Cell type–specific differences in the range and attrition rate of leukocyte telomere length.

<p>A. Cross-sectional median telomere length in nucleated cell types determined by flow FISH in 835 healthy individuals over the age range from birth to 102 years of age. The following nucleated blood cell subtypes were analyzed : lymphocytes, granulocytes, CD45RA positive CD20 positive B lymphocytes (CD20+), CD45RA positive CD20 negative lymphocytes (CD45RA+pos CD20−) “naïve” T cells, CD45RA negative CD20 negative lymphocytes (CD45RA−) memory T cells and CD45RA positive CD57 positive mature NK/T cells (CD57+). Data were analyzed using a piece-wise linear regression model in the age categories 0, 1 yr; 18 yrs and 102 years and for calculation and representation of the telomere length distribution range at any given age (expressed as a percentile): 99^th (red), 90^th (dashed green top), 50^th (green), 10^th (dashed green bottom) and 1^st (blue). Some of the healthy subjects (n = 835) did not have sufficient cells for analysis of one or more of the cell subsets. B. Piece-wise linear regression analysis overlay representing the modeled estimate of telomere length per age for: B lymphocytes (grey), granulocytes (black dashed), “naïve” T lymphocytes (black), memory T lymphocytes (black interrupted dashed) and mature NK/T lymphocytes (grey dashed). Regression breakpoints were set at age 1 and age 18 years. C. Paired comparison of telomere length in granulocytes and memory T lymphocytes from the same individuals. Age groups were as follows: cord blood samples and below age 1 (n = 60, red), age 1 to 18 (n = 171, black), 19 and above 19 (n = 604, green).