The lysosomal enzymes of lymphocytes in the premature and the term infant.

Activity of acid phosphatase, beta-glucuronidase, and beta-glucosaminidase was determined in peripheral blood lymphocytes of 29 premature and 20 term infants with the use of cytochemical methods. The results were expressed semiquantitatively and included the total count of enzyme-positive and the enzyme-negative lymphocytes as well as the intracellular content of enzyme-positive and enzyme-negative lysosomal granules. The premature infant exhibited significantly lower activity of all the studied enzymes than the term infants. It thus argues in favour of the opinion that the lysosomal apparatus in lymphocytes undergoes development in the course of fetal maturation of the immune system. Evaluation of the activity of lysosomal enzymes in lymphocytes can serve as an indicator of fetal maturity and immunological status.