[Studies on HLA specificities in molar conceptions].

Complete mole is a form of natural allograft since it carries paternal genetic traits alone which differ antigenetically from those of the mother. Successful growth of mole is likely to be immunologically protected. Because the immune system is genetically controlled, the effect of HLA system on the development of androgenetic ova into moles is a subject of interest. In this study, HLA-A and -B specificities in the mole and its parent were compared with the ones of general population in Japan. Fifty-six molar tissues were used for absorption of HLA specificities determined by HLA typing of each patient and her husband. Results obtained were as follows. 1) HLA antigens were expressed on all molar tissues examined, and those antigen were derived selectively from paternal specificities, but not maternal one. 2) Fifty molar tissues had received the paternal haplotype and remaining six molar tissues had showed heterozygosity which were consistent with the paternal diplotype. Those suggested the fertilization of an empty egg by two spermatozoa. 3) A significant association was found with decreased frequency of HLA-Aw19 and HLA-Bw22 in the molar tissues (3.6% and 2.7%) compared with general population (16.4% and 11.5%). 4) The compatibility of HLA-A and -B types among moles with sequelae and the parents was higher(81%) than the estimated value(68%) in the control families. As a result, HLA analysis was useful for distinction of zygosity of molar tissues. Decreased frequencies of HLA-Aw19 and -Bw22 in the mole were assumed to be resulted from the wastage of androgenetic ova.(ABSTRACT TRUNCATED AT 250 WORDS)