RESUMO
BACKGROUND/AIM: The immunopathogenesis of occult Hepatitis C virus (HCV) infection is a matter of great controversy and has been suggested to involve a complex balance between cytokines with pro- and anti-inflammatory activity. This work aimed at studying the serum Th1 and Th2 cytokine production in patients with occult HCV infection. MATERIALS AND METHODS: Serum levels of cytokines of Th1 (interleukin [IL]-2, INF-γ) and Th2 (IL-4) were measured in 27 patients with occult HCV infection and 28 patients with chronic hepatitis C infection. RESULTS: The levels of IL-2 and interferon-γ were highly significantly increased in patients with chronic HCV infection (P<0.001). IL-4 was highly significantly increased in occult HCV infection (P<0.001). Significant increases were noted in chronic HCV infection regarding bilirubin (P<0.001), ALT (P = 0.009), AST (P = 0.013), AFP (P<0.001), while serum albumin was significantly higher in occult HCV infection (P<0.001). Necroinflammation (P<0.001), fibrosis (P<0.001), and cirrhosis (P = 0.03) were significantly increased in chronic HCV infection. CONCLUSION: Our data revealed a high prevalence of occult HCV infection (25%) in patients with unexplained persistently abnormal liver function test results. Those patients exhibited a distinct immunoregulatory cytokine pattern, favoring viral persistence and explaining the less aggressive course of this disease entity than chronic HCV infection.