Evaluation of a Manual CD4+ Count Kit for Determination of Absolute CD4+ T-Lymphocyte Counts
Manthana Mitchai MSc*, Wattanachai Susaengrat MD**, Kamoltip Krissadarak MSc***, Jumphol Mitchai MD****, Niramol Leeratanapetch MD**
Affiliation : * The Clinical Pathology Department, Khon Kaen Hospital, Ministry of Public Health, Khon Kaen ** The Medicine Department, Khon Kaen Hospital, Ministry of Public Health, Khon Kaen *** Office of Disease Prevention and Control Region 6, Khon Kaen, Ministry of Public Health, Khon Kaen **** The Pathology Department, Faculty of Medicine, Khon Kaen University, Khon Kaen
Objective : The aim of the present study was to evaluate a manual CD4+ count kit assay (CD4+: cytospheres)
for CD4+ T-lymphocyte count compared with flow cytometric method in HIV infected patients.
Material and Method: One hundred thirty three HIV infected patients were recruited from the out patient
department of Khon Kaen Hospital. Blood samples were done by a manual CD4+ count kit assay (CD4+:
cytospheres) and flow cytometry for CD4+ T-lymphocyte count. The data were analyzed for diagnostic test and
correlation coefficient.
Results : The data of cytospheres assay and flow cytomeric method showed good correlation (r = 0.88) for
the total group. At the absolute CD4+ T-lymphocyte 200 cells/cu.mm, the cytospheres assay demonstrated
sensitivity 83.10% (76.73-89.47%), specificity 93.55% (89.37-97.72%), PPV 93.65% (89.51-97.79%), NPV
82.86% (76.45-89.26%). In the case of CD4+ T-lymphocyte count were lower than 200 cells/cu.mm, the
cytospheres assay displayed progressive decrease in sensitivity successive increase in specificity.
Conclusion : The cytospheres technique is an alternative noncytofluorometric assay for CD4+ T-lymphocyte
count. This test may be useful for screening in HIV infected adult patients in community hospitals where flow
cytometry technique is not available. But the assay is limited in determination only absolute CD4+ T-lymphocyte
count with higher than 30 cells/cu.mm. This technique is not benefit in pediatric HIV/AIDS patient due to
percentage CD4+ value did not obtained. The quality control should be concern technical skill and profi-
ciency testing for laboratory setting.
Keywords : Flow cytometry, Cytospheres, CD4+ count
