Peripheral blood lymphocyte subpopulations in schoolchildren born very preterm

Aim-To investigate whether lymphocytes or serum inflammatory markers are as sociated with obstructive lung disease and bronchial lability in schoolchil dren born very preterm. Method-Lymphocyte subsets were studied in the peripheral venous blood of 29 such children (median age 8.8 years). Serum eosinophil cationic protein (E CP) and myeloperorridase (MPO) concentrations and the association between t hem, lymphocyte subsets, and lung function were studied, Fourteen healthy c hildren born at term, median age 9.1 years, served as controls. T lymphocyt es (CD3), T lymphocyte subpopulations (CD4 and CD8), B lymphocytes (CD19), natural killer cells (CD16+56) and activation markers of T and B lymphocyte s (CD23 and CD25) were determined using flow cytometry. Lung function was m easured in all children both in the clinic and at home (Vitalograph Data St orage Spirometer). Results-Compared with the controls, schoolchildren born very preterm had si gnificantly lower CD4(+) T cell percentages and CD4:CD8 ratios (p < 0.05 fo r both), whereas natural killer cell percentages and serum ECP values were significantly higher (p < 0.05). The very preterm schoolchildren had signif icantly lower spirometric values than the control group (p < 0.05)-except f orced vital capacity. When all the subjects were considered together, a wea k, but significant, negative association was observed between the bronchial responsiveness in peak expiratory flow after a beta(2) agonist during home monitoring, and the CD4(+) T cell percentage (r = -0.45; p = 0.008) and th e CD4:CD8 ratio (r = -0.50; p = 0.003), indicating a relation between bronc hial lability and imbalance of T cell subpopulations. Conclusions-These results suggest that there is an inflammatory basis for l ung function abnormalities in schoolchildren born very preterm.