Influence of human T-lymphotropic virus type 1 coinfection on the development of hepatocellular carcinoma in patients with hepatitis C virus infection

Human T-lymphotropic virus type 1 (HTLV-1) may worsen the clinical course of hepatitis C virus (HCV) infection. The aim of this study was to investigate whether HTLV-1 coinfection influences the clinical characteristics of patients with HCV infection.

This retrospective study included 523 consecutive patients from January 2001 to December 2010 with chronic liver disease due to HCV infection, in whom serum anti-HTLV-1 antibodies were examined. Among these patients, 265 were diagnosed with hepatocellular carcinoma (HCC).

The seroprevalence of anti-HTLV-1 antibodies was significantly higher in patients with HCC (21.1 %) than those without HCC (10.5 %, P = 0.001). This significant difference was observed in female patients (29.5 vs. 8.5 %, P < 0.001), but not in male patients (16.5 vs. 12.9 %, P = 0.501). In multivariate analysis, anti-HTLV-1 antibody positivity was independently associated with HCC in female patients [odds ratio (OR), 5.029; 95 % confidence interval (95 % CI), 1.760–14.369; P = 0.003], in addition to age (≥65 years; OR, 10.297; 95 % CI, 4.322–24.533; P < 0.001), platelet count (<15 × 10⁴/μL; OR, 2.715; 95 % CI, 1.050–7.017; P = 0.039), total bilirubin (≥1 mg/dL; OR, 3.155; 95 % CI, 1.365–7.292; P = 0.007), and total cholesterol (≤160 mg/dL; OR, 2.916; 95 % CI, 1.341–6.342; P = 0.007). In contrast, HTLV-1 coinfection was not associated with HCC in male patients, although age, alcohol consumption, platelet count, and albumin were independently associated with HCC.

HTLV-1 coinfection may contribute to the development of HCC in patients with chronic HCV infection, especially in females.