Evaluating cost-effectiveness in the management of neuroendocrine neoplasms

The rapid evolution of novel, costly therapies for neuroendocrine neoplasia (NEN) warrants formal high-quality cost-effectiveness evaluation. Costs of individual investigations and therapies are high; and examples are presented. We aimed to review the last ten years of standalone health economic evaluations in NEN. Comparing to published standards, EMBASE, Cochrane library, Database of Abstracts of Reviews of Effects (DARE), NHS Economic Evaluation Database and the Health Technology Assessment (HTA) Database were searched for health economic evaluations (HEEs) in NEN published between 2010 and October 2019. Of 12 economic evaluations, 11 considered exclusively pharmacological treatment (3 studies of SSAs, 7 studies of sunitinib, everolimus and/or 177Lu-DOTATATE and 1 study of telotristat ethyl) and 1 compared surgery with intraarterial therapy. 7 studies of pharmacological treatment had placebo or best supportive care as the only comparator. There remains a paucity of economic evaluations in NEN with the majority industry funded. Most HEEs reviewed did not meet published health economic criteria used to assess quality. Lack of cost data collected from patient populations remains a significant factor in HEEs where clinical expert opinion is still often substituted. Further research utilizing high-quality effectiveness data and rigorous applied health economic analysis is needed.

Ileocolonic neuroendocrine tumours identified in the English bowel cancer screening programme

AIM

Ileocolonic neuroendocrine tumours (NETs) are diagnosed as part of bowel cancer screening programmes (BCSPs). The aim of this study was to identify and characterize NETs diagnosed within the English BCSP, a double-screen programme that uses guaic faecal occult blood test (gFOBT) screening and colonoscopy, by interrogating the national colorectal screening database and validating the findings with individual BCSP centres.

METHOD

The Exeter database was interrogated by running queries to identify participants with coded NETs (from the start of the programme in July 2006 - 1 December 2014). A written proforma was sent to the responsible BCSP clinician for validation and characterization.

RESULTS

During this period, 13 061 716 participants were adequately screened using gFOBTs, and 259 765 participants had definitively abnormal results. There were 146 unique participants with NET-related codes from 216 707 BCSP colonoscopies. The diagnosis rates per 100 000 colonoscopies were 29 rectal, 18 colonic and 11 ileal NETs. The majority of rectal NETs had Grade 1 (80%) and Stage T1 (85.1%) disease. Over half of ileal NETs (53.6%) in this study had invasive disease, with 85.2% having nodal and 36.1% having metastastatic disease.

CONCLUSION

The current study highlights the rate of colorectal NETs diagnosed in the English BCSP. These data highlight a higher-than-anticipated incidence, and the potential additional benefit of BCSPs in identifying occult NETs.

Validation of the EORTC QLQ-BIL21 questionnaire for measuring quality of life in patients with cholangiocarcinoma and cancer of the gallbladder

Background:

There is no specific quality of life (QoL) measurement tool to quantify QoL in patients with biliary tract cancer. Quality of life measurement is an increasingly crucial trial end point and is now being incorporated into clinical practice.

Methods:

This International Multicentre Phase IV Validation Study assessed the QLQ-BIL21 module in 172 patients with cholangiocarcinoma and 91 patients with cancer of the gallbladder. Patients completed the questionnaire at baseline pretherapy and subsequently at 2 months. Following this, the psychometric properties of reliability, validity, scale structure and responsiveness to change were analysed.

Results:

Analysis of the QLQ-BIL21 scales showed appropriate reliability with Cronbach's α-coefficients >0.70 for all scales overall. Intraclass correlations exceeded 0.80 for all scales. Convergent validity >0.40 was demonstrated for all items within scales, and discriminant validity was confirmed with values <0.70 for all scales compared with each other. Scale scores changed in accordance with Karnofsky performance status and in response to clinical change.

Conclusions:

The QLQ-BIL21 is a valid tool for the assessment of QoL in patients with cholangiocarcinoma and cancer of the gallbladder.

Review article: the investigation and management of rectal neuroendocrine tumours

BACKGROUND

Rectal neuroendocrine tumours (NETs) are increasingly identified at endoscopy possibly as a result of bowel cancer screening programmes.

AIM

To present a review of the literature to aid clinicians in the diagnosis and management of rectal neuroendocrine tumours.

METHODS

A literature search was conducted through MEDLINE using search terms: rectal, rectum, carcinoid, NET, therapy, endoscopy, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles.

RESULTS

The incidence of rectal neuroendocrine tumours is approximately 1 per 100 000 population per year with the majority (80-90%) being <1 cm and localised to the submucosa. Metastatic disease is infrequent (<20%) with risk factors including size, atypical appearance, grade and depth of invasion. The primary resection modality influences complete resection rates and the need for secondary therapy. A thorough pre-resection diagnostic work up is required for lesions that are at higher risk of invasion and metastasis. Device-assisted endoscopic mucosal resection and endoscopic submucosal dissection are used to resect localised rectal neuroendocrine tumours <2 cm. Transanal surgery is also used to resect localised 1-2 cm rectal neuroendocrine tumours. Oncological surgical resection is used for rectal neuroendocrine tumours that are >2 cm or with invasion and regional disease. The treatment of advanced disease is multimodal.

CONCLUSIONS

The long-term tumour biology of small rectal neuroendocrine tumours remains unclear. There is uncertain impact from bowel cancer screening programmes on rectal neuroendocrine tumour incidence, morbidity and mortality. Referral to neuroendocrine tumour centres for patients with locally advanced disease or metastatic disease is recommended.

Review article: the investigation and management of gastric neuroendocrine tumours

BACKGROUND

Gastric carcinoids (GCs) or neuroendocrine tumours (NETs) are increasingly identified at endoscopy, and account for 0.6-2% of all gastric polyps identified. The SEER database in the US has demonstrated a rising incidence of gastric NETs amongst all NETs; from 2.2% between 1950 and 1969 to 6.0% between 2000 and 2007.

AIM

To review the literature and assist clinicians in managing patients with GCs.

METHODS

A literature search was conducted through MEDLINE using search terms: gastric, carcinoid, neuroendocrine tumour, therapy, endoscopy, mucosal resection, submucosal dissection. Relevant articles were identified through manual review. The reference lists of these articles were reviewed to include further appropriate articles.

RESULTS

There are three types of GCs with important epidemiological, pathophysiological, histological and endoscopic differences that affect prognosis and management. Type 1 and 2 GCs develop in the context of hypergastrinaemia that originates from achlorhydria in atrophic gastritis and a gastrinoma, respectively. Type 3 GCs occur sporadically and independent of gastrin. The histological type, grade and Ki67 index are used to determine prognosis and direct clinical management. Type 1 GCs >1 cm in size and type 2 GCs should be assessed for invasion beyond the submucosa with EUS prior to endoscopic resection with EMR or ESD. Type 3 GCs should be managed as per recommendations for gastric adenocarcinoma. The treatment of advanced disease is multimodal.

CONCLUSIONS

Patients with gastric carcinoids should be discussed in a specialist neuroendocrine tumour multidisciplinary meeting to ensure all treatment options are explored in localised and advanced disease. Areas of controversy exist that need further research.

Midgut neuroendocrine tumours with liver metastases: results of the UKINETS study

We intended to identify the prognostic factors and the results of interventions on patients with liver metastatic midgut carcinoids. Five institutions that are part of United Kingdom and Ireland neuroendocrine tumour (NET) group took part in this study. Patients were included if they had histology proven NET of midgut origin and liver metastases at the time of the study. Clinical and biochemical data were collected retrospectively from hospital charts, pathology reports, radiology reports and biochemistry records for each patient. Three hundred and sixty patients were included in the study. The median survival from date of diagnosis was 7.69 years (confidence interval (CI) 6.40-8.99) and 5.95 years (CI 5.02-6.88) from date of diagnosis of liver metastases. On univariate analysis, increasing age at diagnosis, increasing urinary hydroxyindole acetic acid levels, increasing plasma chromogranin A levels, high Ki67, high tumour volume and treatment with chemotherapy were identified as factors associated with a significantly poorer outcome. Resection of liver metastases, resection of small bowel primary, treatment with somatostatin analogue therapy and treatment with peptide receptor therapy were associated with improved prognosis. Multivariate analysis revealed that age at diagnosis (P=0.014), Ki67 level (P=0.039) and resection of primary (P=0.015) were independent predictors of survival. This is the largest study to our knowledge looking specifically at the prognosis and clinical course of patients with liver metastatic midgut NETs. For the first time, we have shown that Ki67 and resection of primary are independent predictors of survival for this group of patients.

Development of a disease-specific Quality of Life questionnaire module for patients with gastrointestinal neuroendocrine tumours

Quality of life (QoL) measurements are increasingly being used as an end point in cancer clinical trials. Standard generic QoL questionnaires may not assess symptoms produced by neuroendocrine tumours. Here we report the development of a disease-specific quality of life score questionnaire for patients with neuroendocrine tumours of the gut to supplement the EORTC core cancer questionnaire, the QLQ-C30. Phases 1-3 of the EORTC quality of life group guidelines for module development were used to design the new questionnaire. Forty-one relevant issues (questions) were generated after an extensive literature search. Following interviews of 15 health care workers and 35 patients, a 35 question provisional questionnaire was constructed. This was translated into seven European languages and pre-tested in 180 patients resulting in a 21-item module that will be validated in an international clinical trial. The EORTC QLQ-NET21 provides a site-specific module to supplement the QLQ-C30 for patients with neuroendocrine tumours.

Neuroendocrine tumour management: a team approach

This article gives an overview of neuroendocrine tumours of the gut, liver and pancreas and will make the case for a multidisciplinary approach to management.

Are renal microgranulomas related to inflammatory tubular destruction?

Two cases of renal microgranuloma formation are reported, one in a patient with known Crohn's disease and another in a case of acute renal allograft rejection. In both cases, the microgranulomas arose as a result of inflammatory tubular destruction, in a manner analogous to that seen in patients with ulcerative colitis arising adjacent to ruptured epithelial crypts in the large intestine. Microgranulomas may occur at multiple anatomical sites in Crohn's disease, although renal microgranulomas are very rare. Non-specific inflammatory tubular destruction should be considered as a cause of renal microgranuloma formation, in addition to systemic granulomatous diseases, such as tuberculosis, sarcoid, or Crohn's disease, when granulomas are seen in the presence of inflammatory tubular destruction in renal biopsies.

Measurement of quality of life in carcinoid/neuroendocrine tumours

Quality of life is multi-dimensional, including issues relating to symptoms from the disease but also social, emotional, functional and financial domains. Debate remains on the true definition of quality of life and its measurement. Quality of life measurements are best done by patients themselves, although, in some situations a proxy such as carer or relative can be substituted. Healthcare workers can over- or underestimate overall quality of life. Currently used devices for measuring quality of life in cancer include the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, which is a generic tool for all cancers and which requires the use of add-on modules for specific cancers. We are developing a separate module for carcinoid/neuroendocrine tumours, in accordance with the EORTC guidelines on module development, which will be translated into five languages and will be available for use throughout Europe.

Clinical features, diagnosis and outcome of acute portal vein thrombosis

The clinical features of acute portal vein thrombosis (APVT) are poorly defined in the literature. The proportion that progress to chronic PVT and the influences of various treatments are unknown. Between 1996 and 1998, nine patients presented to our hospital with varying upper gastrointestinal symptoms. They were found to have APVT by colour flow Doppler ultrasound, which was confirmed by CT scanning. All were tested for procoagulant tendencies and then treated with intravenous heparin for 7 days and warfarin for 3 months. Colour flow Doppler ultrasound or CT was done regularly to assess response to treatment. There was complete resolution of thrombus in five patients. Four patients had procoagulant tendencies identified; of these the thrombus resolved in two cases and in two cavernous transformation occurred. In most cases, the thrombus disperses on heparin and warfarin, although the effect of this therapy is unknown. A randomized trial of thrombolytic therapy may be appropriate, in an attempt to reduce the rate of progression to chronic PVT.

Churg-Strauss syndrome and granulomatous cholangiopathy

Churg-Strauss syndrome is a vasculitis that is known to have gastroenterological manifestations. There have been no reports associating it with liver disease. We present a case of this syndrome in a man who was found to develop a co-existent cholangiopathy. It is likely that this represents an associated granulomatous reaction consequent to a hepatic manifestation of the vasculitis.

Imaging secondary neuroendocrine tumours of the liver: comparison of I123 metaiodobenzylguanidine (MIBG) and In111-labelled octreotide (Octreoscan)

Functional imaging of neuroendocrine tumours with Octreoscan and I123-metaiodobenzylguanidine (MIBG) is important for assessment prior to various therapies and assessing response. The two imaging methods have not been directly compared in hepatic neuroendocrine tumours. Patients (n = 18) were studied with both imaging techniques. The sensitivity of Octreoscan was 94%, and that of MIBG 39%. No previously occult primary sites were detected. Concurrent octreotide therapy did not reduce the sensitivity of Octreoscan. Widespread bone metastases were seen in two post-liver-transplant patients using Octreoscan. Octreoscan is a sensitive means of detecting hepatic neuroendocrine tumours, and the more specific technique. MIBG has poor sensitivity, reducing its clinical utility. Therapy with I131-MIBG is likely to be applicable to relatively few patients.

p53 Protein overexpression in cholangiocarcinoma arising in primary sclerosing cholangitis

The protein encoded by the p53 tumour suppressor gene plays an important part in the regulation of cell growth. Abnormalities of this gene represent one of the most common genetic changes in the development of human cancers. This study investigated the expression of p53 protein in cholangiocarcinoma arising in association with primary sclerosing cholangitis (PSC). Of the 14 patients with cholangiocarcinoma studied, 13 had underlying PSC. The expression of p53 protein was detected immunohistochemically in paraffin wax embedded liver specimens, after microwave pretreatment. The expression of p53 protein was shown in the cholangiocarcinoma tissue of 11 of 14 (78.5%) patients. In five of 10 patients, the accumulation of p53 protein highlighted the presence of neoplastic cells in biliary tissue separate from the main tumour. These cells were mainly located in the septal bile ducts or in the accessory glands, or both, but occasionally also in large portal areas at the periphery of nerves and lymphatics, and in one case in the mucosa of an extrahepatic bile duct. No p53 protein was detectable in liver tissue obtained at the time of transplantation in 15 patients with PSC but not cholangiocarcinoma. These results show that cholangiocarcinoma development in PSC is commonly associated with abnormalities of p53 and that these occur at a late stage in the development of the malignant process. Staining for p53 protein could represent an additional criterion for the diagnosis of cholangiocarcinoma development in patients with PSC.

Orthotopic liver transplantation in the treatment of metastatic neuroendocrine tumors of the liver

The place of orthotopic liver transplantation (OLT) in the management of metastatic hepatic neuroendocrine tumors has not been adequately defined. The present report is concerned with patient survival, disease recurrence, and symptom relief in 11 such patients in a single center who, at the time of transplantation, had no extrahepatic tumor. All patients obtained complete symptom relief initially but tumor recurrence was observed in 6 of the 11 cases (5 carcinoid and 1 apudoma) at a median of 11 months (range 3.5-26). Five patients have died, 4 in the carcinoid group with recurrence and one from chronic rejection in the other apudoma group. Of the 6 patients currently alive one of 2 carcinoids and one of 4 other apudomas have tumor recurrence. Recurrent deposits were found predominantly in bone and in the transplanted liver. Actuarial survival post transplant was 82% and 57% at 1 and 5 years respectively. It is concluded that OLT is effective at controlling symptoms from secreting carcinoid deposits in the liver. Although the tumor will recur in most cases, this is not necessarily associated with early return of symptoms. Prolonged disease free survival is more likely in the non carcinoid apudoma group.

Overview: the management of metastatic carcinoid tumors

Chemotherapy, IFN, octreotide, and hepatic artery embolization can be useful for palliation, both of local symptoms and of the carcinoid syndrome, but they have little effect on tumor progression, MIBG therapy is still experimental but may have a future role. OLT should be considered as a palliative procedure in those patients with severe symptoms and no evidence of extrahepatic disease.

Serum tumor markers for the diagnosis of cholangiocarcinoma in primary sclerosing cholangitis

BACKGROUND/AIMS

The diagnosis of cholangiocarcinoma in primary sclerosing cholangitis (PSC), even with the use of current imaging techniques and brush cytology, is difficult and particularly important in patients being assessed for liver transplantation. This study investigated the accuracy of serum levels of a combination of the tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in the diagnosis of cholangiocarcinoma in patients with PSC.

METHODS

Seventy-four patients with PSC were studied. Fifteen patients had tumors (11 occult on imaging), 22 had severe PSC that necessitated transplantation (with explanted liver known to be free of tumor), and 37 patients had stable PSC.

RESULTS

An index of the two serum tumor markers [using the formula CA19-9 + (CEA x 40)] gave an accuracy of 86% in diagnosis of cholangiocarcinoma, with 10 of the 15 cases of cholangiocarcinoma having an increased value compared with none in a group of 22 comparable cases with no tumor. In addition, 6 of the 11 patients with occult tumors had abnormal values. Ultrasonography, computerized tomographic scanning, and endoscopic retrograde cholangiopancreatography were poor predictors of the presence of tumor.

CONCLUSIONS

A combination of serum tumor markers will identify most occult tumors and will improve selection of appropriate cases for orthotopic liver transplantation.

Hepatic venous outflow obstruction in patients with polycystic liver disease: pathogenesis and treatment

Polycystic liver disease is commonly asymptomatic but may present with hepatomegaly, abdominal distension, and dull abdominal pain. Transudative ascites is a rare manifestation in these patients but may occur when portal hypertension is present resulting from associated hepatic fibrosis or after deroofing procedure of a cyst. Exudative ascites might suggest hepatic venous outflow obstruction. Four cases are described where hepatic venous outflow obstruction occurred in patients with polycystic liver disease. Three patients had orthotopic liver transplantation and one had a mesocaval shunt. Of the two patients that survived orthotopic liver transplantation both have shown considerable improvement in their symptoms. None of the patients had any confirmed procoagulant disorder. The mechanism of hepatic venous outflow obstruction in these patients seems to be mechanical compression of hepatic veins by the cysts and associated formation of thrombi in small hepatic vein tributaries. Patients with severe polycystic kidney/liver disease are at risk of hepatic venous outflow obstruction and the onset of this complication is heralded by tender hepatomegaly and presence of exudative ascites.

Ribavirin therapy for hepatitis C infection following liver transplantation

Hepatitis C infection following orthotopic liver transplantation may lead to progressive chronic graft dysfunction. In this study, seven liver transplant recipients with chronic allograft dysfunction due to hepatitis C infection (one acquired and six recurrent infections) were treated with oral ribavirin for 6 months. Symptoms of lethargy, nausea and anorexia improved in all patients within 2 weeks of starting the drug, with a fall in serum AST of at least 40% by this time. Ribavirin-induced haemolysis was clinically significant in three patients, necessitating a reduction in the daily dose of ribavirin from 1.2 g to 0.2 g. Comparison of the pre- and post-treatment biopsy specimens in the four patients who tolerated the full dose of ribavirin and who had normal AST levels at the end of 6 months of treatment showed significant histological improvement with reduction in either lobular or periportal inflammation in all of the patients and a reduction in periportal fibrosis in one patient. HCV RNA remained detectable in serum in all of the patients at the end of the study.

Accuracy of radiology in detection of hepatocellular carcinoma before liver transplantation

BACKGROUND/AIMS

Recurrence of hepatocellular carcinoma (HCC) after orthotopic liver transplantation (OLT) depends on tumor size and number; the accuracy of radiology in detecting HCC is uncertain. This study compared tumor size at radiological and pathological examination in 30 patients with HCC who underwent OLT.

METHODS

Pre-OLT radiology included ultrasonography (US), computerized tomography (CT), and hepatic angiography (HA). Sensitivity of radiology was calculated by comparison with pathology.

RESULTS

Radiology missed HCC in two patients but showed five with small (< 4 cm) and eight with large (> 4 cm) lesions. Multicentricity was shown in 15 cases at radiological examination and 24 at pathological examination, including one incidental and 4 of 5 radiologically small HCC. Mean tumor bulk was 3.4, 74, 338, and 1375 cm3, respectively, in patients with incidental, small, large, and multicentric HCC at radiology. Sensitivities of US, CT, and HA in detection of HCC (and multicentricity) were 80% (16.6%), 86.6% (58.3%), and 90% (58.3%). No recurrence was found in patients with incidental or small HCC; even when multicentric.

CONCLUSIONS

US, CT, and HA identified patients with small or large tumor bulk, but sensitivity in detecting satellites was poor; their finding in patients with radiologically small or incidental tumors does not affect outcome. The failure of US, CT, and HA to detect satellites must be considered in patients undergoing partial hepatectomy for HCC.

Randomised trial of variceal banding ligation versus injection sclerotherapy for bleeding oesophageal varices

Injection sclerotherapy of bleeding oesophageal varices is undoubtedly beneficial but it is associated with a substantial complication rate, and variceal rebleeding is common during the treatment period before variceal obliteration is achieved. We aimed to find out whether endoscopic variceal banding ligation is safer and more effective. The two methods were compared in a randomised controlled trial of 103 patients (54 assigned to banding ligation, and 49 to injection sclerotherapy) of whom 21 (39%) and 23 (47%), respectively, had active bleeding at index endoscopy. Both treatments were highly effective in controlling active haemorrhage (91% and 92% respectively). Variceal obliteration was not achieved for 22 patients in each group, but among those whose varices were eradicated, banding ligation achieved obliteration more quickly than did sclerotherapy (mean 39 [SD 4] vs 72 [7] days, p = 0.004) and in fewer endoscopy sessions (3.4 [2.2] vs 4.9 [3.5], p = 0.006). Rebleeding was less common in the banding ligation group than in the sclerotherapy group (16 [30%] vs 26 [53%], p < 0.05). There was no difference in outcome between the groups, but 14 sclerotherapy patients were withdrawn from the trial (7 for orthotopic liver transplantation) compared with only 5 (1 for liver transplantation) in the banding ligation group (p < 0.05). Complication rates were similar in the two groups. Variceal banding ligation is a safe and effective technique, which obliterates varices more quickly and with a lower rebleeding rate than injection sclerotherapy.

Antigen-induced mucosal damage and restitution in the small intestine of the immunized rat

Intestinal mucosal damage and restitution were examined following antigen-induced systemic anaphylaxis in Nippostrongylus brasiliensis immunized rats. The rats were injected intravenously with N. brasiliensis antigen or saline. At 60 min, morphological and biochemical parameters were determined in jejunum and ileum, and the epithelial permeability was assessed by measuring recovery of 51Cr-ethylenediaminetetraacetic acid in the blood after injecting it into a ligated segment. Antigen challenge resulted in significant abnormalities: (1) villus damage with sloughing of enterocytes; (2) decreased activities of brush border enzymes; (3) decreased levels of mucosal histamine and rat mast cell protease II (mast cell mediators), and (4) increased uptake of 51Cr-ethylenediaminetetraacetic acid. Progression of the injury was examined by taking consecutive biopsies at 15-min intervals for 60 min and then at 5 h. At 15 min, an abnormality was present in all sections which ranged from minor oedema and enterocyte detachment at villus tips to virtual complete destruction of the apical region. Restitution occurred by villus contraction with migration of the epithelium over the damaged regions. At 5 h, the epithelium had resealed, but the villi were significantly reduced in height.

Intestinal mucosal injury is associated with mast cell activation and leukotriene generation during Nippostrongylus-induced inflammation in the rat

We examined mucosal injury in the jejunum of the rat during infection with the nematode parasite, Nippostrongylus brasiliensis (Nb). Injury was documented morphologically (increase in crypt length with or without villus atrophy) and biochemically (activities of digestive or proliferative enzymes) and related to mast cell activation and leukotriene generation. At day 4 crypt length and thymidine kinase activity were increased; no changes in villus parameters were recorded. No evidence of mast cell activation was found and leukotriene levels in the mucosa were normal. At day 7, the gut was acutely inflamed and edema was present at the tips of the villi. This progressed to enterocyte detachment, resulting in villus atrophy with decreased activities of brush border enzymes. At this stage mucosal histamine was decreased and rat mast cell protease II (RMCP II) was increased in serum, indicating mast cell activation. In addition, mucosal leukotrienes (LTB4, LTC4, LTE4) were present in significant quantities. Following worm expulsion, the villus abnormalities resolved and serum RMCP II returned to normal. However, the crypt hyperplasia persisted. Our results suggest that during Nb infection at least two components of injury can be identified. One component, epithelial injury at the villus tips, may be related to activation of mucosal mast cells.

Effect of immunologic reactions on rat intestinal epithelium. Correlation of increased permeability to chromium 51-labeled ethylenediaminetetraacetic acid and ovalbumin during acute inflammation and anaphylaxis

In these studies we compared jejunal permeability to two probes--chromium 51-labeled ethylenediaminetetraacetic acid (51Cr-EDTA) (mol wt, 360) and ovalbumin (mol wt, 45,000)--under control conditions, during acute intestinal inflammation, and in response to systemic anaphylaxis. Acute inflammation was produced after infection with Nippostrongylus brasiliensis and rats were studied at day 0 (control), day 4 (early), day 10 (acute), and day 35 (postinfection). At the latter stage, immune rats were also studied during anaphylaxis induced by i.v. N. brasiliensis antigen. In each study, blood and urine were sampled over 5 h after the probes were simultaneously injected into ligated loops in anesthetized rats. In controls, small quantities (less than 0.04% and 0.002% of the administered dose for 51Cr-EDTA and ovalbumin, respectively) appeared in the circulation and plateaued at 1 h. During acute inflammation, the appearance of both probes continued to increase with time. Compared with controls, 5-h values for 51Cr-EDTA and ovalbumin were (a) significantly elevated at day 4 (p less than 0.005), (b) increased approximately 20-fold at day 10 (p less than 0.005 and less than 0.01, respectively), and (c) normal at day 35. Urinary recovery of 51Cr-EDTA followed the same pattern. During anaphylaxis, appearance of the probes in the circulation increased at 1 h to values approximately 10-fold those in controls (p less than 0.001 and less than 0.01, for 51Cr-EDTA and ovalbumin, respectively), and then declined. Urinary recovery of 51Cr-EDTA over 5 h was also significantly increased. We conclude that epithelial barrier function becomes impaired during both acute inflammation and anaphylaxis. In this rat model, gut permeability changes to 51Cr-EDTA reflect gut permeability changes to macromolecular antigens. If similar conditions exist in humans, urinary recovery of 51Cr-EDTA may be useful in monitoring intestinal abnormalities associated with inflammation.

Small bowel and colonic permeability to 51Cr-EDTA in patients with active inflammatory bowel disease

51Cr-EDTA was administered both orally and per rectum via a catheter to controls and to patients with inflammatory bowel disease. The patients were divided into two groups, either with active inflammation of the small bowel or with active inflammation of the colon. Fifteen patients with Crohn's disease of the small bowel and 19 patients with either Crohn's disease of the colon or ulcerative colitis were investigated. After oral administration of the probe, controls showed a median excretion of 1.17%/24 h of the dose compared to 3.47%/24 h by patients with small bowel disease and 6.07%/24 h by patients with colonic disease. After rectal administration, controls showed a median excretion of 0.74%/24 h of the dose compared to 0.93%/24 h by patients with small bowel disease and 5.73%/24 h by patients with colonic disease. The rectal test differentiated small bowel disease from colonic disease with an accuracy of 85%. The results confirmed the inflamed colon as a site of increased intestinal permeation.

Changes in intestinal permeability and epithelial differentiation during inflammation in the rat

We examined changes in gut permeability in a controlled model of inflammation produced in rats after infection with the nematode parasite, Nippostrongylus brasiliensis. The probe, 51Cr-EDTA, was injected into ligated loops of jejunum in vivo and recovery of radioactivity was measured in urine, kidney, and intact loop at five hours. Urinary recovery was significantly increased during the early (day 7) and acute (day 10) stages of the infection compared with values in control rats but subsequently returned to normal. Urinary clearance of the probe after iv injection was unaltered during infection. Villus atrophy occurred only at the stage, whereas crypt hyperplasia was evident at both the early and acute stages. The terminal ileum appeared normal and showed normal permeability when compared with controls. We conclude that permeability changes are local to the site of inflammation, are reversible after healing and may be related to an increase in the proportion of relatively undifferentiated epithelium.

Large single daily dose of histamine H2 receptor antagonist for duodenal ulcer. How much and when? A clinical pharmacological study

The effects of single doses of cimetidine 800, 1200, and 1600 mg, given at 2300 h or 800, and 1600 mg at 1800 h, have been studied in patients with duodenal ulcer disease in symptomatic remission, and compared with cimetidine 400 mg bd (0800 h and 2300 h) and ranitidine 300 mg (given at 1800 h) respectively. A dose related reduction in intragastric acidity was seen. All single nocturnal (2300 h) doses of cimetidine produced anacidity overnight. This was not achieved with dosing at 1800 h although the duration of inhibition of gastric acidity was longer. Inhibition of overnight acid and pepsin outputs were similarly dose and timing related, but inhibition of peptic activity was much less after dosing at 1800 h. Cimetidine 1600 mg and ranitidine 300 mg were similar in their effects.

Effect of cimetidine and pirenzepine in combination on 24 hour intragastric acidity in subjects with previous duodenal ulceration

Intragastric pH was monitored during 24 hours in eight volunteers with duodenal ulcer disease in remission, while on placebo, cimetidine 400 mg bd, pirenzepine 50 mg bd, cimetidine 400 mg bd + pirenzepine 50 mg bd, cimetidine 200 mg bd + pirenzepine 25 mg bd. The control of intragastric acidity during the 24 hour period by the combination of low dose cimetidine and pirenzepine was significantly better than with cimetidine, or pirenzepine alone in full dosage. This difference was most apparent after breakfast but was still present after lunch when cimetidine had no significant effect. Combination treatment is a logical approach when continuous control of intragastric acidity is needed, but a three times daily regimen will be necessary to cover the 24 hours.

Inhibition of food stimulated acid secretion by misoprostol, an orally active synthetic E1 analogue prostaglandin

The effect of 200 micrograms misoprostol (a synthetic prostaglandin E1 analogue) on food stimulated intragastric acidity has been monitored over a 9 h period in 16 normal volunteers. Misoprostol caused a significant inhibition of intragastric acidity for 2 h post-dosing, but no significant effect was seen thereafter on either basal or food stimulated acidity.

Reducing overnight secretion of acid to heal duodenal ulcers. Comparison of standard divided dose of ranitidine with a single dose administered at night

This study was undertaken to assess the clinical usefulness of a single nighttime dose of ranitidine in the short-term healing of duodenal ulcer. One hundred and nine patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine, either 150 mg twice daily or 300 mg as a single nighttime dose for four weeks, in a prospective double-blind, double-placebo trial. Of the 102 patients who completed the study, 48 of 57 (84 percent) healed endoscopically on ranitidine 150 mg twice daily, and 43 of 45 (96 percent) healed on 300 mg at nighttime (Mantel-Haenszel test without continuity correction: X2 = 2.9, p = 0.09). One patient treated with ranitidine 150 mg twice daily had a transient episode of cholestatic hepatitis that did not necessitate stopping the drug; in this patient the ulcer healed after 28 days of treatment. There were no other unwanted effects in either group and no significant abnormal biochemical or hematologic changes. This study shows that ranitidine 300 mg given as one nighttime dose is as safe as 150 mg twice daily, and equally as effective. Three hundred milligrams at night appear to confer protection against the adverse effect of smoking in ulcer healing.

Ranitidine 150 mg twice daily vs 300 mg nightly in treatment of duodenal ulcers

102 patients with endoscopically proven duodenal ulcers were randomly allocated to treatment with ranitidine either 150 mg twice a day or 300 mg every evening for 4 weeks in a prospective double-blind study. The two groups were similar. 48/57 (84%) healed on ranitidine 150 mg twice daily and 43/45 (96%) healed on 300 mg every evening (p = 0.9)--that is, ranitidine 300 mg as a single night time dose is as effective as 150 mg twice daily. The results also indicate the importance of overnight gastric acidity in the pathogenesis of duodenal ulcers.