Chinese Herb-Induced Type II Crescentic Glomerulonephritis: A Case Report of Four Patients

Drug-induced type II crescentic glomerulonephritis is an uncommon but severe renal syndrome, rarely linked to pharmaceutical agents, with no established association to Chinese herbal medicines to date. In this case report, we described 4 patients who developed biopsy-confirmed type II crescentic glomerulonephritis within 1-4 weeks following exposure to Chinese herbal products. Key histopathologic findings included crescent formation in ≥50% of glomeruli and immunofluorescence demonstrating granular mesangial deposits of immunoglobulin G and C3, accompanied by prominent acute tubulointerstitial injury. Clinically, 75% of cases presented with macroscopic hematuria, reflecting severe glomerular capillary damage. The therapeutic regimen comprised intravenous methylprednisolone, cyclophosphamide, and plasma exchange. Persistent hematuria and a longer duration of drug exposure were associated with slower and incomplete renal recovery during follow-up. Our case report suggested that Chinese herbal medicine may be a potential environmental trigger for crescentic glomerulonephritis and highlight the value of clinical inquiry into herbal product use in cases of rapidly progressive glomerulonephritis. Further toxicovigilance and compound-specific risk assessments are urgently needed.