Anti-glomerular basement membrane crescentic glomerulonephritis: A report from India and review of literature

Epidemiology, clinical features, risk factors, and outcomes in anti-glomerular basement membrane disease: A systematic review and meta-analysis

Anti-glomerular basement membrane (GBM) disease is a small-vessel vasculitis that represents the most aggressive form of autoimmune glomerulonephritis. The study aimed to investigate the prevalence, clinical characteristics, risk factors, and outcomes of anti-GBM disease through a systematic review and meta-analysis involving 47 studies with 2830 patients. The overall incidence of anti-GBM disease ranged from 0.60 to 1.79 per million population per annum. In rapidly progressive glomerulonephritis and crescentic glomerulonephritis, the pooled incidence rates were 8.0% and 12.8%, respectively. The pooled prevalence rates of anti-GBM antibodies, antineutrophil cytoplasmic antibodies (ANCA), and lung hemorrhage were 88.8%, 27.4%, and 32.6%, respectively. Patients with combined ANCA positivity demonstrated a prognosis comparable to those patients with only anti-GBM antibodies, though with differing clinical features. The pooled one-year patient and kidney survival rates were 76.2% and 30.2%, respectively. Kidney function on diagnosis and normal glomeruli percentage were identified as strong prognostic factors. This study represents the first comprehensive meta-analysis on anti-GBM disease, providing insights into its management. However, caution is warranted in interpreting some results due to the observational nature of the included studies and high heterogeneity.

Clinical Profile and Renal Survival of Anti-Glomerular Basement Membrane Disease Patients: A Retrospective Case Series from Northern India

Introduction

Anti-glomerular basement membrane (anti-GBM) disease is a rare organ-specific autoimmune disease. The overall and renal outcomes of patients have mostly been reported in small-sized cohorts. We aimed to study the clinical profile, overall survival, and renal survival of anti-glomerular basement membrane disease patients at our center.

Methods

We conducted a retrospective analysis of the data regarding the clinical profile and renal survival of patients diagnosed with anti-GBM disease from October 2019 to March 2022, having a minimum follow-up of 12 months.

Results

There were 15 patients in the study, with the mean age of presentation being 51.6 ± 13.7 years. The median duration of symptoms onset to the nephrologist opinion was 15 (10-23) days. The extrarenal manifestations were seen in the respiratory, otorhinolaryngological, and neurological systems. The mean serum anti-GBM titers were 154.5 (14.9-263.5) U/mL. Serum anti-GBM titers were present in 13/15 (86.6%) patients, and 12/13 (92.3%) patients had above the reference range. Anti-neutrophil cytoplasm antibody (ANCA) levels were assessed in 12/15 (80%) patients, and 9/12 (75%) had higher levels. Renal biopsy was available in 14 patients with more than 50% crescents. Along with crescents, necrotizing lesions, rupture of the Bowman's capsule, and granulomatous lesions were also seen. Among the initial therapies, the steroid pulse was given to 13 (86.6%) patients, whereas membrane plasmapheresis was given to 8 (53.3%) patients. Inj. cyclophosphamide and inj. rituximab were given to 8 (53.3%) and 4 (26.6%) patients, respectively. No difference was seen in clinical characteristics, renal biopsy features, treatment received, and outcomes with ANCA positivity except for age, where patients who were ANCA positive were older compared to patients who were ANCA negative. One-year renal and patient survival was seen in 4 (26.6%) and 6 (40%) patients, respectively.

Conclusion

Most patients of anti-GBM disease have active sediments, raised creatinine, and non-specific symptomatology. There is poor renal and patient outcome as most patients present with advanced renal failure.

Etiological Spectrum and Clinical Features in 215 Patients of Crescentic Glomerulonephritis: Is it Different in India?

INTRODUCTION

Crescentic glomerulonephritis (CrGN) characterized by the presence of crescents in most (≥50%) glomeruli on renal histology clinically presents as rapidly progressive renal failure. It can occur due to diverse etiologies with varying course and renal outcomes. We studied the prognostic significance of its classification as pauci-immune, anti-GBM, and immune-complex mediated CrGN.

MATERIALS AND METHODS

Renal biopsies diagnosed as CrGN over 9 years were included. Clinical, biochemical, serological, and histological features of various classes of CrGN were correlated with renal outcome.

RESULTS

215 biopsies were diagnosed as CrGN during this period. A majority (63%) were immune-complex mediated while 32% were pauci-immune, followed by anti-GBM disease (5%). 85.5% of pauci-immune CrGN were ANCA associated. The levels of proteinuria and serum creatinine were significantly higher in anti-GBM CrGN as compared to the other two classes. The various histological features including Bowman's capsule rupture, peri-glomerular granulomatous reaction, fibrinoid necrosis, and vasculitis were more common in anti-GBM disease and pauci-immune CrGN. The median renal survival was 6.3, 5.3, 2.1 months in immune-complex mediated, pauci-immune, and anti-GBM CrGN, respectively.

CONCLUSION

Immune-complex mediated is the commonest etiology of CrGN in India. Anti-GBM disease has the worst prognosis followed by pauci-immune and immune-complex mediated CrGN. Raised serum creatinine levels (>5mg%) and the degree of glomerulosclerosis at diagnosis were predictors of poor renal survival. High index of suspicion and prompt diagnosis can improve the outcome in these patients.