HLA-B High-resolution Typing

Clinical information

Diagnostic Utility:

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

• Patients undergoing hematopoietic stem cell transplantation.
• Identical family members of patients undergoing 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:

PCR-NGS technique (Long strategy and Short strategy) allows high-resolution HLA typing of class I and II HLA genes. This technique involves several phases: amplification of the HLA genes of interest by PCR, library preparation, sequencing, and result analysis. The Long strategy (long fragments) provides the sequencing of the entire gene, while the Short strategy (short fragments) sequences exons 2, 3, and 4 of HLA-A, -B, and -C genes, and exons 2 and 3 of HLA-DRB1, -DQB1, -DPB1, -DQA1, and -DPA1 genes.

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-B gene are sequenced.

Reference Values

With high-resolution typing, two results are obtained for each HLA gene, for example: HLA-B*18:01 B*27:05.

Diagnostic Algorithm:

Not applicable.

Turnaround Time:

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

• Patient or family members of a patient undergoing 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: EDTA K3 4 ml 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: Coagulated sample

Administrative information

BST Code: LRD2020
Test Description: High-Resolution HLA-B Typing
Synonyms: High-Resolution HLA-B
Section: Histocompatibility and Immunogenetics
BST Fee: Check the updated fees here.

Profiles:

The High-Resolution HLA-B typing test is included in the "High-Resolution Complete HLA Typing" profile (see table).

References

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