A patient with membranoproliferative glomerulonephritis diagnosed by the third biopsy via endocapillary proliferative glomerulonephritis and focal membranoproliferative glomerulonephritis.

We present a girl with type I membranoproliferative glomerulonephritis (MPGN) diagnosed by the third renal biopsy. The first renal biopsy was performed at age 11.2 years after microscopic hematuria (which was revealed by school urinary screening) had persisted for 3 months, along with a low level of serum C3. Pathological examination of the biopsied specimen revealed endocapillary proliferative glomerulonephritis with multiple humps. The serum C3 level increased to within the normal range 2 months after the first renal biopsy, and the microscopic hematuria disappeared at age 12.3. However, microscopic hematuria, proteinuria, and the low serum complement level reappeared at age 12.8. Pathological examination of a further renal biopsy that was performed at age 13.2 revealed focal MPGN with humps. Prednisolone therapy was subsequently initiated. Fluvastatin was added to her treatment regime when she developed hypercholesterolemia at age 13.6 and was continued even after normal cholesterol levels were reestablished. Pathological examination of the third renal biopsy, which was performed at age 15.2, revealed type I MPGN with humps. Serum C3 normalized 6 months after the cessation of prednisolone at age 15.9. It is clinically important that patients with nontypical acute glomerulonephritis should be observed over a long period and repeated renal biopsies should be performed.