A reduction of at least 50% in either of two different Crohn’s disease endoscopic activity scores after 26 weeks of treatment predicted those patients likely to be off of corticosteroid therapy after about 1 year of treatment, with a sensitivity approaching 75%, reported Dr. Marc Ferrante and his coinvestigators.
The study provides evidence that this cutoff could be used as a reliable predictor of clinical response, but it needs to be studied further, according to the authors, who are members of the International Organization for the Study of Inflammatory Bowel Diseases. The study was published in the Novemberissue of Gastroenterology.
Another study, published in the same issue of Gastroenterology, evaluated the reliability of the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), an instrument recently created to assess the endoscopic severity of UC. This study randomized 25 investigators to assess and score 28 endoscopic videos of patients with UC – without knowledge of clinical features in most cases. The results indicated that the UCEIS provides a "satisfactory" level of intrainvestigator and interinvestigator agreement and that it is "a reliable instrument for measuring the endoscopic disease activity of UC," according to Dr. Simon Travis, of the translational gastroenterology unit at John Radcliffe Hospital, Oxford, England, and his coinvestigators.
The version of the UCEIS that provides a score from 0 to 8, based on findings of vascular pattern, bleeding, and erosions/ulcers, is the "favored version" but needs to be validated further, they concluded (Gastroenterol. 2013 July 29 [doi: 10.1053/j.gastro.2013.07.024]).
In the Crohn’s disease (CD) study, which used data on 172 patients enrolled in SONIC (Study of Biologic and Immunomodulator Naive Patients in Crohn’s Disease), Dr. Ferrante, of the department of gastroenterology at University Hospitals Leuven, Belgium, and his colleagues identified a cutoff point in two endoscopic response scores after 26 weeks of treatment that was predictive of clinical response at 50 weeks.
At baseline, the patients had endoscopic lesions and CD Activity Index (CDAI) scores of 220-450 points (median, 277). Their median age was 34 years, and they had been diagnosed with CD for a median of 2.5 years. The patients were dependent on corticosteroids and were randomized to treatment with infliximab (Remicade) infusions and/or oral azathioprine, and were followed to 50 weeks. The primary endpoint of this study was corticosteroid-free clinical remission (CFREM) at week 26, and one of the secondary endpoints was complete healing of mucosal ulcerations.
The investigators evaluated different cutoff points of endoscopic responses for two methods used to score the severity of endoscopic lesions: SES-CD (Simple Endoscopic Score for CD) and CDEIS (CD Endoscopic Index of Severity).
Almost half of the patients achieved mucosal healing at the 26th week.
A decrease from baseline in the SES-CD of at least 50% at week 26 "appeared to be the best discriminative cutoff value" for predicting patients most likely to be in clinical remission (off steroids at week 50). This degree of SES-CD response was met by 112 (65%) patients, with 74% sensitivity and 48% specificity for predicting CFREM at week 50.
For the CDEIS values, the best cutoff was at least a 45% drop from baseline at week 26 for predicting patients most likely to achieve CFREM at week 50, with 75% sensitivity and 45% specificity.
Because of the "subtle" difference between the two measures (50% and 45% cutoffs), "we propose a definition of endoscopic response with a decrease in baseline in CDEIS of at least 50% at week 26 for both tests," the authors wrote. (For CDEIS, the 50% cutoff had a sensitivity of 73% and a specificity of 46%.)
"As such, this endoscopic endpoint could serve as a reliable predictor of the midterm clinical outcome of therapies," Dr. Ferrante and his coauthors concluded. A 50% reduction in endoscopic activity from baseline also has potential for use as an endpoint in studies evaluating pharmacotherapy or treatment strategies "to show healing capacity," they wrote.
These cutoff values should be validated in a prospective study, which should also look at correlations between the endoscopic response and "disease-modifying long-term outcomes," such as a sustained clinical response or surgery, they added.
In the study that evaluated the reliability of the UCEIS, 25 investigators from North America and Europe were randomized to assess 28 of 57 sigmoidoscopy videos of patients with UC, which included some duplicates to evaluate intraobserver reliability. Clinical details such as the number of stools per day were provided for only two of the videos. They were also trained.
The UCEIS provides a score of 0 to 8 based on the sum of three descriptors: vascular pattern (normal, patchy obliteration, or obliterated), bleeding (none, mucosal, luminal mild, luminal moderate, or severe), and erosions and ulcers (none, erosions, superficial ulcer, or deep ulcer). Almost 700 video evaluations were performed.