No change in autoreactive Abs in CPB patients after surgery. Human sera before (d0) and after CPB (d10 and > 4 months) were diluted in 20% FCS/PBS and incubated on commercially available HEp2-ANA slides. Bound Abs were visualized with FITC-conjugated anti–human IgG. The staining did not reveal any increase of autoreactive Abs postoperatively. Patient A is representative of the majority of patients (124 of 166) who showed no autoreactive Abs at any time. The 2 patients shown in panels B and C already had Abs against nuclear or cytoplasmic Ags before surgery. These did not change in quality or quantity after surgery. Twenty of the 166 patients had similar findings.