Long-term Follow Up of Viral Hepatitis in Uremic Patients in Taiwan

Patients are prospectively recruited from 15 hemodialysis units including one medical center, 3 satellite hospitals and 11 local clinics in Taiwan. Patients who provided informed consents for blood tests including genetic study related to HCV spontaneous seroclearance are enrolled for analysis. All the eligible subjects are tested for both HCV antibodies (third-generation, enzyme immunoassay; Abbott Laboratories, North Chicago, IL) and hepatitis B surface antigen (HBsAg). HCV RNA is tested by polymerase chain reaction (Cobas Amplicor Hepatitis C Virus Test, V.2.0; Roche Diagnostics, Branchburg, New Jersey, USA; detection limit: 50 IU/ml) twice for at least 6 months apart if anti-HCV is positive to ensure chronicity of HCV infection. HBsAg is quantified with the use of a standard quantitative chemiluminescent microparticle immunoassay (ARCHITECT HBsAg, Abbott Diagnostics). The concentration of HBsAg in the specimen is determined using a previously generated Architect HBsAg calibration curve (range, 0.05-250 IU/mL). Samples with serum HBsAg titer >250 IU/mL were diluted at 1:20 and 1:500 with the Architect HBsAg diluent and retested to expand the upper limit of the dynamic range from 250 to 125,000 IU/mL. Serum HBV DNA is determined by a standardized automated quantitative PCR assay (Cobas Amplicor HBV Monitor; Roche Diagnostics; detection limit 200 copies/ml) if patients are seropositive for HBsAg.