Bridging the gap: Correlating virtual crossmatch assessments with post-transplant immunologic outcomes

Area of Science:

• Immunology
• Transplantation
• Clinical Diagnostics

Background:

• The virtual crossmatch (VXM) is a standard method for evaluating immunological risk in organ transplantation.
• Current validation often focuses on correlation with flow crossmatch (FXM) rather than clinical outcomes.

Purpose of the Study:

• To compare VXM assessment (acceptable vs. unacceptable) with post-transplant outcomes, including donor-specific antibody (DSA) development and antibody-mediated rejection (AMR).
• To evaluate the VXM as a reliable alternative to the FXM in kidney transplantation.

Main Methods:

• Retrospective analysis comparing VXM status to transplant outcomes.
• Assessment of donor-specific antibody (DSA) development and antibody-mediated rejection (AMR).
• Comparison of VXM results with concurrent flow crossmatch (FXM) results.

Main Results:

• An acceptable VXM correlated with fewer post-transplant adverse events.
• Kidney recipients with unacceptable VXMs had significantly higher rates of memory HLA-DSA, AMR, and HLA-DSA associated AMR.
• A high concordance (94.4%) was observed between acceptable VXM and negative FXM results.

Conclusions:

• The VXM is a reliable predictor of transplant outcomes and a suitable alternative to FXM for most kidney transplant recipients.
• The VXM effectively identifies patients at higher risk for adverse outcomes, including AMR.
• Specific scenarios where FXM may still offer additional benefit are identified.