Recurrent Nephritis and/or Pulmonary Hemorrhage in Patients with Anti-Glomerular Basement Membrane Disease with and without ANCA Positivity

INTRODUCTION: Anti-glomerular basement membrane (anti-GBM) disease is characterized by rapidly progressive glomerular nephritis with or without pulmonary hemorrhage with disease severity correlating with antibody titer. Following treatment, relapse is rare but has been reported in the literature. The objective of this study was to assess for clinical, serologic, and histologic differences associated with disease relapse in patients with anti-GBM disease. METHODS: Patients seen at our facility between 1997 and 2017 were screened for anti-GBM disease by ICD 9/10 codes. They were included if the diagnosis was confirmed by a board-certified rheumatologist or nephrologist and had positive antibodies and/or biopsy results consistent with anti-GBM disease. Relapsing disease was defined as recurrence of pulmonary or renal manifestations after achieving remission following the initial presentation. All charts were reviewed for baseline demographics, clinical manifestations, and antibody positivity and compared between groups. RESULTS: 40 patients were confirmed as having anti-GBM disease. Mean follow-up from disease onset to the date of last follow-up was 56.2 months. 8 patients had relapsing disease and 32 patients had nonrelapsing disease. Baseline characteristics and clinical manifestations were similar between groups. Patients with relapsing disease had a high incidence of anti-neutrophilic cytoplasmic antibody (ANCA) co-positivity as compared to nonrelapsing patients (50 vs. 15.6%, respectively, p = 0.059), but this did not reach statistical significance. In patients with relapsing disease, only one had positive anti-GBM antibodies at time of relapse. CONCLUSIONS: In this study, patients with relapsing disease had a high incidence of ANCA co-positivity (50%). In patients with newly diagnosed anti-GBM disease, ANCAs should be obtained to assess for the risk of relapse and to help guide long-term follow-up and treatment.