NOD2 and Crohn's Disease Clinical Practice: From Epidemiology to Diagnosis and Therapy, Rewired

Crohn's disease (CD) is a chronic inflammatory bowel disease with a multifactorial pathogenesis involving environmental and genetic factors. Since the late 20th century, the discovery of the first susceptibility gene (NOD2, previously referred to as CARD15) for CD has paved the way for further investigations into the correlations between clinical features and genetics, and its potential impact on clinical practice has fueled the research in the last 2 decades. Recent therapeutic advancements involving novel biologic drugs and small molecules have shifted inflammatory bowel disease management from a disease-centered to a patient-centric approach. To date, the role of NOD2 has not been fully understood yet. Recent data suggest that its clinical impact may be greater than currently recognized. This review overviews the most common NOD2 variants' role in real-life clinical practice. These genetic variants increase the risk of developing the disease and can aid in tailoring diagnosis and treatment. They are associated with the stricturing phenotype and ileal involvement and increase the risk of steroid refractoriness. In the meantime, limited and inconclusive evidence exists regarding their predictive role in response to azathioprine, biologic drugs, and small molecules. Eventually, their role in increasing the risk for surgery is evident, especially in those with the L1007fs variant. If further trials will support the initial evidence reported so far, NOD2 genetic variants will emerge as possible candidates for developing precision medicine in CD.

Non-invasive tests in gastric diseases

Although the gastric cancer incidence is decreasing, this neoplasia remains one of the major causes of oncological mortality. Because of an insidious development, gastric cancer is often diagnosed in an advanced stage and consequently with a poor prognosis. Accurate non-invasive tests should be extremely useful in order to detect gastric neoplasm in an early phase. In clinical practice, there is no reliable bio-marker for detecting this malignant disease. However, intestinal as well as diffuse types of gastric cancer are preceded by gastric mucosa inflammation. Furthermore, the intestinal type of the neoplasia is, generally, related to chronic atrophic gastritis, especially if associated with intestinal metaplasia. In particular, the risk of the neoplasm is linked to both extension and severity of gastric atrophy. Serological parameters such as serum pepsinogens I (PGI) and II (PGII), gastrin-17 (G-17) cytokines (e.g. IL-8), antiparietal cells, IgG anti-Hp and CagA antibodies and lastly ghrelin supply information about either atrophic or inflammatory conditions characterising gastric mucosa. Low PGI and PGI/PGII ratio levels, especially if combined with high G-17 levels, are recognised bio-markers of corpus atrophic gastritis. Low G-17 levels could be, also, suggestive of antral atrophic gastritis. Furthermore, plasmatic ghrelin levels seem to be also a bio-marker of corpus atrophy. Anti-Hp IgG and CagA antibodies as well as PGII levels are able to detect gastric inflammation. Serological parameters could select subjects at risk for gastric mucosa alterations such as inflammation or atrophy, rather than gastric cancer itself. This review analyses the information derived from serological bio-markers as well as the involved clinical studies.

Usefulness of a serological panel test in the assessment of gastritis in symptomatic children

BACKGROUND

Non-invasive methods are advisable for the detection of Helicobacter pylori-related chronic gastritis in pediatric patients. Serum pepsinogens I and II (sPGII and sPGII), gastrin-17 (G-17) and anti-H. pylori antibodies (IgG-Hp) have been proposed as a 'serological gastric biopsy'.

AIM

To assess H. pylori infection and to evaluate gastric mucosa status in a pediatric population by means of serological parameters such as sPGI, sPGII, G-17 and IgG-Hp.

METHODS

45 consecutively children evaluated for upper gastrointestinal symptoms were analyzed. All children were submitted to upper gastrointestinal endoscopy with biopsies. Serum samples were analyzed for IgG-Hp, sPGII, sPGI and G-17 (Biohit, Helsinki, Finland).

RESULTS

18 children had H. pylori-related mild or moderate non-atrophic chronic gastritis. They presented significantly higher mean levels of sPGII and of IgG-Hp than negative ones, either under or up to 10 years. sPGI showed significantly increased levels in H. pylori-positive patients only over 10 years. G-17 levels were not different between H. pylori-positive and -negative ones. The best cut-offs of IgG-Hp, sPGII and of product IgG-Hp x sPGII, to identify H. pylori infection, were 30 IU/l, 9 microg/l, and 241 IU/l x microg/l, respectively. The product IgG-Hp x sPGII identified H. pylori infection with a 100% sensitivity, 92% specificity, 90% positive predictive value and 100% negative predictive value. IgG-Hp and IgG-Hp showed a correlation (r = 0.94; p < 0.001).

CONCLUSIONS

Combined analysis of sPGII and IgG-Hp antibody levels could be recommended as a non-invasive panel for the assessment of H. pylori-related histological alterations of gastric mucosa in childhood.

Usefulness of serum pepsinogens in Helicobacter pylori chronic gastritis: relationship with inflammation, activity, and density of the bacterium

We sought to study the relationship between serum pepsinogens and different histopathologic features of Helicobacter pylori-related chronic gastritis. One hundred forty-nine consecutive dyspeptic patients underwent endoscopy with biopsies; serum pepsinogens I and II were measured by immunoassay. Serum levels of pepsinogens (sPG) were significantly correlated with H. pylori density both of the corpus (sPGI: r = 0.32, P < .001; sPGII: r = 0.56, P < .001) and antrum (sPGI: r = 0.41, P < .001; sPGII: r = 0.43, P < .001) as well as with chronic inflammation (sPGI: r = 0.26, P < .001; sPGII: r = 0.49, P < .001) and activity (sPGI: r = 0.38, P < .001; sPGII: r = 0.50, P < .001) in the antrum. Only sPGII was correlated with chronic inflammation (r = 0.44, P < .001) and activity (r = 0.40, P < .001) in the corpus. SPGI was inversely correlated with atrophy (r = -0.33, P < .001) and intestinal metaplasia (r = -0.37, P < .001) in the corpus. sPGII levels could be considered as markers of gastric inflammation all over in the stomach. sPGI levels are inversely related to atrophic body gastritis.

Effects of chronic therapy with non-steroideal antinflammatory drugs on gastric permeability of sucrose: A study on 71 patients with rheumatoid arthritis

AIM: To evaluate the gastric permeability after both acute and chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) and to assess the clinical usefulness of sucrose test in detecting and following NSAIDs- induced gastric damage mainly in asymptomatic patients and the efficacy of a single pantoprazole dose in chronic users.

METHODS: Seventy-one consecutive patients on chronic therapy with NSAIDs were enrolled in the study and divided into groups A and B (group A receiving 40 mg pantoprazole daily, group B only receiving NSAIDs). Sucrose test was performed at baseline and after 2, 4 and 12 wk, respectively. The symptoms in the upper gastrointestinal tract were recorded.

RESULTS: The patients treated with pantoprazole had sucrose excretion under the limit during the entire follow-up period. The patients without gastroprotection had sucrose excretion above the limit after 2 wk, with an increasing trend in the following weeks (P = 0.000). A number of patients in this group revealed a significantly altered gastric permeability although they were asymptomatic during the follow-up period.

CONCLUSION: Sucrose test can be proposed as a valid tool for the clinical evaluation of NSAIDs- induced gastric damage in both acute and chronic therapy. This tecnique helps to identify patients with clinically silent gastric damages. Pantoprazole (40 mg daily) is effective and well tolerated in chronic NSAID users.

Natural course of functional dyspepsia after Helicobacter pylori eradication: a seven-year survey

The role of Helicobacter pylori(Hp) in functional dyspepsia (FD) is controversial and previously published data do not help to clarify whether Hp eradication affects the natural course of FD. The aim of this study was to assess the clinical course of FD during a long follow-up period of 7 years in a homogeneous sample of Hp-eradicated patients. Among patients referred between 1991 and 1996, patients with FD and infected with Hp were enrolled. Patients were administered a structured symptom questionnaire and evaluated after Hp eradication at each 12-month time points. Patients were divided into three FD subgroups: predominantly ulcer-like, dismotility-like, and reflux-like symptom clusters. A composite symptom score ranging from 0 (no symptom) to 3 (severe symptoms) was assigned to each FD cluster. Of the 1685 screened patients, 405 had FD and 211 of them (52.1%) were also Hp-positive. During the follow-up, the amount of missing information varied from 10% to 17.5% within the first 6 years and was 30.8% at 7 years. The rates of improved patients ranged from 33% (reflux-like) to 34.9% (dismotility-like) to 47.3% (ulcer-like). However, only a proportion of 10%-50% of them was symptom-free after eradication and also at each 12-month evaluation, whereas the other patients became symptomatic at different times. FD symptoms slightly improve after Hp eradication over a long period of time but a large percentage of these improved patients may experience FD symptoms again, even after some years of well-being after Hp eradication.

Influence of antisecretory treatment with proton pump inhibitors on serum pepsinogen I levels

It has been reported in literature that serum pepsinogen levels rise during omeprazole and lansoprazole administration. However, the influence of pantoprazole and esomeprazole on serum pepsinogens levels is still to be assessed. The aim of this study was to evaluate the influence of proton pump inhibitor (PPI) therapy on pepsinogen I (PGI) levels. PGI and gastrin (G17) levels (EIA; Biohit, Helsinki, Finland) in 126 consecutive patients (M 57; F 69, mean age 53, range 15-91), with upper gastrointestinal symptoms at baseline condition and after 2 months of PPI treatment, were evaluated. Patients underwent a therapy schedule based on: omeprazole 20 mg b.i.d. (20 patients), pantoprazole 40 mg b.i.d. (27 patients), esomeprazole 40 mg b.i.d. (29 patients), lansoprazole 30 mg b.i.d. (21 patients) and rabeprazole 20 mg b.i.d. (26 patients) for 2 months. A significant increase in serum PGI (sPGI) levels was found after a 2-month treatment for all five different PPIs: omeprazole, pantoprazole, esomeprazole, lansoprazole and rabeprazole (P < 0.05). The effect of rabeprazole on sPGI was less pronounced as compared with other PPIs, whereas esomeprazole achieved superior sPGI levels, with no overall statistically significant difference among the five groups (P > 0.05). However, a comparison within a single group of PPIs showed a statistical significance when the esomeprazole group was compared with the rabeprazole group (P = 0.007). sPGI levels are significantly influenced by antisecretory therapy, rising under PPI treatment. Moreover, a statistically significant difference in sPGI levels between the rabeprazole and esomeprazole groups has been demonstrated.

Clinical usefulness of serum pepsinogens I and II, gastrin-17 and anti-Helicobacterpylori antibodies in the management of dyspeptic patients in primary care

BACKGROUND

Several tests have been proposed for evaluating dyspeptic symptoms and their relationship to the underlying gastric disease. Serum pepsinogens and gastrin-17 are known to be useful biomarkers for the detection of gastric pathologies.

AIM

To evaluate the capability of screening dyspeptic patients in the primary care by analyses of serum pepsinogens I (sPGI) and II (sPGII), gastrin-17 (sG-17) and the IgG anti-Helicobacter pylori antibodies (IgG-Hp).

PATIENTS AND METHODS

Three hundred and sixty-two consecutive patients with dyspeptic symptoms (208 females, mean age 50.6 +/- 16 years, range 18-88 years) referred by general practitioners for upper gastrointestinal endoscopy were enrolled. A blood sample was taken from each subject for IgG-Hp, sPGI, sPGII and sG-17 analyses.

RESULTS

Two hundred and eighty-seven patients had a complete screening; of these, 132 resulted positive for Hp infection. Patients with atrophic chronic gastritis showed significantly lower serum pepsinogen I levels and sPGI/sPGII ratio than patients with non-atrophic chronic gastritis. Moreover, by calculating the values of sPGI by sG-17 and sG-17 by sPGII/sPGI, subjects with atrophic chronic gastritis could be distinguished from those with non-atrophic chronic gastritis and from those with normal mucosa, respectively. sG-17 levels were found to be a useful biomarker for the detection of antral atrophic gastritis, while the combination of sPGI, the sPGI/sPGII ratio and sG-17 was found effective in identifying corpus atrophy.

CONCLUSION

A panel composed of PGI, PGII, G-17 and IgG-Hp could be used as a first approach in the 'test and scope' and/or 'test and treat' strategy in the primary care management of dyspeptic patients.

Clinical usefulness of serum pepsinogen II in the management of Helicobacter pylori infection

BACKGROUND

Serum pepsinogen II (sPGII) levels are known to increase during Helicobacter pylori infection.

AIM

To assess H. pylori infection and success of H. pylori therapy by means of sPGII levels.

METHODS

sPGII levels were determined in 156 H. pylori-positive and 157 H. pylori-negative consecutive patients with dyspeptic symptoms. Additionally, sPGII determination was performed in 70 H. pylori-positive patients 2 months after H. pylori eradication therapy. In 29 of these 70 patients, gastroscopy was performed to evaluate the effect of H. pylori therapy on gastric activity.

RESULTS

H. pylori-positive subjects demonstrated a significantly higher mean of sPGII levels than H. pylori-negative subjects (16.8 +/- 7.4 vs. 8.6 +/- 3.7 microg/l; p < 0.001). The best sPGII cut-off for predicting H. pylori infection was 9.93 microg/l (sensitivity 83%, specificity 73%). The best cut-off values to evaluate success of therapy were: sPGII of 9.47 microg/l, a sPGII variation level (difference between baseline and after therapy) of 4.54 microg/l, and a sPGII Deltavalue (sPGII variation divided by sPGII before therapy) of 25% (sensitivity 93%, specificity 91%).

CONCLUSIONS

sPGII levels may be used as a reliable marker of H. pylori infection in the initial diagnosis as well as to evaluate H. pylori eradication and subsequent changes in gastric inflammation.

'Serological biopsy' in first-degree relatives of patients with gastric cancer affected by Helicobacter pylori infection

BACKGROUND

Relatives of patients with gastric cancer are at increased risk of developing this disease, especially if they are infected by Helicobacter pylori. Moreover, H. pylori-related atrophic gastritis and hypochlorhydria are well-documented risk factors for noncardia gastric cancer. Serum pepsinogen I (sPGI) and II (sPGII) levels are low in this condition. The aim of our study was to assess by means of a 'Gastropanel' blood test, including sPGI, sPGII, gastrin-17 (G-17) and antibodies anti-H. pylori (IgG-Hp). both functional and morphological features of gastric mucosa in Hp + ve subjects with a family history of gastric cancer.

MATERIALS AND METHODS

Twenty-five Hp + ve subjects consecutively referred to our department for gastrointestinal complaints, selected as first-degree relatives of patients suffering from gastric cancer, were enrolled in the study and then matched for sex and age with 25 dyspeptic and Hp + ve subjects with no family history of gastric neoplasia. Blood samples were taken for determination of gastropanel in all patients; in addition, antibodies against CagA were analysed.

RESULTS

No statistically significant differences were detected between the two groups as regards alcohol consumption, coffee intake and smoking habits. Mean sPGI levels in Group A (83.4 +/- 58.4 microg/L) were significantly lower than those in Group B (sPGI 159.5 +/- 80.6 microg/L; P < 0.0001) as well as sPGII (12.5 microg/L = 6.24 versus 20.6 +/- 58 microg/L; P < 0.006). No statistical difference was found between the two groups in relation to G-17 levels, IgG-Hp titres and antibodies against CagA.

CONCLUSION

First-degree relatives of patients with noncardia gastric cancer affected by H. pylori infection present lower sPGI and sPGII levels, possibly due to the increased frequency of atrophic lesions in these patients.