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Lymphocyte immunophenotype reference ranges in healthy Thai adults: implications for management of HIV/AIDS in
H K Webster1, K Pattanapanyasat, P Phanupak
1Becton Dickinson Immunocytometry Systems, San Jose, CA, USA.
Insights
This study established reference ranges for lymphocyte subsets in healthy Thai adults. Thais showed distinct T and NK cell levels compared to Caucasians, impacting HIV/AIDS clinical management.
Area of Science:
- Immunology
- Flow Cytometry
- Clinical Reference Ranges
Background:
- Establishing accurate lymphocyte immunophenotype reference ranges is crucial for clinical diagnostics.
- Previous studies primarily focused on Caucasian populations, necessitating data for diverse ethnicities.
Purpose of the Study:
- To determine lymphocyte immunophenotype reference ranges for healthy adult Thais.
- To compare Thai reference values with those of Caucasians.
- To assess the influence of ethnicity, age, and sex on lymphocyte subset distributions.
Main Methods:
- Multi-center study utilizing flow cytometry on lysed whole blood.
- Standardized protocols for instrumentation, reagents, and quality control were employed.
- Analysis included T, B, and NK lymphocyte subsets (CD3, CD4, CD16+56).
Main Results:
- Significant differences observed in CD3 (T), CD4 (T helper/inducer), and CD16+56 (NK) lymphocyte percentages and CD4 absolute counts between Thais and Caucasians.
- Thais, especially males, exhibited lower CD3 and CD4 T cell percentages and counts, with higher NK cell percentages.
- Age and sex demonstrated observable trends, and biological variation in CD4 T lymphocyte distribution was noted.
Conclusions:
- Ethnicity, age, sex, and environmental factors significantly influence normal lymphocyte immunophenotype reference values.
- The findings highlight the importance of ethnicity-specific reference ranges for accurate clinical interpretation.
- These results have critical implications for HIV/AIDS staging and management in Thailand, particularly concerning CD4+ T lymphocyte monitoring.
Abstract:
Lymphocyte immunophenotype reference ranges for T, B, and NK subsets were determined for healthy adult Thais in a multi-center study in Bangkok. Immunophenotyping was by flow cytometry using lysed whole blood. A standard protocol for flow cytometry instrumentation, reagents and quality control was used to minimize site differences and to facilitate comparison of the Thai reference values to those found for Caucasians in previous studies. Major differences were determined for CD3(T), CD4 (T helper/inducer) and CD16+56 (NK) lymphocyte percentages and CD4 lymphocyte absolute counts. Age trends and sex differences were also observed. Compared to Caucasians, Thais, particularly Thai males, had lower CD3 and CD4 T lymphocyte percentages and absolute numbers whereas the percentage of NK lymphocytes was higher. Heterogeneity attributed to biological variation of CD4 T lymphocyte but not other immunophenotype subset distributions was also observed in a well defined geographic population. This study demonstrates the importance of ethnicity, age, sex and possibly environment as factors that influence distribution characteristics of normal lymphocyte immunophenotype reference values. These observations have important implications for the use of lymphocyte subsets-particularly CD3+ CD4+ T lymphocyte measurements as applied to HIV disease staging, AIDS definition and the overall clinical management of HIV/AIDS in Thailand.