Received February 19, 2008
Accepted on June 20, 2008

ORIGINAL ARTICLES

Clinicopathologic Correlation and Outcome of C1q Nephropathy

Satoshi Hisano ^*1, Yuko Fukuma , Yoshie Segawa , Kazuhiko Niimi , Yoshitsugu Kaku , Ken Hatae , Takao Saitoh , Morishige Takeshita ^*, and Hiroshi Iwasaki ^*

Department of *Pathology and Pediatrics, Faculty of Medicine, Fukuoka University, Fukuoka, Japan; Division of Nephrology and Rheumatology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan; and Department of Nephrology, Fukuoka Municipal Children’s Hospital, Fukuoka, Japan

¹ To whom correspondence should be addressed. E-mail: hisanos1{at}cis.fukuoka-u.ac.jp.

	Abstract

Background and objectives: The number of patients with C1q nephropathy (C1qN) in previous reports is small and the duration of follow-up is short. Our study describes the clinicopathologic correlation and clinical outcome through the mean follow-up period of 7.2 yr in 61 patients.

Design, settings, participants, & measurements: Sixty-one patients, 1 to 67 yr of age, with C1qN were enrolled in this study.

Results: According to presentation at onset, patients were divided into two groups: asymptomatic urinary abnormalities (asymptomatic) (n = 36) and nephrotic syndrome (NS) (n = 25). Light microscopy showed minimal change disease (MCD) in 46 patients (75%), mesangial proliferative glomerulonephritis in 7 (12%), and focal segmental glomerulosclerosis (FSGS) in 8 (13%). The prevalence of MCD was higher in the NS group than in the asymptomatic group. Nine patients in the asymptomatic group and all patients in the NS group were treated with prednisolone and/or cyclosporine. Normal urinalysis was found in 10 patients in asymptomatic group and 8 in NS group during the follow-up. Thirteen patients in the NS group were frequent relapsers at the latest follow-up. Three patients with FSGS developed chronic renal failure 8 to 15 yr after the diagnosis. C1q deposits disappeared in 3 of 8 patients receiving repeat biopsy, and 2 of these 3 showed FSGS.

Conclusions: The prognosis of C1qN is good, associated with MCD in a large number. In some patients, C1q deposits disappear through the follow-up period. FSGS may develop in some patients on repeat biopsies. Further investigation is critically needed to settle this issue.