Adult-onset autoinflammation caused by somatic mutations in UBA1: A Dutch case series of patients with VEXAS.

BACKGROUND: A novel autoinflammatory syndrome was recently described in male patients who harbored somatic mutations in the X-chromosomal UBA1 gene. These patients were characterized by adult-onset, treatment-refractory inflammation with fever, cytopenia, dysplastic bone marrow, vacuoles in myeloid and erythroid progenitor cells, cutaneous and pulmonary inflammation, chondritis, and vasculitis, which is abbreviated as VEXAS. OBJECTIVE: This study aimed to (retrospectively) diagnose VEXAS in patients who had previously been registered as having unclassified autoinflammation. We furthermore aimed to describe clinical experiences with this multifaceted, complex disease. METHODS: A systematic reanalysis of whole-exome sequencing data from a cohort of undiagnosed patients with autoinflammation from academic hospitals in The Netherlands was performed. When no sequencing data were available, targeted Sanger sequencing was applied in cases with high clinical suspicion of VEXAS. RESULTS: A total of 12 male patients who carried mutations in UBA1 were identified. These patients presented with adult-onset (mean age 67 years, range 47-79 years) autoinflammation with systemic symptoms, elevated inflammatory parameters, and multiorgan involvement, most typically involving the skin and bone marrow. Novel features of VEXAS included interstitial nephritis, cardiac involvement, stroke, and intestinal perforation related to treatment with tocilizumab. Although many types of treatment were initiated, most patients became treatment-refractory, with a high mortality rate of 50%. CONCLUSION: VEXAS should be considered in the differential diagnosis of males with adult-onset autoinflammation characterized by systemic symptoms and multiorgan involvement. Early diagnosis can prevent unnecessary diagnostic procedures and provide better prognostic information and more suitable treatment options, including stem cell transplantation.

Interaction between hyperhomocysteinemia, mutated methylenetetrahydrofolatereductase (MTHFR) and inherited thrombophilic factors in recurrent venous thrombosis.

Venous thrombosis is a multicausal disease involving acquired and genetic factors. In this study we investigated a possible interaction between hyperhomocysteinemia (fasting or postload) and factor V Leiden or prothrombin G20210A on the risk of recurrent venous thrombosis. We also looked at the risk due to mutations in the MTHFR-gene (C677T and A1298C). We performed a case-control study in 171 patients with a history of recurrent venous thrombosis and 461 control subjects from the general population. Hyperhomocysteinemia (fasting or 6 h after an oral methionine load) was defined as a homocysteine concentration above the 90th percentile of the distributions in the control group. The odds ratio (adjusted for age and sex) for recurrent venous thrombosis was 1.8 (95% CI: 1.1 to 3.0) for fasting hyperhomocysteinemia, 5.1 (95% CI: 3.0 to 8.6) for factor V Leiden and 1.8 (95% CI: 0.7 to 4.2) for prothrombin G20210A. We found 14 patients and 3 controls with both hyperhomocysteinemia and factor V Leiden, which yielded an odds ratio of 11.6 (95% CI: 3.2 to 42.5). We found no interaction between hyperhomocysteinemia and prothrombin G20210A. The relative risk for MTHFR 677CT was 1.6 (95% CI: 1.1 to 2.4) and for MTHFR 677TT was 1.4 (95% CI: 0.7 to 2.8). The combined risk for MTHFR 677TT and factor V Leiden was 18.7 (95% CI: 3.3 to 108). We conclude that hyperhomocysteinemia and factor V Leiden are risk factors for recurrent venous thrombosis. The risk of thrombosis appeared high for individuals who had both risk factors.

Homocysteine lowering by B vitamins and the secondary prevention of deep vein thrombosis and pulmonary embolism: A randomized, placebo-controlled, double-blind trial.

The Vitamins and Thrombosis (VITRO) study investigated the effect of homocysteine lowering by daily supplementation of B vitamins on the risk reduction of deep vein thrombosis (DVT) and pulmonary embolism (PE). Patients between 20 to 80 years old with a first objectively confirmed proximal DVT or PE in the absence of major risk factors and a homocysteine concentration above the 75th percentile of a reference group were asked to participate (hyperhomocysteinemic group). A similar study was conducted in a random sample of patients with a homocysteine below the 75th percentile of the reference group (normohomocysteinemic group). After informed consent was obtained, patients were randomized to daily multivitamin supplementation (5 mg folic acid, 50 mg pyridoxine, and 0.4 mg cyanocobalamin) or placebo and were followed for 2.5 years. End points were objectively diagnosed recurrent DVT or PE. A total of 701 patients were enrolled (360 in the hyperhomocysteinemic and 341 in the normohomocysteinemic group). The number of recurrent events of venous thrombosis was 43 of 353 in the vitamin group (54/1000 py) and 50 of 348 in the placebo group (64/1000 py). The hazard ratio associated with vitamin treatment was 0.84 (95% CI, 0.56-1.26): 1.14 (95% CI, 0.65-1.98) in the hyperhomocysteinemic group and 0.58 (95% CI, 0.31-1.07) in the normohomocysteinemic group. The results of our study do not show that homocysteine lowering by B vitamin supplementation prevents recurrent venous thrombosis.