Background: Hepatitis C virus (HCV) infection is associated with multiple extrahepatic manifestations. It is unclear to what extent extrahepatic manifestations occur in HIV/HCV coinfection.
Methods: We prospectively assessed cross-sectional frequencies of autoimmune manifestations in HIV/HCV-coinfected patients (n=98), HIV-mono-infected (n=45) and HCV-mono-infected patients (n=78). Diagnostic vasculitis scores, HCV and HIV loads, CD4 cell counts, thyroid-, cardiolipin-, non-organ-specific tissue antibodies (nuclear, smooth muscle, anti-liver-kidney-microsome, neutrophil-cytoplasmic) and cryoglobulins were determined.
Results: Synergistic effects of HCV and HIV infection were observed with respect to the prevalence of antibodies against thyroglobulin (HCV infection 15.4%, HIV infection 8.8%, HIV/HCV coinfection 30.6%; P<0.001) and cardiolipin antibodies (HCV infection 9.0%, HIV infection 31%, HIV/HCV coinfection 46%; P<0.001). Cryoglobulinemia type III, was significantly associated with HCV infection (HCV, 25.6%; HIV/HCV, 20.4%) but not with HIV infection (4.4%, P<0.05). Rheumatoid factor was commonly detected in patients with HCV infection (48%), but occurred considerably less frequently in patients with HIV infection (4.4%) or HIV/HCV coinfection (9.5%, P<0.01).
Conclusion: HIV coinfection appears to differentially modulate the frequency of HCV-related autoimmunity. However, autoimmunity is rarely accompanied by clinical manifestations.