The tool "Determination of HLA antigens present in LSA kits according to the Nomenclature for Factors of the HLA System, 2026," developed by IGEN, is based on the study by Osoegawa et al., 2022 (doi: 10.1111/tan.14662) and was structured using bioinformatics tools. Its serological classification follows the guidelines established by Marsh et al., 2026 (doi: 10.1111/tan.70595). The system assists in the interpretation of DSA (donor-specific antibody) presence, particularly regarding alleles not included in LSA kits. Since the algorithm is based on predictive bioinformatics tools, its use must be exercised with caution and mandatory combination with cellular methodologies, such as crossmatches and adsorption/elution.
How it Works:
1. Data Entry: The user provides the donor's allele (or probable allele). For a more precise determination of the probable allele, it is recommended to consult Annex 2 of the "Guidelines for HLA Reports of Deceased Donors" published by ABHI.
2. Results: The tool returns information categorized into specific dictionaries (such as P group and serological classification) and indicates which beads should be considered for DSA analysis in LSA kits (standard One Lambda, One Lambda Explex, and Immucor).
Important Recommendations:
- Donor antigens that are 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 the B1501 antigen (which encompasses B*15:01, B*15:06, B*15:07, B*15:20, B*15:27, and B*15:04 itself) should be disregarded.
- A physical (real) crossmatch is indispensable in two critical scenarios where the virtual crossmatch is compromised:
1. Discrepancies between alleles of the same antigen (e.g., DQB1*06:01 positive and DQB1*06:04 negative).
2. When the donor's incompatible antigen is not available in the commercial kit (e.g., A*02:11 or B*39:10).
- Due to the risk of false-positive reactions inherent to LSA kits, the interpretation of virtual crossmatches may not be entirely accurate. Laboratories must carefully interpret LSA results before applying this tool.
LSA Kit Information:
This tool was developed based on the following LSA kit lots:
| 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. Developed through bioinformatics and updated according to the 2026 HLA nomenclature, its use is recommended for research purposes only and in combination with cellular tests. IGEN has already identified new splits in recently determined antigens; however, this information will only be released following publication in peer-reviewed journals.