Immunoglobulin A-dominant crescentic glomerulonephritis in a teenage refugee with active methicillin-resistant Staphylococcus aureus urinary infection: a diagnostic and therapeutic dilemma.

Immunoglobulin A (IgA)-dominant infection-related glomerulonephritis (IgA-IRGN) and primary IgA nephropathy (IgAN) can show substantial clinicopathological overlap, creating therapeutic uncertainty when crescentic glomerular inflammation occurs alongside active infection. We describe a refugee in his late teens who presented with rapidly progressive renal failure, nephrotic-range proteinuria and fluid overload requiring haemodialysis. He had chronic perianal sepsis and developed methicillin-resistant Staphylococcus aureus urinary infection during admission. Kidney biopsy showed IgA-dominant immune complex-mediated crescentic glomerulonephritis with extensive chronic damage, including global glomerulosclerosis, 50%-60% interstitial fibrosis and tubular atrophy and an Oxford classification of M1 E1 S1 T2 C1. The differential diagnosis included advanced IgAN with infection-triggered flare versus IgA-IRGN. Given active infection, dialysis dependence and severe chronicity, immunosuppression was withheld. Despite infection clearance, kidney function did not recover. This case highlights the need to balance potential reversibility against infection risk when considering immunosuppression.