Autoantibodies to tissue transglutaminase as predictors of celiac disease

Background & Aims: Immunoglobulin A (IgA) autoantibodies to endomysium (EMA) are highly specific and sensitive markers for celiac disease. Recently, we identified tissue transglutaminase (tTG) as the major if not sole endomysial autoantigen. Methods: An enzyme-linked immunosorbent assay (ELISA) was established to measure IgA anti-tTG titers in serum samples from 106 celiac patients with partial or subtotal villous atrophy, 43 celiac patients on a gluten-free diet, and 114 diseased and healthy controls. Results were correlated with clinical and histological data and with EMA titers. Results: In patients with biopsy-proven celiac disease consuming a normal, gluten-containing diet, 98.1% of the serum samples had elevated IgA titers against tTG, whereas 94.7% of the control sera were negative. IgA anti-tTG correlated positively with semiquantitative IgA EMA titers (r = 0.862; P < 0.0001). Conclusions: An ELISA based on tTG allows diagnosis of celiac disease with a high sensitivity and specificity. IgA anti-tTG and IgA EMA show an excellent correlation, further confirming the enzyme as the celiac disease autoantigen. Because the assay is quantitative, not subjected to interobserver variation, and easy to perform, it will be a useful tool for population screening of a hitherto underdiagnosed disease.GASTROENTEROLOGY 1998;115:1317-1321     

Measurement of serum PSP/reg-protein concentration in various diseases with a newly developed enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay, based on two monoclonal antibodies (Hreg1-1 and Hreg101-1) specific for pancreatic stone protein (PSP)/reg-protein, was developed to determine the concentration of this protein in serum from individuals with various diseases. The serum concentration of PSP/reg-protein was significantly higher in patients with various pancreatic diseases than in normal controls, and was also significantly higher in patients with acute pancreatitis or chronic relapsing pancreatitis than in patients with chronic pancreatitis. Furthermore, the serum PSP/reg-protein concentration was also significantly increased in liver cirrhosis, choledocholithiasis, and various cancers of the digestive system, and was extremely high in all patients tested with chronic renal failure. A significant correlation was apparent between the serum concentration of PSP/reg-protein and elastase-I in 68 patients with chronic pancreatitis or pancreatic cancer. Whereas only 7 of these patients showed a normal serum PSP/reg-protein concentration and a significantly increased elastase-I concentration, 15 of these patients showed a significantly increased serum PSP/reg-protein coecentration and a normal serum elastase-1 concentration. These results indicate that the serum PSP/reg-protein concentration may reflect pancreatic damage, especially in acute pancreatitis, and may be as sensitive a marker for such damage as elastase-I, although false positivity was apparent in renal failure and in some patients with hepatic dysfunction or digestive system malignancies.     

Crohn's disease in Olmsted County, Minnesota, 1940–1993: Incidence, prevalence, and survival

Background & Aims: Many centers worldwide have reported an increased incidence of Crohn's disease, but population-based data in North America are sparse. We studied the incidence and prevalence of Crohn's disease in Olmsted County, Minnesota, and examined temporal trends in incidence and survival. Methods: Residents diagnosed with Crohn's disease between 1970 and 1993 were incidence cases, and residents with Crohn's disease who were alive on January 1, 1991, were prevalence cases. Cases from previous studies were reconfirmed. Rates were adjusted using 1990 U.S. Census figures for whites. Incidence trends were evaluated with a Poisson regression model. Survival from diagnosis was compared with that expected for U.S. north-central whites. Results: Between 1940 and 1993, 225 incidence cases were identified, for an adjusted incidence rate of 5.8 per 100,000 person-years. On January 1, 1991, there were 145 residents with Crohn's disease, an adjusted prevalence rate of 133 per 100,000, 46% higher than that seen in 1980. Incidence rates before 1964 were significantly lower than those of 1989–1993. Observed survival was less than expected (P = 0.007). Conclusions: The incidence of Crohn's disease has stabilized since the 1970s at a rate higher than that seen previously. Prevalence has increased by 46% since 1980. Overall survival is slightly decreased.GASTROENTEROLOGY 1998;114:1161-1168     

Prognostic value of pharmacological stress echocardiography in women with chest pain and unknown coronary artery disease

Objectives. In this study we sought to investigate the prognostic value of pharmacological stress echocardiography in women referred for chest pain, having unknown coronary artery disease.

Background. The noninvasive identification of a high-risk subgroup among women with chest pain and unknown coronary artery disease is an unresolved task to date.

Methods. A total of 456 women (mean [±SD] age 63 ± 10 years) underwent pharmacological stress echocardiography with either dipyridamole (n = 305) or dobutamine (n = 151) for evaluation of chest pain and were followed-up for 32 ± 19 months. None of them had a previous diagnosis of coronary artery disease.

Results. No major complication occurred during stress testing. Five tests (1.1%) were prematurely interrupted because of the appearance of side effects. Echocardiographic positivity was identified in 51 patients. During the follow-up, 23 cardiac events occurred: 3 deaths, 10 infarctions and 10 cases of unstable angina; an additional 21 patients underwent coronary revascularization. At Cox analysis, the echocardiographic evidence of ischemia was found as the only independent predictor of hard cardiac events (death, infarction) (odds ratio [OR] = 27.5; 95% confidence interval [CI] = (6.5 to 115.5; p = 0.0000). When spontaneous cardiac events (death, infarction and unstable angina) were considered as endpoints, the positive echocardiographic result (OR = 23.9; 95% CI = 8.6 to 66.8; p = 0.0000) and family history of coronary artery disease (OR = 3.7; 95% CI = 1.5 to 9.1; p = 0.0037) were independently correlated with prognosis. By using an interactive stepwise procedure, the prognostic value of stress echocardiography was found to be incremental to that provided by clinical variables, both considering hard and spontaneous cardiac events as endpoints. The 3-year survival rate for the negative and the positive population was respectively, 99.5% and 69.5% (p = 0.0000) considering hard cardiac events, 99.2% and 50.6% (p = 0.0000) considering spontaneous cardiac events.

Conclusions. Pharmacological stress echocardiography is safe, highly feasible and effective in risk stratification of women with chest pain and unknown coronary artery disease, also when hard endpoints are considered. Its use can have relevant implications in daily clinical practice for selection of patients needing further investigations.     

Aspirin and mortality in patients treated with angiotensin-converting enzyme inhibitors: A cohort study of 11,575 patients with coronary artery disease

OBJECTIVES

The purpose of this study was to investigate the significance of the possible negative interaction between aspirin and angiotensin-converting enzyme (ACE) inhibitors.

BACKGROUND

Several provocative reports have recently suggested that aspirin is unsafe in patients with heart failure and has negative interaction with ACE inhibitors that might attenuate their beneficial effects upon survival.

METHODS

We analyzed mortality data of 11,575 patients with coronary artery disease screened for the Bezafibrate Infarction Prevention trial. A total of 1,247 patients (11%) were treated with ACE inhibitors. Of them, 618 patients (50%) used aspirin.

RESULTS

Five-year mortality was lower among patients on ACE inhibitors and aspirin than patients on ACE inhibitors without aspirin (19% vs. 27%; p < 0.001). After adjusting for confounders, treatment with aspirin and ACE inhibitors remained associated with lower mortality risk than using ACE inhibitors only (relative risk [RR] = 0.71; 95% confidence interval [CI] = 0.56 to 0.91). Subgroup analysis of 464 patients with congestive heart failure treated with ACE inhibitors revealed 221 patients (48%) on aspirin and 243 patients not on aspirin. Although clinical characteristics and therapy were similar, patients taking aspirin experienced lower mortality than patients who did not (24% vs. 34%; p = 0.001). After adjustment, treatment with aspirin was still associated with lower mortality (RR = 0.70; 95% CI = 0.49 to 0.99).

CONCLUSIONS

Among coronary artery disease patients with and without heart failure who are treated with ACE inhibitors, the use of aspirin was associated with lower mortality than treatment without aspirin. Our findings contradict the claim that aspirin attenuates the beneficial effect of ACE inhibitors and supports its use in patients with coronary artery disease treated with ACE inhibitors.     

Interleukin 15 activity in the rectal mucosa of inflammatory bowel disease

Background & Aims: Interleukin (IL)-15 has been found to share many immunoregulatory activities in lymphocytes with IL-2. The aim of this study was to investigate IL-15 activity in organ cultures, localization of IL-15 messenger RNA (mRNA), and proliferation of lamina propria mononuclear cells (LPMCs) in response to recombinant IL-15 using the mucosal tissues obtained from patients with inflammatory bowel disease (IBD). Methods: The contents of IL-15, tumor necrosis factor α, and IL-2 in the culture supernatant of the rectal mucosal tissues were determined by an enzyme-linked immunosorbent assay. Expression of IL-15 mRNA was analyzed by in situ hybridization, and proliferative response of LPMCs to recombinant IL-15 was determined by [³H]thymidine incorporation into DNA. Results: Significantly greater IL-15 activity was detected in active IBD, and this elevation was also observed in inactive ulcerative colitis. In contrast, greater tumor necrosis factor α activity was observed only in active IBD, and IL-2 was not detected in organ cultures. In situ hybridization showed IL-15 mRNA in macrophages and epithelial cells in active IBD specimens, and recombinant IL-15 induced a dose-dependent proliferative response in LPMCs. Conclusions: Mucosal IL-15 may be involved in the pathogenesis of IBD as one of the important mediators in activation of mucosal immune cells.GASTROENTEROLOGY 1998;114:1237-1243     

Peptide complex containing GLP-1 exhibited long-acting properties in the treatment of type 2 diabetes

The multiple physiological characterizations of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of type 2 diabetes. However, in vivo, the half-life of GLP-1 is short, which is caused by the degradation of dipeptidyl peptidase-IV (DPP-IV) and renal clearance. Thus, the stabilization of GLP-1 is critical for its utility in drug development. Peptides known as GLP-1 protectors are predicted to increase the half-life of GLP-1 in vivo. Protecting peptides are able to form stable complexes by non-covalent interactions with human GLP-1. In this study, the stability of the complex was investigated, and the physiological functions of the GLP-1/peptide 1 complex were compared to those of exenatide and liraglutide in animals. The results indicated that the GLP-1/peptide 1 complex remarkably raised the half-life of GLP-1 in vivo and showed better glucose tolerance and higher HbA_1c reduction than exenatide and liraglutide in rodents. Based upon these results, it is suggested that the GLP-1/peptide 1 complex might be utilized as a possible potent anti-diabetic drug in the treatment of type 2 diabetes mellitus.     

Neutrophils and NADPH oxidase mediate intrapancreatic trypsin activation in murine experimental acute pancreatitis

BACKGROUND & AIMS: Intrapancreatic activation of digestive enzymes is a key event in the parenchymal cell injury of pancreatitis. We hypothesized that neutrophils recruited to the pancreas during pancreatitis may contribute to such activation. METHODS: To cause experimental pancreatitis, rats and mice were treated with high doses of cerulein. Activation of the digestive enzyme, trypsin, was measured in pancreatic homogenates using a fluorogenic assay and localized immunocytochemically with antibody to trypsin-activation peptide (TAP). RESULTS: Compared with controls, rats depleted of neutrophils with antineutrophil serum exhibited a marked attenuation in intrapancreatic trypsin activation and acinar cell TAP labeling induced by high-dose cerulein. To examine the mechanism, mice deficient in either nicontinamide adenine dinucleotide phosphate (NADPH) oxidase, or myeloperoxidase (MPO) were studied for trypsin activation. Mice deficient in NADPH oxidase exhibited attenuation of the cerulein-induced trypsin activation, but those deficient in MPO did not. Using measurements of Western blot analysis, generation of reactive oxygen species, and immunocytochemistry, we demonstrated the NADPH oxidase activity is in neutrophils and not pancreatic acinar tissue. CONCLUSIONS: The results demonstrate a novel role for neutrophils infiltrating the pancreas in pathologic activation of digestive enzymes in acute pancreatitis and indicate that this effect is mediated by products of NADPH oxidase.     

Autoantibody against dendrite in Plasmodium falciparum infection: a singular auto-immune phenomenon preferentially in cerebral malaria

To investigate auto-reactive antibodies against dendrites of neurons (AAD) previously reported in cerebral malaria (CM) for their functional biological activity, a serological study was conducted in a larger cohort of patients with CM and uncomplicated falciparum malaria (UM). Sera from Thai adults with CM (n = 22) and UM (n = 21) were tested to determine the titers of AAD by indirect fluorescent antibody test and specific antibody responses to Plasmodium falciparum antigens by ELISA. Immunoreactivity against the dendrites of neurons was observed in 100% of sera from the cerebral malaria group as compared to 71% from the non-cerebral malaria group, and the median titer of AAD was higher in CM versus UM, though the difference did not reach significance. In contrast an opposite pattern was seen for anti-P. falciparum antibody titers, which were significantly lower among CM than among UM patients, both for IgG and IgM (p = 0.024 and p = 0.0033, respectively). Our results indicate that this auto-immune phenomenon induced by P. falciparum infection occurs preferentially in cerebral malaria despite lower responses in parasite-specific antibody responses.     

HCCR-1-interacting molecule "deleted in polyposis 1" plays a tumor-suppressor role in colon carcinogenesis

BACKGROUND & AIMS: Human cervical cancer oncogene (HCCR-1) has appeared to act as a negative regulator of p53 and contributes to tumorigenesis of various organs including the colon. We identified the HCCR-1 binding protein deleted in polyposis 1 (DP1) and accessed the role of HCCR-1 and DP1 in colon tumorigenesis. METHODS: Yeast 2-hybrid was used to identify HCCR-1 interacting proteins. Various molecular biological approaches were used to examine the expression profile of HCCR-1 and DP1, subcellular localization, epitope mapping, the biological role of DP1, and the serum HCCR-1 level. Loss of heterozygosity frequency around DP1 also was examined. RESULTS: We identified that HCCR-1 interacted with DP1. These 2 proteins colocalized in mitochondria but the expression of HCCR-1 showed negative correlation with that of DP1 in colorectal cancer (CRC). DP1 played a tumor-suppressor role in colon tumorigenesis (ie, DP1-transfected RKO cells showed growth inhibition, apoptosis, decreased telomerase activity, and up-regulation of p53). These phenomena were reversed when HCCR-1 was overexpressed. Loss of heterozygosity around the DP1 gene was observed frequently (50%) in CRCs. We examined the use of serum HCCR-1 in CRC patients. The sensitivity of HCCR-1 (76.0%) for detecting CRC was proven to be much higher than that of CA19-9 (32.0%). CONCLUSIONS: DP1 plays a tumor-suppressor role in CRC. DP1 and HCCR-1 are supposed to regulate each other negatively by interaction, but further study is required to get better insight into the biological significance of the interaction.     

Tissue infiltration of IgG4+ plasma cells in symptomatic patients with ileal pouch-anal anastomosis

Background

Inflammatory bowel disease (IBD) is reported to be associated with autoimmune pancreatitis. The aim of the study was to investigate serum IgG4 and tissue infiltration of IgG4+ plasma cells in symptomatic patients with ileal pouches.

Methods

Ninety-seven consecutive persistent symptomatic patients with ileal pouches from our subspecialty Pouchitis Clinic from January to December 2010 were included in the study. Serum IgG4 was measured at the time of presentation. All patients underwent pouchoscopy with pouch biopsies immunostained for IgG4+ plasma cells. Patients with ≥ 10 per high-power field of IgG4+ plasma cells were considered positive for the stain.

Results

Twenty-eight (28.9%) patients had positive IgG4 immunostaining of pouch and/or afferent limb biopsy, while the remaining 69 patients (71.1%) were IgG4 negative. Demographic and symptoms were similar between the two groups. The median serum IgG4 in the IgG4 positive group was 21.3 (interquartile range 0–41.3) mg/dL vs. 0 (interquartile range 0–18) in the IgG4 negative group. (p = 0.04). On multivariate analysis, the Pouchitis Disease Activity Index (PDAI) endoscopy score in the pouch (odds ratio [OR] 1.66, 95% confidence interval [CI]: 1.21–2.29, p = 0.002) and number of concomitant autoimmune disorders (OR 3.04, 95% CI: 1.22–7.53, p = 0.017) were independent risk factors for the presence of IgG4+ plasma cell infiltration.

Conclusions

Increased IgG4+ plasma cells were found in 1/4 of IPAA patients with persistent symptoms. The presence of tissue infiltration of IgG4+ plasma cells appeared to be associated with chronic pouch inflammation and concurrent autoimmune disorders.     

Combined passive and active immunoprophylaxis for preventing perinatal transmission of the hepatitis B virus in infants born to HBsAg positive mothers in comparison with vaccine alone

BACKGROUND: In order for liver cirrhosis and hepatocellular carcinoma not to be inflicted upon in infants' lifetime, it is essential to prevent hepatitis B virus (HBV) infection in them. OBJECTIVES: The aim of this study is to reveal the efficacy of passive and active immunoprophylaxis in preventing perinatal transmission of HBV in Iran. STUDY DESIGN: In this cohort study with historical controls, 823 children born to the HBsAg positive mothers were evaluated. Out of this number, 638 had received neither hepatitis B (HB) vaccine nor hepatitis B immune globulin (HBIG) and aged more than 16 years (n=481, group 1) or 16 years or less (n=157, group 2). The other 125 persons had received only HB vaccine (group 3), and 60 neonates received both HB vaccine and HBIG (group 4). RESULTS: The prevalence of HBsAg in groups 1, 2, 3 and 4 was 56.1%, 40.3%, 12.6%, and 3.6%, respectively. The prevalence of anti-HBsAb had a significantly descending rate in groups 4 (85.7%), 3 (68.8%), 2 (33.3%), and 1 (21.8%), respectively. CONCLUSIONS: The addition of HBIG to recombinant vaccine will significantly increase the protection against HBV infection in comparison with HB vaccine alone.     

Expression of G protein α subunits in normal rat colon and in azoxymethane-induced colonic neoplasms

Background & Aims: Heterotrimeric G proteins are important in growth-regulating signal transduction. The aim of this study was to characterize the relative expression of G protein α subunits in rat colonocytes, colonocyte antipodal plasma membranes, and colonic neoplasms. Methods: Antipodal plasma membranes were prepared from isolated colonocytes. Azoxymethane was administered to rats to induce colonic neoplasms. K-ras mutations in the neoplasms were determined by oligonucleotide hybridization and confirmed by primer mediated–restriction fragment length polymorphism. Colonocyte and tumor homogenates or membranes were probed for Gα subunits by Western blotting with isoform-specific antibodies. Results: The expressions of Gαi2, αi3, and αq/11 were significantly enriched in the basolateral compared with brush border fraction of colonic antipodal plasma membranes. In neoplasms without K-ras mutations, the expression of Gαi2 increased 4-fold, Gαs(long) increased 2.5-fold, and Gαi3 increased 1.5–2-fold. Expression did not differ among tumor grades. K-ras mutations were associated with lowered expression of G proteins, especially Gαo. Conclusions: In colonocytes, Gα subunits are localized primarily in basolateral plasma membranes. The increased expressions of Gαi2 and, to a lesser degree, Gαi3 and Gαs(long) in tumors was independent of tumor grade but was modulated by the presence of K-ras mutations.GASTROENTEROLOGY 1998;115:1494-1503     

Identification and functional characterization of alpha-enolase from Taenia pisiformis metacestode

Enolase belongs to glycolytic enzymes with moonlighting functions. The role of enolase in Taenia species is still poorly understood. In this study, the full length of cDNA encoding for Taenia pisiformis alpha-enolase (Tpeno) was cloned from larval parasites and soluble recombinant Tpeno protein (rTpeno) was produced. Western blot indicated that both rTpeno and the native protein in excretion–secretion antigens from the larvae were recognized by anti-rTpeno monoclonal antibodies (MAbs). The primary structure of Tpeno showed the presence of a highly conserved catalytic site for substrate binding and an enolase signature motif. rTpeno enzymatic activities of catalyzing the reversible dehydration of 2-phosphoglycerate (2-PGA) to phosphoenolpyruvate (PEP) and vice versa were shown to be 30.71 ± 2.15 U/mg (2-PGA to PEP) and 11.29 ± 2.38 U/mg (PEP to 2-PGA), respectively. Far-Western blotting showed that rTpeno could bind to plasminogen, however its binding ability was inhibited by ?-aminocaproic acid (?ACA) in a competitive ELISA test. Plasminogen activation assay showed that plasminogen bound to rTpeno could be converted into active plasmin using host-derived activators. Immunohistochemistry and immunofluorescence indicated that Tpeno was distributed in the bladder wall of the metacestode and the periphery of calcareous corpuscles. In addition, a vaccine trial showed that the enzyme could produce a 36.4% protection rate in vaccinated rabbits against experimental challenges from T. pisiformis eggs. These results suggest that Tpeno with multiple functions may play significant roles in the migration, growth, development and adaptation of T. pisiformis for survival in the host environment.