[Characteristics of pediatric C3 glomerulopathy with decreased factor H in 3 cases].

OBJECTIVE

To study the characteristics of clinicopathology and prognosis of 3 pediatric cases diagnosed as C3 glomerulopathy, and to improve the understanding of C3 glomerulopathy in children.

METHOD

The medical record, plasma complement C3, Factor H (FH) and its autoantibody, and therapeutic response of the 3 cases were analyzed, and their prognosis were followed up.

RESULT

Of the 3 cases, 2 were male and 1 was female, the age of onset was 9 years, 12 years, 5 years 4 months, the duration from onset to renal biopsy was 3 months, 7 months and 20 days, and the follow-up period were 2.6 years, 8 months and 1.5 years respectively.

CLINICAL MANIFESTATIONS

All the 3 cases showed microscopic hematuria, with or without gross hematuria and proteinuria. Two showed persistently decreased plasma complement C3, in the other one C3 was in normal lower limit, all presented with decreased FH concertration, in 1 case anti-FH antibody was positive. Their clinical diagnosis was post-streptococcal glomerulonephritis, nephrotic syndrome (NS) nephritis type, and mesangial proliferative glomerulonephritis respectively.

PATHOLOGICAL FINDINGS

All showed evident deposition of C3 on glomerular basement membrance (GBM) and mesangial region by immunofluorescence (IF) and electron dense deposit in GBM, mesangial region or para-mesangial region by Electron microscopic (EM) examination Treatment and prognosis: The case with NS showed no response to steroid, so steroid was gradually stopped after renal biopsy and replaced by angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor antagonist (ARB). The other two cases were treated with ACEI and renal protective treatment. Of the 3 cases, one gradually showed elevated serum creatinine (Scr) and decreased creatinine clearance rate (Ccr), the other two were normal, but slightly increased indications for early kidney injury.

CONCLUSION

C3 glomerulopathy is characterized by evident C3 deposition under IF. Its clinical and pathological manifestations vary a lot. The decreased plasma C3 and FH suggest that the abnormal regulation of complement system play an importment role in its pathogenesis.