ABH ANTIGENS EXPRESSION AND SECRETOR STATUS OF PATIENTS WITH ORAL LESIONS

BIONDI C; CAMPI C; ESCOVICH L; RACCA L; RACCA A; GARCÍA BORRÁS S; COTORRUELO C

Madrid - España

Congreso; XVII Regional Congress of the ISBT Europe; 2007

International Society of Blood Transfusion

Background: Histo-blood group ABH(O) antigens are the major allogeneic antigens in humans and they are widely distributed in human tissues. Their presence not only is limited in blood cells but also is found in other cells and secretions. Since most human cancers originate from epithelial cells, changes in blood group antigens are an important topic in human tumor immunology Aim: to investigate ABH antigens expression in fixed tissue sections and the secretor status of patients with oral pre-cancerous and cancerous lesions. Methods: In total 34 subjects were examined, who suffered oral pre-cancerous and cancerous lesions. To analyze the secretor status in saliva we applied an haemoaglutination inhibition test and to reveal A, B and H antigens in tissue sections from these patients we used a modified specific red cell adherence technique (SRCA-test). Paraffin sections from each tissue block were deparafinized, stained with hematoxylin, washed in isotonic Tris – saline buffer for 5 minutes and the excess buffer was drained off, then they were covered with either monoclonal anti-A, anti-B antibodies or Ulex europeaus anti-H lectin for 10 minutes at room temperature. The slides were washed three times, and next, each section was covered with a suspension of homologous indicator erythrocytes for 15 minutes. The slides were washed with destilled water and stained with eosin. All of the sections analyzed microscopically had histological normal and atypical areas. Normal endothelial cells expressed ABH antigens, the presence of indicator erythrocytes at the lumen of the blood vessels served as a built in positive control. The test results were graded from negative adherence to very strongly positive adherence. Negative adherence was defined as a complete absence of adhered indicator erythrocytes. A strongly positive reaction was defined as a sheet of indicator erythrocytes adhered to the epithelia cells. Results The 52.3% of the patients with oral precancerous and cancerous lesions was no secretors, RO= 2.44, IC 95%, in contrast with the healthy population (19.5%).In 21 of the 34 samples analyzed the SRCA test showed slightly positive results on atypical areas, and there was a complete antigen deletion in areas affected by neoplasia. Eight samples showed a total absence of ABH antigens in both histologically normal and pathological areas. We observed a marginal association between secretor status and these lesions. Further it is suggested that areas of blood group isoantigen negative epithelium showing atypia, or in some instances near normal histology, may give rise to relatively low grade carcinomas. Conclusions: Considering these results we suggest the use of this method to monitor probable preneoplastic lesions in risk population, especially in those with no secretor status.