Clinical and pathological features of patients with recurrent anti-glomerular basement membrane disease.

Anti-glomerular basement membrane disease (anti-GBM disease) is a rare autoimmune disease, traditionally considered a monophasic autoimmune disorder, but more and more cases of recurrence have been reported. Through a review of the published literature and analysis of recurrent cases from our institution, we identified key predisposing factors including smoking (21.7%), hydrocarbon exposure (7.2%), prodromal infections (12.0%), and comorbid autoimmune conditions (12.0%). Notably, 43.5% (20/46) of recurrences occurred without identifiable triggers. There are not a few antibody-negative recurrences, challenging the reliability of serological monitoring alone for disease activity, and such recurrences may have an underlying unrecognized pathogenesis. Clinical presentations at recurrence varied: 38.6% of the patients had both lung and kidney involvement, 33.3% had lung involvement only, and 28.1% had kidney involvement only. Patients with concurrent systemic autoimmune diseases exhibited universally poor renal outcomes.