A reliable and inexpensive EasyCD4 assay for monitoring HIV-infected individuals in resource-limited settings.
Serial measurements of absolute CD4+ T-lymphocyte counts are required to initiate and gauge response to therapy and monitor disease progression. Hence, there is an urgent need to evaluate the accuracy and validity of low-cost CD4+ T-cell count assays. Tripotassium EDTA blood specimens from HIV-infected individuals were studied using a novel flow cytometric assay (EasyCD4 assay; Guava Technologies, Hayward, CA) in comparison with standard flow cytometry (FACSCount; Becton Dickinson Immunocytometry Systems, San Jose, CA). The sensitivity, specificity value by EasyCD4 assay in enumerating absolute CD4+ T-cell counts of less than 200 cells/microL were 95% and 100%, respectively. Bland-Altman analysis showed close agreement, with the EasyCD4 assay yielding CD4+ T-cell counts a mean difference of -26 cells/microL (95% confidence interval, -96 to 44 cells/microL) higher than by flow cytometry. Our data suggest that EasyCD4 assay could be a useful alternative assay to conventional flow cytometry, may be appropriate for use in resource-limited settings.
Balakrishnan
Pachamuthu
P
YRG Centre for AIDS Research and Education, Chennai, India. bala@yrgcare.org
Solomon
Suniti
S
Mohanakrishnan
Janardhanan
J
Cecelia
Anitha J
AJ
Kumarasamy
Nagalingeswaran
N
Murugavel
Kailapuri G
KG
Venkatakrishnan
Bhavani
B
Solomon
Sunil S
SS
Crowe
Suzanne M
SM
Ganesh
Aylur K
AK
Thyagarajan
Sadras P
SP
Flanigan
Timothy
T
Mayer
Kenneth H
KH
D000293:Adolescent; D000328:Adult; D018791:CD4 Lymphocyte Count / Q000191:economics / Q000379:methods*; D002648:Child; D003365:Costs and Cost Analysis; D005434:Flow Cytometry / Q000379:methods; D015658:HIV Infections / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D007194:India; D008875:Middle Aged; D015166:Monitoring, Immunologic; D015203:Reproducibility of Results; D040841:Resource Allocation