MOLECULAR CHARACTERIZATION OF HLA CLASS-II GENES IN 3 AUTOIMMUNE-DISEASES IN CROATIAN PATIENTS

Susceptibility to several autoimmune disorders such as insulin depende nt diabetes mellitus (IDDM), rheumatoid arthritis (RA) and coeliac dis ease (CD) is linked to genes within the major histocompatibility compl ex and strong population associations are demonstrable between certain HLA class II alleles and these conditions. Polymerase chain reaction sequence specific oligonucleotide (PCR-SSO) typing combines the abilit y to define the subtypes of HLA. specificities with possibility of stu dying Large numbers of normal and affected individuals. In this study we have analysed HLA-DRB1, DQA1, DQB1 and DPB1 gene polymorphism in 30 IDDM, 40 RA and 20 CD patients while 140 healthy Croatians served as a control group. For all studied diseases an association with HLA clas s II genes has been found: 1.IDDM:positive association with DRB10301, DRB104, DQA1*0301, DQB1*0201 and DQB1*0302; negative association wit h DQB1 0301 and DPB1*0301 2. RA: positive association with DRB1*01 an d negative association with DRB111 3. CD: positive association with D RB10301 DQA1*0501 DQB1* 0201 alleles (extended haplotype). These data clearly define an association of IDDM, RA and CD in Croatian populati on with different subtypes of HLA. class II genes.