Efficacy of thiopurines and adalimumab in preventing Crohn's disease recurrence in high-risk patients - a POCER study analysis

BACKGROUND

Crohn's disease recurs in the majority of patients after intestinal resection.

AIM

To compare the relative efficacy of thiopurines and anti-TNF therapy in patients at high risk of disease recurrence.

METHODS

As part of a larger study comparing post-operative management strategies, patients at high risk of recurrence (smoker, perforating disease, ≥2nd operation) were treated after resection of all macroscopic disease with 3 months metronidazole together with either azathioprine 2 mg/kg/day or mercaptopurine 1.5 mg/kg/day. Thiopurine-intolerant patients received adalimumab induction then 40 mg fortnightly. Patients underwent colonoscopy at 6 months with endoscopic recurrence assessed blind to treatment.

RESULTS

A total of 101 patients [50% male; median (IQR) age 36 (25-46) years] were included. There were no differences in disease history between thiopurine- and adalimumab-treated patients. Fifteen patients withdrew prior to 6 months, five due to symptom recurrence (of whom four were colonoscoped). Endoscopic recurrence (Rutgeerts score i2-i4) occurred in 33 of 73 (45%) thiopurine vs. 6 of 28 (21%) adalimumab-treated patients [intention-to-treat (ITT); P = 0.028] or 24 of 62 (39%) vs. 3 of 24 (13%) respectively [per-protocol analysis (PPA); P = 0.020]. Complete mucosal endoscopic normality (Rutgeerts i0) occurred in 17/73 (23%) vs. 15/28 (54%) (ITT; P = 0.003) and in 27% vs. 63% (PPA; P = 0.002). The most advanced disease (Rutgeerts i3 and i4) occurred in 8% vs. 4% (thiopurine vs. adalimumab).

CONCLUSIONS

In Crohn's disease patients at high risk of post-operative recurrence adalimumab is superior to thiopurines in preventing early disease recurrence.

An ancestral Ashkenazi haplotype at the HMPS/CRAC1 locus on 15q13-q14 is associated with hereditary mixed polyposis syndrome

The putative locus for hereditary mixed polyposis syndrome (HMPS) in a large family of Ashkenazi descent (SM96) was previously reported to map to chromosome sub-bands 6q16-q21. However, new clinical data, together with molecular data from additional family members, have shown 6q linkage to be incorrect. A high-density genomewide screen for the HMPS gene was therefore performed on SM96, using stringent criteria for assignment of affection status to minimize phenocopy rates. Significant evidence of linkage was found only on a region on chromosome 15q13-q14. Since this region encompassed CRAC1, a locus involved in inherited susceptibility to colorectal adenomas and carcinomas in another Ashkenazi family (SM1311), we determined whether HMPS and CRAC1 might be the same. We found that affected individuals from both families shared a haplotype between D15S1031 and D15S118; the haplotype was rare in the general Ashkenazi population. A third informative family, SM2952, showed linkage of disease to HMPS/CRAC1 and shared the putative ancestral haplotype, as did a further two families, SMU and RF. Although there are probably multiple causes of the multiple colorectal adenoma and cancer phenotype in Ashkenazim, an important one is the HMPS/CRAC1 locus on 15q13-q14.

Molecular pathologic analysis enhances the diagnosis and management of Muir-Torre syndrome and gives insight into its underlying molecular pathogenesis

The Muir-Torre syndrome (MTS) is an autosomal dominantly inherited disorder, characterized by visceral malignancies and sebaceous skin lesions. In a subset of MTS families the disease is due to an underlying DNA mismatch-repair defect. We have identified a MTS family whose spectrum of reported neoplasia included adenocarcinomas of numerous gastrointestinal sites, carcinomas of the endometrium, ovary and breast, papillary transitional cell carcinoma of the ureter, a range of cutaneous tumors, as well as keratoacanthomas. All tumors were tested for microsatellite instability and immunohistochemically stained for expression of MLH1 and MSH2 proteins. All tumors were found to be microsatellite unstable and lacking in MSH2 protein expression. The subsequent mutation detection focused on hMSH2, and a germline mutation was identified (CAA-->TAA, Gln-->STOP, codon 337). This mutation was subsequently found in a family member with a single skin lesion only. We propose that the combination of immunohistologic and microsatellite instability analysis can be exploited to screen individuals with characteristic skin lesions even before development of visceral tumors and to direct the subsequent germline mutation search. The profile of microsatellite instability and the genes rendered dysfunctional differed between tumor samples, suggesting that the molecular pathogenesis varied between lesions, despite a common germline mutation.

Low dose interferon gamma for refractory Crohn's disease

AIM

Direct cytokine modulation may benefit patients with inflammatory bowel disease.

PATIENTS

Subcutaneous interferon gamma (1.5 microgram/kg) was given three times a week in an open pilot study to four patients with active Crohn's disease unresponsive to standard immunosuppressive drug treatment.

RESULTS

In one patient, the C-reactive protein and Crohn's disease activity index returned to normal and the patient became asymptomatic. The other three patients did not complete the 12-week treatment course, one because of drug failure, one because of drug side effects, and one because of incidental disease. However, the Crohn's disease activity index fell substantially and the C-reactive protein returned to normal in three out of four patients.

CONCLUSIONS

Interferon gamma may have a role in the treatment of resistant patients, but only if the dose can be optimised and drug side effects overcome.

Photodynamic therapy for polyps in familial adenomatous polyposis--a pilot study

Photodynamic therapy (PDT) produces localised necrosis with light after prior administration of a photosensitising drug. As PDT lesions in the gastrointestinal tract heal so well, the technique is suitable for repeated endoscopic use. In this study, PDT was used to treat large polyps (four duodenal and two colorectal) unsuitable for surgery in 6 patients with familial adenomatous polyposis (FAP). Patients were sensitised with 60 mg/kg 5-aminolaevulinic acid (ALA) orally or intravenous (i.v.) 2.0 mg/kg Photofrin. Laser treatment was performed 6 h after ALA or 48 h after Photofrin using a gold vapour laser. Necrosis was only superficial (up to 1.8 mm) using ALA but much deeper using Photofrin. The one malignant polyp (8 mm diameter in the colon) showed a complete response using Photofrin. All healed safely with no complications. Photofrin worked better, but caused cutaneous photosensitivity lasting up to 3 months. ALA cleared within 2 days, but its use is limited by the superficial effect. Better results with ALA may be obtained using higher drug doses or modified light dosimetry. Fluorescence microscopy showed no evidence of selectivity of photosensitisation between neoplastic and normal tissue. PDT is a promising treatment for inoperable polyps in patients with FAP, but further work is required to optimise the treatment conditions.

Increased sympathetic nervous activity and the effects of its inhibition with clonidine in alcoholic cirrhosis

OBJECTIVE

To study disturbances in sympathetic nervous system function in patients with alcoholic cirrhosis and the effect of clonidine on such disturbances.

DESIGN

Cross-sectional physiologic and neurochemical evaluation of patients with cirrhosis and of healthy controls; an uncontrolled trial of intravenous clonidine in the cirrhotic patients.

PATIENTS

Forty-four hospitalized patients with biopsy-proven alcoholic cirrhosis and 31 healthy controls.

INTERVENTIONS

Intravenous clonidine.

MAIN OUTCOME MEASURES

Radiotracer-derived measures of norepinephrine release to plasma, central hemodynamics, wedge hepatic vein pressure, and measures of renal function.

MAIN RESULTS

In patients with cirrhosis, clonidine reduced previously elevated norepinephrine overflow rates for the whole body, kidneys, and hepatomesenteric circulation. This sympathetic inhibition was accompanied by the following potentially clinically beneficial effects: the lowering of renal vascular resistance (median reduction, 24%; 95% CI, 14% to 31%), the elevation of glomerular filtration rate (median increase, 27%; CI, 14% to 39%), and the reduction of portal venous pressure (median reduction, 25%; CI, 18% to 32%). The norepinephrine and hemodynamic responses to graded clonidine dosing (1, 2, and 3 micrograms/kg body weight intravenously) indicated that the sympathetic outflow to the hepatomesenteric circulation was more sensitive to pharmacologic suppression with clonidine than was the sympathetic outflow to the systemic circulation.

CONCLUSIONS

The sympathetic nerves to the kidneys, heart, and hepatomesenteric circulation are stimulated in patients with cirrhosis. Clonidine inhibits these activated sympathetic outflows differentially, which could possibly provide a basis for the selective pharmacologic treatment of portal hypertension in patients with cirrhosis.