[Biological diagnosis of hepatitic C virus infections].
Biological diagnosis of HCV infections consists of a two steps process. The first one is the detection, rarely induced by evocative symptoms, more often subsequent to systematic screenings. Third generation ELISA tests are used for this purpose on account of their high sensitivity. Their enhanced specificity, reaching 99.5%, still has to be checked using complementary tests, especially immunoblots assays. However, these methods may fail to detect specific antibodies during the acute phase of HCV infections or among immunodeficient patients, resulting in discrepancies or indeterminate conclusions. Then, the detection of HCV viremia by PCR is of great value to assert the diagnosis. The second step, before treatment, consists to identify the genotype and to determine the viral load by quantitation of the HCV RNA. Because the endemicity of HCV infections in France, these methods, although difficult an expansive, should be transferred to the medical laboratories, provided their quality and their accessibility will be preserved.
Buisson
Y
Y
Laboratoire de Biologie clinique, Hôpital d'Instruction des Armées Val-de-Gråce, Paris.
Teyssou
R
R
D005838:Genotype; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification*; D006526:Hepatitis C / Q000175:diagnosis*; D006801:Humans; D016133:Polymerase Chain Reaction; D012698:Serologic Tests