Total lymphocyte count and haemoglobin concentration combined as a surrogate marker for initiating highly active antiretroviral therapy in a resource-limited setting as against CD4 cell count

Abstract

Aim: To find a sensitive and low-cost surrogate marker for CD4 count for initiating highly active antiretroviral therapy (HAART) [CD4 < 200 /mm3], in the form of total lymphocyte count (TLC) < 1200 /mm3 combined with haemoglobin (Hb) with multiple Hb cut-offs. Method: Two hundred and three consecutive treatment-naïve adult HIV positive outpatients attending the virology clinic in World Health Organization (WHO) clinical stage 1, 2 or 3 were enrolled in the study. Their complete blood counts and CD4 counts were done. Descriptive statistics was done by two methods correlating TLC alone with CD4 and the other using combined marker of TLC and Hb with CD4 count. Result: Total lymphocyte count alone did not correlate well with CD4 counts (r = 0.13; p = 0.065). Sensitivity of TLC < 1200 /mm3 to predict CD4 < 200 /mm3 was low (23.27%) and the sensitivity of the combined marker (TLC + Hb) increased with higher Hb cut-offs. Conclusion: Adding Hb to TLC markedly improved the sensitivity of the marker to predict CD4 count < 200/mm3. We also recommend a trade-off Hb cut-off of 10.5 g/dL for optimum sensitivity and specificity in this population subset.