USE OF MULTIPLE TECHNIQUES TO OPTIMIZE HLA TYPING.
Oksana Rosina MS , Margaret L. Hample, BS , Victoria Maresca-Travers MS , Joseph V. Ronquillo, BS and Annamalai Selvakumar PhD . New York NY, USA, Memorial Sloan-Kettering Cancer Center, 10021, Tissue Typing Laboratory .
A potential bone marrow transplant patient and his immediate family of 7 siblings were presented for HLA typing in search of a suitable donor. No parents were available for testing and one of the siblings (SIB) appeared to be half-sibling. According to the established laboratory procedure, the quick screening of the family has been performed by low resolution molecular typing using SSOP protocol. The initial results were as follows:
SIB#1 SIB#2 SIB#3 SIB#4 SIB#5 SIB#6 SIB#7
a/d a/c b/c a/d a/d a/d b/x
The proband appeared to be: axb/c showing a potential recombination event at DRB1* locus. High resolution SSOP typing confirmed the original finding with the best potential match identified as 5/6 match (one allele mismatch at DRB1*locus). The mismatched allele was *1301 vs. *0301. DR 3/5/6 area is difficult for typing, often presenting many problems due to high number of shared nucleotides between DRB1* alleles.
The laboratory decided to use an alternative SSP high resolution method to confirm DRB1* typing in the proband and the matching sibling. SSP results were consistent with the previously determined SSOP typing. HLA molecular typing as the laboratory tool often requires multiple methods for the optimal results and it is important to choose the best suitable technique to verify the findings.