Monitoring the response to antiretroviral therapy in HIV-1 group O infected patients using two new RT-PCR assays

Failure to recognise infection caused by human immunodeficiency virus type 1 (HIV-1) group O variants has been described using both serological and ge netic procedures. Moreover, monitoring the response to antiretroviral thera py is a difficult task in patients infected with HIV-1 group O since commer cial tests are not available so far for the quantitation of this virus. in this study, the virological response to antiretroviral therapy were assesse d in five HIV-1 group O-infected patients living in Spain by using two new and different RT-PCR methods (MUPROVAMA and LCx). Twenty-four plasma sample s belonging to these five patients were selected. As reference, p24 antigen aemia levels and CD4+ cell counts were used. All samples yielded positive v iral load values using MUPROVAMA (range: 138 to 595,500 HIV-RNA copies/ml) and 23 of 24 using LCx (range: < 178 to 98,356 HIV-RNA copies/ml). Overall, the results obtained using both assays showed a good correlation among the mselves, and in respect to p24 antigenaemia and CD4+ cell counts. However, the values provided by LCx were significantly lower (0.33 logs on average) than those provided by MUPROVAMA. In conclusion, both the highly sensitive MUPROVAMA and LCx Quantitative assays might represent an useful tool for gu iding the decision on when start treatment and for monitoring the response to antiretroviral therapy in HIV-1 group O-infected patients. J. Med. Virol . 64:217-222, 2001. (C), 2001 Wiley-Liss, Inc.