Prevalence of Active Hepatitis C Virus Infection in Patients with Systemic Lupus Erythematosus

Hepatitis C virus (HCV) infection is associated with various autoimmune disorders and can mimic systemic lupus erythematosus (SLE) clinically and serologically. There are few reports of prevalence of HCV infection in patients with SLE. The aim of this study was to determine the prevalence of HCV viremia by polymerase chain reaction (PCR) in patients with SLE. We tested sera from 40 consecutive patients with SLE collected from1993 to 2000. All of the patients had HCV viral load measured by PCR. The results were compared with the prevalence of HCV viremia in a control group of blood donors in our geographic area as well as in United States general population. HCV was detected in 4 of 40 patients (10%). The prevalence of HCV in our area blood donors is 130 cases per 100,000 persons (0.13%; P < 0.0001). The prevalence of HCV infection in the United States general population, screened by PCR, is 1330 cases per 100,000 people (1.33%; P = 0.002). The prevalence of HCV infection was significantly higher in our SLE patients than in our area blood donors. The frequency of HCV infection was also higher than that of the United States general population. Our observations support those of other investigators who have reported an increased prevalence of HCV infection in SLE patients. Further detailed investigation of this association may help in understanding the pathogenesis of SLE. HCV infection should be tested when the diagnosis of SLE is considered.