Mini review: A unique case of crescentic C3 glomerulonephritis

Kidney involvement is an under‐recognized complication of non‐Hodgkin lymphomas. They occur in a variety of mechanisms and differ widely in their clinical presentation. We take this opportunity to report a case of a 65 year‐old man who developed a rapidly progressive glomerulonephritis within days after completing his first cycle of R‐CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, Prednisolone) chemotherapy for newly diagnosed mantle cell lymphoma. He was odematous, hypertensive, oliguric with nephrotic range proteinuria and an active urine sediment. A renal biopsy showed a crescentic C3 glomerulonephritis (C3GN) with no evidence endocapillary or mesangial hypercellularity. He was promptly treated with immunosuppression and dialysis, with resumption of his chemotherapy. Genetic testing on complement proteins revealed a homozygous deletion spanning the CFHR1 and CFHR3 genes. Crescentic C3GN is a rare form of kidney injury, and this is the first known case of lymphoma‐associated kidney involvement manifesting as C3GN. This article explores the possible mechanism of disease and reviews the literature of lymphoma‐related kidney disease.