The HLA serotype determination tool developed by IGEN is based on the study by Osoegawa et al. 2022 (doi: 10.1111/tan.14662). It helps in interpreting the presence of DSA (donor-specific antibody), particularly concerning alleles not included in LSA kits. Since the serotype determination algorithm presented by the 18th IHIWS relies on bioinformatics tools, its use should be cautious and combined with cell-based assays (crossmatching and adsorption/elution).
How the Tool Works:
1. Data Entry: The user provides the donor's allele (or probable allele). For a more precise determination of the possible allele, it is advisable to consult the ABHI's Appendix #2 of Deceased Donor HLA Report Guidelines.
2. Results: The tool returns information categorized into different dictionaries, such as P group and serological by IMGT and ABHI. Additionally, it classifies the serotype as defined by the 18th IHIWS and indicates which antigens (beads) should be considered for DSA analysis in LSA kits (standard One Lambda, One Lambda Explex, and Immucor).
Important Recommendations:
- Donor antigens equivalent to the recipient's HLA antigens should not be considered DSA. For example, if the patient is B*15:04, any MFI value present in beads with antigens of serotype B-1501 should not be considered, i.e., B*15:01, B*15:06, B*15:07, B*15:20, B*15:27, and B*15:04 itself.
- Virtual crossmatching may be compromised in two situations (in these cases, real crossmatching is indispensable):
1. Discrepancies between alleles of the same serotype, like DQB1*06:01 positive and DQB1*06:04 negative.
2. When the donor's incompatible serotype is not available in the commercial kit, like A*02:11 (A-0211) or B*39:10 (B-3910).
- Due to false-positive reactions in LSA kits, the interpretation of virtual crossmatching could be misleading. Therefore, laboratories should carefully interpret LSA results before using this tool.
Information about LSA kit:
This tool was developed based on the LSA kits of the following batches:
| One Lambda | Immucor | ||
|---|---|---|---|
| Single I | Single II | Single I | Single II |
| LOT 14 | LOT 15 | LOT 3013550/3013361 | LOT 3013660/3013549 |
| LOT 13 | LOT 14 | LOT 3013288/3013199 | LOT 3013205/3013101 |
| LOT 12 | LOT 13 | LOT 3013021/3012929 | LOT 3012643/2013012 |
| LOT 11 | LOT 12 | LOT 3012700/3012637 | LOT 3013017/3012897 |
| LOT 10 | LOT 11 | LOT 3011313/3011181 | LOT 3012484/3012388 |
Disclaimer:
IGEN emphasizes that it is not responsible for the results generated by this tool. It was developed based on the work of the 18th IHIWS and is recommended only for research purposes and in combination with cellular tests. It is important to note that we have identified splits in some recently determined serotypes. However, these details will only be disclosed after publication in peer-reviewed journals.