Hypocomplementemia and membranoproliferative glomeruloneophritis in children

The incidence of hypocomplementemia detected in the school urinary screening program in Kanagawa Prefecture, Japan, and the number of new patients with membranoproliferative glomerulonephritis (MPGN) diagnosed in our institution were decreasing during the period between 1974 and 1997. Follow-up of this study was performed during the period between 1998 and 2003.

A total of 1,230,398 urine specimens in elementary and junior high school were examined between 1980 and 2003. Serum C3 was measured in children with abnormal urinary findings. Fifty-nine children were diagnosed as having idiopathic MPGN in our hospital between 1974 and 2003.

Serum C3 was measured in 1546 school children with abnormal urinary findings, and 34 had hypocomplementemia between 1980 and 2003. Among 264 children in whom C3 was measured between 1998 and 2003, only 4 had mild hypocomplementemia of 83-86 mg/dl (normal, 87-157 mg/dl). Between 1974 and 2003, 59 children (8.8%) were diagnosed as having idiopathic MPGN in our hospital, whereas only 2 were diagnosed during the period between 1998 and 2003.

The incidence of hypocomplementemia detected in school urinary screening and new cases of MPGN continue to decrease in our experience.