[Sensitivity studies on the demonstration of HIV-1 particles using RT HIV-1 PCR in pooled plasma before virus...

The goal of this study was the establishment of a reverse-transcription polymerase chain reaction (PCR) test and the evaluation of its sensitivity to detect an HIV-1 contamination in pooled plasma samples prior to the solvent-detergent (SD) inactivation procedure. Pooled plasma samples were spiked with known concentrations (1,000-0.1 TCID50/ml) of HIV-1, originated from tissue culture supernatants. Unspiked plasma samples were used as negative controls. After reverse transcription, a PCR in 4 different HIV-gene regions (gag, pol, env, ltr) followed by a hybridisation with specific probes was done. The achieved sensitivity in 3 tests (pol. gag, ltr) was 0.1 TCID50/ml and 1.0 TCID50/ml in the env-PCR system. It was shown in previous studies that by inactivation of pooled plasma with the SD technique a reduction of HIV-1 infectivity greater than 10(6) is achieved. The combination of PCR testing and the SD inactivation procedure makes it possible for the first time to define the maximum amount of contaminating HIV-1 in case of a negative PCR result. According to this procedure, the residual HIV-1 load of virus-inactivated plasma would not exceed 1 TCID50 per 1,000 litres at worst.