Absolute lymphocyte count: A useful surrogate marker to initiate anti retroviral therapy in resource poor settings.

Abstract

ObjectiveInitiation of anti retroviral therapy (ART) is routinely based on the algorithms that combine CD4, HIV load and clinical illness. But their high cost and unavailability at resource poor settings are one of its major limitations. An attempt has been made to find a correlation between CD4 count and Absolute lymphocyte count (ALC) so that timely initiation of ART could be done in peripheral areas of developing countries where automation and established technologies have not been reached. MethodsThis cross sectional study included 200 patients between 18-60 year of ages who are HIV seropositive with and without clinical evidence of oral candidiasis (100 case; 100 control). ALC was calculated as per the percentage of lymphocyte in total leukocyte count as seen in peripheral smear. CD4 cell count estimation was done by flow cytometry method. ResultsA good correlation was found between CD4 count and ALC in both cases (R=0.656) and controls (R=0.642). There was an increase in sensitivity (St) and decrease in specificity (Sp) of predicting CD4 count <200 cells/mm3 and < 350 cells/mm3 as the cut off value for ALC increased. ALC cut off value of 1700 cells/mm3 is likely to be the best predictor of CD4 count of < 200 cells/mm3 and ALC cut off value of 1800 cells/mm3 for CD4 count <350 cells/mm3. ConclusionsWe recommend the use of ALC as a surrogate marker for or in combination with CD4 count to determine when to start therapy and to enable routine monitoring in resource poor settings .