Introduction
Human leucocyte antigen (HLA) strongly associated with autoimmune diseases. In some studies it was demonstrated, that achalasia is an autoimmune disease and associated with genetic factors.
Aims & Methods
The aim of our study was to investigate the association of genes of the HLA system in patients with achalasia and in healthy citizens of Russian Federation.
Material and methods: 140 patients with achalasia were included in this study: 75 females (55%), age from 18 to 75. The diagnosis of idiopathic achalasia was established by upper endoscopy and high resolution water-perfused manometry (MMS, Netherland). Healthy 332 volunteers from 21 to 74 y.o. (asymptomatic) were included in this study: there were 305 females.The DNA from blood samples was isolated using QIAamp DNA Blood Mini Kit (Qiagen, Germany) according to the manufacturer's recommendations. The concentration of DNA samples was measured by fluorimetric method on a Qubit 4 fluorimeter using the Qubit dsDNA BS Assay Kit (Thermo Fisher Scientific, USA). All patients underwent HLA typing by massively parallel sequencing (NGS): HLA-A, HLA-B, HLA-C, HLA-DQB1, HLA-DRB1, HLA-DPB1, on the platform MiSeq (Illumina, USA) v.2, Omixon. The analysis of the HLA gene sequences obtained as a result of sequencing was carried out using a computer program TypeStream Visual Software (TSV) (One Lambda, USA), and database IPD-IMGT/HLA.
Results
The allelic variants HLA-A*02, HLA-B*37, HLA-B*39, HLA-C*5, HLA-C*7, HLA-C*14, HLA-C*15, HLA-DRβ1*01, HLA-DRβ1*03, HLA-DRβ*08, HLA-DRβ1*13, HLA-DPβ1*06, HLA-DPβ1*11, HLA-DPβ1*05, HLA-DPβ1*15 and HLA-DQβ1*04 were evaluated equally in healthy volunteers and achalasia patients. The allelic variants HLA-A*66, HLA-B*15, HLA-B*44, HLA-B*52, HLA-C*12, HLA-C*16, HLA-DPβ1*01, HLA-DPβ1*02, HLA-DPβ1*23, DRβ1*11, HLA-DRβ1*14, DQβ1*06 were found statistically more frequently in patients with achalasia than in healthy volunteers. The allelic variants HLA-A*11, HLA-A*23, HLA-A*25, HLA-A*26, HLA-B*7, HLA-B*57, HLA-C*3, HLA-C*06, HLA-DPβ1*03, HLA-DPβ1*13, HLA-DPβ1*17, DRβ1*13, HLA-DRβ1*15 were insignificantly evaluated more frequently in group with achalasia than in healthy volunteers.
Conclusion
The absence of differences in some allelic variants of genes of HLA in patients with achalasia and healthy volunteers confirm that they are not specific for achalasia in Russian Federation. The statistical difference in predominance of some allelic variants of HLA system indicates, that these findings should be compare with medical history and symptoms. After that these allelic variants of genes of HLA can be consider as a prognostic factor.