HLA polymorphism in the Murcia population (Spain): in the cradle of the archaeologic Iberians.

Human leukocyte antigen (HLA) study in Murcian individuals was performed in order to provide information of their historical origins and relationships with other Iberian and Mediterranean populations. HLA class I and class II alleles were determined in 173 unrelated Caucasoid donors from Murcia Region in the Southeast of Spain by serologic and DNA based polymerase chain reaction (PCR) typing. Class I antigen and class II allele frequencies of our series were not very different to those found in Spaniards. The analysis of extended haplotypes showed that the three haplotypes most frequent in our population were respectively, A29-B44-Cwb-DRB1*0701-DRB4*0101-DQA1*0201-DQB1*0202, A1-B8-Cw7-DRB1*0301-DRB3*0101-DQA1*0501-DQB1*0201 and A30-B18-Cw5-DRB1*0301-DRB3*0101-DQA1*0501-DQB1*0201. They were followed by A26-B38-Cwb-DRB1*1301-DRB3*0202-DQA1*0103-DQB1*0603, which could point to an ancestral relationship between Murcian and Portuguese Iberian populations, and by A2-B7-Cw7-DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0602 also present in all Iberian Peninsula populations. Allelic frequencies, populations distance dendrogram and correspondence analysis were used to study the relationships between Murcian and other populations. The closest relation was observed with Spaniards and Portuguese, followed in decreasing order by French, Italians, Algerians, Germans, Catalans, Basques, Cretans, Sardinians, and Greeks. Thus, Murcian population seems to belong to the European genetic pool, revealing a lesser genetic distance with the North Africans and the rest of populations from the Iberian Peninsula.

HLA-DRB1 and -DQB1 polymorphism in liver recipients: relationship between HLA-DQB1*0302 allele frequency and acute rejection.

Polymorphism of HLA-DRB1 and HLA-DQB1 loci was performed in fifty-three orthotopic liver graft recipients as well as in 108 unrelated healthy controls. Nonradioactive SSOPs were used to study PCR-amplified DNA from peripheral blood lymphocytes and biopsied material. The comparison frequency for DQB1 alleles did not reveal any significant differences between the total group of liver recipients and controls. However, when the liver recipients were subgrouped according to their rejection episode manifestations, increased and significant frequencies were observed for HLA-DQB1*0302 allele in patients showing acute rejection episodes compared to healthy controls or patients without acute rejection. This relationship did not appear influenced by the amino acid beta alanine residue in the 57th position. On the other hand, the study of the DRB1 allele frequencies did not show significant differences in any study. These results suggest that HLA-DQB1 genes could be important in the liver graft alloresponses, opening a way to a better understanding of the special tolerance state, normally observed in this type of transplant, leading us to consider the possible HLA-DQB1*0302 allele effect on tolerance rupture.