Age-dependent variation of lymphocyte function in the postoperative child.

Circulating lymphocyte profiles and reactivity normally vary with age. Operation results in depression of both lymphocyte counts and blastogenesis but the relationship of age to these alterations has not been previously evaluated in the pediatric surgical patient. This report analyzes the relationship of age to lymphocyte alteration in the postoperative child. Thirty-five healthy children (age range 1 mo to 12 yr), admitted for elective herniorrhaphy, underwent perioperative lymphocyte assay. Anesthesia consisted of halothane and NO2, and operative time averaged 54 minutes. Three milliliters of heparinized whole blood was obtained at induction of anesthesia and at 2 hours postoperatively. Lymphocytes were separated by Histopaque gradient and assayed for absolute count, total T-cells, and total B-cells. Lymphocyte reactivity was determined by 3H-Thymidine incorporation during incubation with the mitogens phytohemagglutinin (PHA), pokeweed (PWM), and/or concanavalin A (Con A) and results expressed as the logarithm of scintillation counts per minute. Differences in preoperative and postoperative values were analyzed for significance by paired T-test. The same differences were evaluated for relationship to age by regression analysis. Operation resulted in significant decreases in all lymphocyte counts (absolute, T- and B-cells), and the operative-induced alteration in both absolute and total B-cell counts were significantly correlated with age (P less than .03, P less than .007, respectively). Similarly, operation resulted in significant depression of lymphocyte reactivity and alteration in B-cell response (PWM) was significantly correlated with age (P less than .008). In all instances of significant correlation, lymphocyte alterations were inversely related to age.(ABSTRACT TRUNCATED AT 250 WORDS)