Fig. 4.

Scattergram showing the optical density (OD) values for serum human tropomyosin (hTM)1 IgG in each of the unaffected inflammatory bowel disease (IBD) relatives in comparison with controls (C). OD values above the dotted line indicate positive sera (OD > mean OD from laboratory controls (LC) + 2 s.d.). Solid lines show the median OD value in each group. As indicated, serum hTM1 IgG were higher in unaffected UC relatives than both healthy Crohn's disease (CD) relatives (P = 0.006) and C (P < 0.001).