Heterogeneity of HLA-DRB1*04 alleles and haplotypes in the Croatian population

The Association Between Knee Osteoarthritis and HLA-DRB1*0101 in the East of Iran

BACKGROUND

Osteoarthritis (OA) is a painful social problem, which breaks down the articular cartilage, causes the failure of synovial joints and subchondral bone sclerosis. OA etiology is not completely understood, but joint trauma, infection, obesity, and diseases are the most important risk factors for OA developing. Recent studies suggested inflammatory factors and genetic components can be involved in the pathogenesis of OA. Experimental evidences suggest a linkage between Human Leukocyte Antigen (HLA) genetic diversity and OA. But a few studies have been conducted in this subject.

OBJECTIVE

To investigate the association between HLA-DRB1*0101 and OA in Iranian patients.

METHODS

Thirty patients with knee osteoarthritis and 30 healthy people as the control group were included in the study. Sex, weight, age, Body mass index (BMI) and height of all participants were recorded. HLA-DRB1*0101 was typed by PCR using the sequence-specific primer.

RESULTS

Our results showed 80% of knee osteoarthritis patients were positively HLA-DRB1*0101 (n=24), while only 26.7% of controls were positive (n=8) (P= 0.015).

CONCLUSION

These findings proposed that there is a significant association between HLADRB1* 0101 and susceptibility to knee osteoarthritis.

The distribution of the DRB4*01:03:01:02N null allele in HLA-DRB1~DQB1 haplotypes in the Croatian population

The aim of the present study was to investigate frequency and haplotype distribution of DRB4 alleles in the Croatian population. The investigated sample consisted of 288 cadaveric donor samples positive for one of the DR53 alleles. HLA-A, -B, -C, -DRB1, and -DQB1 typing was performed using the polymerase chain reaction-sequence specific primers (PCR-SSP) low resolution method, while HLA-DRB4 and selected HLA class II specificities typing was performed using PCR-SSP at the allelic level. Three different DRB4 alleles were observed among DRB1*04 samples; DRB4*01:02 (2.38%), DRB4*01:03 (91.27%), and DRB4*01:03:01:02N (6.35%). The DRB4*01:03:01:02N allele was predominantly observed among DRB1*04:02-positive samples, while DRB4*01:02 and DRB4*01:03 alleles did not associate preferably with any of the DRB1*04 subtypes. Among DRB1*04~DRB4~DQB1 haplotypes, the predominant DQB1 allele was DQB1*03:02 (69.94%). Seven different DRB4 alleles were found among DRB1*07:01-positive samples. The analysis of DRB1*07~DRB4~DQB1 haplotypes showed that DRB4*01:03 was found in the majority of HLA-DRB1*07:01~DQB1*02:02 (49.09%) haplotypes while DRB1*07:01~DQB1*03:03 haplotypes carried the DRB4*01:03:01:02N allele almost exclusively (98.21%). Among six DRB1*09:01-positive samples, HLA-DRB1*09:01~DRB4*01:03~DQB1*03:03 was the only detected haplotype. The extended haplotype analysis showed a high frequency of HLA-B*15(B62)~C*03(Cw9)~DRB1*04:02~DRB4*01:03:01:02N~DQB1*03:02 and HLA-B*57~C*06~DRB1*07:01~DRB4*01:03:01:02N~DQB1*03:03 haplotypes. In conclusion, the data presented in this study should prompt other population studies focused on DRB3/4/5 genes and be used as a basis for future investigations of the clinical relevance of these genes in transplantation setting.