Absolute lymphocyte count as a surrogate marker for CD4+ cell count in monitoring of antiretroviral therapy, Northwest Ethiopia: retrospective evaluation

ObjectiveTo determine the use of total lymphocyte count as a surrogate marker for CD4+ cell count among HIV infected patients at the University of Gondar Hospital.MethodsA retrospective cross sectional study was conducted at the University of Gondar Hospital antiretroviral therapy laboratory from December 2011 to May 2012. Data on CD4+ cell count, total lymphocyte count, sex, and age were collected from 2964 HIV infected patients and analyzed using SPSS version 16 computer software.ResultsTotal lymphocyte count was significantly correlated with CD4+ cell count (P<0.001; r2=0.434). The sensitivity, specificity, positive predictive value, negative predictive value of total lymphocyte count<1 200 cells/mm3 to predict CD4+ cell count <200 cells/mm3 was 57.8%, 86.4%%, 34.1%, 86.39%, respectively. A total lymphocyte count<1 000cells/mm3 was found to have suboptimal sensitivity (69.0%), and specificity (85.0%) for predicting a CD4+ cell count <200 cells/mm3.ConclusionsTotal lymphocyte count and CD4+ cell count was positively correlated. Hence, lymphocyte count less than or equal to 1 000/mm3 can be used as a cutoff value in place where there is no CD4+ cell counting machine.