2007, Number S2
Gac Med Mex 2007; 143 (S2)
Contreras-Navarro AM, Tornero-Romo CM, Orozco-Hernández A, Hernández-Lugo MI, Romero-Flores P, Celis RA
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ABSTRACTThe hepatitis C antibody (anti-HCV) is the screening test used for the hepatitis C virus (HCV) infection. Recently, the following antibody characteristics were described: (a) it is a semiquantitative test expressed by the S/CO ratios, (b) has high repeatability between duplicates, (c) the S/CO ratios of the anti-HCV vary due to the generation and immunoenzymatic methods, (d) true and false results of the antibody and its association with the S/CO ratio, and (e) the high level of the S/ CO ratio is a serologic marker for viremia. A reactive unique test is enough to conclude reactivity in the screening of HCV infection. We propose a new screening strategy using the Abbott MEIA AxSYM® HCV, Ortho ChLIA VITROS® HCV and Abbott ChLIA PRISM® HCV immunoassays. These new diagnostic strategies for hepatitis C use the level of the S/CO ratio to choose the supplemental test (RIBA or HCV RNA) to confirm the hepatitis C diagnosis with an optimal costeffectiveness strategy. The low positive levels of S/CO ratio predict false positive results in the antibody and the high level is associated with true positive results. It is also a serological marker for viremia. These levels are specific for each immunoassay due to differences between methods. Notification of the screening test results should be modified to include reactivity (and avoid the interpretation as positive or negative), generation and immunoassay methods, the level of S/CO ratio and the interpretation guidelines for each immunoassay with the reflex supplemental testing. The application of these guidelines will reduce costs increasing the efficiency of the screening and diagnostic strategies for hepatitis C.