NOTE: formerly known as “HLA-B*57:01 TYPING FOR DRUG HYPERSENSITIVITY”
Scheme Description
Pharmacogenetics, generally accepted as the study, or clinical testing, of genetic variation that gives rise to differing responses to drugs, is increasingly being applied to a variety of drugs where a hypersensitivity reactivity is noted in association with a specific HLA type. For example, the prospective testing of patients for HLA-B*57:01 who are to be treated with the antiretroviral drug abacavir. This scheme tests participants’ ability to define relevant HLA types using the method(s) they employ for routine clinical service testing for hypersensitivity or drug suitability.
**New for 2025-26**
In addition to Abacavir, participants can choose to be assessed for HLA genotypes associated with other hypersensitivity reactions including Allopurinol*, Carbamazepine*, Oxcarbazepine, Lamotrigine, Flucloxacillin, Phenytoin* as well as Tebentafusp suitability*.
*previously assessed as part of scheme 8: HLA genotyping for coeliac disease and other HLA-associated diseases
Purpose
To assess participants’ ability to correctly determine relevant HLA type for the drug specified:
- Abacavir Hypersensitivity – B*57:01
- Allopurinol Hypersensitivity – B*58:01
- Carbamazepine Hypersensitivity – A*31:01, B*15:02
- Oxcarbazepine Hypersensitivity – B*15:02
- Lamotrigine Hypersensitivity – B*15:02
- Flucloxacillin Hypersensitivity – HLA-B*57:01
- Phenytoin Hypersensitivity – B*15:02
- Tebentafusp Suitability – A*02:01
Samples
A total of ten blood samples will be sent each year as three distributions. Participants will receive three blood samples (previously frozen) in the first shipment, four samples the second shipment and three samples in the final shipment.
Reporting
At registration participants must designate the drug they wish to be assessed for. Participants are required to report their HLA genotyping findings relevant to each drug registered for.
Participants are required to report on the relevant HLA allele status as positive or negative.
Participants can report other alleles for information purposes but these will not be assessed.
Participants must only use the reporting forms provided within the UK NEQAS for H&I Participant’s Portal and are required to return results within 10 days.
Assessment
The consensus HLA status of each sample is determined by at least 75% of laboratories agreeing on the presence or absence of a relevant HLA allele for each drug. A reference result will be used for assessment for samples failing to reach the 75% consensus level (see section 10.5).
Assessment Procedure
Each report in agreement with the consensus/reference HLA type – Acceptable
Each report not in agreement with the consensus/reference HLA type – Unacceptable
Each sample not reported – with valid reason, or equivocal – Not Assessed
Each sample not reported / late submission of results – Unacceptable
Satisfactory Performance
Satisfactory performance is making ten sample reports in agreement with the consensus/reference HLA type in a year per drug that they have registered for.
Laboratories with unsatisfactory performance will receive written notification of their status and will be expected to reply to UK NEQAS for H&I detailing their corrective actions. For UK laboratories, unsatisfactory performance will be reported to UK NQAAP for Immunology. For UK laboratories, failure to reply or replies deemed unsatisfactory are likely to be further actioned by UK NQAAP for Immunology.
Information/Analysis Provided to Participants
- Anonymised summary table of all participant results, comments and methodology. Including sample assessment result (acceptable/unacceptable classification) for each participant.
- End of year summary of participant performance.