Effects of concomitant hepatitis C virus infection in patients with underlying lupus nephritis on long-term renal outcome

Abstract

Despite recent advances in the management of lupus nephritis (LN), these unfortunate patients are at a higher risk of developing chronic kidney disease (CKD). Concomitant chronic hepatitis C virus (HCV) infection is associated with adverse outcome in patients with LN and further compounds the risk as some of these patients choose to undergo kidney transplantation in the near future. Objectives. The aim of the present study is to evaluate the long-term impact of chronic HCV infection in patients with underlying Class IV LN on renal function, progression to end-stage renal disease (ESRD) and patient survival. Retrospective analysis of the medical records of 134 nondialysis-dependent patients with biopsy-proven World Health Organization Class IV LN with chronic HCV infection was done from January 1995 to January 2008 at King Khalid University Hospital, Riyadh, Saudi Arabia. Primary and the secondary end points were death or the development of ESRD. The patients were followed over a period of 6.7 ± 3.3 (1-14.4) years. From a total of 134 biopsy-proven Class IV LN patients, 15 (11.2%) patients were HCV positive of which 2 (13.3%) patients were male and 13 (86.7%) patients were female. One hundred and nineteen (88.8%) patients were HCV negative of which 17 (14.3%) were male and 102 (85.7%) were female. The mean age was 32.47 ± 11.8 years. Eight (53.3%) patients in the HCV-positive group versus 19 (22.6%) patients in the HCV-negative group progressed to severe renal impairment with serum creatinine >350 μmol/L (P = 0.024). A total of 8 (53.3%) patients in the HCV-positive group versus 18 (17.3%) in HCV-negative group progressed to ESRD (P = 0.005). The mean creatinine clearance was higher (43.3 ± 33 mL/min) in the HCV-negative LN group at last follow-up than in the HCV-positive patients (25 ± 34.9 mL/min) with a statistically significant P-value of 0.0463. Five patients (33.3%) with HCV-positive LN died in comparison to eight (7.6%) patients who were HCV negative P = 0.03; however, the cause of hospital mortality was mainly cardiovascular disease (CVD) and infection and none of the patients died of chronic liver disease, although there was significant deterioration of the liver function at the end of the study. Kaplan-Meier survival estimates showed a significantly inferior renal function and rapid deterioration to ESRD in LN patients with concomitant HCV infection, with a dialysis free survival of 95 and 80% for the HCV-negative group and 90 and 65% for the HCV-positive groups at the end of 5 and 10 years respectively, with a highly significant P-value of <0.05 at the end of 10 years. The present study highlights that concomitant HCV infection in patients with LN is associated with worse renal outcome, higher rate of progression to ESRD and reduced patient survival.