Lymphocyte subset reference intervals in blood donors from northeastern Brazil

Area of Science:

• Immunology
• Hematology
• Clinical Laboratory Science

Background:

• Current leukocyte and lymphocyte reference intervals lack diversity, being primarily based on North American and European populations.
• This limits the accuracy of diagnostic interpretations for other ethnic groups.

Purpose of the Study:

• To determine reference values for peripheral blood immune cells in a Brazilian population.
• Specifically analyze B lymphocytes, T lymphocyte subsets (CD4+, CD8+, naïve, memory, regulatory, TCRαβ+, TCRγδ+), and NK cells.

Main Methods:

• Analysis of peripheral blood from blood donors in Salvador-Bahia, Brazil.
• Flow cytometry was used to quantify lymphocyte subsets.

Main Results:

• The study included 73.7% males, with similar median ages for males (34) and females (35).
• Absolute lymphocyte counts were 1,956 (1,060-4,186) cells, representing 34% of leukocytes.
• Females showed a statistically significant higher percentage of B lymphocytes (p=0.03).

Conclusions:

• Established reference values for key immune cell populations in a Brazilian cohort.
• Highlights the need for population-specific reference intervals in clinical laboratories.
• Observed differences, such as higher B lymphocyte percentages in females, warrant further investigation.