Collagenous colitis in a Japanese patient

Growth hormone abolishes the negative effects of everolimus on intestinal wound healing

AIM: To investigate whether the simultaneous treatment with human growth hormone (hGH) abolishes the negative effects of everolimus on anastomotic healing.

METHODS: Forty-eight male Sprague-Dawley-rats were randomized to three groups of 16 animals each (I: vehicle; II: everolimus 3 mg/kg po; III: everolimus 3 mg/kg po + hGH 2.5 mg/kg sc). Animals were pre-treated with hGH and/or everolimus daily for seven days. Then a standard anastomosis was created in the descending colon and treatment was continued for another seven days. The anastomosis was resected in toto and the bursting pressure was assessed as a mechanical parameter of intestinal healing. Moreover, biochemical (Hydroxyproline, PCNA, MPO, MMP-2 and MMP-9) and histological (cell density, angiogenesis, amount of granulation tissue) parameters of intestinal healing were assessed.

RESULTS: Anastomotic bursting pressure was significantly reduced by everolimus and a simultaneous treatment with hGH resulted in considerably higher values (I: 134 ± 19 mmHg, II: 85 ± 25 mmHg, III: 114 ± 25 mmHg; P < 0.05, I vs II; P = 0.09, I vs III and II vs III) Hydroxyproline concentration was significantly increased by hGH compared to everolimus alone (I: 14.9 ± 2.5 μg/mg, II: 8.9 ± 3.6 μg/mg, III: 11.9 ± 2.8 μg/mg; P < 0.05, I vs II/III and II vs III). The number of MPO-positive cells was reduced significantly by hGH compared to everolimus alone (I: 10 ± 1 n/mm², II: 15 ± 3 n/mm², III: 9 ± 2 n/mm²; P < 0.05, I vs II and II vs III), while the number of PCNA-positive cells were increased by hGH (I: 28 ± 3 /mm², II: 12 ± 3 /mm², III: 26 ± 12 /mm²; P < 0.05, I vs II and II vs III). Corresponding to these biochemical findings, HE-histology revealed significantly increased amount of granulation tissue in hGH-treated animals.

CONCLUSION: Inhibition of intestinal wound healing by everolimus is partially neutralized by simultaeous treatment with hGH. Both inflammation as well as collagen deposition is influenced by hGH.

Everolimus interferes with the inflammatory phase of healing in experimental colonic anastomoses

BACKGROUND

Delayed wound healing is a serious side effect of mTOR inhibitor-based immunosuppression after solid organ transplantation. The aim of this study was to test the hypothesis that the mTOR inhibitor everolimus interferes with the inflammatory phase of healing in experimental colonic anastomoses.

MATERIALS AND METHODS

Thirty male Sprague-Dawley rats received a colonic anastomosis. Then, animals were randomized to three groups of daily treatment with either vehicle or everolimus in two different dosages (1.0mg/kg or 3.0mg/kg). After 7 d, rats were sacrificed, and mechanical, histologic, and biochemical parameters of intestinal healing were assessed.

RESULTS

Anastomotic bursting pressure was significantly decreased by everolimus in both dosages, whereas hydroxyproline content was reduced only by the high everolimus dosage. Everolimus diminished cellular proliferation and new vessel growth. Furthermore, both quantity as well as quality of newly synthesized collagen fibers in the anastomotic granulation tissue was reduced. On the other hand, myeloperoxidase-positive (MPO) cells and interleukin-6 (IL-6) concentrations were increased, as was the activity of matrix-metalloproteinases MMP-2 and MMP-9.

CONCLUSION

Everolimus interferes with the inflammatory phase of healing. However, it remains unclear whether this phenomenon is involved in everolimus impairment of experimental anastomotic repair.

Linear mucosal defect may be characteristic of lansoprazole-associated collagenous colitis

BACKGROUND

Although some cases of collagenous colitis have been induced by lansoprazole (LPZ), the clinicopathologic features of LPZ-associated collagenous colitis have not been elucidated.

OBJECTIVE

To elucidate the clinical, endoscopic, and histopathologic features of LPZ-associated collagenous colitis.

DESIGN

Retrospective case study.

PATIENTS

The subjects were 13 patients with collagenous colitis diagnosed during a period from 2002 to 2007.

MAIN OUTCOME MEASUREMENTS

The colonoscopic and histopathologic findings were compared retrospectively between 9 cases of LPZ use (LPZ group) and 4 cases without the use of LPZ (non-LPZ group).

RESULTS

A colonoscopy revealed a linear mucosal defect more frequently in the LPZ group (7 of 9 cases [78%]) than in the non-LPZ group (0 of 4 cases [0%], P = .02). Friable mucosa was also noted in 4 patients (44%) in the LPZ group but none in the non-LPZ group. The colonoscopic finding in the non-LPZ group was either normal mucosa or nonspecific minimal abnormalities, whereas patients in the LPZ group had either a linear mucosal defect, mucosal bleeding, or both (P = .001). On histologic examination, the subepithelial collagen band was thicker in patients in the LPZ group than in those in the non-LPZ group (median 45 vs 26.3 mum). All patients in the LPZ group recovered from diarrhea after discontinuance of LPZ.

LIMITATION

A small number of patients.

CONCLUSIONS

Linear mucosal defects and friable mucosa may be characteristic colonoscopic findings in cases of LPZ-associated collagenous colitis.

Systematic review: microscopic colitis

BACKGROUND

Collagenous and lymphocytic colitis are fairly common causes of chronic non-bloody diarrhoea, especially in elderly female.

AIM

To present a systematic review of microscopic colitis.

METHODS

A PubMed search using the MeSH terms microscopic colitis, collagenous colitis, lymphocytic colitis and chronic diarrhoea was performed.

RESULTS

Annual incidence of each disorder is 4-6/100,000 inhabitants. The aetiology is unknown. Clinical characteristics are well described and there is an association with autoimmune diseases. Budesonide is the best-documented short-term treatment of collagenous colitis. In meta-analysis pooled odds ratio for clinical response after 6-8 weeks of treatment was 12.3 (95% CI: 5.5-27.5) in comparison with placebo. The evidence for bismuth subsalicylate is weaker and the effectiveness of other alternatives such as loperamide, cholestyramine, aminosalicylates, probiotics, or Boswellia serrata extract is unknown. Although unproven, in unresponsive severe disease azathioprine or methotrexate may be tried. No controlled trials have been carried out in lymphocytic colitis. The long-term prognosis of microscopic colitis is good, serious complications are rare and there is no increased mortality.

CONCLUSIONS

Clinical and epidemiological aspects of microscopic colitis are well described. Budesonide is the best-documented short-term therapy in collagenous colitis, but the optimal long-term strategy needs further study. Controlled treatment data of lymphocytic colitis are awaited for.