CD4 ⁺ CD8 ⁺ T Cell Reference Values in the Mexico City Population

Abstract

T he quantification of CD4ϩ and CD8 ϩ T lymphocytes is the most important laboratory test used to evaluate and monitor the success of antiretroviral treatment for HIV infection (1, 2). In Mexico, this test has been performed for more than 12 years. However, the reference values for healthy people are adopted from textbooks or the flow cytometry supplier and are usually based on Caucasian populations. Studies in different countries have reported variations in T lymphocyte subset reference values, emphasizing the importance of considering gender, age, environment, and ethnicity when evaluating cell counts (3, 4). The objective of this study was to determine reference values for absolute CD4 ϩ and CD8 ϩ T cell counts for the adult Mexican population according to sex and age.Subjects. A total of 400 healthy Mexicans (200 women and 200 men) participated in this study. A demographic and epidemiological questionnaire was administered to all participants to gather information on age, address, education level, and family history. All individuals who were born in Mexico City and had ancestors born in Mexico City for at least three generations were included. Individuals from well-delimited ethnicities were not included in this analysis. The epidemiology of HIV in Mexico has been reported to be 4 HIV-infected adults for every 1,000 Mexicans. With regard to age group, people between 25 and 34 years of age represent the highest percentage of AIDS cases. Thus, the participants in the present study were grouped into the following 4 age ranges: 20 to 25, 26 to 30, 31 to 35, and 36 to 40 years old. We analyzed 50 individuals in each age and gender group. All study participants were examined by a medical doctor. The health statuses of the participants were assessed by reviewing their medical records and conducting a physical examination and clinical laboratory tests, including a negative HIV probe. The participants were recruited from private medical care facilities and medical societies. The samples were analyzed at the National Reference Institute Instituto de Diagnostico y Referencias Epidemiologicos in Mexico City. Patient information and informed consent letters were signed by all participants.Specimen characteristics. Whole blood was collected with a Vacutainer system in 5-ml tubes containing EDTA. The samples were processed within 10 h of collection.Flow cytometric analysis. Lymphocyte subsets were analyzed with a FACSCount (Becton, Dickinson) with monoclonal antibodies (MAbs) against the following proteins: immunoglobulin G1 and immunoglobulin G2 as controls, CD3, CD3-CD4, and CD3-CD8. In addition to the monoclonal antibodies, the reagent tubes also contained fluorochrome-labeled reference beads, which act as a fluorescence standard to identify lymphocytes and a quantification standard (CD3 PE-Cy5 and CD4 phycoerythrin [PE], CD3 PE-Cy5 and CD8 PE). To evaluate accuracy and linearity, the instrument was calibrated with control beads at four different concentrations (0, 50, 250, and 1,000 particles/50 l). In brief, 50 l of w...

Haematological and immunological reference intervals for adult population in the state of Amhara, Ethiopia

“…CD4 cell counts were higher than in Addis Ababa , Tanzania and Central African Republic ; but lower than in Gojjam, Ethiopia , Gauteng, South Africa and Turkey . CD4 percentages RI in this study were generally lower than in other countries , possibly due to ethnic and environmental factors . There was a significant gender difference in absolute CD4 cells and CD4 percentages.…”

Establishment of Reference Range of CD4 T-Lymphocyte in Healthy Nepalese Adults

“…The mean value of absolute CD4 count obtained in this study, (819 ± 294) cells/µl is comparable to the previous study by Shakya et al carried out in three development regions of Nepal [1]. The result is also similar to the studies from Mexico city (800 ± 230), Indonesia (753 ± 270), England (830 ± 290), Nigeria (847 ± 307) and Tanzania (745 ± 256) [11,[16][17][18][19]. However, the CD4 mean value obtained in our study is comparatively lower than those from India (919 ± 311), Turkey (1095 ± 391) and South India (1048) and, higher than Chinese adults (727 ± 255) [2,10,20,21].…”

Establishment of Reference Range of CD4 T-Lymphocyte in Healthy Nepalese Adults

“…The mean value of absolute CD4 count obtained in this study, (819 ± 294) cells/μl is comparable to the previous study by Shakya et al carried out in three development regions of Nepal [1]. The result is also similar to the studies from Mexico city (800 ± 230), Indonesia (753 ± 270), England (830 ± 290), Nigeria (847 ± 307) and Tanzania (745 ± 256) [11,[16][17][18][19]. However, the CD4 mean value obtained in our study is comparatively lower than those from India (919 ± 311), Turkey (1095 ± 391) and South India (1048) and, higher than Chinese adults (727 ± 255) [2,10,20,21].…”