Effects of theophylline on the neonatal immune response

Theophylline has recently shown to affect lymphocyte reactivity. In view of its widespread use in newborn intensive care units, the effects of both lymphocyte proliferation and immunoglobulin production at varied theophylline concentrations were measured. In 12 adults and 10 term infants lymphocyte proliferation, as assessed by a whole blood micromethod, was significantly decreased in vitro at 7.5 micrograms/ml. Immunoglobulin production in adults was decreased, by both a plaque forming cell assay and a radioimmunoassay in vitro at 12.5 micrograms/ml. Ten premature infants on theophylline, mean serum level 7.8 +/- 0.4 micrograms/ml, followed for 3-5 wk, showed a slight increase in lymphocyte proliferative responses to pokeweed mitogen. These data demonstrate no in vivo suppression of lymphocyte proliferation in theophylline-treated neonates at low theophylline levels.