...
Match probabilities for A, B Antigen, DRB1 ARD level CBU searches are calculated in the same way as "regular" searches. This means that the indicated overall and locus-specific match probabilities are based on ARD match, also for HLA-A and HLA-B.
...
HLA match grade categorisation
Whether a potential CBU is a 6/6, 5/6 or 4/6 considering the special rules for A, B Antigen, DRB1 ARD level CBU searches is determined by whether it is an antigen match at HLA-A and HLA-B and whether it is an ARD level match at DRB1. Allele mismatches are therefore not considered regarding the categorisation.
...
Sorting is performed in the regular way based on the match probabilities as explained below.
- HLA match grade (e.g. first 6/6 then 5/6, 4/6)
- ARD level match probability in 10% intervals (descending)
- Number of total nucleated cells (TNC, descending) or, if chosen, CD34 count, descending
Known behaviour
As mentioned, CBUs are assigned the right match class (6/6 vs 5/6 vs 4/6) in A, B Antigen, DRB1 ARD level CBU searches. We are aware of a small issue. In some cases we may not indicate that a locus has a mismatch where there is one. This is only the case in A, B Antigen, DRB1 ARD level CBU searches and not in regular searches. We are working on a fix for this.