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Background: The second-generation hepatitis C virus (HCV) enzyme immunoassay (EIA 2), an antibody-detection test, has high sensitivity and is one of the recommended screening tests for detecting HCV infection in the United States. However, its sensitivity among oncology patients is unknown.
Objective: Assess the EIA 2 sensitivity among a group of oncology patients at a Nebraska clinic where an HCV outbreak occurred during 2000–2001 using nucleic acid testing (NAT) and recombinant immunoblot assay (RIBA) as the gold standards.
Study design: Serum specimens were collected from patients 16 months after transmission had stopped. We tested the specimens using EIA 2 (Abbott HCV EIA 2.0), a NAT assay based on transcription-mediated amplification (TMA) (Gen-Probe TMA assay) and RIBA (Chiron RIBA® HCV 3.0 SIA). HCV infection was defined as a positive RIBA or TMA test in an oncology patient. Alanine aminotransferase (ALT) levels were determined in EIA 2-negative/TMA-positive samples.
Results: A total of 264 samples were included in the study.We identified 92 HCV infections, 76 of which were Abbott EIA 2 positive. Abbott EIA 2 sensitivity was 83% (76/92), lower than that reported among healthy adults (90%) (p = 0.01) and poor sensitivity was associated with receipt of chemotherapy during the outbreak period (p = 0.02). Only 1 (6%) of the 16 EIA 2-negative cases had elevated ALT.
Conclusions: In this study, EIA 2 sensitivity among oncology patients was lower than that previously reported among immunocompetent persons. Impaired antibody production related to cancer and/or chemotherapy might explain the reduced sensitivity. These findings indicate that, when assessing HCV status in oncology patients, a NAT test should be routinely considered in addition to EIA.