COVID-19 in celiac disease: a multicentric retrospective cohort study.

OBJECTIVE: Celiac disease (CD) is an autoimmune disorder, characterized by increased susceptibility to bacterial and viral infections. Therefore, the CD patients could be exposed to an increased risk of contracting SARS-CoV-2, a virus for which the WHO declared a pandemic status in March 2020. This study aims to investigate the incidence of SARS-CoV-2 infection in CD patients, to assess the impact of CD on the risk of contracting this virus. PATIENTS AND METHODS: This retrospective multicentric cohort study evaluated 542 celiac patients, who answered a questionnaire concerning both the underlying disease (adherence to the gluten-free diet, residual symptoms) and the possible SARS-CoV-2 infection (swab outcome, presence and characteristics of symptoms and type of treatment received), referring to the period between 20th January 2020 and 27th October 2020. RESULTS: Five patients (0.92%) tested positive; of these, 2 were asymptomatic and 3 developed symptoms of COVID-19. The incidence of SARS-CoV-2 infection in CD patients was not significantly different from the general population. The ratio of positive/diagnostic swabs tends to be higher in CD patients than in the general population (IR: 0.15; 0.06; p=0.06), whereas the number of subjects who performed the swab in this group is significantly lower (IR: 0.06; 0.15; p<0.001). CONCLUSIONS: Although CD patients are more susceptible to infections, the incidence of SARS-CoV-2 infection in our sample was not significantly different from the general population. However, the positive/diagnostic swabs ratio seems to be higher, probably also due to the lower number of patients tested.

mTOR sustains inflammatory response in celiac disease.

Celiac disease (CD) is an enteropathy triggered by the ingestion of gluten proteins in genetically predisposed individuals and characterized by excessive activation of effector immune cells and enhanced production of inflammatory cytokines. However, factors/mechanisms that amplify the ongoing mucosal inflammation in CD are not fully understood. In this study, we assessed whether mammalian target of Rapamycin (mTOR), a pathway that combines intra- and extra-cellular signals and acts as a central regulator for the metabolism, growth, and function of immune and non-immune cells, sustains CD-associated immune response. Our findings indicate that expression of phosphorylated (p)/active form of mTOR is increased in protein lysates of duodenal biopsy samples taken from patients with active CD (ACD) as compared to normal controls. In ACD, activation of mTOR occurs mainly in the epithelial compartment and associates with enhanced expression of p-4EBP, a downstream target of mTOR complex (mTORC)1, while expression of p-Rictor, a component of mTORC2, is not increased. Stimulation of mucosal explants of inactive CD patients with pepsin-trypsin-digested (PT)-gliadin or IFN-γ/IL-21, two cytokines produced in CD by gluten-specific T cells, increases p-4EBP expression. Consistently, blockade of such cytokines in cultures of ACD mucosal explants reduces p-4EBP. Finally, we show that inhibition of mTORC1 with rapamycin in ACD mucosal explants reduces p-4EBP and production of IL-15, a master cytokine produced by epithelial cells in this disorder. Our data suggest that ACD inflammation is marked by activation of mTORC1 in the epithelial compartment.

Disability, and not diabetes, is a strong predictor of mortality in oldest old patients hospitalized with pneumonia.

BACKGROUND: Pneumonia causes more deaths than any other infectious disease, especially in older patients with multiple chronic diseases. Recent studies identified a low functional status as prognostic factor for mortality in elderly patients with pneumonia while contrasting data are available about the role of diabetes. The aim of this study was to evaluate the in-hospital, 3-month and 1-year mortality in elderly subjects affected by pneumonia enrolled in the RePoSi register. METHODS: We retrospectively analyzed the data collected on hospitalized elderly patients in the frame of the REPOSI project. We analyzed the socio-demographic, laboratory and clinical characteristics of subjects with pneumonia. Multivariate logistic analysis was used to explore the relationship between variables and mortality. RESULTS: Among 4714 patients 284 had pneumonia. 52.8% were males and the mean age was 80 years old. 19.8% of these patients had a Barthel Index ≤40 (p ˂ 0.0001), as well as 43.2% had a short blessed test ≥10 (p ˂ 0.0117). In these subjects a significant CIRS for the evaluation of severity and comorbidity indexes (p ˂ 0.0001) were present. Although a higher fasting glucose level was identified in people with pneumonia, in the multivariate logistic analysis diabetes was not independently associated with in-hospital, 3-month and 1-year mortality, whereas patients with lower Barthel Index had a higher mortality risk (odds ratio being 9.45, 6.84, 19.55 in hospital, at 3 and 12 months). CONCLUSION: Elderly hospitalized patients affected by pneumonia with a clinically significant disability had a higher mortality risk while diabetes does not represent an important determinant of short and long-term outcome.

Platelet Count Does Not Predict Bleeding in Cirrhotic Patients: Results from the PRO-LIVER Study.

OBJECTIVES: Thrombocytopenia is a hallmark for patients with cirrhosis and it is perceived as a risk factor for bleeding events. However, the relationship between platelet count and bleeding is still unclear. METHODS: We investigated the relationship between platelet count and major or clinical relevant nonmajor bleedings during a follow-up of ∼4 years. RESULTS: A total of 280 cirrhotic patients with different degrees of liver disease (67% males; age 64±37 years; 47% Child-Pugh B and C) were followed up for a median of 1,129 (interquartile range: 800-1,498) days yielding 953.12 patient-year of observation. The annual rate of any significant bleeding was 5.45%/year (3.57%/year and 1.89%/year for major and minor bleeding, respectively). Fifty-two (18.6%) patients experienced a major (n=34) or minor (n=18) bleeding event, predominantly from gastrointestinal origin. Platelet counts progressively decreased with the worsening of liver disease and were similar in patients with or without major or minor bleeding: a platelet count ≤50 × 103/µl was detected in 3 (6%) patients with and in 20 (9%) patients without any bleeding event. Conversely, prothrombin time-international normalized ratio was slightly higher in patients with overall or major bleeding. On Cox proportional hazard analysis, only a previous gastrointestinal bleeding (hazard ratio (HR): 1.96; 95% confidence interval: 1.11-3.47; P=0.020) and encephalopathy (HR: 2.05; 95% confidence interval: 1.16-3.62; P=0.013) independently predicted overall bleeding events. CONCLUSIONS: Platelet count does not predict unprovoked major or minor bleeding in cirrhotic patients.

In irritable bowel syndrome, postprandial abdominal distention is associated with a reduction of intestinal tone.

BACKGROUND: The pathophysiology of abdominal distention in irritable bowel syndrome (IBS) is still a matter of debate, but the relationship between modifications of intestinal tone and abdominal volume has never been analyzed. METHODS: Eighty-four patients affected by IBS and reporting moderate to severe abdominal distention were enrolled. Thirty-nine presented abdominal distention immediately after and forty-five presented abdominal distention independently of meal intake. Twenty healthy volunteers (HV), comparable for gender and age, were also enrolled. All the subjects underwent fasting and postprandial recto-sigmoid volume monitoring with barostat and abdominal girth measurement to evaluate abdominal distention. KEY RESULTS: In comparison with HV (75±13 mL) and with patients with meal-unrelated abdominal distention (135±56 mL), in the subgroup of patients with severe meal-related abdominal distention recto-sigmoid tone response to the meal was significantly reduced (mean increase of balloon volume 184±89 mL; P<.001), paralleling abdominal girth increase and occurring immediately after test meal intake. Meal-induced abdominal girth modification was significantly correlated with meal-related modification of recto-sigmoid tone (r=.71) and abdominal symptoms. CONCLUSIONS: In patients with IBS suffering from severe postprandial abdominal distention, a postprandial reduction of intestinal tone is associated with this bothersome symptom. Further studies are needed to evaluate whether drugs acting on the modification of intestinal tone could be useful in the treatment of these patients.

-295 T-to-C promoter region IL-16 gene polymorphism is associated with Whipple's disease.

Whipple's disease (WD) is a rare systemic condition caused, in genetically predisposed subjects, by Tropheryma whipplei, a common bacterium widespread in the environment. The relevance of genetic predisposition in WD is shown by the association with HLA alleles DRB1*13 and DQB1*06 and by the demonstration that, in patients with WD, the cytokine genetic profile is skewed toward a Th2 and Treg response. Since IL-16 is involved in hampering the development of a protective macrophagic response against Tropheryma whipplei, we investigated whether the genetic background of IL-16 is different between patients with WD and controls. The -295 T-to-C polymorphism of the promoter region of the IL-16 gene was studied in 90 patients with WD and 152 healthy controls. Levels of serum IL-16 protein were also tested. The frequency of the wild type T allele was significantly higher in patients with WD compared to the controls (155/180 vs. 235/304; p = 0.02 for the Chi(2) test), odds ratio 1.82 [95 % confidence interval (CI) 1.07-3.10]. The TT genotype was found in 65/90 patients with WD and 88/152 controls (p = 0.026). No relationship was found between serum levels of IL-16 and genotypes. Although the functional consequences of this genetic background on levels of IL-16 and on the course of the disease are still unknown, we found, for the first time, that the wild type T allele and the TT genotype of the -295 polymorphism are associated with WD.

Prevalence of Whipple's disease in north-western Italy.

Whipple's disease (WD) is a rare systemic infection due, in genetically susceptible individuals, to Tropheryma whipplei, a heterogeneous Gram-positive actinobacteria. Although it has already been recognised that WD affects mainly middle-aged Caucasian men, the prevalence of WD is virtually unknown. The annual incidence of WD in the general population is said to be less than 1 per 1,000,000, but scientific evidence for these figures is still lacking. On the basis of the number of patients recorded with a diagnosis of Whipple's disease in the regional registers for rare diseases of Lombardia, Liguria and Piemonte-Valle d'Aosta regions, we studied the prevalence of WD in the north-western part of Italy. Forty-six patients with Whipple's disease were recorded in these regions (13 females; mean age at diagnosis 52.1 ± 11.1 years). Since 16,130,725 inhabitants live in these four regions, prevalence of WD in the general population is 3/10(6) and almost 30% of the patients are females. WD is certainly a rare disease but it also affects women in a considerable proportion of cases.

Hydrogen breath test in patients with severe constipation: the interference of the mixing of intestinal content.

BACKGROUND: The diagnostic accuracy of the hydrogen (H2 ) breath test might be reduced by the release of preformed H2 , trapped in hard stools. Test solution ingestion might induce the mixing of colonic content and a false positive result. We studied severely constipated patients, at diagnosis and after the normalization of bowel function, to clarify whether this mechanism affects test results. METHODS: Twenty functional constipated patients, 10 consecutive patients with functional diarrhea and 10 healthy volunteers underwent (i) a H2 breath test after lactulose, to exclude differences among the groups in fermenting capacity; (ii) breath H2 excretion monitoring after non-absorbable, non-fermentable PEG-electrolyte solution, to exclude the role of the delivery to the colon of preexisting fermentable substrates or of the release of preformed H2 entrapped in the feces; (iii) H2 measurement during a 7-h fasting period, to exclude the role of spontaneous variations of breath gas excretion; and (iv) breath H2 excretion monitoring after PEG, after normalization of bowel function. KEY RESULTS: All the subjects excreted similar amounts of H2 after lactulose. After PEG, only severely constipated patients showed significant breath H2 excretion, theoretically able to induce a false positivity of the lactose breath test in 70% of patients and a false positivity of glucose breath tests in 50% of patients. Breath H2 excretion after PEG disappeared if fecal consistency improved after therapy. CONCLUSIONS & INFERENCES: Severely constipated patients may harbor preformed gas in hard stools which can be released when mixing of the intestinal content is induced. This mechanism may interfere with breath test results.

Serum regenerating islet-derived 3-alpha is a biomarker of mucosal enteropathies.

BACKGROUND: The clinical presentation of organic and functional intestinal disorders can overlap and clinicians often rely on invasive and time-consuming procedures to make a final diagnosis. Regenerating islet-derived 3-alpha (Reg3α) is detectable in the circulation of patients with intestinal graft-versus host disease and patients with inflammatory bowel disease (IBD). AIM: To determine whether serum Reg3α testing is useful for discriminating mucosal enteropathies from functional intestinal disorders. METHODS: We prospectively included 47 patients with active coeliac disease (ACD), 13 patients with refractory coeliac disease (RCD), seven patients with common variable immunodeficiency (CVID), 72 patients with active Crohn's disease, 22 patients with active ulcerative colitis (UC) and 28 patients with irritable bowel syndrome (IBS)-related diarrhoea. Sera were also taken from 10 CD patients before and after 6-12 months of a gluten-free diet (GFD) and from 14 patients with IBD before and after induction therapy with Infliximab (IFX). Sera of 119 healthy volunteers were used to determine the cut-off value. Reg3α levels were measured by a commercial ELISA kit. RESULTS: Levels of Reg3α exceeded the cut-off value of the assay in 43/47(91%) ACD patients, 13/13(100%) RCD patients, 7/7(100%) CVID patients, 65/72(90%) Crohn's disease patients, 17/22(77%) UC patients and one patient with IBS(4%). Reg3α levels distinguished mucosal enteropathies from IBS with a sensitivity of 90% and a specificity of 96%. Reg3α levels significantly decreased in CD patients following a GFD and in IBD patients after treatment with IFX. CONCLUSION: Reg3α is a serum biomarker of intestinal damage that, combined with clinical data, identifies patients who should undergo invasive tests for diagnosing enteropathies.

Targeting the immunogenetic diseases with the appropriate HLA molecular typing: critical appraisal on 2666 patients typed in one single centre.

We compared the immunogenetic data from 2666 patients affected by HLA-related autoimmune diseases with those from 4389 ethnically matched controls (3157 cord blood donors CBD, 1232 adult bone marrow donors BMD), to verify the appropriateness of HLA typing requests received in the past decade. The frequency of HLA-B∗27 phenotype was 10.50% in 724 ankylosing spondylitis, 16.80% in 125 uveitis (3.41% BMD, 4.24% CBD, P < 0.0001); HLA-B∗51 allele was 15.57% in 212 Behçet's disease (12.91% BMD, 9.88% CBD, P < 0.0001); the HLA-DRB1-rheumatoid arthritis (RA) shared epitope was 13.72% in 554 RA (10.85% BMD, 13.48% CBD, P = 0.016); the carriers of almost one of HLA-DQB1 susceptibility alleles were 84.91% in 795 celiac disease (CD) and 59.37% in 256 insulin-dependent diabetes mellitus (IDDM) (46.06% in 875 CBD, 42.75% in 662 BMD P < 0.0001). Overall, our results show that the HLA marker frequencies were higher in patients than controls, but lower than expected from the literature data (excluding CD and IDDM) and demonstrate that, in complex immunogenetic conditions, a substantial number of genetic analyses are redundant and inappropriate, burdening to the public health costs. For this reason, we suggest the Italian Scientific Society of Immunogenetics to establish guidelines to improve the appropriateness of typing requests.

Usefulness of abdominal ultrasonography with studies of the intestinal loops in Turner syndrome patients.

Turner syndrome, a chromosomal disorder caused by partial or complete absence of one of the two X chromosomes, is characterized by an increased incidence (compared with that in the normal population) of either autoimmune disorders, including chronic inflammatory bowel diseases, or angiodysplasia of the small intestine. Because ultrasonography and color Doppler ultrasound are widely used to investigate gastrointestinal disorders, we decided to carry out an ultrasound-based screening study in patients with Turner syndrome to determine whether this method might be useful in the follow-up of this population.

Hydrogen breath test and intestinal gas production.

Despite extensive use in clinical practice, difficulties regarding interpretation of hydrogen breath test are still very frequent, even on research grounds. After the administration of a non-absorbable sugar, such as lactulose, an increase of breath hydrogen and methane is evident; this phenomenon is considered an index of colonic fermentation. It is not clear, however, if the levels of these compounds correlate with the presence and severity of functional symptoms, nor if they accurately reflect gas production at colonic level. So far, apart from flatulence, we have no indications regarding the ability of hydrogen or methane to act as biomarkers of intraluminal events. On the other hand, it has been shown that in functional bowel disease a colonic dysbiosis exists, and that the modification of bacterial flora might result in a reduction of symptom severity. Consequently, it is not clear if hydrogen and methane colonic production could have a role in the pathophysiology of functional complaints, but it is possible that other fermentation products should be taken into consideration, such as acetate, propionate, and alcohol.

IL-15 positively regulates IL-21 production in celiac disease mucosa.

Celiac disease (CD)-associated inflammation is characterized by high interleukin- 21 (IL-21), but the mechanisms that control IL-21 production are not fully understood. Here we analyzed IL-21 cell sources and examined how IL-21 production is regulated in CD. Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs), isolated from CD patients and non-CD controls, were analyzed for cell markers, cytokines, and transcription factors by flow cytometry. IL-21 was highly produced by CD4+ and CD4+/CD8+ IELs and LPLs in active CD. IL-21-producing cells coexpressed interferon-γ (IFN-γ) and to a lesser extent T helper type 17 (Th17) cytokines. Treatment of control LPLs with IL-15, a cytokine overproduced in CD, activated Akt and STAT3 (signal transducer and activator of transcription 3), thus enhancing IL-21 synthesis. Active CD biopsies contained elevated levels of Akt, and blockade of IL-15 in those samples reduced IL-21. Similarly, neutralization of IL-15 in biopsies of inactive CD patients inhibited peptic-tryptic digest of gliadin-induced IL-21 expression. These findings indicate that in CD, IL-15 positively regulates IL-21 production.

IgA anti-epidermal transglutaminase autoantibodies: a sensible and sensitive marker for diagnosis of dermatitis herpetiformis in adult patients.

BACKGROUND: Dermatitis herpetiformis (DH) is a rare gluten-sensitive blistering itchy skin disease, strictly related to coeliac disease (CD). Direct immunofluorescence, demonstrating IgA granular deposits localized either in the dermal papillae or along the dermo-epidermal junction, is currently the gold standard for diagnosis of DH. It has been shown that DH immunocomplexes contain epidermal transglutaminase (eTG) and that sera from patients with DH contain antibodies specifically directed against eTG. OBJECTIVES: We studied the usefulness of serum eTG antibodies in discriminating between DH, CD and other gastrointestinal and dermatologic diseases. METHODS: eTG antibodies were tested in 308 adult patients' sera: 44 patients with untreated dermatitis herpetiformis (UDH), 99 patients with untreated coeliac disease (UCD), 70 dermatological controls and 95 gastrointestinal controls. RESULTS: In UDH eTG antibody levels were significantly higher than in DH patients on gluten-free diet, UCD, gastrointestinal controls and dermatological controls. In UCD eTG antibodies strongly correlated with tissue transglutaminase (tTG) antibodies, whereas in UDH no significant correlation was observed. CONCLUSION: Serum IgA eTG antibody determination can efficiently distinguish UDH from other dermatological itchy diseases and is highly sensitive to gluten-free diet.

Cytokine genetic profile in Whipple's disease.

Whipple's disease (WD) is a very rare chronic systemic condition characterised by a Th2/T regulatory (Treg) dysregulated immune response versus Tropheryma whipplei, a bacterium widely diffuse in the environment. To investigate whether this Th2/Treg polarised response has a genetic background, we investigated the Th1, Th2, Th17 and Treg cytokine genetic profile of 133 patients with WD. Thanks to the European Consortium on WD (QLG1-CT-2002-01049), the polymorphism of 13 cytokine genes was analysed in 111 German and 22 Italian patients using the polymerase chain reaction with sequence-specific primers (PCR-SSP) technique. The frequencies of the genotypes, haplotypes and functional phenotypes were compared with those obtained in 201 German and 140 Italian controls. Clinical heterogeneity was also considered. Functionally, WD patients may be considered as low producers of TGF-ß1, having an increased frequency of the genotype TGF-ß1+869C/C,+915C/C [12.3 % vs. 3.81 %, odds ratio (OR) = 4.131, p = 0.0002] and high secretors of IL-4, carrying the genotype IL-4-590T/T (5.34 % vs. 1.17 %, OR = 5.09, p = 0.0096). No significant association was found between cytokine polymorphism and clinical variability. Analogously to the recent cellular findings of a Th2/Treg polarised response, we showed that the cytokine genetic profile of WD patients is skewed toward a Th2 and Treg response. This was similar in both German and Italian populations. However, the significant deviations versus the controls are poorer than that expected on the basis of these recent cellular findings.

The endogenous cannabinoid system in the gut of patients with inflammatory bowel disease.

Activation of cannabinoid receptors (CBs) by endocannabinoids impacts on a number of gastrointestinal functions. Recent data indicate that CB1 agonists improve 2,4-dinitrobenzene sulfonic acid-induced colitis in mice, thus suggesting a role for the endocannabinoid agonist anandamide (AEA) in protecting the gut against inflammation. We here examined the gut endocannabinoid system in inflammatory bowel disease (IBD) patients, and investigated the ex vivo and in vitro effects of the non-hydrolysable AEA analog methanandamide (MAEA) on the mucosal proinflammatory response. The content of AEA, but not of 2-arachidonoyl-glycerol and N-palmitoylethanolamine, was significantly lower in inflamed than uninflamed IBD mucosa, and this was paralleled by lower activity of the AEA-synthesizing enzyme N-acyl-phosphatidylethanolamine-specific phospholipase D and higher activity of the AEA-degrading enzyme fatty acid amide hydrolase. MAEA significantly downregulated interferon-γ and tumor necrosis factor-α secretion by both organ culture biopsies and lamina propria mononuclear cells. Although these results are promising, further studies are needed to determine the role of cannabinoid pathways in gut inflammation.

Interleukin-25 production is differently regulated by TNF-α and TGF-ß1 in the human gut.

An altered balance between effector and regulatory factors is supposed to sustain the tissue-damaging immune response in inflammatory bowel disease (IBD). We have recently shown that in IBD, there is a defective synthesis of the counter-regulatory cytokine, interleukin (IL)-25. In this study we investigated factors that control IL-25 production in the gut. IBD patients produced less IL-25 when compared with normal controls. Stimulation of normal intestinal explants with tumor necrosis factor-α (TNF-α), but not interferon-γ (IFN-γ) or IL-21, reduced IL-25 synthesis. Consistently, IL-25 production was enhanced by anti-TNF-α both in vitro and in vivo. Upregulation of IL-25 was also seen in normal colonic explants stimulated with transforming growth factor-ß1 (TGF-ß1). As in IBD, TGF-ß1 activity is abrogated by Smad7, we next assessed whether inhibition of Smad7 with an antisense oligonucleotide enhanced IL-25 expression. Knockdown of Smad7 was accompanied by an increase in IL-25 production. Data show that IL-25 production is differently regulated by TNF-α and TGF-ß1 in the human gut.