DEFECTIVE IMMUNOREGULATION IN CHILDREN WITH PERSISTENT MIDDLE EAR EFFUSION

Abstract

Otitis media and middle ear effusions (MEE) are most common clinical problems in early childhood for which an estimated one million tympanostomies are performed each year in the US. Although many factors have been associated with MEE (age, sex, genetics, otitis media, socioeconomic status, feeding style, atopy or hypersensitivity, a certain bacteria and viruses), a defective immunoregulatory mechanism in the host may also contribute to the pathogenesis. During the past 2 years, we have evaluated immune function in 78 randomly selected children who underwent tympanostomy for persistent MEE. The T-cell subset ratio (OKT-4/OKT-8) was reduced (below 1.25) in 30%. In 8 children, generation of T-cell growth factor (IL-2) by peripheral blood lymphocytes (PBL) was evaluated and found to be decreased in all; below 50 units (normal 50-180 units). The mitogenic response to PHA stimulation was normal in most cases. The subsets of lymphocytes were examined in the tonsils from those patients who underwent tonsillectomy at the time of tympanostomy. The tonsillar lymphocytes had an increased ratio of T-4/T-8 and an increased proportion of B-cells as compared to the matched PBL. Imbalance of T-cell subsets and decreased production of IL-2 indicate a defective immunoregulatory function in some of these children, which may play a role in the pathogenesis of persistent MEE. (Supported in part by USPH grant DE-05505).