Chronic tonsillitis in children: Activation of polymorphonuclear cells from peripheral blood and tonsillar tissue. In vitro production of MPO, ECP and EPX

Activation of polymorphonuclear cells (PMNs), neutrophils and eosinophils, occurs in response to infections. Myeloperoxidase (MPO) is an enzyme contained in neutrophils with toxic activity for many microorganisms including bacteria. Eosinophil cationic protein (ECP) and eosinophil X protein (EPX) are released by activated eosinophils in response to different inflammatory stimuli. Determination of serum levels of MPO, ECP and EPX permits assessment of the state of activation of these cells. The purpose of this study was to evaluate the state of activation of neutrophils and eosinophils present in tonsillar tissue and peripheral blood from 30 children (18 boys and 12 girls) undergoing tonsillectomy for chronic tonsillitis. For determination of serum levels of MPO, ECP and EPX, peripheral blood samples were obtained at the time of surgery: PMNs were separated by erythrosedimentation from peripheral blood and from tonsillar tissue after surgery and cultured for 7 days. The cells were plated (10⁵ well) and the plates were incubated in 5% CO₂, 7% O₂, 80% N₂. After 2, 24, 48, 72, 96, 120, 144 h, supernatants were removed from the cultures of both tonsillar tissue and peripheral blood PMNs for determination of in vitro release of MPO, ECP and EPX. The assays were carried out using a radioimmunotechnique (RIA, Pharmacia) and the concentrations of the three proteins (mean/6 wells) for each time were expressed in μg/l. The data suggest activation of PMNs in children with chronic tonsillitis.