Lot-to-Lot Variation in Anti-Hepatitis C Signal-to-Cut-

Hepatitis C virus (HCV), the most common chronic viral infection in North America, affects an estimated 2.7 mil-lion individuals in the US (1). Hepatitis C is more common in certain populations, including injection drug users, prison inmates, the homeless, dialysis patients, and those seeking care in Veterans Affairs medical centers (2–5). Hepatitis C is the leading cause for end-stage liver complications, including hepatocellular carcinoma and need for liver transplantation; the frequency of these is expected to increase two- to threefold by 2030 (6). Antibodies to HCV (anti-HCV) can indicate one of three possible conditions: current active infection with HCV, past infection with HCV, or a false-positive reaction (7). Although tests are usually interpreted as positive or negative, samples with low-positive anti-HCV results ar