Chinese Expert Consensus on Antigen Panel Composition for Unexpected Red Blood Cell Antibody Screening and Identification

Recommendations for Antibody Screening Panel Cells‌

1. ‌Cell Composition‌
   • Composed of red blood cells (RBCs) from ‌at least three separate O-type donors‌, confirmed via genetic sequencing to exclude A or B subtypes.
2. ‌Antigen Expression‌
   • Must include: ‌C, c, D, E, e, M, N, S, s, P1, Lea, Leb, Fya, Fyb, Jka, Jkb, Dia, Dib, Mur‌.
3. ‌Antigen Dosage‌
   • Must include homozygous donor RBCs with double-dose expression of: ‌D, C, E, c, e, M, N, S, s, Fya, Fyb, Jka, Jkb‌.
4. ‌Cell Usage‌
   • ‌Do not mix cells from different donors‌ to achieve desired antigen profiles.

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‌Recommendations for Antibody Identification Panel Cells‌

1. ‌Cell Composition‌
   • A combination of ‌≥8 reagent RBCs‌ from individual O-type donors (non-O types allowed for rare antigens but must be clearly labeled).
2. ‌Antigen Expression‌
   • Include cells with phenotypes: ‌R1R1 (CCDee), R2R2 (ccDEE), r’r (Ccddee), r’’r (ccddEe)‌, and ‌three rr (ccddee)‌.
   • Must express: ‌M, N, S, s, P1, Lea, Leb, K, k, Fya, Fyb, Jka, Jkb, Dia, Mur, Wra‌ (to avoid missing low-frequency antibodies in Chinese populations).
3. ‌Antigen Dosage‌
   • Include ‌2–3 homozygous cells‌ for Duffy (at least ‌1 Fyb homozygote‌ due to scarcity of Fya-negative donors in China), MNS, and Kidd systems to avoid missing dosage-dependent antibodies.
4. ‌Antigen Phenotype Patterns‌
   • Ensure ‌dispersed reactivity patterns‌ where a single antibody’s reaction profile does not overlap with others in the panel.
5. ‌Special Cases‌
   • If antibody identification panels are unavailable, combine multiple screening panels to construct identification panels that meet antigen requirements.

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‌Quality Control Recommendations for Panel Cells‌

1. ‌Pre-Market QC‌
   • Test screening/identification panels with ‌weak anti-D controls (<0.1 IU/mL)‌ or other weak antibodies to validate antigen integrity.
   • Perform ‌direct antiglobulin test (DAT)‌ on new batches; discard DAT-positive cells unless corrected.
2. ‌Laboratory QC‌
   • Validate antigen reactivity and test validity using ‌weak antibodies‌ or in-house controls.
   • Perform ‌DAT‌ on new batches to assess compatibility with anti-human globulin (AHG) test cards; discard DAT-positive cells unless corrected.
3. ‌Cell Dilution and Storage‌
   • Dilute reagent cells with ‌low-ionic strength saline (LISS)‌ or dedicated diluents compatible with AHG cards.
   • Label diluted cells with ‌preparation date, storage conditions, and expiration‌.
4. ‌Use of Expired Cells‌
   • Expired panels may be used for ‌confirming/excluding antibody specificity‌ if validated via ‌antigen reactivity controls‌ to ensure accuracy.