CA titers in CAD patient plasma correlate with the extent of C3 fragment staining on the RBC surface. (A) Complement deposition, quantified as the percentage of hRBCs staining positive for surface C3 fragments after sensitization in CAD plasma and subsequent NHS exposure, is correlated with CA titers in the plasma sample. Correlation analyses were performed on natural log transformed values (see “Materials and methods”) but are depicted as 1:Ab titer for simplicity. All 40 CAD samples were run on the same plate using the same source of NHS and hRBCs. Line represents the line of best fit. n = 40 samples with 2 independent experiments per sample; see also supplemental Table 1. (B) C1s levels were found to correlate with CA titers. As in (A), correlation analyses were performed on natural log transformed values but graphed as 1:Ab titer. n = 40 samples with 2 independent experiments per sample.