FIG. 4.

Serum IgG and IgA binding to HupB. (A and B) ELISA wells coated with GST-HupB or GST-histone H1(69-171) were reacted with sera from 31 UC patients (closed symbols) and nine healthy controls (open symbols) and detected with anti-human IgG. Specific absorbances were calculated by subtracting nonspecific binding to GST alone. pANCA titers were previously determined for this serum panel. (A) Comparison of IgG anti-HupB binding and pANCA titer. (B) Comparison of IgG anti-HupB and anti-histone H1(69-171). Data are shown for a 1:1,000 dilution of primary sera; qualitatively similar results were observed for 1:200 to 1:2,000 dilutions. (C) Sera from 30 patients (10 each for UC and CD patients and healthy controls [Normal]) were reacted with GST-HupB and detected with anti-human IgA. Specific absorbances (after subtraction of binding to GST alone) are shown for a 1:200 serum dilution; qualitatively similar results were obtained with dilutions between 1:100 and 1:1,000. Positive and negative values are defined as those above or below the mean plus 2 standard deviations for the healthy control group.