P018 Evaluation of labtype CWD and XR assays utilizing labscan3d for high throughput/resolution HLA typing

Abstract

Aim High resolution HLA typing with clinical applications is preferred in some applications of transfusion and transplantation medicine. Concordance of results was determined between new reverse sequence specific oligonucleotide assays (rSSO; LABType CWD and LABType XR, One Lambda, Canoga Park, CA) and our current assays, rSSO (LABType SSO) and sequence-based typing (SBT; SeCore). Methods Forty-eight patient samples previously tested by our current rSSO and SBT assays were selected randomly. The 2 new assays and a new multiplex flow analyzer (LABScan3D TM ) were utilized to detect HLA-A common and well-defined alleles (LABType CWD) and HLA-B and DRB1 alleles at high resolution (LABType XR). DNA was amplified with group specific primers targeting exons 2, 3, 4, and 5 for HLA-A and HLA-B, and exon 2 for HLA-DRB1. Results We determined the concordance between the 2 new and our current assays (Table 1). The LABType CWD identified 6 out of 96 HLA-A alleles (6.25%) at the allele level (4-digit resolution) and was also able to resolve 1 ambiguous allele combination, exceeding the resolution obtained by our current LABType SSO. The LABType XR assay provided results with shorter allele strings in 59 out of 96 HLA-B alleles (61.5%) and 22 out of 96 HLA-DRB1 alleles (22.9%), respectively, exceeding the resolution obtained by our current SeCore SBT without reflux testing. Discordances were observed resulting from false bead reactions or ambiguous allele combinations. Conclusions The new LABType CWD and XR assays are suitable platforms for high throughput testing. Utilization of the LABType XR kits potentially could yield better results than SBT thus making them a consideration for clinical applications requiring quicker turn around time. However, even with LABType XR, additional testing may still be necessary to resolve any remaining discrepancies and ambiguities. Download high-res image (157KB) Download full-size image