[Establishment of a quality control system for HLA allele typing and its key points]

To list the key points for quality control during HLA-A, B, C, DRB1 and DQB1 allele typing by taking consideration of hardware, software and experimental procedures.

A total of 10 167 samples from randomly selected healthy blood donors and donor-recipient pairs from Shenzhen were typed for exons 2-4 of HLA-A, B, C, exon 2 of HLA-DRB1, and exons 2 and 3 of HLA-DQB1 by PCR- sequence-based typing. For 56 cases whose forward and reverse sequences were inconsistent, the samples were re-checked by a PCR-sequence specific oligonucleotide probe method. Novel alleles not included in the IMGT/HLA database were cloned and sequenced using in-house primers.

Eight novel HLA alleles were identified. A table for key positions of single nucleotide polymorphisms (SNPs) were generated, which summarized the key points for quality control during HLA-A, B, C, DRB1 and DQB1 allele typing. Among the listed SNPs, 3 were located at the HLA-A locus, 8 were at the HLA-B locus, 6 were at the C locus, 6 were at the DQB1 locus, and 4 were at the DRB1 locus. To ensure the quality control, an unique sample number for DNA transferring tubes in the process of experiment should be considered.

A protocol for quality control should be enforced by checking all of the key points. The SNPs and critical control points of the alleles should be examined to ensure the accuracy of HLA typing results.