RESUMEN
The capacity of polymorphonuclear leukocytes (PMNs) to kill Staphylococcus aureus strains 502 A was studied in 25 patients receiving theophylline therapy and in normal healthy controls. A significant difference in PMN bactericidal capacity was found between controls and patients with serum theophylline levels higher than 8 micrograms/ml, as determined by high-pressure liquid chromatography. The bactericidal capacity of PMNs from both the patient and control populations was reduced in the presence of theophylline levels above 8 micrograms/ml. In addition, a transient but significant drug-independent reduction was found in the bactericidal capacity of transient but significant drug-independent reduction was found in the bactericidal capacity of PMNs from patients receiving theophylline.