Impact of mixed cryoglobulinemia on patients with spontaneous hepatitis C virus clearance: A 13-year prospective cohort study.

BACKGROUND: The prevalence and associations of mixed cryoglobulinemia (MC) in patients with spontaneous clearance of hepatitis C virus (HCV) remain elusive. MATERIALS AND METHODS: A 13-year prospective cohort study of patients with spontaneous HCV clearance was conducted in a tertiary care centre. Baseline characteristics, incident cardiovascular and neurologic events and cancers were analysed. RESULTS: Of 104 consecutive patients (mean age: 54.08 years old; females: 71 [68%]), 37 (34.6%) had MC and 6 (5.8%) had cirrhosis. MC (+) patients were more female (86% vs 58%, P = .002), had higher rate of cirrhosis (14% vs 1.5%, P = .012), higher levels of Immunoglobulin G (IgG; P = .001), IgM (P = .002) and fibrosis-4 (FIB-4) (P = .004), but lower levels of complement C4 (P = .034) than the MC (-) patients. Female gender (95% confidence interval [CI] of odds ratio: 1.402-26.715), levels of IgG (1.000-1.004), IgM (1.009-1.037) and FIB-4 (1.217-3.966) were independently associated with MC. Baseline rheumatoid factor (RF) levels were independently associated with incident cancer (95% CI hazard ratio [HR]: 1.001-1.030 [HR: 1.015], P = .039). With a cut-off value of 11.3 IU/mL, RF levels significantly predicted incident cancer (area under curve: 0.865, P = .002). No different cumulative incidences of cardiovascular and neurologic events, cancers or mortalities were identified between MC (+) and MC (-) patient. CONCLUSIONS: Approximately 1/3 of patients with spontaneous HCV clearance yielded MC, which harboured similar characteristics of MC in patients with chronic hepatitis C. Despite the negligible role of MC in the prognosis of patients with spontaneous HCV clearance, the connection between RF and incident cancer demands further investigation.