Glomerulonephritis associated with hepatitis B surface antigenemia. Report of a case with features of both membranous and IgA nephropathy.

A 40-year-old man with hepatitis B surface (HBs) antigenemia developed the nephrotic syndrome. Renal biopsy revealed a glomerulonephritis with features of both membranous glomerulonephropathy and IgA nephropathy. Histologically some glomeruli showed mesangial expansion and hypercellularity only, while others contained sclerotic segments. Direct immunofluorescence demonstrated granular IgG-bearing deposits along the peripheral glomerular capillaries and IgA-containing ones in the mesangium. HBs antigen was detected by indirect immunofluorescence both along the glomerular capillary walls and within the mesangium. Granular epimembranous and mesangial deposits were observed by electron microscopy. A few mesangial deposits consisted of spherical particles, 35-100 nm in diameter. Although 3 cases of mixed membranous and IgA nephropathy have been previously reported, this appears to be the first one to be associated with HBs antigenemia.