Distribution of HLA antigens in families of patients with leukaemias

Abstract

Since the discovery of major histocompatibility complex influence on cause leukaemia in 1964, an HIA association with leukaemia in humans has been considered as a possible genetic risk factor that contributes to development of leukaemia. In addition to associations of several HLA antigens with leukaemias, it has been observed that patients with leukaemia have an increase in the frequency of HLA identical siblings, higher degree of HLA compatibility with their parents as well as higher parental HLA sharing rate in comparison to the families without patients suffering from leukaemia. To test hypothesis that susceptibility to leukaemia can be caused by influence of a recessive genes associated with the major histocompatibility complex in man, we analysed the distribution of I class HLA antigens in 77 families of patients suffering from different types of leukaemia. In the affected families and in 72 families of healthy controls, we investigated HLA identical sibling frequency, parental sharing of one, two or three HLA antigens and degree of compatibility of parents and offsprings: existence of haploidentity, compatibility in l' and 4/4 HLA antigens of A and B loci. We have found that in families with affected persons there is a statistically significant difference in number of HLA identical siblings in comparison to the group of healthy controls (t = 2.63). Also the results have shown that among the parents of affected persons there is a statistically significant difference in mutual compatibility in one (t = 3.012) and two (t = 2.4) HLA antigens. In addition, we observed an increase in the frequency of higher rate of compatibility between patients and their parents (t = 3.88) in l' HLA antigens, to their mothers (t = 2.83) and to their fathers (t = 2.55), respectively, in comparison to the healthy control group. The results of this study show that in families with persons suffering from leukaemia there are possible recessive factors associated with HLA system which could cause distorsion of HLA antigens segregation and as a possible genetical risk factor contribute to development of leukaemia.