Examining the role of patient-reported external factors and risk of relapse in anti-neutrophilic cytoplasmic autoantibody vasculitis.

The role of stressors, insect bites, and infections on disease relapse of ANCA vasculitis has yet to be entirely explored, with limited retrospective studies focused on disease onset from small participant cohorts. Our study analyzes longitudinal survey data from 2011-2022 to evaluate this perspective from a large ANCA vasculitis cohort. We collected surveys every three to six months to obtain information on self-reported psychological stressors and significant life events, insect bites, and infections throughout clinical disease. We defined cohorts as those who relapsed (Relapse Cohort) and controls as those who did not relapse (Remission Cohort) during the study period. Survey responses were retrospectively reviewed during a 15-month timeframe prior to relapse or during 15 months of remission and categorized by type of stress event, insect bite, and infections at every available 3-month interval. There were no significant differences in stress and insect bites between the relapse and remission cohorts. Patients who relapsed reported more frequent upper respiratory infections and other infections, such as those affecting the skin and eyes, but there were no significant differences in the incidence of pulmonary or urinary infections compared to the remission cohort. There was a significant difference in reported upper respiratory infections 9 to 15 months prior to the relapse date, indicating a remote history of infections as a potentially significant physical stressor that may contribute to disease relapse. More frequent patient-reported infections, specifically upper respiratory infections, may contribute to patient vulnerability to relapse. Counseling and close monitoring of patients after infectious symptoms could aid in earlier detection of disease flares. Future studies are essential to further understand the importance of distal risk factors and how they impact relapse.

Immunological Interaction of HLA-DPB1 and Proteinase 3 in ANCA Vasculitis is Associated with Clinical Disease Activity.

BACKGROUND: PR3-ANCA vasculitis has a genetic association with HLA-DPB1. We explored immunologic and clinical features related to the interaction of HLA-DPB1*04:01 with a strongly binding PR3 peptide epitope (PR3225-239). METHODS: Patients with ANCA vasculitis with active disease and disease in remission were followed longitudinally. Peripheral blood mononuclear cells from patients and healthy controls with HLA-DPB1*04:01 were tested for HLA-DPB1*04:01 expression and interaction with a PR3 peptide identified via in silico and in vitro assays. Tetramers (HLA/peptide multimers) identified autoreactive T cells in vitro. RESULTS: The HLA-DPB1*04:01 genotype was associated with risk of relapse in PR3-ANCA (HR for relapse 2.06; 95% CI, 1.01 to 4.20) but not in myeloperoxidase (MPO)-ANCA or the combined cohort. In silico predictions of HLA and PR3 peptide interactions demonstrated strong affinity between ATRLFPDFFTRVALY (PR3225-239) and HLA-DPB1*04:01 that was confirmed by in vitro competitive binding studies. The interaction was tested in ex vivo flow cytometry studies of labeled peptide and HLA-DPB1*04:01-expressing cells. We demonstrated PR3225-239 specific autoreactive T cells using synthetic HLA multimers (tetramers). Patients in long-term remission off therapy had autoantigenic peptide and HLA interaction comparable to that of healthy volunteers. CONCLUSIONS: The risk allele HLA-DPB1*04:01 has been associated with PR3-ANCA, but its immunopathologic role was unclear. These studies demonstrate that HLA-DPB1*04:01 and PR3225-239 initiate an immune response. Autoreactive T cells specifically recognized PR3225-239 presented by HLA-DPB1*04:01. Although larger studies should validate these findings, the pathobiology may explain the observed increased risk of relapse in our cohort. Moreover, lack of HLA and autoantigen interaction observed during long-term remission signals immunologic nonresponsiveness.

Association of Lupus Nephritis Histopathologic Classification With Venous Thromboembolism-Modification by Age at Biopsy.

INTRODUCTION: Lupus nephritis (LN) is an independent risk factor for venous thromboembolism (VTE). The risk of VTE has not been analyzed by International Society of Nephrology/Renal Pathology Society or World Health Organization LN class. Study goals were to measure VTE incidence in an LN patient cohort, to evaluate associations between VTE and LN class, and to investigate factors modifying associations between VTE and LN class. METHODS: A retrospective analysis was performed using Glomerular Disease Collaborative Network data. Image-confirmed VTE was compared between patients with any LN class V lesion and patients with only LN class III or IV. Logistic regression was used to calculate odds ratios and 95% confidence intervals. Effect modification was assessed between main effect and covariates. RESULTS: Our cohort consisted of 534 LN patients, 310 (58%) with class III/IV and 224 (42%) with class V with or without class III/IV, including 106 with class V alone. The VTE incidence was 62 of 534 (11.6%). The odds of VTE were not significantly different between patients with class III/IV and class V in adjusted analyses (odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.45-1.48). An age interaction was observed (P = 0.009), with increased odds of VTE with class III/IV diagnosed at a younger age (2.75, 0.90-8.41 estimated at age 16 years) and decreased odds with class III/IV diagnosed at an older age (0.23, 0.07-0.72 estimated at age 46 years), compared to class V. CONCLUSIONS: The VTE incidence was similar among patients with LN classes III/IV and V, suggesting that VTE risk is not limited to class V-related nephrotic syndrome and that age may modulate LN class-specific VTE risk.

Understanding Long-term Remission Off Therapy in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

INTRODUCTION: In antineutrophil cytoplasmic antibody-associated (ANCA) vasculitis, relapse risk and long-term immunosuppressive therapy are problematic. Stopping immunotherapy has not been well described. METHODS: The Glomerular Disease Collaborative Network ANCA vasculitis inception cohort was evaluated. Patients who stopped all immunotherapy and those continuously on immunotherapy (≥2 years) were included. Time to first period off therapy was modeled with end-stage kidney disease and death as competing risks to understand influences of stopping therapy. Cause-specific hazard ratios (HRs) with 95% confidence intervals (CI) and P values are reported. Models controlled for age, sex, ANCA specificity, organ involvement, diagnosis era, and treatments (yes/no). Repeated events analysis was used to assess the time-dependent variable of time off treatment on recurrent relapse with HRs, 95% CIs, and P values are reported (same control variables without treatments). RESULTS: In 427 patients, 277 (65%) stopped therapy (median 20 months from initial induction); 14% for ≥2 different periods of time and 23% for periods ≥5 years. In multivariable models of time to discontinuation of treatment, women (HR 1.33; 95% CI 1.04-1.70; P = 0.024) and those treated with pulse methylprednisolone (HR 1.39; 95% CI 1.05-1.84; P = 0.020) were more likely to stop. The time-dependent variable of time off treatment was associated with fewer recurrent relapses (HR 0.51; 95% CI 0.41-0.63; P < 0.001). CONCLUSIONS: Stopping immunotherapy was common. Women and those treated with methylprednisolone stop treatment more often, but underlying mechanisms are unknown. Stopping treatment was associated with fewer relapses, suggesting that even without guidelines there may be benefits without an untoward detriment of relapse.