HLA antigens and Ia antibody in the gastric cancer patient.

The possible association of 18 HLA specificities in HLA-A locus and 23 specificities in HLA-B locus with susceptibility to gastric cancer was investigated in a total of 87 patients and 355 controls in Japan. Significantly decreased antigen, HLA-B5 (17.2%) was found in gastric cancer patients compared with 40.0% in controls. X2 for this antigen difference is 15.8 (corrected P less than 0.005). The most frequent HLA haplotype was A9-B5 in controls and A2-Blank B locus antigen in gastric cancer patients. No reaction was found of HLA antiserum, Bou-Pri with cells of gastric cancer patients, compared with 29.4% in control subjects. No linkage was observed between HLA-A and -B locus antigens and gastric cancer in family study with double the frequency of HLA haplotype A2-BW40. Ia-like B cell specific antibody was found 10% in 2 out of 20 gastric cancer patients in a preliminary study. There was no clear association between B cell specific antibody and clinical implications.