Abstract
Background:
We have previously developed an alternative approach for undertaking absolute cell counting based upon flow‐rate calibration using cell bead (FCB), in which cell bead (CB) can be used as a flow‐rate calibration material for generating the absolute microparticle counts. Here, we extended our work of counting CD4+ T‐lymphocytes in HIV‐infected blood samples with the FCB method.
Methods:
CD4+ T‐lymphocyte counts in EDTA blood samples from 30 healthy subjects and 80 HIV‐1‐infected patients were determined using TriTEST reagent. The absolute CD4+ T‐lymphocytes were measured by FCB, and the results were compared with the absolute counting by commercial latex bead (CLB) or with flow rate‐based calibration method (FR). Statistical correlation and agreement were analyzed using linear regression and Bland–Altman analysis.
Results:
There was no significant difference in the absolute number of CD4+ T‐lymphocyte counts enumerated by FCB when compared with those two reference methods (CLB and FR). The absolute CD4+ T‐lymphocyte counts obtained from FCB method was highly correlated with those obtained from CLB [r^2^= 0.99, y = 1.04__x__ − 12.37, P < 0.001, and mean bias 11.96 cell/μl, limit of agreement (LOA) −57.82 – 81.74 cell/μl], FR method (r^2^ = 0.98; y = 0.97__x__ − 3.13, P < 0.001, and mean bias −24.15 cell/μl, LOA −114.44 − 66.13 cell/μl).
Conclusions:
The use of FCB is comparable with the use of CLB and FR. This approach showed the effective in reducing cost for generating the absolute CD4+ T‐lymphocyte counts. Such an approach should facilitate and ensure the success of the ongoing antiretroviral therapy program in resource‐limited countries. © 2010 Clinical Cytometry Society