Significance of anergy to dinitrochlorobenzene (DNCB) in inflammatory bowel disease: Family and postoperative studies

To evaluate the pathogenetic significance of impaired cellular immunity in inflammatory bowel disease (IBD), we have measured the cutaneous responsiveness to dinitrochlorobenzene (DNCB) among 58 patients with IBD, 33 with Crohn's disease and 25 with ulcerative colitis, 63 of their clinically normal relatives, 24 additional ileitis and colitis patients who had undergone resection of all visibly diseased bowel, and 23 control subjects. Cutaneous anergy to DNCB was demonstrated among 70% of the patients with CD and 48% of those with UC, as against only 9% of controls (P < 0.001). There was no increased incidence of anergy among either 44 first-degee relatives (7%) or 19 spouses (0%), nor was there any special proclivity toward anergy among six pairs of patients with familial inflammatory bowel disease. In Crohn's disease, anergy was still present after bowel resection in six of 10 patients (60%), while in ulcerative colitis anergy was found after colectomy in only two of 14 patients (14%). Our data suggest that the immune defect in patients with inflammatory bowel disease may be a secondary phenomenon. In ulcerative colitis, the defect appears to reverse after colectomy, but in Crohn's disease it persists despite resection. This finding is consistent with the observed tendency of Crohn's disease, but not ulcerative colitis, to inexorable postoperative recurrence.