RESUMO
The presence of HCV RNA in PMBC, with simultaneous absence of the virus in the plasma (7.8%), suggests that blood is better material for HCV RNA detection than plasma or serum in the diagnostic procedures of patients with chronic hepatitis C as well as in monitoring the antiviral therapy. We studied 111 patients with chronic hepatitis C (anti-HCV+) and elevated level of at least one biochemical marker: AST, ALAT, GGT, AP and bilirubin. Inhibition of amplification was 2% in plasma and 34% in whole blood samples. We applied modification of extraction to reduce the inhibitory effect on PCR, by introducing additional purification of the RNA extract in the Chomczynski method. After our modification of extraction was applied, inhibition was reduced to 1%. In attempt to identify such inhibitory markers that would label the samples, in which additional RNA extract purification should be applied, we analysed the activity of AST and ALAT enzymes, the key markers for parenchymal liver damage; GGT and AP, the markers for cholestatic hepatitis as well as bilirubin. We observed that the increased GGT and AST activities were correlated with the inhibition of RT-PCR. This correlation was statistically significant; for AST (Mann-Whitney test p = 0.09654 and Kolmogorow-Smirnow test p = 0.01543) and for GGT (Mann-Whitney test p = 0.02419 and Kolmogorow-Smirnow test p = 0.01921).
