How do you approach a positive crossmatch after transplant when the clinical picture doesn't support rejection?

Work with your immunology lab to determine if it is a false positive:

1. B cell or T cell positive XMatch? B cells give more false positives.
2. What are the MFI’s - extremely high or close to background?
3. Has the subject recently received antibody infusions that can give high background, such as IVIG, RA...