Mucus antibodies in pulmonary tuberculosis and chronic obstructive lung disease.

An indirect immunofluorescence technique and an indirect immunoperoxidase technique were used on cryostat sections of human group-O submaxillary salivary gland and rat stomach. Circulating antibodies reacting with mucus antigen(s) were found in sera from 52-7% of patients with active pulmonary tuberculosis and in 21-8% of patients with chronic obstructive lung disease. Among hospital patients with other diseases and healthy controls, mucus antibodies were found in 7-2 and 5.4% respectively. The mucus antibodies were not absorbed by an excess of red blood-cells derived from group AD+ healthy subjects or from the rat donor of the stomach, while the fluorescence and the immunoperoxidase reactions were almost completely abolished after the absorption of positive sera with human dried bronchial secretion. It is postulated that mucus antibody may be a new and important serological marker of disorders accompanied by mucus accumulation in the lung and possibly other organs and/or by severe changes of the anatomical structures which act as a barrier to the reabsorption of abnormal amounts of mucus.