Úsek pro vědu a výzkum

Department of HLA

The department is included in the Complement of the laboratories of the IHBT. It continuously advocates an independent and impartial assessment of the professional competence of the Complement of Laboratories according to the ČSN EN ISO 15189 standard, the application of which is verified by the Czech Institute for Accreditation. The test methods within the scope of accreditation are defined by the Annex to the Certificate of Accreditation in the current version, which is available on the IHBT website.

The HLA department performs specialized genetic testing of patients and donors of hematopoietic stem cells and also tests samples of patients with suspected congenital HLA predisposition to diseases such as celiac disease. All examinations are performed using molecular genetic methods.

In the examination of patients and in the search for suitable hematopoietic stem cell donors, the main human immune system - HLA (Human Leukocyte Antigens) - is tested at a high resolution level using massively parallel sequencing. In addition, KIR genes (killer cell immunoglobulin-like receptors) are also tested for this purpose.

In the context of testing the association of HLA with diseases, especially HLA genes associated with the risk of celiac disease, the department works as a reference facility and ensures and coordinates the exchange of information with other DNA laboratories in the Czech Republic. It also provides consultation services and organises inter-laboratory comparisons of tests.

Since 2007, the department has been accredited by the international professional organisation European Federation for Immunogenetics. Within this organization we regularly participate successfully in international quality controls for all tests performed. The HLA department is part of the NRL for DNA diagnostics.

The staff is bound by confidentiality according to the Health Services Act, 372/2011 Coll.

Confidence and high data security is one of the basic priorities within the activities of the Complement of Laboratories of the IHBT. The established procedures are carried out in accordance with the Personal Data Processing Act 110/2019 Coll. and Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data, and repealing Directive 95/46/EC. More information is available on the IHBT website.

Since 1993, the HLA genotyping has been performed by the HLA department as the first in the Czech Republic for the needs of patients of the IHBT, the Department of Pediatric Hematology and Oncology of Motol University Hospital and other clinical sponsors.

The HLA system (Human Leukocyte System) is the main histocompatibility system of humans. Genetically, it maps to the short arm of chromosome 6 (position 6p21.31 - 6p21.33). The products of its enormously polymorphic genes (there are hundreds of alleles, but the final numbers have not yet been determined) are antigenic structures (transmembrane glycoproteins) that recognize structures foreign to the organism and thus initiate a cascade of immune responses.

Determination of the exact HLA genotype of the patient and its donor is one of the basic conditions for the success of allogeneic hematopoietic stem cell transplantation. A mismatch in the HLA region between donor and recipient can induce graft rejection or cause Graft Versus Host Disease (GvHD), a serious or fatal complication.

Currently, we routinely perform genotyping of the most important HLA class I and II transplant loci: HLA -A, -B, -C, -DRB1, -DQB1 in patients indicated for allogeneic hematopoietic stem cell transplantation and as confirmatory testing of unrelated donors selected for them from Czech and foreign registries.

It is also known that some diseases (e.g. rheumatoid arthritis, coeliac disease, narcolepsy, insulin-dependent diabetes mellitus) are associated with specific alleles of the HLA system, which is reflected by an increase in the relative risk of disease in the presence of a given allele. However, none of these associations is absolute.

The laboratory determines the HLA traits associated with the diseases:

For these HLA traits, the laboratory organizes annual MPZ programs for those interested.

By agreement, we also perform genotyping of selected loci of the HLA system as additional information for the diagnosis of certain HLA-associated diseases.

The study of the HLA system is also beginning to be an important tool in pharmacogenetics, where the HLA trait can predict a patient's response/non-response or sensitivity to a therapeutic agent (e.g., Abacavir administration in HIV-positive patients).

We use a number of accurate methodologies for genotyping:

  • polymerase chain reaction with sequence-specific primers (PCR-SSP)
  • direct sequencing (SBT)

The evaluation of the results is performed by special software that is linked to the international HLA allele database and is regularly updated depending on this database. This ensures maximum predictive power of the results.