[Investigation of HBV-DNA using the polymerase chain reaction (PCR) in HBsAg-negative, anti-HBc-positive Venezuelan donors].

Objective: In our Center the disposal of blood with HBV positive markers is approximately 6%, being 90% AgsHB negative and anti HBc positive. With the purpose of knowing the infected capacities of these donations and to consider the possibility of using them for transfusion, the presence of the viral genoma was investigated by PCR, in a group of samples with these characteristics that were also anti sHB positive. They were correlated with the readings of the anti cHB total, with the anti cHB-IgM and with the titration of the anti sHB.

Materials And Methods: 87/100 random samples, from February to June 1996, were frozen at -30 degrees C for their later evaluation. In the serological screening were used Auszyme Monoclonal of Abbott and the Heprofile anti cHB, ADI-Diagnostic. The readings of the anti cHB was considered strong, moderate or weak according to its distance to the cut off. For the determination of the anti sHB, Hepanostika anti sHB, Organon Technika was used. They were considered with low titers (< 10 UI/L), high (> or = 10 UI/L) and very high (> or = 100 UI/L). In the determination of the anti cHB-IgM, Heprofile ADI-Diagnostic was used. For the investigation of the viral genoma, it was carried out with double PCR-ADN, using two internal and two external primers for the core-precore region.

Results: 70/87 (80.45%) of the samples presented high readings of anti cHB with high titers of anti sHB, being positive for anti cHB-IgM seven of them and one was HBV-ADN positive (1.42%) suggesting the possibility to be cronic carrier. In the remaining 19.55% of the samples we didn't detect positive results in the amplification assays.

Conclusions: 1. The donors showed high levels of immunocompetence. 2. High titer of anti sHB doesn't guarantee the absence of viral genoma and therefore the absence of infectivity can not be sure. This doesn't allow us to come in like donors neither to use their blood in the transfusional therapy.