Anti-Glomerular Basement Membrane Antibody Disease: Clinicopathologic Profile and Outcomes

Anti-glomerular basement membrane antibody disease is a rare autoimmune disease caused by antibodies to α3 chain of type 4 collagen. Patients presenting with severe renal involvement requiring dialysis have poor response to treatment. We conducted a retrospective and prospective study at Institute of Nephrology, Madras Medical College, Chennai, India by analyzing the data of patients with biopsy-proven anti-GBM antibody disease treated from January 2013 to December 2019. There were 2,949 kidney biopsies in the study period and 92 showed crescentic glomerulonephritis (GN). Of those, 20 patients (10 males) had anti-GBM antibody disease. Mean age was 40.75 ± 14.75 years. Rapidly progressive renal failure was the most common mode of presentation (95%); five (25%) patients had diffuse alveolar hemorrhage (DAH) and nineteen patients (95%) required dialysis at presentation. Seven patients (35%) were positive for anti-neutrophil cytoplasmic antibody (anti-myeloperoxidase in six and anti-proteinase 3 in one). Of the twelve patients (60%) who received immunosuppression (cyclophosphamide, steroids, and plasma exchange), two patients (10%) attained remission, and two patients (10%) expired due to sepsis. Crescentic GN was the predominant pathology in kidney biopsy in 19 patients (95%). Mesangial hypercellularity with deposition of IgA and C3 in mesangium was present in one patient. In our study, anti-GBM antibody disease accounted for 21.7% of crescentic GN. Majority of patients presented late, requiring dialysis. Patient survival was 90%, while renal survival was only 10%. One patient had co-occurrence of IgA nephropathy with anti-GBM antibody disease.