Performance of GBTsol ICA System: A New Point-of-Care Testing Instrument for HIV Monitoring Through CD4 and CD8 Enumeration in Resource-Poor Settings

Author(s): Stephen Sung, Hyon-Suk Kim, Jae-Woo Song, Jae-Young Lee, Shabnam Aghamoradi, Seung-Lim Back

This study demonstrates the application of a POCT microchip platform for enumerating leukocytes, CD4+ T-lymphocytes, and CD8+ T-lymphocytes in whole blood, using fluorochrome-conjugated primary antibodies as a detection method. Specifically, we used phycoerythrin conjugated primary antibodies specific to CD4 and CD8 antigens to enumerate CD4+ and CD8+ T cells. Comparative analysis was performed using Fluorescence-Activated Cell Sorting (FACS) count to evaluate total leukocytes, CD4+ T cell count, and CD8+ T cell count in whole blood samples, aiming at monitoring the immune systems of patients with human immunodeficiency virus infection. Statistical analyses for precision, correlation, and agreement were performed. Coefficients of variation ranging from 0.67% to 12.78%, 0.81% to 13.68%, and 0.29% to 8.33% were obtained for CD4, CD8, and leukocyte recovery, respectively. A significant correlation was identified between the two assays for CD4 and CD8 counts, exhibiting correlation coefficients of 0.90 and 0.91, respectively. Using Bland–Altman plots, we determined a mean bias of 23, 38, and 490 cells/µ L (95% CI, n = 113) for CD4, CD8, and total leukocyte counts, respectively. These findings affirm that the GBTsol ICA (Immune Cell Analyzer) is comparable to the FACS count platform method, providing a cost-effective, user-friendly, and expeditious approach for quantifying CD4 T cells, CD8 T cells, and total leukocytes in blood samples, facilitating the monitoring of HIV/AIDS patients.