Mechanisms of action of duodenal mucosal resurfacing in insulin resistant women with polycystic ovary syndrome

BACKGROUND

Duodenal mucosal resurfacing (DMR) is a novel day-case endoscopic intervention which results in weight loss-independent reductions in HbA1c in patient with type 2 diabetes mellitus (T2DM). We hypothesized that DMR works by increasing insulin sensitivity and we aimed to investigate the mechanism of action of DMR through longitudinal metabolic phenotyping in humans.

METHODS

Thirty-two insulin-resistant women with polycystic ovary syndrome (PCOS) and obesity were randomised in a double-blinded manner to DMR or sham endoscopy. They underwent measurements of insulin sensitivity using euglycaemic hyperinsulinaemic clamps, insulin secretion using oral glucose tolerance tests and reproductive function using weekly reproductive hormone profiles and ovarian ultrasonography for 6 months post-intervention.

RESULTS

A small increase in total body insulin sensitivity measured by the clamp was observed in both groups at week 12. An increase in insulin sensitivity, as measured by HOMA-IR, was observed in both groups at week 24. There was an increase in the number of menses (median 2 DMR, 0.5 sham). There were no significant differences between the two groups in these outcomes or insulin secretion.

CONCLUSIONS

These findings suggest that DMR does not work by increasing insulin sensitivity in euglycaemic, insulin resistant women with PCOS. The procedure may exert its effects only in the context of hyperglycaemia or pathologically hyperplastic, insulin-desensitised duodenal mucosa.

Acute gastrointestinal haemorrhage: a rare presentation of aortic dissection

A 72-year-old woman presented with a 24-hour history of severe upper jaw pain and more recent onset central chest pain. She denied difficulty breathing or nausea. Her ast medical history included cluster headaches, mild chronic obstructive airways disease and hypertension. She had been well on review in outpatient clinic the day before.

On examination, she was apyrexial, blood pressure 130/60 mmHg, pulse 95 beats per minute and regular, oxygen saturation 96% on room air. Clinical examination was unremarkable. There were no new electrocardiogram changes and a chest X-ray was reported as normal. Blood tests showed haemoglobin 9 g/dl, a 2 g/dl drop from the previous day in clinic. The remaining laboratory tests were normal. With no identified source of bleeding or associated rise in urea, her full blood count was repeated to exclude a spurious result.

Over the next 24 hours, her chest and jaw pain eased but she developed diarrhoea and tachycardia. Her blood pressure remained stable at 140/65 mmHg. The haemoglobin drop was confirmed with a repeat value of 8.7 g/dl but still no source of bleeding was identified. Over the course of the day, the patient's diarrhoea continued with increasing abdominal discomfort, until she suddenly passed fresh blood per rectum associated with a blood pressure drop to 70 mmHg systolic. She was resuscitated promptly and a decision made to manage her conservatively with oesophagogastroduodenoscopy and colonoscopy scheduled for 24 hours later, as it was the weekend and endoscopy services were limited.

However, she continued to pass fresh blood per rectum and suffer severe generalized abdominal pain, and so an urgent computed tomography scan with contrast was performed (Figure 1). This showed a type A aortic dissection extending from the left coronary artery to involve the carotid arteries and extend down below the renal arteries. The Stanford classification divides dissections into 2 types: A and B. Type A involves the ascending aorta, type B does not. The ascending and transverse colon appeared thickened and oedematous on the scan. The most likely cause of bleeding in this case was ischaemic colitis, secondary to aortic dissection impeding inferior mesenteric artery blood flow. Cardiomegaly raised the probability of pericardial involvement.

On the basis of these findings, the patient was immediately reviewed by the on-call vascular surgical team. Given the extent of the dissection, surgery was not felt to be an option. Shortly afterwards she became profoundly hypotensive and died. The most likely cause of death was cardiac tamponade, although an echocardiogram was never performed. The family declined a post mortem.

A preliminary trial of high-dose ursodeoxycholic acid in primary sclerosing cholangitis

BACKGROUND & AIMS

Ursodeoxycholic acid (UDCA) is used for the treatment of cholestatic liver diseases including primary biliary cirrhosis (PBC) for which it has a positive effect on laboratory values, may delay the development of liver failure and prolong the transplant-free disease period. Standard doses of UDCA (8-15 mg/kg daily) have been shown to be ineffective in the treatment of primary sclerosing cholangitis (PSC). We report on the findings (clinical, biochemical, histological, and cholangiographic) and side effects of a 2-year double-blind placebo-controlled preliminary study of high-dose UDCA in PSC patients.

METHODS

Twenty-six patients with PSC were randomized to high-dose (20 mg/kg daily) UDCA or placebo. Cholangiography and liver biopsy were performed at entry and after 2 years. Symptoms, clinical signs, and liver biochemical tests were recorded at 3 monthly intervals.

RESULTS

High-dose UDCA did not influence symptoms, but there was a significant improvement in liver biochemistry (serum alkaline phosphatase, P = 0.03; gamma-glutamyl transferase, P = 0.01) and a significant reduction in progression in cholangiographic appearances (P = 0.015) and liver fibrosis as assessed by disease staging (P = 0.05). In the treatment group, a significant increase in total bile acids and saturation with UDCA >70% confirmed patient compliance. No significant side effects were reported.

CONCLUSIONS

High-dose UDCA may be of clinical benefit in PSC, but trials with a larger number of participants and of longer duration are required to establish whether the effect of high-dose UDCA on liver biochemistry, histology, and cholangiography in patients with PSC is translated into improved long-term survival.

Fibrosing colonopathy in an adult owing to over use of pancreatic enzyme supplements

A woman, then in her late 20s, underwent a cholecystectomy in 1962 for gallstone disease and subsequent common bile duct stones were managed endoscopically. However, because of unrelenting pain, a pylorus preserving pancreaticoduodenectomy was done in 1990 and in the following years the patient took large amounts of pancreatic enzyme supplements. She developed large bowel obstruction in 1997 and a right hemicolectomy was undertaken. Histology confirmed fibrosing colonopathy of the ascending colon and caecum. Her pancreatic enzyme dose was reduced and her subsequent course has been uncomplicated.

Detection of antineutrophil cytoplasmic antibodies in primary sclerosing cholangitis: a comparison of the alkaline phosphatase and immunofluorescent techniques

BACKGROUND

The reported prevalence of antineutrophil cytoplasmic antibodies (ANCA) in primary sclerosing cholangitis (PSC) varies considerably (26-85%). Part of this may reflect methodological differences but part may reflect the differences in the patient groups analysed. To resolve this issue we compared the sensitivity and specificity of the immunoalkaline phosphatase (IALP) and immunofluorescence (IF) techniques in four different populations.

METHOD

Sera from four centres were tested blind on alcohol-fixed neutrophils using both techniques.

PATIENTS

USA: 14 PSC, 14 primary biliary cirrhosis (PBC); Sweden: 32 PSC, 3 autoimmune hepatitis (AIH), 14 PBC, 11 chronic liver disease; Norway: 32 PSC, 14 AIH, 13 PBC, 1 hepatitis C. Italy: 8 PSC, 14 PBC, 8 viral hepatitis. Thirty-six normal healthy volunteers from Oxford, together with positive and negative controls, were also tested.

RESULTS

The healthy controls were all ANCA negative. The diagnostic sensitivity and specificity, respectively, of ANCA for PSC using the IALP technique for the different test sera were: USA 71% and 93%, Sweden 66% and 96%, Norway 69% and 46%, Italy 50% and 95%. The diagnostic sensitivity and specificity, respectively, of the IF technique on the same sera were: USA 50% and 86%, Sweden 56% and 86%, Norway 47% and 61%, Italy 50% and 91%. Overall, combining all four groups, detection of ANCA using the IALP technique gave a diagnostic sensitivity of 66% with a specificity of 74% for PSC. In contrast, the IF technique gave an overall diagnostic of only 51% (P = 0.044, compared with IALP) with a specificity of 73%. Although overall the IALP technique was more sensitive than IF, the differences in sensitivity and specificity between the two techniques did not reach statistical significance for any individual group. Furthermore, the small differences in sensitivity between the four groups using either technique were not significant. However, the IALP technique had greater specificity in the US, Swedish and Italian groups compared with the Norwegian group (P < 0.05) whereas no statistically significant differences in specificity were noted between the groups using the IF technique.

CONCLUSION

This study shows that the IALP method of ANCA detection is at least as sensitive as IF for the serological diagnosis of PSC. Indeed, combining data from all four centres, the IALP technique was significantly more sensitive than IF. We therefore recommend the use of the IALP technique, which is also easier to interpret and does not require the use of a specialist fluorescent microscope. The lack of a wide variation in sensitivity between IALP and IF for any individual patient group reported in this study suggests that the previously reported regional differences in ANCA prevalence in PSC of between 26% and 85% may be patient, related, rather than due to ethnic or methodological differences in ANCA detection, perhaps reflecting possible disease heterogeneity within PSC, or case selection bias. Further studies are needed to investigate this intriguing possibility. Such differences, if confirmed, will need to be taken into account when assessing the use of ANCA as a serological marker of PSC.

Increased prevalence of Listeria monocytogenes in the faeces of patients receiving long-term H2-antagonists

BACKGROUND

Human listeriosis is an uncommon infection caused by the Gram-positive organism Listeria monocytogenes.

OBJECTIVE

To investigate the effects of therapeutic gastric acid suppression on faecal isolation of L. monocytogenes and the incidence of human listeriosis.

METHODS

Five stool specimens from each of 20 patients on continuous H2-antagonist therapy and two faecal samples from each of 47 healthy controls were investigated for the presence of Listeria spp.

RESULTS

A higher faecal isolation rate of L. monocytogenes was detected amongst the patients (20%) compared with the controls (2.1%) (P < 0.025). All subjects with stools positive for Listeria spp. were female, this sex difference being significant in the patient group (P < 0.0036) compared with controls. No patient, however, developed listeriosis.

CONCLUSION

Patients on long-term gastric acid suppressive therapy may be at increased risk of faecal carriage of L. monocytogenes.

Prevalence and diagnostic role of antineutrophil cytoplasmic antibodies in inflammatory bowel disease

BACKGROUND

Antineutrophil cytoplasmic antibodies (ANCA) are of proven diagnostic value in a variety of vasculitides, where they are also thought to play a pathogenic role. ANCA has also been detected in the serum of patients with idiopathic inflammatory bowel disease (IBD), both ulcerative colitis (UC) and Crohn's disease (CD), and primary sclerosing cholangitis (PSC) with or without concomitant IBD. Although the prevalence in PSC and UC is reported to be up to 85%, a much lower prevalence of around 10-20% has been reported in CD.

AIM

To determine ANCA prevalence in a group of British patients with IBD and evaluate their use as a serological marker to distinguish between UC and CD.

METHODS

A total of 99 UC-only patients (44 males, median age 50) and 41 CD patients (11 males, median age 47) were tested for ANCA using an alkaline phosphatase technique at a 1:5 serum dilution. Controls were other diarrhoeal diseases including 17 coeliac disease (4 males, median age 41), 23 irritable bowel syndrome (5 males, median age 42), 5 infectious colitis (2 male, median age 64) and 36 healthy volunteers (13 males, median age 43).

RESULTS

ANCA was detected in 42/99 (42.4%) UC patients but in only 2/41 (5%) CD (P < 0.0001). All ANCA were perinuclear in distribution. No ANCA was detected in the control sera. The sensitivity of the test for the diagnosis of UC was 42% with a specificity of 98%. In patients with UC, no association was found between presence of ANCA and age, sex, disease extent, treatment or activity. However, ANCA-positive UC patients had longer median duration of disease (50 months vs. 29 months, P = 0.037). Both CD ANCA-positive patients had colonic involvement, but one also had ileal disease. Both had inactive disease and one was on mesalazine.

CONCLUSIONS

ANCA is highly specific for UC and may be a helpful diagnostic test in distinguishing UC from CD and other diarrhoeal illnesses. Although ANCA positivity may reflect disease heterogeneity within UC, no association with clinical features or treatment of UC was demonstrated and it is therefore unlikely to play a pathogenic role. The correlation with disease duration needs further investigation.

Importance of antineutrophil cytoplasmic antibodies in primary sclerosing cholangitis and ulcerative colitis: prevalence, titre, and IgG subclass

Antineutrophil cytoplasmic antibodies (ANCA) have been reported in up to 87% of patients with primary sclerosing cholangitis with or without ulcerative colitis (PSC +/- UC) and in 68% of those with UC only. Compared with other liver and diarrhoeal diseases, ANCA have high specificity for PSC (+/- UC) and UC only. This study aimed to determine the prevalence and significance of ANCA in these two diseases and whether the ANCA titre or IgG subclass, or both, could distinguish between PSC + UC and UC only. Subjects included 63 patients with PSC, 85 with UC, 17 with coeliac disease, and 10 with dermatitis herpeteformis and 36 normal subjects. ANCA was detected using the immunoalkaline phosphatase method. The IgG subclass of ANCA was determined in 27 PSC + UC and 30 UC only patients using a panel of mouse monoclonal antibodies specific for the IgG subclasses. At a serum dilution of 1:5, ANCA had a diagnostic sensitivity of 65% for all PSC and 45% for UC only. For PSC + UC the sensitivity was 70% at 1:5 (p = 0.004 v UC only). At 1:50, the sensitivity values were 54% and 25% respectively for PSC + UC and UC only (p = 0.0006). In PSC, ANCA positivity was significantly associated with extensive involvement of the biliary tree but not with other clinical parameters. In UC only, the median disease duration was significantly greater in ANCA positive patients. The PSC + UC ANCA showed increased IgG3 compared with UC only ANCA (p < 0.05), together with increased IgG2 and IgG4 (p = NS). ANCA is a diagnostic marker in PSC and UC. While the higher titres and different IgG subclass distribution of ANCA in PSC + UC patients compared with those with UC only may reflect differences in underlying immune regulation, determination of the ANCA titre and IgG subclass is unlikely to have a role in distinguishing between PSC + UC and UC only ANCA. Future identification of the antigen(s) for ANCA should allow the development of a more sensitive and specific test for the diagnosis of these two conditions and also determine if ANCA is associated with UC or PSC.

Absence of antineutrophil cytoplasmic antibodies in relatives of UK patients with primary sclerosing cholangitis and ulcerative colitis

OBJECTIVE

Perinuclear antineutrophil cytoplasmic antibodies (ANCA) have been reported in patients and relatives of patients with ulcerative colitis and primary sclerosing cholangitis, suggesting that ANCA may be a genetic marker of disease susceptibility. The reported frequency of ANCA in relatives has varied greatly, between 0 and 30%. We therefore studied the prevalence of ANCA in unaffected first-degree relatives of British patients with primary sclerosing cholangitis and ulcerative colitis.

DESIGN

Thirty-six patients with ulcerative colitis, 33 with primary sclerosing cholangitis and 187 relatives were studied. Ninety-seven relatives were from the primary sclerosing cholangitis proband and 90 were from the ulcerative colitis proband. As an environmental control, 32 spouses were included: 14 from the primary sclerosing cholangitis group and 18 from the ulcerative colitis group. Eighteen healthy volunteers were additional controls.

METHODS

ANCA was detected using immunoalkaline phosphatase method.

RESULTS

Only 3 of 97 (3%) of the primary sclerosing cholangitis proband relatives had ANCA. One of these had ulcerative colitis, one had rheumatoid arthritis and the third systemic lupus erythematosus. Both rheumatoid arthritis and system lupus erythematosus are known to exhibit ANCA. All other sera were negative.

CONCLUSION

ANCA was found only in patients with primary cholangitis and ulcerative colitis and not in their healthy first-degree relatives. ANCA is therefore not a genetic marker for increased disease susceptibility to primary sclerosing cholangitis or ulcerative colitis in the British population.

Anti-neutrophil cytoplasmic antibodies in inflammatory bowel disease: do they recognize different subsets of a heterogeneous disease?

OBJECTIVE

To evaluate the prevalence of anti-neutrophil cytoplasmic antibodies in a series of patients with inflammatory bowel disease, the discriminatory value of these antibodies in differentiating between ulcerative colitis and Crohn's disease, their antigen specificity and their correlation with epidemiological and clinical variables.

METHODS

Serum anti-neutrophil cytoplasmic antibodies were evaluated by indirect immunofluorescence and immunoblotting using neutrophils isolated from peripheral blood and by enzyme-linked immunosorbent assays (ELISAs) using proteinase 3 and myeloperoxidase as antigens.

RESULTS

Anti-neutrophil cytoplasmic antibodies were detected by immunofluorescence in 43 (39.8%) of 108 patients with ulcerative colitis, in 11 (11.9%) of 92 patients with Crohn's disease (P < 0.001) and 5 (6.8%) of 73 control patients. The predominant pattern was perinuclear staining around neutrophil nuclei (44 of 59, 75%); a homogeneous cytoplasmic staining was present in 15 (25%) of 59 sera, mainly among Crohn's disease and control patients. The ELISAs gave no positive results. Recognition of proteins of relative molecular masses 27,000 and 49,000 at immunoblotting was common to ulcerative colitis, Crohn's disease and control sera. The proteins of relative molecular masses 32,000 and 106,000 were recognized exclusively by 11% of anti-neutrophil-positive ulcerative colitis sera. No significant correlation was found between the presence of anti-neutrophil cytoplasmic antibodies and the demographic and clinical characteristics of the patients.

CONCLUSION

Anti-neutrophil cytoplasmic antibodies are detectable in a large proportion of patients with ulcerative colitis, but their prevalence in a limited proportion of patients with Crohn's disease reduces their discriminatory capability. The persistence of anti-neutrophil cytoplasmic antibodies after total colectomy and the absence of a correlation between the activity of the disease and the presence or titre of these antibodies support the hypothesis that anti-neutrophil cytoplasmic antibodies are not simply an epiphenomenon of colonic inflammation.