COMPARISON OF QUANTITATIVE CDNA-PCR WITH THE BRANCHED DNA HYBRIDIZATION ASSAY FOR MONITORING PLASMA HEPATITIS-C VIRUS-RNA LEVELS IN HEMOPHILIA PATIENTS PARTICIPATING IN A CONTROLLED INTERFERON TRIAL

The branched DNA (bDNA) assay was compared with a semi-quantitative cD NA-polymerase chain reaction (cDNA-PCR) assay for monitoring HCV RNA l evels in plasma in 17 haemophilia patients participating in a controll ed cr-interferon trial. Good correlation between the HCV RNA levels as detected by the two assays was observed, with a correlation co-effici ent of 0.83 (P < 0.0001) and 0.90 (P < 0.0001) at week 0 and 24, respe ctively. Hepatitis C virus RNA (HCV RNA) levels could be assessed with the bDNA assay in 14/17 (82 percent) HCV cDNA-PCR positive pretreatme nt samples. The bDNA assay apparently failed to detect low viral titre s. Interferon treated patients (n = 11) showed either a complete respo nse, being a large reduction in HCV RNA level to below the detection l imit of the HCV cDNA-PCR assay (6/11) or no significant reduction in H CV RNA level (5/11). A ''partial'' virological response was not observ ed. The changes in HCV RNA plasma levels in non-responders during inte rferon (IFN) treatment were similar to the (small) natural fluctuation s in viral load observed in controls (untreated patients). Although th e bDNA assay was not as sensitive as cDNA-PCR, given its user friendli ness and quantitative results, it is concluded that it is a useful tes t for monitoring HCV RNA levels in patients treated with interferon. H owever, patients who are nonreactive in the bDNA assay have to be rete sted by cDNA-PCR because low viral titres are not detected by the bDNA assay. (C) 1994 Wiley-Liss, Inc.