Date: Monday, May 1, 2017
Session Time: 6:00pm-7:00pm
Presentation Time: 6:00pm-7:00pm
Location: Hall D1
Clinical relevance of HLA antibodies identified in solid phase assays includes their ability to generate a positive crossmatch (XM) test, which often precludes transplantation. The aim of the present study was to evaluate the ability of individual solid-phase platforms in predicting positive XM testing.
Methods. Sixty deceased donor (DD) transplant candidate sera with donor-specific anti-HLA antibody (DSA) were included in the study. Antibody identification was done on single-antigen beads (Luminex), with antibody strength expressed in mean fluorescence intensity (MFI). In addition, all samples were also screened for the Luminex C1q (Positive or Negative) and Fc Receptor (FcR)-binding, which was further categorized as Negative (<10%), Weak (11-20%), Moderate (21-50%) or Strong (>50%) of Positive Control value. All sera were cross-matched both by complement-dependent cytotoxicity (CDC) and flow-cytometry (pronase) with T- and B-lymphocytes from deceased donors.
Results. Out of 60 crossmatches, 30 were positive both by CDC and flow-cytometry, 10 were negative by CDC but positive by flow-cytometry and 20 were negative
|DD Crossmatch||DSA MFI||C1q +||FcR Strong||FcR Moderate||FcR Weak||FcR Neg||FcR vs C1q p=|
|Pos CDC / Pos Flow (N=30)||16073±8348||18||30||0||0||0||0.0001|
|Neg CDC / Pos Flow (N=10)||5771±5206||1||4||6||0||0||0.0001|
|Neg CDC / Neg Flow (N=20)||2816±2410||4||0||1||10||9||0.34|
Virtual predictors for a positive CDC crossmatch were: 1) Antibody strength (MFI: 16073±8348 CDC positive vs 3801±3342 CDC negative, p<10-8); 2) Strong positive FcR binding assay (30/30 CDC positive vs 4/30 CDC negative, [Chi]2=42, p<10-8); 3) positive C1q assay (18/30 CDC positive vs 5/30 CDC negative, [Chi]2=10.15, p=0.001).
Virtual predictors for a positive flow/negative cytotoxic crossmatch were: 1) Antibody strength (MFI: 5771+/-5206 flow positive vs 2816±2410 flow negative, p<10-7); 2) Strong/moderate positive FcR binding assay (10/10 flow positive vs 1/20 flow negative, [Chi]2=22, p<10-6).
Conclusions. Strong FcR antibody binding assay predicted positive CDC crossmatches, while moderate FcR antibody binding assay predicted negative CDC/positive flow crossmatches. Positive C1q binding assay correlated with positive CDC crossmatches, but had no prediction value for positive flow/negative CDC crossmatches.
CITATION INFORMATION: Girnita A, Woodle E. Prediction of Positive Cytotoxic and Flow Crossmatches for Sensitized Wait List Candidates: Comparison of Luminex MFI, C1q and FcR Binding Assays. Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:Girnita A, Woodle E. Prediction of Positive Cytotoxic and Flow Crossmatches for Sensitized Wait List Candidates: Comparison of Luminex MFI, C1q and FcR Binding Assays. [abstract]. Am J Transplant. 2017; 17 (suppl 3). https://atcmeetingabstracts.com/abstract/prediction-of-positive-cytotoxic-and-flow-crossmatches-for-sensitized-wait-list-candidates-comparison-of-luminex-mfi-c1q-and-fcr-binding-assays/. Accessed December 13, 2019.
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