M. Le Besnerais

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.

Antiphospholipid antibodies (aPL) promote endothelial dysfunction, inflammation and procoagulant state. We investigated the effect of hydroxychloroquine (HCQ) on prothrombotic state and endothelial function in mice and in human aortic endothelial cells (HAEC). Human aPL were injected to C57BL/6 mice treated or not with HCQ. Vascular endothelial function and eNOS were assessed in isolated mesenteric arteries. Thrombosis was assessed both in vitro by measuring thrombin generation time (TGT) and tissue factor (TF) expression and in vivo by the measurement of the time to occlusion in carotid and the total thrombosis area in mesenteric arteries. TGT, TF, and VCAM1 expression were evaluated in HAEC. aPL increased VCAM-1 expression and reduced endothelium dependent relaxation to acetylcholine. In parallel, aPL shortened the time to occlusion and extended thrombus area in mice. This was associated with an overexpression of TF and an increased TGT in mice and in HAEC. HCQ reduced clot formation as well as TGT, and improved endothelial-dependent relaxations. Finally, HCQ increased the p-eNOS/eNOS ratio. This study provides new evidence that HCQ improves procoagulant status and vascular function in APS by modulating eNOS, leading to an improvement in the production of NO.

Recently, we showed that ADAMTS13 circulates in an open conformation during the acute phase of immune-mediated thrombotic thrombocytopenic purpura (iTTP). Although the cause of this conformational change remains elusive, ADAMTS13 is primarily closed in iTTP patients in remission with ADAMTS13 activity >50% and undetectable anti-ADAMTS13 autoantibodies, as well as after rituximab treatment, suggesting a role for anti-ADAMTS13 autoantibodies. Therefore, immunoglobulin G from 18 acute iTTP patients was purified and added to closed ADAMTS13 in healthy donor plasma. This resulted in open ADAMTS13 in 14 of 18 (78%) samples, proving that anti-ADAMTS13 autoantibodies can induce an open ADAMTS13 conformation. To further elucidate the conformation of ADAMTS13 in iTTP patients, we studied a novel iTTP patient cohort (n = 197) that also included plasma samples from iTTP patients in remission in whom ADAMTS13 activity was <50%. The open ADAMTS13 conformation was found during acute iTTP, as well as in patients in remission with ADAMTS13 activity <50% and in half of the patients with ADAMTS13 activity >50%, although free anti-ADAMTS13 autoantibodies were not always detected. Thus, open ADAMTS13 is a hallmark of acute iTTP, as well as a novel biomarker that can be used to detect subclinical iTTP in patients in remission. Finally, a long-term follow-up study in 1 iTTP patient showed that the open conformation precedes a substantial drop in ADAMTS13 activity. In conclusion, we have shown that anti-ADAMTS13 autoantibodies from iTTP patients induce an open ADAMTS13 conformation. Most importantly, an open ADAMTS13 conformation is a biomarker for subclinical iTTP and could become an important tool in TTP management.

Digital ischemia associated with cancer (DIAC) is increasing in frequency and recent reports have suggested the concept of paraneoplastic manifestation. The aims of this study were to characterize the clinical presentation of DIAC and identify clinical features that could lead physicians to diagnose underlying cancer.From January 2004 to December 2011, 100 patients were hospitalized in the Department of Internal Medicine at Rouen University Hospital, France for a first episode of DI. Fifteen (15%) exhibited symptomatic or asymptomatic cancer during the year preceding or following vascular episode and constituted the DIAC group. Other patients without cancer made up the digital ischemia (DI) group.Median time between diagnosis of cancer and episode of digital necrosis was 2 months [0.25-9]. Diagnosis of DI and concomitant cancer was made in 7 of the 15 patients, while DI preceded the malignant disorder in 2 cases and followed it in 6 cases. Histological types were adenocarcinoma for 7 (46.7%), squamous cell carcinoma for 4 (26.7%), and lymphoid neoplasia for 3 patients (20%). Six patients (40%) had extensive cancer. Three patients were lost to follow-up and 5 patients died <1 year after diagnosis of cancer. Cancer treatment improved vascular symptoms in 6 patients (40%). Patients with DIAC, compared to patients with DI, were significantly older (56 years [33-79] vs 46 [17-83] P =0.005), and had significantly lower hemoglobin and hematocrit levels (12.7 g/dl vs 13.9 g/dl; P =0.003 and 38% vs 42%; P =0.003, respectively). Patients with DIAC had a higher platelet rate (420 vs 300 G/L P =0.01), and 6 patients with DIAC (40%) had thrombocytosis. There was no difference between groups either in C-reactive protein level (12 mg/L vs 5 mg/L; P =0.08) or regarding cardiovascular risk factors, presence of autoimmunity, or monoclonal protein.This retrospective study suggests that DIAC may be more prevalent than previously reported. Outcomes of the 2 diseases were not strictly chronologically parallel. However, in the majority of cases, treatment of the tumor resolved vascular involvement. Our findings suggest that age >50 years and thrombocytosis should alert physicians to consider a possible occult malignancy when digital necrosis occurs.