Flow cytometry PRA using lymphocyte pools from random donors.

Area of Science:

• Immunology
• Transplantation Immunology
• Clinical Chemistry

Background:

• Flow cytometry (FC) panel reactive antibody (PRA) assays traditionally use lymphocytes from selected donors.
• Predicting positive HLA crossmatches is crucial for successful organ transplantation.

Purpose of the Study:

• To develop and evaluate a novel FC PRA assay utilizing mixed lymphocyte pools from a large number of randomly selected donors (RD FC PRA).
• To assess the RD FC PRA assay's accuracy in predicting positive HLA crossmatches compared to existing methods.

Main Methods:

• Prepared lymphocyte pools from 120 randomly selected donors.
• Calculated %PRA based on anti-IgG FITC histogram of T cells.
• Compared RD FC PRA with bead FC PRA, antiglobulin-augmented CDC (AHG-CDC) PRA, and calculated %PRA.

Main Results:

• RD FC PRA demonstrated 100% positivity rate in 29 FC crossmatch-positive sera, similar to bead FC PRA.
• RD FC PRA detected low-level HLA antibodies in sensitized patients with negative FC crossmatches (21% positivity rate).
• RD FC PRA showed comparable performance to bead FC PRA in identifying HLA antibodies.

Conclusions:

• The RD FC PRA assay simplifies panel preparation and reduces costs.
• This assay naturally reflects the probability of a positive crossmatch within the relevant donor population.
• RD FC PRA offers a valuable alternative approach for determining % PRA and improving crossmatch prediction.