Flow cytometry antibody screening using pooled red cells.

Area of Science:

• Transfusion Medicine
• Immunology
• Clinical Pathology

Background:

• Column agglutination technique (CAT) is standard for red cell alloantibody screening.
• Flow cytometry (FC) offers accurate, rapid, and cost-effective screening.
• Investigating FC's potential for pooled red cell screening, a technique not viable with CAT.

Purpose of the Study:

• To evaluate the feasibility of pooling screening red cells for flow cytometry (FC) analysis.
• To compare the sensitivity of pooled versus individual red cells in FC screening.
• To assess the impact of pooling on FC-based red cell alloantibody detection.

Main Methods:

• Prepared individual cells (CSi), 1:2 pooled cells (CSp), and 1:3 pooled cells (CS1/3) from a commercial panel for FC screening.
• Created a pooled panel (RSp) from 120 group O donors.
• Compared endpoint titrations and sensitivities of different pooling strategies with and without polyethylene glycol (PEG).

Main Results:

• Pooled cells diluted 1 in 3 (CS1/3) showed slightly reduced sensitivity compared to individual cells (CSi).
• FC screening of CSi and CSp showed no significant difference without PEG (P = 0.125) but a significant difference with PEG (P = 0.016).
• Reactivity in the RSp panel correlated with local donor antigen frequencies.

Conclusions:

• A trend toward decreased sensitivity was observed when using pooled red cells with FC.
• Pooled red cells, particularly from group O donors, may serve as a viable method for characterizing known antibodies.
• FC offers a sensitive platform, but pooling strategies require careful consideration to maintain diagnostic accuracy.