ARE ABH ANTIGENIC DETERMINANTS ON HUMAN OUTER EAR CANAL EPITHELIUM RESPONSIBLE FOR PSEUDOMONAS-AERUGINOSA INFECTIONS

The outer ear canal expression of ABH human blood group antigens has b een analyzed with a standardized routine histological procedure by mon oclonal antibodies in the case of blood groups A and B, and a correspo nding lectin in the case of blood group 0, respectively. In all 20 cas es the blood groups were histochemically confirmed. Furthermore, Pseud omonas aeruginosa-specific inhibition experiments were performed with different sugar solutions as well as A-like substance incubating outer ear canal tissue sections with P. aeruginosa strain (No. 60) presenti ng lectin specificity for N-acetyl-galactosamine (GalNAc). P. aerugino sa lectins with GalNAc specificity apparently adhere to GalNAc as term inal blood group A determinant and indicate that patients presenting w ith blood group A may have a genetic predisposition to this form of ot itis externa.