Expression and clinical significance of antinuclear antibody in hepatitis C virus infection

Background: The prevalence of antinuclear antibody (ANA) has been documented in patients with hepatitis C virus (HCV) infection. We attempted to determine the titer and to characterize the patterns and clinical significance of ANA in HCV infection. Study: Forty-eight consecutive patients with positive anti-HCV antibody and positive HCV RNA were included in this study. Sera from patients were tested for ANA and anti-smooth muscle antibody by indirect immunofluorescence. Serum aminotransferase, alkaline phophatase, alpha-fetoprotein, and cryoglobulin levels also were determined. Results: Eleven (23%) of 48 HCV-infected patients were positive for ANA. Antinuclear antibody revealed speckled pattern in 10 (91%) of the 11 ANA-positive HCV-infected patients. Twenty (54%) of 37 ANA-negative HCV-infected patients had detectable pattern with equivocal titer (titer <1.5). The ANA pattern was speckled in all 20 patients. Hepatitis C virus-infected patients with positive ANA were older than the HCV-infected patients with negative ANA (62.90 ± 11.05 years vs. 56.46 ± 14.94 years, respectively; p < 0.1). Serum levels of aspartate aminotransferase (39.36 ± 14.98 IU/L vs. 30.70 ± 23.15 IU/L, p < 0.05), alkaline phosphatase (189.00 ± 75.63 IU/L vs. 122.41 ± 40.88 IU/L, p < 0.01), and alpha-fetoprotein (47.72 ± 80.47 pg/dL vs. 7.00 ± 8.28 pg/dL, p < 0.01) were higher in ANA-positive HCV-infected patients than in ANA-negative HCV-infected patients, respectively. There were no significant differences in gender, alanine aminotransferase, anti-smooth muscle antibody, or cryoglobulin between the two groups. Conclusions: Antinuclear antibody was present in 11 (23%) of 48 patients with HCV infection in our study. Speckled pattern is the major expression pattern of ANA in HCV infection. Antinuclear antibody-positive HCV-infected patients have significantly higher serum aspartate aminotransferase, alkaline phosphatase, and alpha-fetoprotein levels than ANA-negative HCV-infected patients.