A 48-year-old patient is on the kidney transplant waiting list. They are found to be highly sensitized with a Panel Reactive Antibody (PRA) of 95%. The most important cross-match test performed before transplantation is:

• A Complement-dependent cytotoxicity (CDC) crossmatch
• B Flow cytometry crossmatch (FCXM) ✓
• C Virtual crossmatch using solid-phase DSA testing
• D Mixed lymphocyte culture (MLC)

Explanation

The flow cytometry crossmatch (FCXM) is the most sensitive crossmatch technique, detecting low levels of donor-specific antibodies (DSA) missed by CDC crossmatch due to its 10–100 times greater sensitivity. In highly sensitized patients (PRA >80%), FCXM is critical as even low-level DSA can mediate hyperacute or acute ABMR. Virtual crossmatch using solid-phase Luminex DSA testing is used for preliminary matching before organ allocation but cannot fully replace a physical crossmatch in high-risk sensitized patients. CDC crossmatch detects complement-fixing, high-titer antibodies only. MLC detects T-cell alloreactivity but is too slow for clinical use.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

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Written and medically reviewed by the StethoPrep medical team.