Membranoproliferative glomerulonephritis related to a streptococcal infection in a girl with IgA deficiency: a case report

BACKGROUND: IgA deficiency associated with glomerulonephritis is rare. In particular, there is no prior report regarding the association between IgA deficiency and membranoproliferative glomerulonephritis (MPGN) in children. Herein, we describe the case of a 5-year-old girl with selective IgA deficiency and MPGN. CASE PRESENTATION: The patient presented with persisting urinary abnormality and hypocomplementemia following a group A treptococcal infection. Renal biopsy revealed the presence of diffuse mesangial hypercellularity, endocapillary proliferation, and focal thickening of the walls of the glomerular capillaries using light microscopy, with IgG and moderate C3 deposits observed using immunofluorescence. Electron microscopy images revealed nodular deposits in the subendothelial areas, with hump-shaped subepithelial deposits. The pathological diagnosis was confirmed as MPGN. Treatment using oral prednisolone (PSL), mizoribine (MZR), and angiotensin-converting enzyme inhibitors reduced the proteinuria. The PSL dose was gradually tapered, with the low dose of PSL and MZR continued for 4 years. Histological findings were improved on repeated renal biopsy, and PSL and MZR administration was discontinued. CONCLUSIONS: We report a rare case of MPGN related to a streptococcal infection in a child. The clinical presentation included selective IgAD, with several pathological findings and a clinical course typical of glomerulopathy. The patient was successfully treated using multidrug therapy.