Utility of total lymphocyte count as a surrogate for absolute CD4 count in the adult Indian HIV population: A prospective study

Abstract

Background:Standard methods of CD4 counts and plasma viral load estimation require specialized equipment, highly trained personnel and are extremely expensive. This remains a major challenge for the initiation of anti-retroviral therapy for patients in resource-limited settings.Objective:To assess the clinical utility of the total lymphocyte count (TLC) to serve as a surrogate marker for predicting a CD4 counts <350 cell/mm3 in patients with HIV.Materials and Methods:A prospective study of 200 consecutive newly detected highly active anti-retroviral therapy (HAART) naïve HIV patients admitted over a one year period was conducted. Linear regression, Pearson correlation and receiver operating characteristic (ROC) curves were used to calculate the relationship between TLC and CD4 counts.Results:A significant correlation between TLC and CD4 count was observed (r = 0.682, P < 0.001). TLC cut off of 1200 cell/mm3 as a predictor of CD4 count <350 cell/mm3 had 73.1% sensitivity, 100% specificity, 100% positive predictive value (PPV) and 51.4% negative predictive value (NPV). Raising the cutoff to 1500 cells/mm3 improved the sensitivity to 82.1% with 88.2% specificity, 96.5% PPV, 44.4% NPV. The ROC curve demonstrated highest area under curve (AUC = 0.8) for TLC of 1500 cell/mm3.Conclusion:The study showed that TLC cutoff value of 1500 cells/mm3 was a cost effective surrogate marker for CD4 counts <350 cells/mm3 in resource-limited settings.

Relation Between Clinical Profile, CD4 Count and Total Lymphocyte Count in HIV Infected Persons

“…8 Whereas, study conducted in K. M. C. Manipal (2003) showed a that a significant correlation existed between TLC of less than 1200 cells/μL and CD4 counts of less than 200 cells/μL. 9 In our study CD4 count correlates to TLC better, when counts were less than 200 cells/μL (Table 6).…”

Absolute Lymphocyte Count as a Surrogate Marker of CD4 Count in Monitoring HIV Infected Individuals: A Prospective Study

“…To the best of our knowledge many studies showed low sensitivity of ALC less than 1200/µl for predicting CD4 cell count less than 200 cells/µl [Table/ Fig-4] [6,9,10,12,13]. However, study by Karanth SS et al, and Obirikorang C et al, show higher sensitivity(73% and72.22% ) and specificity (100% and 100%), respectively, for TLC cut-off of 1200 cells/µl to predict CD4 cell count less than 200/ µl [11,14]. This difference could be due to different ethnic, racial, epidemiological and socioeconomic factors.…”

“…Kumarasamy N et al, found ALC cut-off < 1400 cells/µl had sensitivity of 73%, specificity 88%, PPV 76% and NPV 86% for predicting CD4 cell count of <200 cells/µl [6]. Other studies from India also suggested higher ALC cut-off for predicting CD4 cell count of <200 cells/µl [11][12][13]. Study from Ethiopia and Brazil also agree with higher cutoff of ALC for predicting CD4 cell count <200 cells/µl [9,10].…”

“…To the best of our knowledge, few studies have compared the utility of ALC as a surrogate for CD4 count in monitoring HIV infected individuals in resource limited society [2][3][4][5][6][7][8][9][10][11][12][13][14].…”

Development of an algorithm of haematologic parameters as surrogate markers for CD4 cell count in resource-limited settings

“…Similarly, a recent study by Mwenda in 2015 in Kenya, found a TLC cut-off of 2000 cells/ mm 3 to best predict CD4 500 cells/mm 3 or less (sensitivity of 78.1%, specificity of 35.9% PPV 66.1%) concluding that TLC still retains some usefulness in detecting CD4 counts of less than 500 cells/mm 3 . Nonetheless, most authors have recommended TLC with a higher cut-off be used in areas with limited access to CD4 count until a cheaper alternative is found (Karanth et al, 2014). Other studies have shown TLC to be an imperfect predictor of CD4 count (Charles et al, 2014).…”