Insufficient inactivation of HIV-1 in human cryo poor plasma by beta-propiolactone: results from a highly accurate virus detection method.

Human cryo poor plasma was spiked with high titre HIV-1 and subjected to a beta-propiolactone (beta-PL) inactivation procedure. The residual titre of HIV-1 was measured using a sensitive and accurate titration technique based upon the killing of MT-4 cells by HIV and the subsequent inability to incorporate 3H-thymidine. It was found that under these conditions a reduction of only 1 log virus titre was achieved after one hour exposure to beta-PL and of 1.8 logs after 5 h. The presence of viable HIV was confirmed using immunohistochemical techniques, by transfer of live virus to fresh cells, and by production of reverse transcriptase. These results have obvious implications for products where human plasma is treated with beta-PL as the only virus inactivation step.