HLA-DRB1 High-Resolution Typing

Clinical information

Diagnostic Utility:

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

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

Method:

The PCR-NGS technique (Long strategy) allows high-resolution HLA typing of class I and II HLA 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 the HLA-A, -B, and -C genes and exons 2 and 3 of the HLA-DRB1, -DQB1, -DPB1, -DQA1, and -DPA1 genes are sequenced.

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 and 3 of the HLA-DRB1 gene are sequenced.

Reference Values

With high-resolution typing, for each HLA gene, two results are obtained, for example: HLA-DRB1*03:01 DRB1*13:02.

Diagnostic Algorithm:

Not applicable.

Turnaround Time:

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

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

Specimen information

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

Stability:

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

Transport instructions: Preferably at room temperature

Reason for rejection: Clotted sample

Administrative information

BST Code: LRD2009
Test Description: High-resolution HLA-DRB1 typing
Synonyms: High HLA-DRB1
Section: Histocompatibility and Immunogenetics
BST Rate: Check the updated rates here.

Profiles:

The high-resolution HLA-DRB1 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).