Two-stage immunological examination was performed in 59 subjects aged 12-55 years from 27 families with respiratory pathology in three generations. Their proband had chronic bronchitis. Prognostic estimation of changes in the immune status was made with matrix statistic analysis. The findings show heterogenic characteristics of physiological systems of the examinees from families with chronic bronchitis and non-uniform metabolic processes leading to respiratory pathology and allergic diseases. Disorders in immunologic homeostasis in the descendants of the probands with chronic bronchitis, chief signs in pathogenesis of chronic bronchitis in three generations, essential immunological factors in allergic persons are outlined.