An association between chronic hepatitis C virus (HCV) infection and fibromyalgia (FM) remains controversial, mainly because previous studies were based on prevalent case series or comparisons with less than optimal control groups. We investigated whether there might be an association between chronic HCV infection and FM.
We prospectively investigated the prevalence of HCV infection in a series of 115 patients with FM and compared it with the prevalence in the general population of our community reported in the same period. Anti-HCV antibodies were determined by ELISA. In positive cases, infection was confirmed by recombinant immunoblot assay and HCV-RNA was detected by PCR using sera samples. Differences between prevalence rates were assessed by chi-square test.
HCV infection was confirmed in 3 of 115 patients with FM (2.6%). Two of these patients (1.74%) had active HCV infection shown by the presence of viral RNA in serum, whereas HCV RNA was undetectable in the third patient. In these cases, liver disease had previously been undiagnosed and HCV infection manifested itself by extrahepatic symptoms. Although the prevalence of HCV infection was slightly higher in patients with FM than in the general population in the age groups 25-44 and 45-64 years, when we compared prevalence rates in the total group and the different age groups, no statistically significant differences were found.
From our results, it seems unlikely that HCV infection plays a pathogenic role in FM.