Absolute Lymphocyte Count as a Surrogate Marker of CD4 Count in Monitoring HIV Infected Individuals: A Prospective Study EC17-EC19
Dr. Preeti Balkisanji Agrawal,
H.NO.174/A, P Road, Bhupalpura, Udaipur-313001, Rajasthan, India.
Introduction: CD4 cell count has been proposed to be substituted by Absolute lymphocyte count in monitoring HIV infected individuals as methods of CD4 cell count and plasma viral estimation require expensive, specialized equipments and highly trained personnel.
Aim: To assess the clinical utility of the Absolute Lymphocyte Count (ALC) to serve as a surrogate marker for predicting a CD4 count < 200 cells/µl in patients with HIV infection in resource poor countries.
Materials and Methods: A prospective study of 61 patients with HIV/AIDS was conducted. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) of various ALC cut-offs were computed for CD4 cell count < 200 cells/µl for age < 30 or age = 30 years. Pearson correlation, Linear regression and Receiver Operating Characteristics (ROC), were used.
Results: For patients aged = 30 years, sensitivity, specificity, positive and negative predictive value of ALC <1200 cells/µl to predict CD4 cell count < 200 cells/µl were 34.48%, 67.5%, 43.48%, 58.69% respectively. For subjects aged < 30 years, these values were 27.27%, 67.5%, 18.75%, 77.14%, respectively. A ALC < 1643 was found to have maximal sensitivity for predicting a CD4 cell count <200/ µl.
Conclusion: Our data revealed good correlation between ALC and CD4 cell counts but ALC cut-off of 1200 was not a surrogate marker for CD4 cell count < 200 cells/µl. As we increase the cut-off to <1643/ µl it could be the cost-effective surrogate marker for CD4 cell counts < 200 cells/µl in resource limited settings.