Flow cytometry PRA using lymphocyte pools from random donors

Abstract

Results: In 29 FC crossmatch positive sera, the positivity rate for the bead FC, RD FC, and AHG-CDC PRA was 100, 100, and 79%, and the mean %PRA was 77% 6 20%, 73% 6 21%, and 33% 6 33%, respectively. The RD FC %PRA was not significantly different from the bead FC %PRA (P 5 0.205). In 19 sensitized patients with a negative FC crossmatch, the positivity rate was 21% using the RD FC PRA and 16% using the bead FC PRA, which suggested that both assays had similar abilities to detect low levels of HLA antibodies.Conclusions: The RD FC PRA assay allows easy panel preparation, reduces cost, and naturally reflects the probabilities of a positive crossmatch in the population to which the cadaveric donor belongs. Therefore, this new assay is expected to be useful as another approach to determine the % PRA. q 2007

A Novel Flow Cytometric Method for the Simultaneous Detection of Antibodies Against Platelet, Lymphocyte, And Neutrophil

“…2). In a given pool, alloantibodies can be suspected to exist based on the percentage of the positive peaks of the total gated cells, according to the assumed number of reactive donors among the total number of donors in the pool (15)(16)(17). First, if a single peak arose, the M1 region was set around its major portion.…”

“…2) was created equidistantly around the position of the modal value for the entire gated cells, the upper and lower ends of which were set to maximally cover the symmetric portion of the peak (13,14). When multiple peaks arose, the M1 region was drawn around one or more positive peaks only (15)(16)(17). The individual MFI ratio for each of the three cell types for a patient were then calculated by dividing the average MFI value of the patient's samples in duplicate by the average MFI value of the six negative controls included in the run.…”

Report From a Consensus Conference on the Sensitized Patient Awaiting Heart Transplantation

“…17 The FlowPRA test consists of a pool of microparticle beads coated with full HLA Class I or Class II phenotype derived from purified HLA-bearing cell lines. 18 The percentage of PRAs can be determined by calculating the percentage of beads that react positively with patient sera.…”

Flow cytometry antibody screening using pooled red cells

“…This method is more sensitive than the MFI ratio for comparisons between a control and a sample, and is particularly useful in cases in which an ancillary peak is formed (7).…”

“…Flow cytometry (FC) has been previously utilized for antibody detection, including the detection of red cell autoantibodies (4,5), HLA alloantibodies (6,7), platelet crossmatching (8)(9)(10), and other immmunohematological applications (11,12). Recently, FC was also introduced for the screening of antibodies to red cells for automation by Roback et al (3,13).…”