Interventions for treating lymphocytic colitis

BACKGROUND

Lymphocytic colitis is a cause of chronic diarrhea. It is a subtype of microscopic colitis characterized by chronic, watery, non-bloody diarrhea and normal endoscopic and radiologic findings. The etiology of this disorder is unknown.Therapy is based mainly on case series and uncontrolled trials, or by extrapolation of data for treating collagenous colitis, a related disorder. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate the efficacy and safety of treatments for clinically active lymphocytic colitis.

SEARCH METHODS

The MEDLINE, PUBMED and EMBASE databases were searched from inception to 11 August 2016 to identify relevant papers. Manual searches from the references of included studies and relevant review articles were performed.Abstracts from major gastroenterological meetings were also searched to identify research submitted in abstract form only. The trial registry web site www.ClinicalTrials.gov was searched to identify registered but unpublished trials. Finally, the Cochrane Central Register of Controlled Trials and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register were searched for other studies.

SELECTION CRITERIA

Randomized controlled trials assessing medical therapy for patients with biopsy-proven lymphocytic colitis were considered for inclusion DATA COLLECTION AND ANALYSIS: Data was independently extracted by at least two authors. Any disagreements were resolved by consensus. Data were analyzed on an intention-to-treat (ITT) basis. The primary outcome was clinical response as defined by the included studies. Secondary outcome measures included histological response as defined by the included studies, quality of life as measured by a validated instrument and the occurrence of adverse events. Risk ratios (RR) and 95% confidence intervals (CI) were calculated for dichotomous outcomes. The methodological quality of included studies was evaluated using the Cochrane risk of bias tool. The overall quality of the evidence supporting the primary outcome and selected secondary outcomes was assessed using the GRADE criteria. Data were combined for analysis if they assessed the same treatments. Dichotomous data were combined using a pooled RR along with corresponding 95% CI. A fixed-effect model was used for the pooled analysis.

MAIN RESULTS

Five RCTs (149 participants) met the inclusion criteria. These studies assessed bismuth subsalicylate versus placebo, budesonide versus placebo, mesalazine versus mesalazine plus cholestyramine and beclometasone dipropionate versus mesalazine. The study which assessed mesalazine versus mesalazine plus cholestyramine and the study which assessed beclometasone dipropionate versus mesalazine were judged to be at high risk of bias due to lack of blinding. The study which compared bismuth subsalicylate versus us placebo was judged as low quality due to a very small sample size and limited data. The other 3 studies were judged to be at low risk of bias. Budesonide (9 mg/day for 6 to 8 weeks) was significantly more effective than placebo for induction of clinical and histological response. Clinical response was noted in 88% of budesonide patients compared to 38% of placebo patients (2 studies; 57 participants; RR 2.03, 95% CI 1.25 to 3.33; GRADE = low). Histological response was noted in 78% of budesonide patients compared to 33% of placebo patients (2 studies; 39 patients; RR 2.44, 95% CI 1.13 to 5.28; GRADE = low). Forty-one patients were enrolled in the study assessing mesalazine (2.4 g/day) versus mesalazine plus cholestyramine (4 g/day). Clinical response was noted in 85% of patients in the mesalazine group compared to 86% of patients in the mesalazine plus cholestyramine group (RR 0.99, 95% CI 0.77 to 1.28; GRADE = low). Five patients were enrolled in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks versus placebo). There were no differences in clinical (P=0.10) or histological responses (P=0.71) in patients treated with bismuth subsalicylate compared with placebo (GRADE = very low). Forty-six patients were enrolled in the trial studying beclometasone dipropionate (5 mg/day or 10 mg/day) versus mesalazine (2.4 g/day). There were no differences in clinical remission at 8 weeks (RR 0.97; 95% CI 0.75 to 1.24; GRADE = low) and 12 months of treatment (RR 1.29; 95% CI 0.40 to 4.18; GRADE = very low). Although patients receiving beclometasone dipropionate (84%) and mesalazine (86%) achieved clinical remission at 8 weeks, it was not maintained at 12 months (26% and 20%, respectively). Adverse events reported in the budesonide studies include nausea, vomiting, neck pain, abdominal pain, hyperhidrosis and headache. Nausea and skin rash were reported as adverse events in the mesalazine study. Adverse events in the beclometasone dipropionate trial include nausea, sleepiness and change of mood. No adverse events were reported in the bismuth subsalicylate study.

AUTHORS' CONCLUSIONS

Low quality evidence suggests that budesonide may be effective for the treatment of active lymphocytic colitis. This benefit needs to be confirmed by a large placebo -controlled trial. Low quality evidence also suggests that mesalazine with or without cholestyramine and beclometasone dipropionate may be effective for the treatment of lymphocytic colitis, however this needs to be confirmed by large placebo-controlled studies. No conclusions can be made regarding bismuth subsalicylate due to the very small number of patients in the study, Further trials studying interventions for lymphocytic colitis are warranted.

Oral 5-aminosalicylic acid for induction of remission in ulcerative colitis

BACKGROUND

Oral 5-aminosalicylic acid (5-ASA) preparations were intended to avoid the adverse effects of sulfasalazine (SASP) while maintaining its therapeutic benefits. Previously, it was found that 5-ASA drugs in doses of at least 2 g/day, were more effective than placebo but no more effective than SASP for inducing remission in ulcerative colitis. This updated review includes more recent studies and evaluates the efficacy and safety of 5-ASA preparations used for the treatment of mild to moderately active ulcerative colitis.

OBJECTIVES

The primary objectives were to assess the efficacy, dose-responsiveness and safety of oral 5-ASA compared to placebo, SASP, or 5-ASA comparators for induction of remission in active ulcerative colitis. A secondary objective of this systematic review was to compare the efficacy and safety of once daily dosing of oral 5-ASA with conventional (two or three times daily) dosing regimens.

SEARCH METHODS

A computer-assisted literature search for relevant studies (inception to July 9, 2015) was performed using MEDLINE, EMBASE and the Cochrane Library. Review articles and conference proceedings were also searched to identify additional studies.

SELECTION CRITERIA

Studies were accepted for analysis if they were randomized controlled clinical trials of parallel design, with a minimum treatment duration of four weeks. Studies of oral 5-ASA therapy for treatment of patients with active ulcerative colitis compared with placebo, SASP or other formulations of 5-ASA were considered for inclusion. Studies that compared once daily 5-ASA treatment with conventional dosing of 5-ASA (two or three times daily) and 5-ASA dose ranging studies were also considered for inclusion.

DATA COLLECTION AND ANALYSIS

The outcomes of interest were the failure to induce global/clinical remission, global/clinical improvement, endoscopic remission, endoscopic improvement, adherence, adverse events, withdrawals due to adverse events, and withdrawals or exclusions after entry. Trials were separated into five comparison groups: 5-ASA versus placebo, 5-ASA versus sulfasalazine, once daily dosing versus conventional dosing, 5-ASA versus comparator 5-ASA, and 5-ASA dose-ranging. Placebo-controlled trials were subgrouped by dosage. SASP-controlled trials were subgrouped by 5-ASA/SASP mass ratios. Once daily versus conventional dosing studies were subgrouped by formulation. 5-ASA-controlled trials were subgrouped by common 5-ASA comparators (e.g. Asacol, Claversal, Salofalk and Pentasa). Dose-ranging studies were subgrouped by 5-ASA formulation. We calculated the relative risk (RR) and 95% confidence intervals (95% CI) for each outcome. Data were analyzed on an intention-to-treat basis.

MAIN RESULTS

Fifty-three studies (8548 patients) were included. The majority of included studies were rated as low risk of bias. 5-ASA was significantly superior to placebo with regard to all measured outcome variables. Seventy-one per cent of 5-ASA patients failed to enter clinical remission compared to 83% of placebo patients (RR 0.86, 95% CI 0.82 to 0.89). A dose-response trend for 5-ASA was also observed. No statistically significant differences in efficacy were found between 5-ASA and SASP. Fifty-four per cent of 5-ASA patients failed to enter remission compared to 58% of SASP patients (RR 0.90, 95% CI 0.77 to 1.04). No statistically significant differences in efficacy or adherence were found between once daily and conventionally dosed 5-ASA. Forty-five per cent of once daily patients failed to enter clinical remission compared to 48% of conventionally dosed patients (RR 0.94, 95% CI 0.83 to 1.07). Eight per cent of patients dosed once daily failed to adhere to their medication regimen compared to 6% of conventionally dosed patients (RR 1.36, 95% CI 0.64 to 2.86). There does not appear to be any difference in efficacy among the various 5-ASA formulations. Fifty per cent of patients in the 5-ASA group failed to enter remission compared to 52% of patients in the 5-ASA comparator group (RR 0.94, 95% CI 0.86 to 1.02). A pooled analysis of 3 studies (n = 1459 patients) studies found no statistically significant difference in clinical improvement between Asacol 4.8 g/day and 2.4 g/day used for the treatment of moderately active ulcerative colitis. Thirty-seven per cent of patients in the 4.8 g/day group failed to improve clinically compared to 41% of patients in the 2.4 g/day group (RR 0.89; 95% CI 0.78 to 1.01). Subgroup analysis indicated that patients with moderate disease may benefit from the higher dose of 4.8 g/day. One study compared (n = 123 patients) Pentasa 4 g/day to 2.25 g/day in patients with moderate disease. Twenty-five per cent of patients in the 4 g/day group failed to improve clinically compared to 57% of patients in the 2.25 g/day group (RR 0.44; 95% CI 0.27 to 0.71). A pooled analysis of two studies comparing MMX mesalamine 4.8 g/day to 2.4 g/day found no statistically significant difference in efficacy (RR 1.03, 95% CI 0.82 to 1.29). There were no statistically significant differences in the incidence of adverse events between 5-ASA and placebo, once daily and conventionally dosed 5-ASA, 5-ASA and comparator 5-ASA formulation and 5-ASA dose ranging (high dose versus low dose) studies. Common adverse events included flatulence, abdominal pain, nausea, diarrhea, headache and worsening ulcerative colitis. SASP was not as well tolerated as 5-ASA. Twenty-nine percent of SASP patients experienced an adverse event compared to 15% of 5-ASA patients (RR 0.48, 95% CI 0.37 to 0.63).

AUTHORS' CONCLUSIONS

5-ASA was superior to placebo and no more effective than SASP. Considering their relative costs, a clinical advantage to using oral 5-ASA in place of SASP appears unlikely. 5-ASA dosed once daily appears to be as efficacious and safe as conventionally dosed 5-ASA. Adherence does not appear to be enhanced by once daily dosing in the clinical trial setting. It is unknown if once daily dosing of 5-ASA improves adherence in a community-based setting. There do not appear to be any differences in efficacy or safety among the various 5-ASA formulations. A daily dosage of 2.4 g appears to be a safe and effective induction therapy for patients with mild to moderately active ulcerative colitis. Patients with moderate disease may benefit from an initial dose of 4.8 g/day.

Differential expression of two tropoelastin genes in zebrafish

Elastin is the extracellular matrix protein responsible for properties of extensibility and elastic recoil in large blood vessels, lung and skin of most vertebrates. Elastin is synthesized as a monomer, tropoelastin, but is rapidly transformed into its final polymeric form in the extracellular matrix. Until recently information on sequence and developmental expression of tropoelastins was limited to mammalian and avian species. We have recently identified and characterized two expressed tropoelastin genes in zebrafish. This was the first example of a species with multiple tropoelastin genes, raising the possibility of differential expression and function of these tropoelastins in elastic tissues of the zebrafish. Here we have investigated the temporal expression and tissue distribution of the two tropoelastin genes in developing and adult zebrafish. Expression was detected early in skeletal cartilage structures of the head, in the developing outflow tract of the heart, including the bulbus arteriosus and the ventral aorta, and in the wall of the swim bladder. While the temporal pattern of expression was similar for both genes, the upregulation of eln2 was much stronger than that of eln1. In general, both genes were expressed and their gene products deposited in most of the elastic tissues examined, with the notable exception of the bulbus arteriosus in which eln2 expression and its gene product was predominant. This finding may represent a sub-specialization of eln2 to provide the unique architecture of elastin and the specific mechanical properties required by this organ.