Low clinical relevance of the nonalcoholic fatty liver disease activity score (NAS) in predicting fibrosis progression.

BACKGROUND/AIMS: The nonalcoholic fatty liver disease (NAFLD) activity score (NAS) is a newly proposed system to grade the necroinflammatory activity in liver biopsies of NAFLD patients. This study evaluates the usefulness of the NAS in predicting clinical deterioration and fibrosis progression in NAFLD. METHODS: One hundred and twenty-nine patients with biopsy-proven NAFLD were included in a long-term histological follow-up study. Clinical course and change in fibrosis stage were compared between nonalcoholic steatohepatitis (NASH), "borderline NASH," and "not NASH" patients. Significant fibrosis progression was defined as progression of more than one fibrosis stage or development of end-stage liver disease during follow-up. RESULTS: Eighty-eight patients accepted reevaluation and 68 underwent repeat liver biopsy. Mean time between biopsies was 13.8 ± 1.2 years (range 10.3-16.3). At baseline, NASH was diagnosed in 2 (1.6%) patients, and at follow-up, in 1 (1.5%) patient. A trend toward higher baseline NAS was seen in patients (n = 7) who developed end-stage liver disease (3.1 ± 0.9 vs. 2.2 ± 1.0; p = 0.050). Baseline NAS was associated with progressive disease in a univariate binary logistic regression analysis (p = 0.024), but no difference was seen in the multivariate analysis including the NAS, portal inflammation, and perisinusoidal fibrosis. Moreover, 18% of patients without NASH progressed significantly in fibrosis stage. CONCLUSIONS: The ability of the NAS to predict progression of NAFLD is poor. The clinical usefulness of the score is limited due to the significant overlap in clinical development between NAS score groups. To use the NAS as endpoint in treatment trial is not justified.

Nonselective matrix metalloproteinase but not tumor necrosis factor-α inhibition effectively preserves the early critical colon anastomotic integrity.

BACKGROUND: Increased matrix metalloproteinase (MMP) activity has been implicated in the pathogenesis of colorectal anastomotic leakage. Tumor necrosis factor-α (TNF-α) induces MMPs and may influence anastomosis repair. METHODS: We assessed the efficacies of the nonselective hydroxamate MMP inhibitor GM6001, the selective hydroxamate MMP inhibitor AG3340 and a TNF-α antagonist with respect to anastomotic breaking strength of left-sided colon anastomoses in male Sprague-Dawley rats. RESULTS: Systemic GM6001 treatment effectively blocked MMP activity and maintained the initial breaking strength day 0 of the anastomoses when administered subcutaneously as daily depositions (100 mg/kg) or continuously (10 mg/kg/day). In contrast, the anastomotic biomechanic strength was lowered by 55% (p < 0.001) in vehicle-treated rats on postoperative day 3. GM6001 treatment increased breaking strength by 88% (p < 0.0005) compared with vehicle-treated rats day 3 and reduced (p = 0.003) the occurrence of spontaneous anastomotic dehiscence. Histologically, the anastomotic wound was narrower (p < 0.05) in the longitudinal direction in GM6001-treated animals whereas GM6001 had no significant effect on inflammatory cell infiltration or epithelialization. AG3340 (10 mg/kg) increased (p < 0.012) breaking strength by 47% compared with vehicle on day 3 but did not significantly prevent the reduction of the initial breaking strength on day 0. Although the increased TNF-α levels in the wound were attenuated, the anastomotic breaking strength was not improved (p = 0.62) by the TNF-α (10 mg/kg) inhibitor given systemically. CONCLUSIONS: Pharmacological nonselective MMP inhibition ought to be explored as a prophylactic regimen to reduce anastomotic complications following colorectal resection. The involvement of TNF-α was insignificant in anastomotic wound healing in an experimental model.

Characterization of the gastric cardia in volunteers from the general population. Type of mucosa, Helicobacter pylori infection, inflammation, mucosal proliferative activity, p53 and p21 expression, and relations to gastritis.

The aim of this research was to characterize the mucosa of the gastric cardia in relation to infection with Helicobacter pylori and the occurrence of chronic gastritis in other parts of the stomach in a sample of the general population. In this study, 80 adult volunteers underwent esophagogastroscopy with biopsies from the gastric cardia, corpus, and antrum. Gastritis was classified according to the Sydney system. Chronic gastritis (cardia excepted) was diagnosed in 35 subjects, 30 with H. pylori infection. Epithelial proliferative activity (Ki-67), p53- and p21 expression were examined quantitatively with cell counting after immunohistochemical stainings. Esophagitis was diagnosed macroscopically. Fourty eight subjects had cardia-type and 32 corpus-type mucosa in the anatomical cardia. The prevalence of esophagitis (nine cases) did not differ between these groups. Carditis was more prevalent among subjects with cardia-type mucosa (73 vs. 28%, P < 0.0001). H. pylori was present in 48% of those with cardia-type and 25% of those with corpus-type mucosa (P = 0.06). Of the 44 subjects with carditis, 31 had H. pylori in this location. The group with H. pylori infection had significantly higher mucosal proliferative activity when compared to uninfected subjects. Among the subjects with H. pylori-associated carditis, more p53-positive epithelial cells were detected compared to both the non-infected group (P = 0.0004) and to subjects with non-H. pylori-associated carditis (P = 0.03). In subjects with cardia-type mucosa, and both carditis and gastritis, the degree of chronic inflammation was higher in the cardia compared to the corpus and antrum and the p53 expression was significantly higher in the cardia compared to the corpus, but similar to that in the antrum. The proliferative activity was significantly higher in the antrum compared to the cardia and corpus, respectively. In conclusion, H. pylori infection, carditis, and increased p53 expression are more common in subjects with cardia- than corpus-type mucosa in the gastric cardia. Carditis is mainly related to H. pylori infection. There are some differences regarding inflammation, proliferative activity, and p53 expression between the cardia and other regions of the stomach, yet the significance of these differences remains to be clarified.

Alcohol consumption is associated with progression of hepatic fibrosis in non-alcoholic fatty liver disease.

OBJECTIVE: Moderate alcohol consumption has been reported to be inversely associated with cardiovascular disease and total mortality. The importance of non-alcoholic fatty liver disease (NAFLD) is increasing and many NAFLD patients suffer from cardiovascular disease. In these patients, moderate alcohol consumption could be beneficial. The aim of this study was to investigate whether low alcohol intake, consistent with the diagnosis of NAFLD, is associated with fibrosis progression in established NAFLD. MATERIAL AND METHODS: Seventy-one patients originally referred because of chronically elevated liver enzymes and diagnosed with biopsy-proven NAFLD were re-evaluated. A validated questionnaire combined with an oral interview was used to assess weekly alcohol consumption and the frequency of episodic drinking. Significant fibrosis progression in NAFLD was defined as progression of more than one fibrosis stage or development of endstage liver disease during follow-up. RESULTS: Mean follow-up (SD) was 13.8 (1.2) years between liver biopsies. At follow-up, 17 patients (24%) fulfilled the criteria for significant fibrosis progression. The proportion of patients reporting heavy episodic drinking at least once a month was higher among those with significant fibrosis progression (p=0.003) and a trend towards higher weekly alcohol consumption was also seen (p=0.061). In a multivariate binary logistic regression analysis, heavy episodic drinking (p<0.001) and insulin resistance (p<0.01) were independently associated with significant fibrosis progression. CONCLUSIONS: Moderate alcohol consumption, consistent with the diagnosis of NAFLD to be set, is associated with fibrosis progression in NAFLD. These patients should be advised to refrain from heavy episodic drinking.

A morphometric study of antral G-cell density in a sample of adult general population: comparison of three different methods and correlation with patient demography, helicobacter pylori infection, histomorphology and circulating gastrin levels.

Helicobacter pylori infection has been linked to hypergastrinemia and either decreased or normal G-cell content in the antral mucosa. To clarify this controversial issue, we quantitatively determined antral G-cell content on the same biopsy specimens with three different methods and examined whether these methods are intercorrelated and the relation of these methods to plasma gastrin concentrations, demography, the occurrence of H. pylori infection and chronic gastritis. Gastric antral mucosal biopsy sections from 273 adults (188 with and 85 without H pylori infection) from a general population sample were examined immunohistochemically for G-cells using cell counting, stereology (point counting) and computerized image analysis. Gastritis was scored according to the updated Sydney system. Basal plasma gastrin concentrations were measured by radioimmunoassay. The three methods for G-cell quantification were poorly correlated and the results showed no correlation with basal plasma gastrin concentrations. The antral G-cell density and scores for H. pylori colonization were positively related to age. Neither the scores for chronic inflammation, nor the scores for inflammatory activity, atrophy or intestinal metaplasia were consistently related to the antral G-cell content. In conclusion, the results of three techniques for G-cell quantification in the gastric antral mucosa were poorly intercorrelated and none of the methods correlated with plasma gastrin concentrations. Age and scores for H pylori colonization seem to be determinants of the G-cell density. That common morphometric techniques correlate poorly is of utmost importance to bear in mind when quantitative morphological studies are planned, compared or interpreted.

Probiotics enhance pancreatic glutathione biosynthesis and reduce oxidative stress in experimental acute pancreatitis.

Factors determining severity of acute pancreatitis (AP) are poorly understood. Oxidative stress causes acinar cell injury and contributes to the severity, whereas prophylactic probiotics ameliorate experimental pancreatitis. Our objective was to study how probiotics affect oxidative stress, inflammation, and acinar cell injury during the early phase of AP. Fifty-three male Sprague-Dawley rats were randomly allocated into groups: 1) control, 2) sham procedure, 3) AP with no treatment, 4) AP with probiotics, and 5) AP with placebo. AP was induced under general anesthesia by intraductal glycodeoxycholate infusion (15 mM) and intravenous cerulein (5 microg.kg(-1).h(-1), for 6 h). Daily probiotics or placebo were administered intragastrically, starting 5 days prior to AP. After cerulein infusion, pancreas samples were collected for analysis including lipid peroxidation, glutathione, glutamate-cysteine-ligase activity, histological grading of pancreatic injury, and NF-kappaB activation. The severity of pancreatic injury correlated to oxidative damage (r = 0.9) and was ameliorated by probiotics (1.5 vs. placebo 5.5; P = 0.014). AP-induced NF-kappaB activation was reduced by probiotics (0.20 vs. placebo 0.53 OD(450nm)/mg nuclear protein; P < 0.001). Probiotics attenuated AP-induced lipid peroxidation (0.25 vs. placebo 0.51 pmol malondialdehyde/mg protein; P < 0.001). Not only was AP-induced glutathione depletion prevented (8.81 vs. placebo 4.1 micromol/mg protein, P < 0.001), probiotic pretreatment even increased glutathione compared with sham rats (8.81 vs. sham 6.18 miccromol/mg protein, P < 0.001). Biosynthesis of glutathione (glutamate-cysteine-ligase activity) was enhanced in probiotic-pretreated animals. Probiotics enhanced the biosynthesis of glutathione, which may have reduced activation of inflammation and acinar cell injury and ameliorated experimental AP, via a reduction in oxidative stress.

Statins in non-alcoholic fatty liver disease and chronically elevated liver enzymes: a histopathological follow-up study.

BACKGROUND/AIMS: The effect of statins on hepatic histology in non-alcoholic fatty liver disease (NAFLD) is not known. This study explores hepatic histology in NAFLD patients before and after initiation of statin therapy and compares histological outcome with NAFLD patients who had not been prescribed statins. METHODS: Sixty-eight NAFLD patients were re-evaluated. Follow-up ranged from 10.3 to 16.3 years. Subjects were clinically investigated and a repeat liver biopsy was obtained. No patient was taking statins at baseline while 17 patients were treated with statins at follow-up. RESULTS: At baseline, patients that later were prescribed statins had significantly higher BMI and more pronounced hepatic steatosis. At follow-up patients on medication with statins continued to have significantly higher BMI. Diabetes was significantly more common among patients on medication with statins and they had significantly more pronounced insulin resistance. However, they exhibited a significant reduction of liver steatosis at follow-up as opposed to patients not taking statins. Despite exhibiting a high risk profile for progression of liver fibrosis, only four patients on statin treatment progressed in fibrosis stage. CONCLUSIONS: Statins can be prescribed in patients with elevated liver enzymes because of NAFLD.

Long-term follow-up of patients with NAFLD and elevated liver enzymes.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of elevated liver enzymes in patients of developed countries. We determined the long-term clinical and histological courses of such patients. In a cohort study, 129 consecutively enrolled patients diagnosed with biopsy-proven NAFLD were reevaluated. Survival and causes of death were compared with a matched reference population. Living NAFLD patients were offered repeat liver biopsy and clinical and biochemical investigation. Mean follow-up (SD) was 13.7 (1.3) years. Mortality was not increased in patients with steatosis. Survival of patients with nonalcoholic steatohepatitis (NASH) was reduced (P = .01). These subjects more often died from cardiovascular (P = .04) and liver-related (P = .04) causes. Seven patients (5.4%) developed end-stage liver disease, including 3 patients with hepatocellular carcinoma. The absence of periportal fibrosis at baseline had a negative predictive value of 100% in predicting liver-related complications. At follow-up, 69 of 88 patients had diabetes or impaired glucose tolerance. Progression of liver fibrosis occurred in 41%. These subjects more often had a weight gain exceeding 5 kg (P = .02), they were more insulin resistant (P = .04), and they exhibited more pronounced hepatic fatty infiltration (P = .03) at follow-up. In conclusion, NAFLD with elevated liver enzymes is associated with a clinically significant risk of developing end-stage liver disease. Survival is lower in patients with NASH. Most NAFLD patients will develop diabetes or impaired glucose tolerance in the long term. Progression of liver fibrosis is associated with more pronounced insulin resistance and significant weight gain.

Semiquantitative evaluation overestimates the degree of steatosis in liver biopsies: a comparison to stereological point counting.

The degree of steatosis in liver biopsies is usually assessed by a morphological semiquantitative approach in which the histopathologist uses a four-graded scale: 0-3 or none, slight, moderate and severe. Scores 1-3 are considered to correspond to fat deposition in <33, 33-66 and >66% of the hepatocytes. There is a considerable inter- and intra-individual variation in such scoring methods and a more standardized and quantitative approach is preferable. In the present study, we compare the semiquantitative technique with the stereological point counting method in the assessment of hepatic steatosis. A total of 75 archived liver needle biopsies were used. They were selected according to the original routine diagnosis of slight, moderate or severe steatosis. In all, 10 randomly selected images from each biopsy were digitized into a computer, a point grid lattice was superimposed and the number of hits on fat globules was counted. A pathologist scored the specimens in a four-graded scale as described above. The mean liver biopsy area (volume) with fat in hepatocytes was 2.2% for grade 1, 9.2% for grade 2 and 23.1% for grade 3. The kappa value for the semiquantitative estimates was 0.71 for the unweigthed kappa and 0.87 for weighted kappa. The intraclass correlation coefficient (ICC) was 0.99 for images counted twice and 0.95 when two sets of images were captured from the same biopsy. These ICCs indicate excellent agreement and above that of the semiquantitative estimates. In conclusion, the area/volume of fat content of the hepatocytes is greatly overemphasized in semiquantitative estimation. Furthermore, the point counting technique has a better reproducibility than visual evaluation and should be preferred in estimates of liver steatosis in scientific studies and in clinical contexts when the amount of steatosis is important for treatment and prognosis, such as liver transplantation.

Gastric epithelial proliferation and p53 and p21 expression in a general population sample: relations to age, sex, and mucosal changes associated with H. pylori infection.

Helicobacter pylori infection is the main cause of chronic gastritis. The infection has been linked to altered proliferative activity and changes in various cell cycle regulating proteins. To determine, in a general population sample, the proliferative activity and expression of p53 and p21 in males and females of different age groups with and without H. pylori-associated chronic gastritis, gastric biopsies from 273 subjects (188 with and 85 without H. pylori infection) randomly selected from a general population were examined immunohistochemically for Ki-67, p53, and p21. One thousand epithelial cells, including the surface, neck, and glandular areas, were counted in both the corpus and the antrum. Results are expressed as the percentage of positive cells. Subjects with H. pylori infection showed significantly increased proliferative activity and expression of p53 compared to uninfected individuals. Regarding the expression of p21, no difference was detected. Multiple linear regression analysis showed significant associations between chronic inflammation or inflammatory activity, on the one hand, and the degree of proliferation in both the corpus and the antrum, on the other hand. In the antrum, the degree of H. pylori colonization was related to the expression of p53. H. pylori seems to cause increased proliferation and increased expression of p53 (but not p21) in the gastric mucosa, neither of which is age or sex dependent. The proliferative activity is related mainly to events associated with inflammation, while the expression of p53 in the antrum is associated with the degree of H. pylori infection. The action of p53 appears to be independent of p21 activity.

Helicobacter pylori-specific antibodies impair the development of gastritis, facilitate bacterial colonization, and counteract resistance against infection.

In recent years, Abs have been considered a correlate rather than an effector of resistance against Helicobacter pylori infection. However, it is still poorly understood to what extent Ab production correlates with gastric immunopathology. Here we report that Abs not only are dispensable for protection, but they are detrimental to elimination of the bacteria and appear to impair gastric inflammatory responses. We found that the initial colonization with H. pylori bacteria was normal in the B cell-deficient (microMT) mice, whereas at later times (>8 wk) most of the bacteria were cleared, concomitant with the development of severe gastritis. In contrast, wild-type (WT) mice exhibited extensive bacterial colonization and only mild gastric inflammation, even at 16 wk after inoculation. Oral immunizations with H. pylori lysate and cholera toxin adjuvant stimulated comparable levels of protection in microMT and WT mice. The level of protection in both strains correlated well with the severity of the postimmunization gastritis. Thus, T cells were responsible for the gastritis, whereas Abs, including potentially host cell cross-reactive Abs, were not involved in causing the gastritis. The T cells in micro MT and WT mice produced high and comparable levels of IFN-gamma to recall Ag at 2 and after 8 wk, whereas IL-4 was detected after 8 wk only, indicating that Th1 activity dominated the early phase of protection, whereas later a mixed Th1 and Th2 activity was seen.

Protection against Helicobacter pylori infection following immunization is IL-12-dependent and mediated by Th1 cells.

The regulatory roles of Th1 and Th2 cells in immune protection against Helicobacter infection are not clearly understood. In this study, we report that a primary H. pylori infection can be established in the absence of IL-12 or IFN-gamma. However, IFN-gamma, but not IL-12, was involved in the development of gastritis because IFN-gamma(-/-) (GKO) mice exhibited significantly less inflammation as compared with IL-12(-/-) or wild-type (WT) mice. Both IL-12(-/-) and GKO mice failed to develop protection following oral immunization with H. pylori lysate and cholera toxin adjuvant. By contrast, Th2-deficient, IL-4(-/-), and WT mice were equally well protected. Mucosal immunization in the presence of coadministered rIL-12 in WT mice increased Ag-specific IFN-gamma-producing T cells by 5-fold and gave an additional 4-fold reduction in colonizing bacteria, confirming a key role of Th1 cells in protection. Importantly, only protected IL-4(-/-) and WT mice demonstrated substantial influx of CD4(+) T cells in the gastric mucosa. The extent of inflammation in challenged IL-12(-/-) and GKO mice was much reduced compared with that in WT mice, indicating that IFN-gamma/Th1 cells also play a major role in postimmunization gastritis. Of note, postimmunization gastritis in IL-4(-/-) mice was significantly milder than WT mice, despite a similar level of protection, indicating that immune protection is not directly linked to the degree of gastric inflammation. Only protected mice had T cells that produced high levels of IFN-gamma to recall Ag, whereas both protected and unprotected mice produced high levels of IL-13. We conclude that IL-12 and Th1 responses are crucial for H. pylori-specific protective immunity.