All India Institute of Medical Sciences, New Delhi
Abstract
Background. Enumeration of lymphocyte subsets has been
widely used for the diagnosis and monitoring of several
haematological and immunological disorders. Various studies have
demonstrated age, sex and racial differences in lymphocyte subset
expression. Reference values are not available for Indian children
and there is a need for this information to replace commonly used,
but inappropriate, adult lymphocyte subset ranges.
Methods. One hundred thirty-eight healthy children be
tween 3 and 15 years of age, attending a local government school
in Chennai, South India were included in the study. Haemoglobin
levels, and total and differential cell counts were determined
using an automated counter and lymphocyte subsets were
analysed by flowcytornetry.
Results. The mean (SD) absolute lymphocyte count declined
with age from 4338 (1031) at 3 years to reach a plateau of
3096 (914) at 11-13 years (p < 0.05). A significant decline
was also observed in the absolute numbers of CD3+, CD4+,
CD8+ and CD19 + cells. However, the percentage values of
CD3+, CD4+, CD8+, CD16/56+ cells and the CD4/CD8
ratio remained fairly stable across the age range.
Conclusion. Our data would prove useful in interpreting
disease-related changes in lymphocyte subsets in Indian children
of different age groups. Age-related decrease in the absolute
lymphocyte count as well as numbers of CD4 and CD8 cells was
found to occur between the ages of 3 and 11 years. A
normogram relating age to CD4 count has been developed