Auto and allo prospective T- and B-cell cross-matches by complement-dependent cytotoxicity (CDC), Anti-human globulin (AHG)-enhanced CDC methods are performed for all new transplant candidates. Serum collected within 2 months is used in the preliminary cross-match. If a sensitization event is documented, a serum collected within 2–3 weeks after should be used for cross-match.
Flow T- and B-cell allo cross-matches are performed on all sensitized and/ or retransplant patients. Additionally, auto prospective T and B Flow cross-matches will be done for patients in whom autoimmune disease as the cause of ESRD is communicated at the time of new patient evaluation.
Alternative cross-match: For patients with >80% cPRA, the donor’s HLA typing via buccal swab can be requested instead of cross-matching. Donors can be ruled out if unacceptable donor-specific antigens are present.
The extent of sensitization of each patient at the time of his/her initial evaluation and the following of potentially sensitizing events are monitored by the transplant coordinator and communicated to the histocompatibility laboratory. The pretransplant coordinator should obtain serum samples 2–3 weeks after known sensitizing events and have them sent to the HLA laboratory for storage or testing. Such information is recorded in the HLA management database.
Results of this comprehensive evaluation are submitted to the transplant program within 1 week of the initial visit, and the patient will be listed with UNOS if qualified. The kidney donor options are live donor (both related and unrelated), deceased donor (UNOS waitlist), and paired exchange program.
B. Monthly antibody screening program
All renal transplant candidates are required to submit monthly serum to be screened or used for cross-match. Rotated regularly sera under the program is screened by single antigen bead assay or PRA antibody screen.
Changes in specificity or strength are reviewed and updated in the UNET. All negative-to-positive conversion has to be confirmed by the single antigen bead assay.
C. Interim antibody screen and cross-match
In the case of a sensitizing event after the completion of preliminary patient donor workup, an interim antibody screening by single antigen bead assay is advised to reassess the patient’s antibody specificities and identify possible donor-specific antibody (DSA). The pretransplant coordinator will obtain the serum sample 2–3 weeks after known sensitizing events and have them sent to the HLA laboratory. If antibody profile changes, the Laboratory Director and the transplant team may require interim cross-match by CDC and/or flow.
D. Final cross-match
Prior to transplant
Complete DNA typing for both the patient and donor.
Two HLA antibody samples from two separate appointments and one preliminary CDC/AHG-CDC cross-match with the donor.
Final XM (performed within 2 weeks of scheduled transplant):
Allo T- and B-cell CDC, AHG-CDC, and Flow cross-match, antibody screen on Patient.
Auto T- and B-cell CDC, AHG-CDC (optional).
Serum selection:
Selection of sera for final cross-matching of patients should address the impact of historic and current sensitizing events. Selection recommendations:
