Frequently relapsing Crohn's disease is characterized by persistent elevation in interleukin-6 and soluble interleukin-2 receptor serum levels duringremission

We examined immune and inflammatory activation during remission in patients with Crohn's disease who presented with various clinical profiles (prolong ed remission vs, relapsing disease). Thirty-six patients with at least 3 ye ars' follow-up starting: from a remission period were studied retrospective ly. Relapses were defined by a retrospective calculation of the Crohn's dis ease activity index or by the clinical judgement of the physicians in charg e of the patients. Disease course over the study period was assessed by the mean number of annual relapses. Analysis used measurements during remissio n of the following: erythrocytes sedimentation rate, relative lymphocytosis , acid alpha(1)-glycoprotein, interleukin-6 (IL-6), and soluble interleukin -2 receptor (sIL-2R) serum levels. During the study period 21 patients expe rienced at least one relapse and 15 did not. Mean serum levels of sIL-2R an d mean relative lymphocytosis in remission significantly discriminated betw een relapsing and nonrelapsing patients. Only the mean sIL-2R serum level w as selected by multivariate analysis, with a cutoff value of 82 pM/1 (sensi tivity of 76% and specificity of 80%). The only features correlated with me an number of annual relapses in the relapsing patients were mean serum leve ls of sIL-2R (r=0.58, P=0.015) and IL-6 in remission (r=0.45, P=0.039). Mul tivariate analysis demonstrated statistical significance only for the mean serum level of IL-6 (P=0.014). In Crohn's disease the persistent elevation in sIL-2R serum levels during remission corresponds to chronic active disea se, while high serum levels of IL-6 in these patients is associated with a high frequency of relapse.