IntroductionAntibodies against cyclic citrullinated peptides (CCPs) are useful for diagnosing rheumatoid arthritis (RA). Antibodies to mutated citrullinated vimentin (MCV) were described recently in RA. The aims of this study were to evaluate the usefulness of anti-MCV for diagnosing RA in anti-CCP-negative patients and to monitor anti-MCV titres during infliximab therapy for RA.MethodsWe studied two groups of RA patients, one with (n = 80) and one without (n = 76) anti-CCP antibodies. The specificity of anti-MCV was evaluated by investigating 50 healthy controls and 158 patients with other rheumatic diseases (51 psoriatic rheumatism, 58 primary Sjögren syndrome, and 49 ankylosis spondylitis). Serum anti-MCV and anti-CCP titres were measured in 23 patients after 6, 12, 18, and 24 months of infliximab treatment. Anti-CCP2 and anti-MCV levels were assayed using a commercial enzyme-linked immunosorbent assay. IgM rheumatoid factor was determined by nephelometry.ResultsIn accordance with the cutoff values recommended by the manufacturer, the specificity of anti-MCV antibodies was 90.9%. We adjusted the cutoff values to obtain the same specificity as that of anti-CCP antibodies (94.2%). With this optimal cutoff, anti-MCV antibodies were found in 11.8% (9/76) of RA patients without anti-CCP, and similarly, anti-CCP antibodies were found in 11.2% (9/80) of RA patients without anti-MCV. Anti-MCV antibodies were positive in 6 patients who tested negative for both anti-CCP and rheumatoid factor. Anti-MCV titres were significantly decreased after 18 and 24 months of infliximab therapy compared with baseline (P < 0.01) as a significant decrease of anti-CCP levels occurred only at 24 months (P < 0.04). Moreover, an anti-MCV decrease was significantly associated with DAS28 (disease activity score using 28 joint counts) improvements 12 months into therapy.ConclusionsOur results suggest that anti-MCV antibodies may be valuable for diagnosing RA in anti-CCP-negative patients without replacing them as an equivalent number of anti-CCP-positive RA patients test negative for anti-MCV. Moreover, anti-MCV antibodies could be useful for monitoring the effects of infliximab therapy.

Sensitivity of the QAM test (84.2%), together with its simplicity and suitability for routine laboratory use, makes it a valuable tool, in conjunction with skin tests, for diagnosing NMBA sensitivity in patients who react after NMBA injection. The QAM test is of particular interest when skin tests are not available or not reliable or give results poorly compatible with mediator release or clinical features.

Objective: To evaluate the clinical course of and risk factors for arterial thrombotic events in adult inpatients with coronavirus disease 2019 . Methods: All consecutive adult patients admitted for COVID-19 infection in a referral center in France and discharged from the hospital between April 1 and April 30, 2020, were included. All arterial thrombotic events that occurred through discharge were considered for analysis. Epidemiologic, demographic, clinical, laboratory, treatment, and outcome data were extracted from electronic medical records with use of a standardized data collection form. Results: Overall, 531 COVID-19þ patients were analyzed. Among them, 30 (5.6%) experienced arterial thrombotic events. Arterial thrombotic events in the setting of COVID-19 infection happened at a median of 11 (5-20) days after the first symptoms of infection; occurred in high-risk patients according to traditional cardiovascular risk factors; had an atypical pattern, such as thrombosis of the aorta, upper limb, or renal arteries or cerebral microvasculopathy in 7 (23.3%) cases; and were associated with an in-hospital mortality rate of 40%. Arterial thrombotic events increased the risk of death by 3-fold in COVID-19þ patients (hazard ratio, 2.96; 95% CI, 1.4 to 4.7; P¼.002). A subdistribution survival hazard model showed that a concentration of D-dimer above 1250 ng/mL increased the risk of arterial thrombotic events in COVID-19þ patients by more than 7 (subdistribution hazard ratio, 7.68; 95% CI, 2.9 to 20.6; P<.001). Conclusion:A dramatically high rate of in-hospital death was observed in patients who suffered arterial thrombotic events in the setting of COVID-19 infection. A D-dimer level above 1250 ng/mL at entry may identify COVID-19þ patients at risk for arterial thrombotic events.