Association between hypogammaglobulinaemia and severe infections during induction therapy in ANCA-associated vasculitis: from J-CANVAS study.

OBJECTIVES: To investigate the association between decreased serum IgG levels caused by remission-induction immunosuppressive therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and the development of severe infections. METHODS: We conducted a retrospective cohort study of patients with new-onset or severe relapsing AAV enrolled in the J-CANVAS registry, which was established at 24 referral sites in Japan. The minimum serum IgG levels up to 24 weeks and the incidence of severe infection up to 48 weeks after treatment initiation were evaluated. After multiple imputations for all explanatory variables, we performed the multivariate analysis using a Fine-Gray model to assess the association between low IgG (the minimum IgG levels <500 mg/dl) and severe infections. In addition, the association was expressed as a restricted cubic spline (RCS) and analysed by treatment subgroups. RESULTS: Of 657 included patients (microscopic polyangiitis, 392; granulomatosis with polyangiitis, 139; eosinophilic granulomatosis with polyangiitis, 126), 111 (16.9%) developed severe infections. The minimum serum IgG levels were measured in 510 patients, of whom 77 (15.1%) had low IgG. After multiple imputations, the confounder-adjusted hazard ratio of low IgG for the incidence of severe infections was 1.75 (95% confidence interval: 1.03-3.00). The RCS revealed a U-shaped association between serum IgG levels and the incidence of severe infection with serum IgG 946 mg/dl as the lowest point. Subgroup analysis showed no obvious heterogeneity between treatment regimens. CONCLUSION: Regardless of treatment regimens, low IgG after remission-induction treatment was associated with the development of severe infections up to 48 weeks after treatment initiation.

Treatment of rheumatoid arthritis and its outcomes in an aging society: a single-center cohort study in Japan from 2011 to 2020.

BACKGROUND: We conducted a single-center cohort study of rheumatoid arthritis (RA) patients from 2011 to 2020 to understand their real world treatment and outcomes, especially changes in physical function and quality of life (QOL) in elderly patients, including those aged ≥ 80 years. METHODS: For RA patients attending our outpatient clinic, we annually recorded tender and swollen joint counts, laboratory findings, therapeutic drugs, and scores from the Japanese Health Assessment Questionnaire and EuroQoL-5 Dimensions questionnaire. We examined changes in treatment and outcomes over time, by age group, in patients enrolled over a 10-year period, from 2011 to 2020. RESULTS: One thousand eight hundred thirty RA patients were enrolled and data were recorded once a year, and a total of 9299 patient records were evaluated. The average age of patients increased by 3.7 years during the study period; the patients aged rapidly. Intensive pharmacological treatment was more frequent in younger patients. Disease activity, physical function, and QOL showed improvement in all age groups over the study period. Physical function and QOL showed greater changes with aging, compared with disease activity. This may be due to the effects of accumulated RA damage, disability due to aging, and depression. CONCLUSIONS: Intensive pharmacological treatment contributes to not only control of disease activity but also the improvement of physical activity and QOL, even in elderly patients. Relieving age-related physical impairment and depression may improve the QOL of very elderly RA patients.