HLA association with the susceptibility to anti-synthetase syndrome.

OBJECTIVE: To investigate the human leukocyte antigen (HLA) association with anti-synthetase syndrome (ASSD). METHODS: We conducted the largest immunogenetic HLA-DRB1 and HLA-B study to date in a homogeneous cohort of 168 Caucasian patients with ASSD and 486 ethnically matched healthy controls by sequencing-based-typing. RESULTS: A statistically significant increase of HLA-DRB1*03:01 and HLA-B*08:01 alleles in patients with ASSD compared to healthy controls was disclosed (26.2% versus 12.2%, P=1.56E-09, odds ratio-OR [95% confidence interval-CI]=2.54 [1.84-3.50] and 21.4% versus 5.5%, P=18.95E-18, OR [95% CI]=4.73 [3.18-7.05]; respectively). Additionally, HLA-DRB1*07:01 allele was significantly decreased in patients with ASSD compared to controls (9.2% versus 17.5%, P=0.0003, OR [95% CI]=0.48 [0.31-0.72]). Moreover, a statistically significant increase of HLA-DRB1*03:01 allele in anti-Jo-1 positive compared to anti-Jo-1 negative patients with ASSD was observed (31.8% versus 15.5%, P=0.001, OR [95% CI]=2.54 [1.39-4.81]). Similar findings were observed when HLA carrier frequencies were assessed. The HLA-DRB1*03:01 association with anti-Jo-1 was unrelated to smoking history. No HLA differences in patients with ASSD stratified according to the presence/absence of the most representative non-anti-Jo-1 anti-synthetase autoantibodies (anti-PL-12 and anti-PL-7), arthritis, myositis or interstitial lung disease were observed. CONCLUSIONS: Our results support the association of the HLA complex with the susceptibility to ASSD.

Two tagging single-nucleotide polymorphisms to capture HLA-DRB1*07:01-DQA1*02:01-DQB1*02:02 haplotype associated with asparaginase hypersensitivity.

AIMS: Asparaginase (ASP) hypersensitivity is a well-known challenge in the treatment of lymphoblastic malignancies. In terms of cost considerations, the cheap native Escherichia coli ASP, the most immunogenic form of this medication, is used in the first line in middle-income countries. Previously, the role of the HLA-DRB1*07:01-DQA1*02:01-DQB1*02:02 haplotype had been established to associate with E. coli ASP hypersensitivity. We investigated a possible cost-effective genetic testing method to identify patients harbouring the risk HLA haplotype in order to pave the way for safer ASP treatment. METHODS: In 241 patients with previously determined HLA-DRB1*07:01-DQA1*02:01-DQB1*02:02 haplotype and known ASP hypersensitivity status, 4 candidate HLA-tagging single-nucleotide polymorphisms (SNP)s were measured, and the performance of the different sets of these tag SNPs was evaluated. RESULTS: We identified a combination of 2 SNPs - rs28383172 and rs7775228 - as a tag for HLA-DRB1*07:01-DQA1*02:01-DQB1*02:02 haplotype with sensitivity and specificity values >95%. In line with previous findings, we found complete concordance between HLA-DRB1*07:01 and rs28383172. With bioinformatics methods, the results were also confirmed in the 1000 Genomes dataset in different ethnic groups. CONCLUSION: Rs28383172 and rs7775228 are suitable for identifying HLA-DRB1*07:01-DQA1*02:01-DQB1*02:02 carriers. Compared to the rest of the population, patients with hypersensitivity-prone genotype would benefit more from the administration of less immunogenic PEGylated ASP before the hypersensitivity evolves, incurring minimal extra cost.

A novel HLA-DRB1*07 allele, HLA-DRB1*07:01:22, identified in a Chinese individual.

HLA-DRB1*07:01:22 differs from HLA-DRB1*07:01:01:01 at position 244 (C>T) in exon 2.

Identification of a novel HLA-DRB1*07 allele, HLA-DRB1*07:01:19.

HLA-DRB1*07:01:19 differs from DRB1*07:01:01:01 by a single nucleotide substitution at position 261 of exon 2.