Serum immunoglobulin A in chronic bronchial inflammation.

Serum IgA was determined by the single radial immunodiffusion method in specimens collected during 1 year from 178 patients suffering from chronic bronchitis syndrome. The IgA level was permanently, significantly higher in the group of patients than in the group of healthy controls. The difference between the patients and controls increased until middle age. This phenomenon was parallel with an aggrevation of the average functional severity of the pulmonary disease. Despite the continued aggravation, the difference lessened after the age of 49. Three cases of severe quantitative IgA abnormality were detected among the patients: one case of IgA myeloma and two cases of almost total IgA deficiency. One of the latter also showed IgE deficiency.