that the proportion of iTTP patients with ADAMTS13 activity improvement was higher in patients who decreased (Dec+) their antibodies titer within the 7-14 days interval post-TPE compared to those without decrease (Dec-) (65% vs. 25% of cases, respectively, p < 0.001), a finding confirmed in a validation cohort (N = 51). These results highlight the possibility of intensifying immunosuppression in an early period post-TPE to shorten time to ADAMTS13 activity recovery. Close monitoring of anti-ADAMTS13 antibodies titer may guide immunomodulation strategies, including additional courses of B-cell depleting agents when appropriate.

OBJECTIVES:To describe the characteristics of patients with Sjögren's disease (SjD) and inclusion-body myositis (IBM), and how they compare to SjD patients with other inflammatory myopathies (IM). METHODS:Patients were retrospectively recruited from 13 French centres and included if they met the ACR/EULAR criteria for SjD and for IM. They were categorized as SjD-IBM if sub-criteria for IBM were met, or as SjD-other IM if not. RESULTS:SjD-IBM patients (n = 22) were mostly females (86%), with a median [Q1; Q3] age of 54 [38.5; 64] years at SjD diagnosis, and 62 [46.5; 70] years at first IBM symptoms. Although most patients displayed glandular and immunological abnormalities, additional extra-glandular manifestations were uncommon, resulting in moderate disease activity at SjD diagnosis (ESSDAI 5.5 [1; 7.8]). Classic IBM features were frequent, such as progressive symptom onset (59%), asymmetrical (27%) and distal (32%) involvements, dysphagia (41%), low CPK (386.5 [221.8; 670.5] UI/l) and CRP (3.0 [3; 8.5] mg/l) levels. Immunosuppressants were reported as efficient in 55% of cases. Compared with SjD-IBM patients, SjD patients with other IM (n = 50) were significantly younger, displayed more frequent additional extra-glandular disease, higher ESSDAI score (11 [3; 30]), shorter delay between SjD diagnosis and myositis onset (0 [-0.5; 26]), more frequent CPK values over 1000 UI/l (36%), and less frequent classic IBM features. CONCLUSION:IBM can occur in SjD patients, with muscle features reminiscent of classic sporadic IBM characteristics, but mostly affecting women. In SjD patients with muscle involvement, extra-glandular manifestations, high ESSDAI score, elevated CPK values and shorter delay after SjD diagnosis plead against IBM.

OBJECTIVE:The association of immune-mediated thrombotic thrombocytopenic purpura (iTTP) and SLE was previously described, but patients with iTTP with coexistent SLE remain poorly characterised. METHODS:We compared the clinical presentation and the outcome of patients with iTTP with coexistent SLE (SLE-iTTP) to an age-sex matched cohort of patients with idiopathic iTTP without SLE. RESULTS:During the study period, 1409 patients with iTTP were recruited in our registry. Of these, 79 (6%) had a prior or concurrent diagnosis of SLE at the time of iTTP diagnosis, and 437 (31%) had detectable ANAs without other clinical features of SLE. When compared with idiopathic iTTP, patients with SLE-iTTP had more severe renal involvement, and cardiac involvement was more prevalent, whereas central nervous system involvement was less common. Patients with SLE-iTTP received more immunosuppressive agents. There was no difference in response categories during the acute phase. During follow-up, SLE-iTTP had superior ADAMTS13 relapse-free survival than idiopathic iTTP. Among patients with ANAs without other clinical features of SLE, 33 (8%) were diagnosed with SLE 27 months (IQR: 7-65 months) following iTTP diagnosis; 32 additional patients (7%) developed another systemic autoimmune disease. No patient from the idiopathic iTTP group developed clinical SLE during follow-up. CONCLUSION:Patients with iTTP are prone to develop autoimmune features, and patients with SLE-iTTP have distinct clinical features and outcome. Relapse-free survival seems better in patients with SLE-iTTP, underscoring the need for tailored management strategies in this population, including a specific follow-up to assess early features suggestive of SLE. TRIAL REGISTRATION NUMBER:NCT00426686.

OBJECTIVE:To compile a list of approved training sites for the Residency Training Program [Diplôme d'Études Spécialisées] in Internal Medicine and Clinical Immunology (DES-MIIC) in France. METHOD:All local coordinators of the DES-MIIC were contacted to establish the list of approved internship sites for the MIIC DES within their geographical subdivision. RESULTS:We listed 244 approved training sites, of which 87 (35.7%) were in university hospitals. Depending on the region/subdivision, the number of approved training sites varied significantly. Internship sites within and outside of university hospitals were approved for the core-phase in 85% (74/87) and 63.7% (100/157) of cases, for the "development phase" in 94.3% (82/87) and 84.1% (132/157) of cases and for the consolidation phase 80.5% (70/87) and 52.2% (82/157) of cases, respectively. The vacancy rate for selection was lower in university hospitals than in general hospitals with ratios of 1.5 (89.3% vs. 61%), 1.8 (88.8% vs. 48.9%) and 1.6 (88,5% vs. 55.4%) - for respectively the core, development and consolidation phases. CONCLUSION:Thirty-five percent of internship sites were located in University hospitals. Depending on the region/subdivision, the number of approved training sites for the DES-MIIC varies greatly. Half of internship positions are vacant outside of University hospitals, just as nearly half of training sites in these same hospitals lack approval for the "consolidation phase".