Total Lymphocyte Count as surrogate marker for CD4 Cell Count in HIV-Infected Individuals in Gondar University Hospital, Northwest Ethiopia.

BACKGROUND

The high cost of CD4 count estimation in resource-limited countries is a major challenge in initiating patients on highly active antiretroviral therapy (HAART). Therefore, assessment of inexpensive and simple laboratory diagnostic marker is mandatory to diagnose immuno-suppression.

OBJECTIVE

To evaluate utility of total lymphocyte count (TLC) as surrogate marker for CD4 count in HIV-infected patients.

MATERIALS AND METHODS

In this cross sectional study, 400 ART-naive HIV-positive patients enrolled in Gondar University Hospital, from March 2011 to May 2011, were tested for CD4 count & TLC. The cutoffs were determined as: 200 cells/μL for CD4 count and 1200 cells/μL for TLC by using BD FACS count and CELL DYN 1800 Flow Cytometrys respectively. Spearman correlation between TLC and CD4 cell count were assessed. Sensitivity, specificity, positive and negative predictive values for different age a group, TLC ≤1200 was computed for CD4 count ≤200 cells/cu.mm.

RESULTS

Among 400 ART naive HIV infected patients, 278 (69.5%) were females. The mean age of the study participants was 33.7. TLC and CD4 count were positively correlated (r = 0.33, p = 0.001). A TLC of ≤1200 cells/m m3 was found to have a sensitivity (32.86%), specificity (95.33%), PPV (79.7%), and NPV (71.9%) for predicting a CD4 count of <200 cells/mm3.

CONCLUSION

This study showed that low sensitivity and specificity of TLC as a surrogate measure for CD4 count. Moreover, CD4 cell counts of < 200 cells/mm3 were found in 96 cases (24%) with TLCs of ≤1200 cells/mm3. Thus, 1 in 4 individuals would have been deprived of needed treatment. Therefore, we recommend keep on expansion of access to CD4 counter.