A new extended haplotype Cw*0602-B57-DRB1*0701-DQA1*0201-DQB1*0201 associated with psoriasis in the Croatian population

Association of HLA Alleles and HLA Haplotypes with Psoriasis, Psoriatic Arthritis and Disease Severity in a Miscegenated Population

Background

The study of HLA classes I and II in Brazilian psoriasis patients may contribute to a better understanding of their association with the disease.

Objective

To describe HLA classes I and II of Brazilian patients with psoriasis, with or without arthritis, compare them to controls and correlate HLA markers with epidemiological and evolutional aspects of psoriasis.

Methods

A total of 55 patients with more than 5 years of psoriasis, with or without arthritis, answered a questionnaire on ethnic background and disease severity. A total of 134 bone marrow donors were controls. HLA class I and II genotyping was determined by PCR-SSP.

Results

Mean age was 42.4 years; 23 women and 32 men. HLA-B*57 was present in 23.6% patients and in 7.5% controls (p=0.00200, OR= 3.8381), and HLA-C*06 in 29.1% patients and in 16.4% controls (p= 0.04832, OR=2.0886). HLA-B*57 and HLA-C*18 were significantly present in patients with arthritis (p=0.00104, OR=6.6769 and p=0.00269, OR=16.50, respectively). HLA-B*57 was significantly present in patients with history of erythroderma (p=0.00548, OR= 5.1059), as was HLA-C*06 (p=0.02158, OR=3.0545). HLA-B*57 was also frequent in patients with history of hospital internment due to psoriasis (p= 0.00094, OR=7.8909) and in the ones with history of systemic treatment for psoriasis (p= 0.00011, OR= 5.3733). Haplotype HLA-A*02 B*57 C*06 DRB1*07DQB1*03 was the most common among the patients (p= 0.00069, OR= 3.528).

Conclusion

HLA-B*57 and HLA-C*06 were significantly increased in the patients indicating risk for psoriasis. HLA-B*57 remained high in patients with history of erythroderma, hospital internment, systemic treatment, and psoriatic arthritis, showing association with disease severity. HLA-C*18 was significantly high only in patients with psoriatic arthritis. HLA-B*57 and HLA-C*06 and haplotype HLA-A*02B*57Cw*06DRB1*07 DQB1*03 seen in this study were already described before, associated with psoriasis. HLA-Cw*18 was not described in other populations in association with psoriasis.

A genome-wide association study of atopic dermatitis identifies loci with overlapping effects on asthma and psoriasis

Atopic dermatitis (AD) is the most common dermatological disease of childhood. Many children with AD have asthma and AD shares regions of genetic linkage with psoriasis, another chronic inflammatory skin disease. We present here a genome-wide association study (GWAS) of childhood-onset AD in 1563 European cases with known asthma status and 4054 European controls. Using Illumina genotyping followed by imputation, we generated 268 034 consensus genotypes and in excess of 2 million single nucleotide polymorphisms (SNPs) for analysis. Association signals were assessed for replication in a second panel of 2286 European cases and 3160 European controls. Four loci achieved genome-wide significance for AD and replicated consistently across all cohorts. These included the epidermal differentiation complex (EDC) on chromosome 1, the genomic region proximal to LRRC32 on chromosome 11, the RAD50/IL13 locus on chromosome 5 and the major histocompatibility complex (MHC) on chromosome 6; reflecting action of classical HLA alleles. We observed variation in the contribution towards co-morbid asthma for these regions of association. We further explored the genetic relationship between AD, asthma and psoriasis by examining previously identified susceptibility SNPs for these diseases. We found considerable overlap between AD and psoriasis together with variable coincidence between allergic rhinitis (AR) and asthma. Our results indicate that the pathogenesis of AD incorporates immune and epidermal barrier defects with combinations of specific and overlapping effects at individual loci.

HLA-C, DRB1 and DQB1 alleles involved in genetic predisposition to psoriasis vulgaris in the Slovak population

Psoriasis vulgaris is a complex chronic skin disease with immunological and genetic background. The most important predisposing genetic factors in psoriasis are genes of the human leukocyte antigen (HLA) region. Accumulative evidence has shown that several HLA alleles are closely associated with psoriasis; however, they tend to vary in different racial and ethnic backgrounds. One hundred forty-seven unrelated Slovak patients with psoriasis vulgaris (average age at onset 28 ± 14 years) were genotyped for the HLA-C, DQB1 and DRB1 alleles by the polymerase chain reaction using sequence-specific primers. Allele frequencies observed in the group of psoriatic patients were compared to those obtained in the ethnically matched control group comprising 194 subjects with no history of psoriasis. Susceptibility to psoriasis vulgaris in our study group is significantly associated with HLA-C*06 (odds ratio (OR) = 3.85), DRB1*07 (OR = 2.56) and DQB1*02 (OR = 1.09), respectively, whereas DRB*01 (OR = 0.05) is associated negatively. Hereby, we provide the first report on the association of HLA-C, DRB1 and DQB1 alleles with psoriasis in the Slovak population. Our findings confirm HLA-C*06 and DRB1*07 as the most important genetic risk factors for psoriasis. However, the role of HLA genes as causative in the pathogenesis of the disease remains unclear. Identification of genetic factors that increase the risk of psoriasis is a precondition that helps to elucidate the pathogenesis of this troubling disease and identify targets for a more specific and effective therapy.

Psoriasis vulgaris and human leukocyte antigens

BACKGROUND

Psoriasis vulgaris is a skin disease with a complex immunological and genetic background, triggered by environmental factors. The association of human leukocyte antigens (HLA) and psoriasis has long been reported on population and familial studies.

OBJECTIVES

To review and discuss studies on psoriasis vulgaris and HLA, in Caucasian and non-Caucasian populations.

METHODS

The major population studies on psoriasis vulgaris and the associated HLA antigens and alleles are described and discussed based on a review of the current literature.

RESULTS

Population studies demonstrate the presence of different HLA specificities as well as extended haplotypes in patients with psoriasis, when compared to controls. Some alleles occur in a lower frequency in patients with psoriasis, indicating they could be protection alleles. In all studies which HLA class I was typed, Cw6 or Cw*0602 was present in a significant frequency in patients with psoriasis, mainly when early onset and positive family history were considered. HLA-DRB1*0701 was also present in a higher frequency in patients in different populations.

CONCLUSIONS

Different antigens and alleles from both HLA classes I and II were seen in a significantly higher frequency in patients with psoriasis vulgaris. HLA Cw*0602 and DRB1*0701 were represented in different reports, and the former was related mainly to psoriasis type I.

Antígenos de histocompatibilidade humanos e dermatologia: da pesquisa para a prática clínica

A participação do sistema de histocompatibilidade humano (HLA: human leukocyte antigens) na patogênese das doenças auto-imunes é bem conhecida. Situado no braço curto do cromossomo 6, o sistema HLA se destaca por seu polimorfismo e por sua capacidade de conferir susceptibilidade ou proteção a diferentes enfermidades. Em Dermatologia, esse sistema desempenha papel importante na patogenia e história natural de várias doenças. A força e o tipo de associação variam com a dermatose e, algumas vezes, com o grupo étnico-racial estudado. O surgimento de métodos moleculares para tipificação dos alelos HLA e as recentes atualizações de sua nomenclatura têm contribuído para o melhor entendimento desse sistema. Infelizmente, essas informações não têm sido veiculadas de maneira adequada na literatura clínica, o que dificulta o entendimento da associação do HLA com as doenças cutâneas. Nesta revisão, são discutidos alguns aspectos do sistema HLA, métodos de detecção, nomenclatura e sua associação com vitiligo, pênfigo, psoríase, lúpus eritematoso, escabiose, leishmaniose cutânea, hanseníase, paracoccidioidomicose e dermatite atópica.