It has come to the attention of the ARB that after database changes in 2011 and the changes to the HLA nomenclature that became operational in 2010, some stand-alone typing methods, used in isolation, may no longer meet the requirements for high resolution typing. Laboratories are reminded that in order to remain accredited for high resolution, their typing methodologies must be able to meet the requirements for high resolution typing according to NMDP guidelines and the ARB Operations Manual (Chapter XIII Section D Subsection j: Requirements for Low and High Resolution DNA typing, part iv.). The NMDP/ASHI policy (HLA Confirmatory Requirements) is available at http://bioinformatics.nmdp.org/Policies/Policies.aspx.
The NMDP policy states:
Reporting Results to the NMDP
A. Summarizing the requirements detailed in the manuscript, final reporting of high resolution HLA typing results must meet one of the following criteria: - must contain only one unambiguously assigned genotype.
- may contain multiple alternative genotypes if one includes two CWD alleles, and the others do not include any alleles listed in the tables from Cano et al, with the following exceptions:
- Laboratories are not required to resolve CWD alleles that encode identical protein sequences in the antigen recognition site.
- When alternative genotypes include combinations with one CWD allele plus a rare allele the resolution to a single genotype may not be required. If the laboratory possesses information or data relevant to the particular ambiguity being evaluated, which provides evidence that the resolution to a single genotype may not be required, the laboratory may decide to claim a deviation from this policy and to report the result as completed.
We recognize that high resolution typing often requires multiple methods for such resolution. Laboratories that have high resolution typing accreditation are strongly urged to utilize all of the methods necessary to attain the required level of resolution. The ARB will instruct inspectors to be observant that a laboratory accredited for high resolution typing is meeting the criteria listed above. Laboratories are encouraged to check with the manufacturers of their kits to ensure that their typing kits, if used in isolation, still meet the NMDP and ASHI guidelines for high-resolution typing.
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