Glomerulonephritis without IgA deposits in a case of Henoch-Schönlein purpura.

A boy aged 3 years 8 months with Henoch-Schönlein purpura (HSP) developed significant proteinuria with hematuria 2 days after the appearance of purpura rash. Although thought to be purpura nephritis, a percutaneous renal biopsy revealed diffuse mesangial proliferative glomerulonephritis (MesPGN) without deposition of immunoglobulin A or complement. Since his urine screening test during a health check at the age of 3.5 years had been unremarkable, HSP might have played a role in the pathogenesis of his non-IgA MesPGN. To our knowledge, non-IgA MesPGN is an uncommon renal manifestation of HSP.