Membranous glomerulonephritis with extra-renal disorders in children

Thirty of 85 children with membranous glomerulonephritis (MGN) had associated extraglomerular disorders. The relation of these associations to membranous glomerulonephritis (MGN) is discussed. The causal relationship of acute hepatitis (5 cases), persistent hepatitis B antigenemia (6 cases), systemic lupus erythematosus (2 cases) and syphilis (1 case) may be ascertained; in similar conditions a definite antigen (Ag) has been found in MGN deposits. The association with SS or SA hemoglobinopathy (3 cases) ans with a preceding streptococcal infection (4 cases) raises the possible responsibility of renal tubular epithelium (RTE) Ag and of a streptococcal Ag. D-penicillamine therapy (1 case) is a well-known cause of MGN although the acting Ag remains unknown. Four children had serum sickness-like symptoms, two had hematologic disorders and two had proximal tubular dysfunction, one of them with proven anti-tubular and anti-alveolar basement membrane antibodies. A decrease in plasma C4, Clq, and factor B with normal C3 was frequently observed. The multiple Ag previously described as causative of MGN are recalled. The prevalent incidence of HBsAg is stressed, and the necessity for further investigations in patients with MGN in order to find an underlying disease is emphasized.