1.2000
#31
A COMPARISON STUDY OF THE RELATIVE SENSITIVITIES OF AHG-CDC, FLOW CTYOMETRY AND LABSCREEN™ TECHNIQUES FOR DETECTING HLA ANTIBODIES.
S. Pereira, PhD, K. Cunniffe, V. Lim, K. Plamenco, MD and L.A. Baxter-Lowe, PhD. San Francisco CA, UCSF, Surgery.
In renal transplantation, the presence of donor-specific HLA antibodies is associated with early rejection and/or graft loss. Detecting preformed HLA antibodies is vital to donor-specific risk assessments, which in turn dictates clinical management. The sensitivity of three techniques for detecting Class I and II HLA specific antibodies was compared: AHG-CDC crossmatch (XM), flow cytometry (FC) XM after pronase treatment, and LABScreenTM. Previously characterized serum samples (n= 44) were selected to represent the range of HLA titers and specificities that are encountered in routine antibody screening. Cells from individuals with known HLA types were utilized in AHG-CDC and FC XM. Serial dilutions of serum samples containing either Class I and/or Class II HLA alloantibodies were tested with T and B-cells. Preliminary data confirms that flow cytometry and LABScreenTM are comparable and are significantly more sensitive than the AHG-CDC assay in specifically detecting Class I and II alloantibodies. In general, positive results were obtained with both assays at higher dilutions of sample sera. Sera that were clearly negative for HLA antibodies in CDC-AHG XM were unequivocally positive by the FC XM and LABScreenTM methods. In addition, the LABScreenTM method was 100% predictive of a positive FCXM. In conclusion, while FC might be the 'Gold Standard' for XM analysis, the ability to identify HLA antibodies by a method as highly sensitive as LABScreenTM can clearly enhance the diagnostic accuracy of pretransplant HLA antibody analysis and can be a reliable predictor of positive FC XM.