The HLA antigen distribution in the Gipsy population in Hungary.

A group of Gipsies living in two distinct geographic areas in Hungary was determined for HLA-A,B,C,DR antigens during the 8th Histocompatibility Workshop. A quite strange distribution of HLA antigens was found after comparing the data to those of Hungarian population. HLA-A1, Bw52, Bw22, B40, Cw1, DR2 and DRw8 are significantly increased in Gipsies, while A3, B7, B12, Cw3, DRw6 and DR7 are decreased. The strongest gametic associations were determined between the allele pairs A1/Bw61, A2/Bw52, Bw22/Cw1, DR2/Bw52 and DRw8/B40. Some deviations from the Hungarian controls were detected in the distribution of the blood groups too. Specifically, the incidence of Rh/D negativity and Gm/2/ factor positivity is much lower and the incidence of Gm/1/ factor positivity is much higher than in the control Hungarian population. These differences between Gipsy and Hungarian populations indicate their different ethnic origin, and suggest the Middle-Eastern roots of the Gipsy population.

Characteristics of different rhesus alloantibodies in lymphocyte dependent (K cell) cytotoxicity to human erythrocytes.

The property of rhesus alloantibodies to elicit antibody-dependent, cell-mediated cytotoxicity (ADCC) against target erythrocytes carrying various Rh genotypes was studied. The killer activity of normal peripheral lymphocytes on human erythrocyte target cells carrying the appropriate antigens elicited by alloantisera was measured by 51Cr release at 18 h. There was no correlation between ADCC and antibodies directed to the antigens present on the surface of different genotypes of Rh-positive red blood cells. The agglutinin titre of different Rh antibodies showed no correlation with the level of ADCC although the degree of cellular cytotoxicity was different with different anti-D sera. Anti-C + D+ E antibody caused higher ADCC than anti-C + D and the lowest cytotoxicity was observed with anti-D and anti-D+ E. This raised the possibility that ADCC was elicited by antibodies directed to other specificities. K cell lysis of human red cells by human peripheral blood lymphocytes in vitro suggests that a similar mechanism may operate in vitro in the destruction of erythrocytes coated by allo or autoantibodies.