HLA-A High Resolution Typing

Clinical information

Diagnostic Utility:

High-resolution HLA typing allows us to determine the HLA typing at an allele level (4 digits) of:

• Patients candidate for hematopoietic stem cell transplantation.
• Identical relatives of patients candidate for hematopoietic stem cell transplantation.
• Voluntary donor registry.
• Expansion of HLA typing in voluntary donors.
• Registry and verification of umbilical cord blood units.
• Pre-transplant confirmation of donor and recipient.

Method:

The PCR-NGS technique (Long strategy and Short strategy) allows high-resolution HLA typing of HLA class I and II genes and non-classical HLA genes. This technique consists of several phases: amplification of the HLA genes of interest by PCR, library preparation, sequencing, and result analysis. With the Long strategy (long fragments), the sequencing of the entire gene is obtained, while with the Short strategy (short fragments) exons 2, 3, and 4 of HLA-A, -B, and -C genes are sequenced, as well as exons 2 and 3 of HLA-DRB1, -DQB1, -DPB1, -DQA1, and -DPA1 genes.

The PCR-SBT technique allows high-resolution HLA typing of an isolated HLA gene. This technique consists of two phases: amplification of the exons of the HLA genes of interest by PCR and sequencing reaction of the amplified products. Finally, the sequences are analysed by electrophoresis. Exons 2, 3, and 4 of the HLA-A gene are sequenced.

Reference Values

With high-resolution typing, for each HLA gene two results are obtained, for example: HLA-A*02:01 A*26:01.

Diagnostic Algorithm:

Not applicable.

Turnaround Time:

The turnaround time for high-resolution HLA typing depends on the sample origin:

• Patient or family members of patient candidate for hematopoietic stem cell transplantation (20 working days).
• Voluntary donor registry (20 working days).
• Expansion of HLA typing in voluntary donors (10 working days).
• Registry of umbilical cord blood units (20 working days).
• Verification of umbilical cord blood units (20 working days).
• Pre-transplant confirmation of donor and recipient (20 working days).

Specimen information

Sample: Whole blood
Tube: 4 ml K3 EDTA Tube
Minimum volume: 500 µl.

Stability:

• In refrigeration: 2 weeks.
• At -20°C: from 2 weeks onwards.

Transport instructions: Preferably at room temperature

Reason for rejection: Clotted sample

Administrative information

BST Code: LRD2019
Test Description: High-resolution HLA-A typing
Synonyms: High HLA-A
Section: Histocompatibility and Immunogenetics
BST Fee: Check the updated fees here.

Profiles:

The high-resolution HLA-A typing test is included in the "High-resolution HLA complete typing" profile (see table).

References

Manual dels "Standards for Histocompatibility Testing" de l'EFI (darrera versió).