HLA PHENOTYPE DISTRIBUTION IN LACTOSE ABSORBERS FROM SOUTHERN ITALY (CAMPANIA REGION)

Abstract

The frequence of HLA antigens for ABC loci in 22 adult lactose (L) absorbers from the Neapolitan area and surrounding was compared to a panel of general population (n=254)from the same area, with high prevalence of lactose malabsorbers (78-83%)(1).L.absorbers were defined by an excretion of less than 20 ppm of H2 by analysis of breath test after standard oral lactose load. The HLA antigen analysis was performed on lymphocytes isolated from peripheral blood samples by the standard two stage microcitotoxicity test.The A1 and B8 antigen frequencies in L.absorbers are 50.5% and 40.9%, respectively, as compared to 15%(p corr=0.001) and to 11%(p corr=0.002) in the general population (2).The A1B8 haplotype frequency (0.057%)in the L.absorbers follows the same pattern of the single antigens, and is significantly greater than in general population (0.019%) (p<0.001). Comment: HLA phenotype distribution in the L.absorbers from the Neapolitan area appears to approach the distribution of the same antigens in high lactose persistence populations from northern Europe (i.e., the Danes). Further investigation is required to clarify the nature of this relationship. 1) Lancet 1:335, 1984. 2)Tissue Antigens 16:286, 1980.