Supplementary Material for: Influence of Age, Gender and Lifestyle in Lymphocyte Subsets: Report from the Spanish Gait-2 Study

Introduction: Flow cytometry analysis of lymphocyte subsets in peripheral blood is a common technique in diagnostic laboratories. Abnormal values have been identified in prevalent infections, autoimmune disorders and neoplastic diseases. Reference ranges for lymphocyte subsets of a healthy population from Spain are scarce. Methods: The study was performed on 319 healthy subjects, aged 4–88 years, from 709 individuals enrolled in the GAIT-2 Project (Genetic Analysis of Idiopathic Thrombophilia). Health status, age, sex, fertility, BMI and lifestyle (physical activity, cigarette smoking and ethanol intake) were assessed using standardized criteria. The percentage of lymphocyte subsets was determined using flow cytometry (Lymphogram™). Percentages of CD3+, CD4+, CD8+, CD19+, CD3–CD56+, CD3+CD4–CD8– double-negative (DN) T cells, CD3+CD4+CD8+ double-positive T cells and the CD4+/CD8+ ratio were recorded for each case. Results: Children had a significantly higher percentage of CD19+ and DN cells than adults. Women had a significantly higher percentage of CD3+ and CD4+ and a lower percentage of natural killer cells than men. Increases in BMI were inversely associated with the percentage of DN cells. Physical activity increased the percentage of lymphocytes and DN cells. Alcohol consumers had a lower percentage of CD19+ and DN cells, and a higher percentage of CD4+. Conclusion: This study provides reference ranges for lymphocyte subsets of healthy children and adults in a Mediterranean population (Spain) and determines the influence of lifestyle factors on these values.