Abstract:

Ｏｂｊｅｃｔｉｖｅ：To explore the clinical and patholgical features of C3 glomerulonephritis（C3 GN） associated with monoclonal gammopathy from Chinese patients．
Ｍｅｔｈｏｄｏｌｏｇｙ：From March 2004 to May 2015，patients who were diagnosed as C3 GN and meanwhile with a monoclonal immunoglobulin in serum were selected and their clinical and pathological features were retrospectively analyzed.
Ｒｅｓｕｌｔｓ：Seven patients with C3 GN had evidence of a monoclonal immunoglobulin in serum. Patients were 5 males and 2 female with age 4465 years old．All of them had proteinuria with 104-734 g/d of urine protein excretion. Microscopic hematuriawas observed in 6 patients, elevated serum creatine（SCr） in 3 patientshypertension, hypertension in 6 patients, low serum complement C3 in 4 patients, and complement C4 was normal in all patients. No abnormalities were found for serum C3 nephritic factors（C3NeFs）, Factor H and anti factor H antibody. The most common monoclonal gammopathy was IgG  λ（3 patients）.Other gammopathies included IgG κ(2 patients), IgA λ（one patient）, and light chain κ(one patient). Elevated plasma cells were observed in 2 of 6 patients. Membranoproliferative GN was presented in all patients. Two patients with abnormal plasma cells received Thalidomide plus Dexamethasone, of whom, one achieved a longtime complete remission in renal disease, and one had progression in kidney disease. The other 5 patients received either Tripterygium wilfordii and/or prednisone, of whom, one lost the followup, 4 had improvement in urine analysis,3 had stable renal function.
Ｃｏｎｃｌｕｓｉｏｎ：Monoclonal gammopathy was a predominant cause of C3 GN in the older patients. Pattern of pathological injury was membranoproliferative. Immunodepressive therapy may be effective, but the key point of therapy should be targeting monoclonal gammopathy.