Head to head comparison of two commercial fecal calprotectin kits as predictor of Mayo endoscopic sub-score and mucosal TNF expression in ulcerative colitis.

BACKGROUND: Fecal calprotectin is widely used to monitor disease activity in patients with inflammatory bowel disease. Multiple commercial kits exist, however, since the analyses are not standardized, these kits cannot be used interchangeably. We aimed to perform a technical evaluation of two kits (Calpro from Calprolab, Norway and Calprest from Eurospital, Italy) and perform a tuning for detection of clinically relevant disease states in ulcerative colitis. MATERIALS AND METHODS: For tuning against different clinical states a total of 116 patients with ulcerative colitis were recruited (67 of which were part of an earlier publication). For the technical evaluation an additional series of 80 random samples from the hospital lab were included. Technical evaluation was done by correlation and limits of agreement analysis; cut-off levels were explored by ROC analysis against clinically relevant actual states. RESULTS: The technical evaluation revealed good correlation between assays, however a non-linear difference was found: At values below 200 mg/kg, no significant bias was found; in the interval 200-1000 mg/kg the Calprest assay measured on average 30% lower than Calpro; and at higher values Calprest measured 60% higher values than Calpro. Both assays predicted Mayo endoscopic score (MES) 0 (cutoff 28: sensitivity 0.38; specificity 0.82 for Calprest; cutoff 28: sensitivity 0.50; specificity 0.77 for Calpro), and MES 2-3 (cutoff 148: sensitivity 0.72; specificity 0.80 for Calprest; cutoff 208: sensitivity 0.64; specificity 0.80 for Calpro), but did not predict normalization of mucosal TNF transcript per se. A combination of calprotectin and MES predicted mucosal TNF transcript values reasonably well (Calpro: sensitivity 0.85, specificity 0.58; Calprest: sensitivity 0.85, specificity 0.61). CONCLUSION: The Calpro and Calprest assays correlated well, but subtle differences were found, underlining the need for kit-specific cut-off values. Both kits were most precise in predicting active inflammation (MES 2-3), but less so for prediction of mucosal healing (MES 0) and normalization of mucosal TNF gene expression.

Repeated intensified infliximab induction - results from an 11-year prospective study of ulcerative colitis using a novel treatment algorithm.

BACKGROUND: Anti-tumour necrosis factor (TNF) agents play a pivotal role in the treatment of moderate to severe ulcerative colitis (UC), and yet, no international consensus on when to discontinue therapy exists. OBJECTIVE: The aim of this study is to study the long-term performance of a treatment algorithm of repeated intensified induction therapy with infliximab (IFX) to remission, followed by discontinuation in patients with UC. PATIENTS AND METHODS: Patients with moderate to severe UC were enroled in an open prospective study design. The following algorithm was implemented: (a) intensified induction treatment to remission (Ulcerative Colitis Disease Activity Index score 0-2); (b) discontinuation of IFX; and (c) reinduction treatment if relapse. Mucosal gene expression for TNF was measured with qPCR. RESULTS: A total of 116 patients were included. The median observation time was 47 and 51 months in intention to treat and per protocol. Remission rates of the first three inductions were 95, 93 and 91% per protocol and 83, 56 and 59% by intention to treat. The median time in remission was 40 months per protocol and 34 months by intention to treat. Long-term remission without further anti-TNF treatment during the observation period was obtained for 41%, with a median observation time of 48 months (range: 18-129 months). The median time to relapse was 33 and 11 months with/without normalization of mucosal TNF, respectively. The 5-year success rate for maintaining the effect of IFX in the algorithm was 66%. CONCLUSION: The treatment algorithm is highly effective for achieving long-term clinical remission in UC. Normalization of mucosal TNF gene expression predicts long-term remission upon discontinuation of IFX.