Absolute lymphocyte count as a surrogate marker for CD4 counts after six months of HAART initiation in a resource-limited setting in India.

ABSTRACT

Background & objectives: Owing to the ever-expanding access to HAART (highly active anti-retroviral therapy) in resource-limited settings, there is a need to evaluate alternate markers like absolute lymphocyte count (ALC) as a surrogate for CD4 counts. This study was done to assess the usefulness of ALC as a surrogate marker for CD4 counts in monitoring HIV-infected patients after HAART initiation. Methods: In this study, 108 HIV-positive adult patients of both sexes fulfilling the inclusion criteria were included. CD4 and ALC were recorded at baseline. After initiation on HAART, these patients were followed up at three month intervals. Results: ALC and CD4 counts were positively correlated (Spearman correlation coefficient= 0.553). After six months of HAART, the sensitivity of an ALC increase as a marker for CD4 count increase at six months was 82 per cent, specificity was 100 per cent, PPV was 100 per cent and NPV was 31 per cent. Area under the corresponding ROC curve for CD4 increase of >100 cells/μl was 0. 825 ± 0.053. Interpretation & conclusions: ALC may be a useful surrogate marker in predicting an increase in CD4 counts as a response to HAART, but of questionable value in predicting a decrease in CD4 counts.