Virologic and immunologic response to nucleoside reverse-transcriptase inhibitor therapy among human immunodeficiency virus-infected infants and children

Plasma human immunodeficiency virus RNA and CD4 lymphocyte response to nucl eoside reverse-transcriptase therapy were evaluated in a large, comparative pediatric trial. Both baseline values and changes in the two laboratory ma rkers over time correlated well with clinical outcome and possessed indepen dent predictive value. In comparison of RNA reduction from baseline between the dideoxyinosine (ddI) and zidovudine+ddI therapeutic arms, marginal sup eriority of the combination arm was not correlated with an observed clinica l benefit. Despite the size of this trial and the significantly higher rate of clinical end points in the zidovudine monotherapy group, attempts to es tablish surrogacy for plasma RNA were difficult. Nevertheless, plasma RNA a nd CD4 lymphocyte count together possess strong clinical predictive power a nd are valuable tools for both the clinician and the evaluation of new ther apies.