Objective: To determine the reference ranges of various lymphocyte subsets in healthy Indian children.
Design: Descriptive cross-sectional study.
Setting: Four centers in India representing four geographical regions.
Participants: 1104 children from neonatal age to 18 years of age.
Measurement: One time measurement of absolute count and percentages of different lymphocyte subsets i.e. T lymphocytes (CD3+T, CD4+T, CD8+T cells), B lymphocytes (CD19+B cells) and Natural Killer lymphocytes (CD15/16+NK cells) in whole blood using multicolor flow cytometry.
Results: The absolute cell counts of various lymphocytes were found to increase from newborn to 10 months of age, followed by gradual decline until 18 years; however, the proportion of immune cells remained largely similar. Gender did not have a significant impact on the reference ranges, whereas counts were found to vary as per the geographical locations.
Conclusions: These reference ranges will be useful to monitor and predict the immune status in pediatric population. The variation in region wise ranges could be confirmed by testing more number of samples in the specific age groups.