Hepatitis B Virus-related Membranous Nephropathy with Crescentic Formation in an Inactive Carrier of Positive Hepatitis B Surface Antigen with Undetectable DNA under Anti-viral Treatment.

A man who was an inactive hepatitis B virus (HBV) carrier with positive hepatitis B surface antigen (HBs antigen) and undetectable HBV-DNA under anti-viral treatment developed nephrotic syndrome at 52 years old, and a renal biopsy revealed advanced membranous nephropathy (MN) with focal cellular crescents, interstitial hemorrhaging, and peritubular capillaritis. Immunofluorescence studies demonstrated granular IgG deposition and HBs antigen-positivity along the capillaries. Glomeruli were negative for phospholipase A2 receptor 1. There were no clinical findings of systemic vasculitis. We considered MN combined with small-vessel vasculitis due to HBV infection. These results suggest that HBV-related kidney disease should be considered even in patients with an inactive HBV carrier status under treatment.