Predictors of viral load response in triple therapy with protease inhibitor in HIV infected patients

As many factors may be involved in therapeutic response to triple therapy with protease inhibitor (PI), the aim of this study was to determine the influence of epidemiological factors (sex, risk factors), clinical status (previous number of AIDS defining events), immunological status (baseline CD4 T cells count), virological factor (baseline viral load), previous antiretroviral therapy and duration of AZT therapy (> or < 6 monts), number of prescribed reverse transcriptase inhibitors (RTI), therapeutic strategy (switch to different RTI or only addition of PI) and compliance, on early virological response (M2-M3) after initiation of triple therapy with PI. These results concerned 167 patients treated with triple therapy including PI. A viral load response was defined in three types : complete response (undetectable : < 500 copies/ml) for 100 patients; partial response (significant decrease: > 0,5 log from baseline) for 30 patients and no response for 37 patients. Only two parameters were associated of good virological response: no previous antiretroviral therapy (p < 0,001) and good compliance (p < 0,001). No significant difference was observed between patients with no prior therapy and pretreated patients, in terms of median baseline CD4 count and observance. The baseline median viral load was higher in naive patients despite a better response. In pretreated patients, the type of response appeared to be dependent on the duration of AZT treatment (p = 0,06) and good compliance (p = 0,06). Among the 100 patients with initial complete response, only 23/81 were still undetectable after a median of 13 months of therapy.