56-P: Correlation of HLA donor specific antibody (DSA) titers with the luminex mean fluorescence intensity (MFI)

A comparison of two robotic platforms to screen plateletpheresis donors for HLA antibodies as part of a transfusion‐related acute lung injury mitigation strategy

“…For TRALI mitigation, however, detection of antibodies of fixed low‐titer and/or narrow specificity may not appreciably benefit blood recipients but could dramatically shrink the donor base and lead to dangerous apheresis PLT shortages. There appears to be a general correlation between the Luminex NBG ratio and both the MFI (which appears to be related to antibody titer) and the PRA (representing the breadth of donor antigen recognition) 35,36 . As one sets progressively lower cutoff ratios, a few additional strong sera and more low to midlevel MFI/PRA sera are detectable (Fig.…”

“…First, for each alloexposed donor serum, we noted the highest single antigen bead's MFI. The MFI has been positively correlated with antibody titer 35,36 . Second, we calculated a virtual PRA value for each serum sample.…”

“…Weak specificity was assigned when adjusted MFIs less than 1000 were seen on multiple beads containing antigen from the same serologic group, with little or no fluorescence on other beads. Adjusted MFIs have been reported to correlate with antibody titer 35,36 . The maximum adjusted MFI value on any bead within the Class I and II single‐antigen sets was also entered into the database.…”