Accurate and Reproducible Enumeration of Cd4 T Cell Counts and Hemoglobin Levels Using a Point of Care System: Comparison With Conventional Laboratory Based Testing Systems in a Clinical Reference Laboratory in Cameroon

Abstract

Background Measurements of CD4 T cells and hemoglobin (Hb) are used to determine the immunological state and information about disease progression for HIV-infected patients. We analyze the correlation in CD4 and Hb measurements using BD FACSPresto™ system compared with the BD validated FACSCanto™ II clinical software analyzer and Sysmex XN 1000 haematology analyzer. We evaluated the advantages of using the POC device in the era of scale up in access for HIV patient management in resource limited settings Method The analytical performance of the BD FACSPresto compared with the FACSCanto II flow cytometer and the Sysmex XN 1000 haematology analyzer was evaluated testing 241 routine clinical specimens collected in EDTA tubes from patients attending the Immunology and Microbiology laboratory of Chantal BIYA International Reference Centre (Yaounde, Cameroon) between January and May 2016. Results The mean in absolute counts and percentage of CD4 T cells was 606 cells/mL and 25% respectfully via the FACSPresto and 574 cells/mL and 24% respectfully via the BD FACSCanto II. The mean concentration of Hb levels was 11.90 on the Sysmex XN 1000 and 11.45 via the BD FACSPresto. A high correlation (R2 = 0.95, P < 0.001) of Hb level measurements was noted between the BD FACSPresto™ and Sysmex XN 1000 hematology analyzer. Overall, Bland-Altman plot of the differences between the two methods showed an excellent agreement for absolute and percentage CD4 counts and hemoglobin measurements between POC and conventional methods evaluated here. Furthermore, the study demonstrated the ease of use of the BD FACSPresto POC technology in remote areas. Conclusion The BD FACPresto is a suitable tool for CD4 enumeration in resource-limited settings, specifically providing a deployable, reliable POC testing option. The BD FACSPresto™ performed appropriately in comparison to the conventional reference standard technologies The BD FACSPresto system provides accurate, reliable, precise CD4/%CD4/Hb results on venous blood sampling. The data showed good agreement between the BD FACSPresto, BD FACSCanto and Sysmex XN 1000 XN 1000 systems.