Related Experiment Videos
CD4 enumeration in HIV infected individuals
Insights
Two new methods for counting CD4+ T-cells were compared to flow cytometry. While both correlated well, one overestimated counts, and the other struggled with low CD4 counts in patients.
Area of Science:
- Immunology
- Cell Biology
- Clinical Diagnostics
Background:
- Accurate enumeration of peripheral blood (PB) CD4+ lymphocytes is crucial for monitoring immune status, particularly in conditions like HIV/AIDS.
- Conventional flow cytometry (FCM) is the standard method, but alternative, potentially more accessible or efficient, methods are continually being explored.
Purpose of the Study:
- To compare the accuracy and reliability of two alternative methods for enumerating PB CD4+ lymphocytes against conventional FCM.
- To evaluate the TRAxCD4™ enzyme immunoassay and a novel method utilizing a lyophilized lymphocyte internal standard.
Main Methods:
- Peripheral blood (PB) CD4+ lymphocyte counts were determined using conventional flow cytometry (FCM).
- Two alternative methods were employed: the TRAxCD4™ enzyme immunoassay and a direct enumeration method using lyophilized lymphocytes as an internal standard.
Main Results:
- Both alternative methods demonstrated a high overall degree of correlation with conventional FCM.
- The TRAxCD4™ immunoassay significantly overestimated PB CD4+ T-cell counts, partly due to monocyte-derived CD4 molecules.
- The method using lyophilized lymphocytes showed a low correlation for patients with low CD4 counts.
Conclusions:
- While alternative methods show promise, careful validation is needed, especially for specific patient populations or low cell count scenarios.
- The TRAxCD4™ immunoassay may require adjustments to account for overestimation, and the lyophilized standard method needs further refinement for low CD4 count accuracy.
Abstract:
In the present study, two alternative methods for the enumeration of PB CD4+ lymphocytes are compared with conventional flow cytometry (FCM): the TRAX CD4 tm enzyme immunoassay test kit and a new method using an internal biological standard (liophilized lymphocytes) for the direct enumeration of total PB CD4+ T-cells. Both methods showed an overall high degree of correlation with conventional FCM. However, the TRAxCD4 tm enzyme immunoassay showed a significant overestimation of PB CD4+ T-cells that was not only due to monocyte-derived CD4 molecules and the use of liophilized lymphocytes as an internal biological standard showed a low level of correlation for patients displaying low CD4 counts.