Improvement in HLA-C typing by a new sequence-specific oligonucleotides kit.

PCR-sequence-specific oligonucleotide (PCR-SSO) is commonly used for HLA-typing. We recently replaced LabType SSO HD kit for HLA-C typing with the XR kit (OneLambda, Inc.). We used 137 patients' samples representing unique most likely HLA-C allele combinations to compare these kits' performance. The XR kit decreased the number of allele ambiguities with a median of 26.1% (first to third quartiles 20% to 36.2%, range 0% to 96.1%). The XR kit did not resolve all the common, intermediate and well-documented HLA allele ambiguities, which may be important in the clinical setting. The XR kit eliminated 23.6% of null allele ambiguities. In conclusion, the HLA-C XR kit provides a moderate yet valuable improvement of HLA-typing resolution in comparison with the HLA-C HD kit.