Immunoglobulin-coated bacteria in effusions obtained during chronic maxillary sinusitis.

Local protection of the maxillary sinuses against bacterial invasion takes both specific and non-specific forms. The present study is intended to evaluate the participation of the specific protective factors, immunoglobulins IgG, secretory IgA, IgM and complement, in protecting the maxillary sinuses during chronic maxillary sinusitis (CMS). We collected 47 sinus effusion samples from 37 patients (17 male, 20 female) with current CMS of at least 3 months' duration. Patients' ages ranged from 3 to 80 years. The effusion material was subjected to qualitative and quantitative bacteriological analyses, while bacterial coating with IgG, SIgA, IgM and C3b was determined using an immunofluorescence technique. Detectable bacteria were harboured by 55% of the samples, the most common species being Moraxella catarrhalis, Streptococcus pneumoniae and Staphylococcus aureus. The bacterial counts ranged from 0 to 10(9) per ml effusion. Half of the samples hosting detectable bacteria showed microorganisms coated with protective immunoglobulins. Antibacterial factors had completely eradicated the microorganisms in 45% of the CMS cases and coated the organisms with specific immunoglobulins in a further 28%.