Phagocytic activity and bactericidal capacity of polymorphonuclear leukocytes in children with recurrent otitis media.

In 19 children with recurrent otitis media the phagocytic activity of blood granulocytes was studied and indirectly also their bactericidal capacity by means of the NBT test and myeloperoxidase activity. The mean value of granulocytes containing latex particles was 44.32% in the patients group, which differed significantly from the mean value established in controls: 66.54%. The mean phagocytic number in the patients group, 1.82 was also significantly diminished in comparison to controls: 2.41. The average number of nitroblue tetrazolium (NBT)-positive cells in patients, 86.74% as well the mean myeloperoxidase index, 2.52 did not differ from the mean control values, 92% and 2.42, respectively. In two patients a lower percentage of NBT-positive cells was determined. They are probably heterozygous carriers of an enzyme deficiency related to a depressed bactericidal activity of phagocytes. Patients with recurrent otitis media should be tested on possible phagocytic dysfunctions which may be helpful in understanding the pathogenesis of infections and also in identifying infants at particular risk of otitis media.