HCV antibodies in Hungarian blood donations. Experiences collected by ELISA tests, immunoblot assays and polymerase chain reaction and protocols for donor management

Abstract

Routine screening of Hungarian blood donors for anti-HCV commenced in the second half of 1992. Before this, five available anti-HCV ELISA kits were compared in pilot studies. In the first series, 831 random donor samples were tested by one of the tests and the 12 (1.4%) reactives found were retested by the other four. Six of the reactives were positive in all ELISA. In the second series, 325 samples from donors with elevated transaminase levels were tested by all five kits. Forty-four were found to be reactive by one or more of the tests and 32 (10%) were positive in all five assays. Samples concordantly reactive in the ELISA were positive in second or third generation recombinant immunoblot assay (RIBA 2 or RIBA 3); those that gave discordant results were indeterminate or negative. Eleven concordantly reactive samples from the second series were HCV RNA positive by polymerase chain reaction (PCR). In the first period of screening with Abbott ELISA 2 a repeat-reactivity rate of 0.98% was observed in 171,106 samples tested. Reactives were retested for supplementary testing by Wellcozyme anti-HCV. Donors reactive in both tests and strongly reactive (ELISA ratio (ER) = optical density/cut off > or = 2.5) in either of them were permanently deferred. Those negative in the supplementary ELISA or weakly reactive (1.0 < or = ER < 2.5) in both tests were subjected to RIBA 2. On the basis of RIBA, positive donors were permanently deferred, indeterminates were excluded for 1 year and negatives were readmitted. In 1992, 1,347 supplementary tests were completed; 824 (61%) of the respective donors were permanently deferred, 218 (16%) were deferred for 1 year and 305 (23%) were readmitted.

False positive viral marker results in blood donors and their unintended consequences

“…One effective strategy is the use of sequential screening IAs whereby donations are screened on a primary IA and, if reactive, screened on a secondary IA . Only samples that are reactive on both IAs are further tested by IB . Another approach, which has been applied to anti‐HCV screening, is to interpret the anti‐HCV status based on the s/co ratio of the screening IA, either without IB testing or only performing IB testing on samples with IA s/co ratios below a predefined value (s/co ratios equal to or greater than this predefined value would be assessed as confirmed positive without IB testing) .…”

True positivity of anti-Hepatitis C Virus Enzyme-linked immunosorbent assay reactive blood donors: A prospective study done in western India

“…In a study done in Hungary, by Hejjas et al . [13] in blood donors, 11 samples out of 32 (34.37%), which were concordantly reactive in five ELISA kits, were positive for HCV RNA by PCR. These results were similar to the present study (30.19% positive by NAT).…”