C1q Assay Results in Complement-Dependent Cytotoxicity Crossmatch Negative Renal Transplant Candidates with Donor-Specific Antibodies: High Specificity But Low Sensitivity When Predicting Flow Crossmatch.

In complement dependent cytotoxicity crossmatch negative renal transplant candidates with human leukocyte antigen donor-specific antibodies (DSA), both the presence of DSA C1q+ and the dominant DSA fluorescence were significantly associated with a positive flow cytometry crossmatch (FXM+). The C1q+ assay was highly specific, but had low sensitivity when predicting FXM+, so the clinical significance of a FXM+ in the absence of DSA C1q+ remains to be clarified in future studies.