Characteristic features of functional status of lymphocytes in premature newborns

Aim. To characterize the functional properties of peripheral blood lymphocytes in association with peculiarities of the period of neonatal adaptation of premature newborns.

Materials and methods. Sixty-one conditionally healthy premature infants with gestation period of 28-37 weeks and their mothers as well as 12 full-term newborns were examined. The functional status of small lymphocytes was assessed by the activity of chromatin of their nuclei. For this purpose, there were used cytochemical and fluorometric methods with acridine orange staining of the smears obtained from leukocytic suspension that was followed by measuring intensity of luminescence in the light wave diapason of 530-580 nm. The study was implemented thrice – on the days 6^th, 16^th, and 26^th of infants’ life.

Results. During the neonatal period, premature infants demonstrated the growth of the absolute and relative number of lymphocytes. The mentioned indices have an inverse dependence on the period of gestation. Activity of chromatin of small lymphocyte nuclei in newborns is significantly higher than in adults. Its maximum values are registered in prematurely born infants. Newborn small lymphocytes are characterized by marked functional heterogeneity. Unfavorable course of neonatal period in these patients is accompanied by lower values of the absolute number of lymphocytes and activity of their nuclei chromatin.

Conclusions. The index of activity of small lymphocyte nuclei chromatin can be used to predict the course of neonatal period in prematurely born infants.