Abstract:
The objective of this study was to compare different methods in PRA testing and
crossmatching using pronase. The CDC, AHG-CDC and FlowPRA methods were evaluated in
30 renal transplant patients for class I and 41 for class II. DTT treatment was also performed
in CDC. The PRA were measured in the percentage and PRA>10% considered to be positive.
Evaluated FCXM using pronase was used to compare with undigested FCXM.
For HLA class I antibodies, PRA were compared using CDC, AHG-CDC and
FlowPRA. There was only one positive for all three different techniques. Of these 29 CDC
negative, 4 (14%) and 5 (17%) were positive by AHG-CDC and FlowPRA, respectively. PRA
percentage showed <30% by CDC and AHG-CDC, whereas 3/5 of FlowPRA positive showed
percentage >30%. For HLA class II antibodies, CDC and FlowPRA were compared. Three
patients were positive by CDC and by FlowPRA. Nevertheless, when observed PRA
percentage 2/3 of these positive showed PRA>50% by FlowPRA, but CDC showed <30%. For
pronase FCXM, in non T-cell MCF of NC and PC were declined, on average, from 476±45 to
318±50 and 559±28 to 482±41 (p<0.0001), respectively. For T-cell MCF of PC, it declined
from 501±58 to 461±56 but increased from 168±37 to 243±28 in NC.
This study showed discrepancies in the results of PRA by different methods. We
suggest that, FlowPRA is the most sensitive and AHG-CDC is more sensitive than CDC-PRA
in detecting CYNAP antibodies. However, the cost and clinical correlation of FlowPRA
should be considered. In the FCXM, pronase treatment could decrease background
fluorescence or false positive, especially for non-T cell FCXM