SIALIC ACID IN ASTHMATICS AS DETECTED BY TRITHRICOMONAS MOBILILENSIS LECTIN (TML) HISTOCHEMISTRY

Auditorium A

Objective. To detect and compare sialic acid expression in asthmatic subjects and controls. Background. Expression of carbohydrates on the lung surface is the basis of the interaction of microorganisms and the host. Methods. We examined asthmatic (4) and control (4) lungs. The tissues were obtained at autopsy and used for histochemical analysis. Trithrichomonas mobiliensis lectin (TML) is a sialic acid-specific lectin from a colonic parasite of squirrel monkeys. TML recognizes the sialic acid in a number of stereological configurations. Due to the high specificity for sialic acid, its long term stability and its wide commercial availability, TML is a useful probe in sialic acid histochemistry. Lectin binding was detected by Avidin-Biotin, Vector Kit® in the histological sections. Digital images were used for evaluation of staining density on a scale from 0 = no staining to 4 = dense staining. Results. Sialyl residues in the lung surface of asthmatics were more abundant when compared to controls; in bronchi 2.29 vs 0.00; in bronchioles, 1.50 vs 0.53 and in glands 1.67 vs 0.00. This preliminary data show an unexpected prevalence of sialic acid residues expressed in the asthmatic airways as compared to controls. Further examination of this carbohydrate distribution should be made. Conclusion. We conclude that these findings indicate a shift in the expression of an important glycocalyx component that participates in the host defense. Grants. Supported by NSU Faculty Research Grant.