Table 1.

Overview of methods used to detect donor-recipient compatibility and identify DSA.

HLA Antibody Detection Method	Features	Advantages	Disadvantages
Single-antigen bead (SAB) assay	Multiplexed detection of antibodies against ~100 HLA Class I and Class II antigens simultaneously.	• Most sensitive and granular method of identifying HLA antibodies. • Possible identification of allele-specific antibody.	• Potential detection of antibodies that are not clinically relevant. • False positive reaction patterns (e.g. denatured and cryptic epitope reactivity). • Variation in cut-offs for positive threshold between centers.
Flow cytometric crossmatch	Detection of antibodies that bind to donor HLA present on the cell surface.	Detects anti-donor HLA antibodies that are present at moderate strength.	• Reliability dependent on quality and source of target cells. • Difficulty in identifying HLA antibody specificities for highly and broadly sensitized patients. • Unreliable detection of low level but clinically relevant HLA antibodies.
CDC crossmatch	Detection of antibodies that bind to donor HLA present on the cell surface and can mediate cell lysis in the presence of complement.	Detects anti-donor HLA antibodies that are present at high strength.	• Not sensitive at detecting moderate or low-level HLA antibodies that are clinically relevant for HSCT.