[T and B lymphocytes in the ontogenetic development of man]

The study of the ontogenesis of immunity in man is still in progress and development. In this paper the two major subpopulations of human lymphocytes--T (thymus dependent) and B (bursal equivalent or thymus independent) were examined during the ontogenetic development of man. These subpopulations can be examined in vitro by the methods distinguishing superficial receptors on these cells--namely by the rosseting methods. B lymphocytes with the receptor for Fc of immunoglobulin can be distinguished by the EA test, and with receptor for C3 by the the EAC test. T lymphocytes can be detected in blood by the E test using their capacity to bind sheep red cells forming rossetes. This phenomena is very dependent upon temperature changes during the experimental procedures and this may partly explain the widely different proportions of E rosseting forming cells found by different authors ranging from 37% to 81% in blood of healthy adults. So there is a great necessity for each laboratory to have their own normal value in the healthy children in different age to compare it with those estimated in different states of the disease. Percentages of T and B lymphocytes were evaluated in children in 5 different age groups: below 1 year, 2-3 years, 4-5 years and over 10 years. Moreover the number of T and B lymphocytes was evaluated in the peripheral blood of pregnant women (2 and 3 trimester), of women at delivery, in the cord blood and the blood of newborns on 5-th day of life. The normal control group consisted of 71 healthy adults. In some children of four age groups the absolute counts of T and lymphocytes were estimated. The results are presented in Tabl. I, II and. fig. 1, 2. We found significantly decreased percentage of T lymphocytes in some estimated groups versus control--it is in peripheral blood of pregnant women, women at delivery, in cord blood, in newborns at 5-th day of life (p less than 0.001) and in the groups of children below 5 years (0,01 less than p less than 0,02 and 0,02 less than p less than or equal to 0,05). In children older than 5 years the number of T lymphocytes was within normal limits. Total number of peripheral T lymphocytes was significantly increased in children age 2-5 years (p less than 0.001) and in children below 10 years (0.02 less than p less than or equal to 0.05). Percent of B lymphocytes estimated by the EA and EAC tests was elevated in pregnant women and women at delivery. The statistical difference between these two groups from one site and the group of healthy adults was highly significant (p less than 0.001). In some newborns we found also elevated percent-age of B lymphocytes with the receptor for C3 (EAC test) on 5-th day of life. The difference between this group and adults was not so great (0,02 less than p less than or equal to 0.05). It was also stated that absolute counts of B lymphocytes estimated by EA and EAC tests was elevated in children below 10 years of age.