Abstract
Background: In resource-limited settings, laboratory assessment of HIV-infected individuals requires the consideration of simple markers for the initiation and monitoring of HAART. Absolute lymphocyte count (ALC) could serve as a simple cost-effective tool for determining when to initiate ART in resource-constrained settings.
Objective: To determine the possibility of using absolute lymphocyte count as a surrogate marker for CD4+ cell count for the initiation of antiretroviral therapy (ART) in resource-limited settings.
Methods: Blood samples from 273 symptomatic HIV-positive individuals aged 18 to 57 years (33.3% males, 66.7% females) who presented for assessment for ART-eligibility were analyzed for CD4 count by flow-cytometry and ALC by automated haematology cell counter. Spearman rank correlation between CD4 count and ALC was assessed and positive predictive value (PPV), negative
predictive value (NPV), sensitivity and specificity of varying ALC cutoffs were computed for CD4 counts <200 cells/μL and <350 cells/μL.
Results: High degree of correlation was noted between CD4 and ALC counts (r = 0.71, p<0.0001). PPV, NPV, sensitivity, and specificity maximally aggregated at ALC <1400 cells/μL for CD4 <200 cells/μL and ALC <2300 cells/μL for CD4 <350 cells/μL. ALC <1400 cells/μL had a 90% PPV, 87% NPV, 86% sensitivity and 90% specificity for CD4 counts <200 cells/μL. ALC <2300 cells/μL had 89% PPV, 51% NPV, 83% sensitivity and 62% specificity for CD4 counts <350 cells/μL.
Conclusion: Our results have demonstrated the capability of absolute lymphocyte count to serve as a surrogate marker for CD4+ cell count for the initiation of antiretroviral therapy (ART) in resource-limited settings.
Key words: Absolute lymphocyte count, CD4+ cell count, antiretroviral therapy, resource-limited settings