The role of resistance characteristics of viral strains in the prediction of the response to antiretroviral therapy in HIV infection.
OBJECTIVE
To study the role of resistance characteristics of viral mutants in the prediction of virologic and immunologic response to antiretroviral therapy in HIV-infection.


METHODS
This study is based on a mathematical model that generates viral and immunologic dynamics of HIV infection, taking into account drug-resistant mutants and therapy. We analyzed predictive factors of the increase in CD4 cell count and of the decrease in viral load from baseline after 6 months of HAART on a sample of 300 simulated individuals. The set of potential predictors was constituted by patients' state at initiation of therapy and by resistance characteristics of viral strains at that time. Predictive models, obtained by stepwise regression, were selected and compared using Mallows' Cp criterion.


RESULTS
In addition to baseline viral load and CD4 cell count, known to influence response to therapy, baseline CD8 cell count and resistance characteristics of detectable strains are shown to improve the accuracy of the prediction. On the contrary, resistance parameters of low frequency viral mutants have no predictive value.


CONCLUSIONS
Characteristics of preexisting detectable resistant mutants as determinants of virologic and immunologic response to antiretroviral therapy increase the capacity to predict the outcome of the treatment. Therefore, the use of phenotypic and genotypic testing could be crucial and should be considered for the choice of therapy.
Vergu
Elisabeta
E
INSERM U436, Mathematical and Statistical Modeling in Biology and Medicine, CHU Pitié-Salpêtriére, Paris, France. eve@biomath.jussieu.fr
Mallet
Alain
A
Golmard
Jean-Louis
JL
D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D024882:Drug Resistance, Viral; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D006801:Humans