Reduced dietary omega-6 to omega-3 fatty acid ratio and 12/15-lipoxygenase deficiency are protective against chronic high fat diet-induced steatohepatitis

Obesity is associated with metabolic perturbations including liver and adipose tissue inflammation, insulin resistance, and type 2 diabetes. Omega-6 fatty acids (ω6) promote and omega-3 fatty acids (ω3) reduce inflammation as they can be metabolized to pro- and anti-inflammatory eicosanoids, respectively. 12/15-lipoxygenase (12/15-LO) enzymatically produces some of these metabolites and is induced by high fat (HF) diet. We investigated the effects of altering dietary ω6/ω3 ratio and 12/15-LO deficiency on HF diet-induced tissue inflammation and insulin resistance. We examined how these conditions affect circulating concentrations of oxidized metabolites of ω6 arachidonic and linoleic acids and innate and adaptive immune system activity in the liver. For 15 weeks, wild-type (WT) mice were fed either a soybean oil-enriched HF diet with high dietary ω6/ω3 ratio (11∶1, HFH), similar to Western-style diet, or a fat Kcal-matched, fish oil-enriched HF diet with a low dietary ω6/ω3 ratio of 2.7∶1 (HFL). Importantly, the total saturated, monounsaturated and polyunsaturated fat content was matched in the two HF diets, which is unlike most published fish oil studies in mice. Despite modestly increased food intake, WT mice fed HFL were protected from HFH-diet induced steatohepatitis, evidenced by decreased hepatic mRNA expression of pro-inflammatory genes and genes involved in lymphocyte homing, and reduced deposition of hepatic triglyceride. Furthermore, oxidized metabolites of ω6 arachidonic acid were decreased in the plasma of WT HFL compared to WT HFH-fed mice. 12/15-LO knockout (KO) mice were also protected from HFH-induced fatty liver and elevated mRNA markers of inflammation and lymphocyte homing. 12/15-LOKO mice were protected from HFH-induced insulin resistance but reducing dietary ω6/ω3 ratio in WT mice did not ameliorate insulin resistance or adipose tissue inflammation. In conclusion, lowering dietary ω6/ω3 ratio in HF diet significantly reduces steatohepatitis.Fil: Lazic, Milos. University of California at San Diego; Estados UnidosFil: Inzaugarat, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Povero, Davide. University of California at San Diego; Estados UnidosFil: Zhao, Iris C.. University of California at San Diego; Estados UnidosFil: Chen, Mark. University of California at San Diego; Estados UnidosFil: Nalbandian, Madlena. University of California at San Diego; Estados UnidosFil: Miller, Yury I.. University of California at San Diego; Estados UnidosFil: Cherñavsky, Alejandra Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Feldstein, Ariel E.. University of California at San Diego; Estados UnidosFil: Sears, Dorothy D.. University of California at San Diego; Estados Unido

Azathioprine in refractory sprue: results from a prospective, open-label study

OBJECTIVE: Refractory sprue is a rare and severe malabsorptive disorder that mimics celiac disease but is refractory to a gluten-free diet and is without initial evidence of overt lymphoma. Treatment is largely empiric and often ineffective, with steroids and immunosuppression being the mainstream therapeutic options. The aim of this study was to evaluate prospectively the effect of azathioprine on a group of patients diagnosed with refractory sprue. METHODS: We studied seven consecutive patients (five women and two men) with a well-defined diagnosis of refractory sprue and a lack of response to oral or parenteral steroids. At diagnosis, five patients had endoscopic evidence of ulcerative jejunitis, and five underwent exploratory laparotomy for exclusion of malignancies. The characteristic monoclonal TCR gene rearrangement was shown in five of six patients studied. Patients were treated for a mean of 11 months (range 8–12 months), and clinical, biochemical, molecular, and histological parameters were reassessed at the end of the trial. The study was a prospective, open-label, non–placebo-controlled study using azathioprine (2 mg/kg/ day) plus oral prednisone (1 mg/kg/day). A gluten-free diet (n 7) as well as enteral (n 6) and parenteral nutrition (n 5) were administered during the trial. RESULTS: After treatment, five patients had a complete clinical remission, and biochemical and nutritional parameters were significantly improved. Steroids were tapered after the onset of azathioprine, and no patient was on steroids at the end of the trial. Intestinal histology improved significantly in all cases (normal histology in three cases and minor infiltration in the lamina propria in two). Two patients did not respond to treatment at any time and died in months 10 and 9, of an irreversible ventricular fibrillation and sepsis, respectively. No overt lymphoma was demonstrated during the follow-up. CONCLUSIONS: The present study confirms earlier anecdotal reports on the efficacy of azathioprine in refractory sprue, with clear clinical and histological improvement shown in most patients. However, monoclonality persisted after treatment. We consider that a larger number of patients should be evaluated before a definitive recommendation is adopted for use of this drug in refractory sprue.Fil: Maurino, Eduardo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; Argentina. Universidad del Salvador; ArgentinaFil: Niveloni, Sonia Isabel. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cherñavsky, Alejandra Claudia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. Laboratorio de Inmunogenética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Pedreira, Silvia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Mazure, Roberto. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Vazquez, Daniel Horacio. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Reyes, Hugo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Fiorini, Alcira. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Smecuol, Edgardo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cabanne, Ana. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Capucchio, Monica. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. Laboratorio de Inmunogenética; ArgentinaFil: Kogan, Zulema. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Bai, Julio C.. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; Argentina. Universidad del Salvador; Argentin

Características clínicas y evolución a largo plazo de una serie de pacientes con sprue refractario diagnosticados en una sola institución

Background: Refractory sprue (RS) is a rare and severe celiac-like enteropathy not responding to a strict gluten-free diet. Although prognosis is generally poor, little is known about the long-term outcome of patients. Aim: to report baseline characteristics and long-term outcome of a series of patients diagnosed and treated in a single institution. Materials: We report a retrospective cohort of 25 consecutive patients (15 females; mean age 46 yr; range 28-71) diagnosed with RS based on the presence of a non-responsive celiac-like enteropathy. All patients were intensively treated with a gluten-free diet, steroids, nutritional support and immunosupression. Results: Clinical and biological characteristics of patients suggest that, at least, 24 patients had clear evidences of celiac disease. HLA DQ2/DQ8 genes were present in all the 24 patients typed and autoimmune enteropathy was excluded in all. According to the genotyping, 12 patients had a polyclonal lymphocyte population (RS type I) and 13 exhibited monoclonal TCR-γ gene rearrangements (RS type II). Sixteen patients had evidence of ulcerative jejunitis (UJ) (7 in RS type I and 9 in type II). Overall median follow-up time after diagnosis of RS was 29 mo/patient (range 7 to 204) (45 mo for type I and 24 mo for type II). Overall mortality was 48% (12 patients), 6 in each type. Eight patients with UJ (50%), 3 with lymphoma (two T-cell and one B-cell type) and 4 (44%) without ulcers died during follow-up. The causes of death were sepsis in the context of a progressive deterioration but without overt malignancies (n=5), vascular causes (n=3) and severe malnutrition (n=1). Three- and 5-yr survival rate after diagnosis of RS for the overall population was 60% and 56%. There was no differences between type I (67%, 58%) and type II RS patients (54% for both periods). Patients with UJ had lower but non-significant 3- and 5-yr survival rates (56% and 50%, respectively) compared with patients without ulcers (78% and 66%). Survivors had a favorable outcome. While 11 patients persists asymptomatic, two other cases still have mild diarrhea and one low body weight. Conclusions: We confirm that RS is a severe celiac disease-related disorder with very high mortality. Diagnosis of overt lymphoma (12%) in our long-term follow-up was not as frequent as was reported by other groups. A proportion of patients persist in good health for a long time irrespective of the nature of the IEL infiltration or the presence of UJ.Fil: Mauriño, Eduardo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Niveloni, Sonia Isabel. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cherñavsky, Alejandra Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. Laboratorio de Inmunogenética; ArgentinaFil: Sugai, Emilia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Vázquez, Horacio. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Pedreira, Silvia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Periolo, Natalia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. Laboratorio de Inmunogenética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mazure, Roberto. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Smecuol, Edgardo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Moreno, Maria L.. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Litwin, Néstor. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Nachman, Fabio. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Kogan, Zulema. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Bai, Julio C.. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; Argentin

Evidences of the involvement of Bak, a member of the Bcl-2 family of proteins, in active coeliac disease

Apoptosis of enterocytes is a feature that characterises the development of lesions in coeliac disease (CD). However, the intracellular pathways that lead to apoptosis of enterocytes have not been completely clarified. Bak is a member of the Bcl-2 family of proteins that acts as an endogenous promoter of apoptosis in normal enterocytes. However, its role in coeliac lesions has not been explored. We used small intestinal mucosa from patients with CD to evaluate the differential expression of members of the Bcl-2 family of proteins. Gene expression of Bak was analysed by RT-PCR of biopsies from 14 patients with untreated CD and from 19 controls without CD. In these samples, we also investigated the localisation of the Bak protein by immunohistochemistry and its apoptotic activity. In patients with untreated CD there was a 2.3-fold higher expression of Bak mRNA (p = 0.026), without significant differences in the expression of related genes bax or bcl-2. The higher expression of interferon gamma (IFNγ) (p = 0.036) and the higher number of apoptotic cells identified by the TUNEL method (p = 0.032) confirmed the proapoptotic status in the intestinal mucosa of CD patients. We found a significant positive correlation (p < 0.0001) between the expression of IFNγ and Bak mRNA in patients with untreated CD. The expression of Bak protein was higher in patients with CD, and the immunoreactivity was almost restricted to the epithelium. We found that Bak mRNA and its protein were overexpressed in the intestinal lesions of CD patients and that IFNγ confers increased susceptibility for enterocytes to undergo apoptosis via upregulation of Bak.Fil: CherÑavsky, Alejandra C.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Rubio, Andrea. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Vanzulli, Silvia. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Rubinstein, Natalia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Rosa, Susana. Fundacion Hospital de Pediatria Professor Dr. Juan P. Garrahan; ArgentinaFil: Fainboim, Leonardo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentin

Alterations in innate and adaptive immune leukocytes are involved in paediatric obesity

Background: Adipose tissue is the main source of the cytokines and adipokines that are increased in the context of obesity. The production of reactive oxygen species (ROS) and cytokines by circulating immune cells can be regulated by these pro-inflammatory factors even before infiltration into adipose tissue. Objective: To investigate the alterations that can occur in circulating monocytes and lymphocytes in paediatric obesity. Methods: In this study, 54 paediatric obese patients and 30 age-matched metabolically healthy individuals were enrolled. Intracellular cytokines were analyzed after phorbol myristate acetate (PMA) or leptin plus PMA stimulation of lymphocytes and monocytes by flow cytometry. ROS generation was measured using dichlorofluorescein-diacetate. Both a 'stimulation index' and a 'fold of increase' were calculated for statistical purposes. Results: Both interferon gamma (IFN-γ) production by circulating CD4+ and CD8+ lymphocytes and ROS production by monocytes following PMA stimulation were increased in obese patients. Leptin induced an increased production of IFN-γ in both subsets of T cells and tumour necrosis factor alpha in monocytes, and linoleic acid induced a higher ROS production in monocytes. Conclusions: The distinct functional responses of circulating cells suggest that alterations in both innate and adaptive immune cells are involved in the maintenance of low-grade inflammation in paediatric obesity.Fil: Inzaugarat, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Billordo, Luis Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Vodánovich, F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Cervini Bohm, Gabriela Marta . Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Casavalle, Patricia Lucía. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Vedire, C.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Cherñavsky, Alejandra Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo; Argentin

IL-15 controls T cell functions through its influence on CD30 and OX40 antigens in Celiac Disease

AIM: To evaluate the ability of interleukin (IL)-15 to control T cell functions through its influence on CD30 and OX40 expressing cells in Celiac Disease (CD). In peripheral blood (PB), by examining the expression of OX40 in conventional effectors cells and T cells with a phenotypic specialization of regulatory cells [CD4+CD25high forkhead box protein 3 (Foxp3)+], and the co stimulation of IFN-γ and IL-4 production within CD30 and OX40 positive subsets of T cells. At the duodenal mucosa, by assessing the expression of CD30 and OX40 in intraepithelial (IE) and lamina propria (LP) lymphocytes (IEL, LPL). PATIENTS AND METHODS: PB and duodenal mucosal biopsies were obtained from 38 patients with classic CD (Cel) and 38 healthy controls (HC). Analysis of cell surface and/or intracellular antigens was performed in anti-CD3-treated PB mononuclear cells (PBMC) before and after treatment with recombinant IL-15 (rIL-15), and in IE and LP cellular suspensions prepared from duodenal biopsies pre-treated with/without rIL-15. RESULTS: A subpopulation of CD3+OX40+ T blasts was induced in Cel and HC by a 3days treatment of PBMC with anti-CD3 and decreased its size thereafter, regardless of the presence of rIL-15. However, the addition of rIL-15 to T blasts distinctively induced the survival of T cells with a regulatory phenotype that expresses OX40 antigen in Cel (p<0.05). Celiac patients showed higher frequencies of IFN-γ-producing CD3+CD30+ blasts before and after treatment with rIL-15 (p<0.05, vs. HC). IL-15 increased the frequencies of CD3+CD30+ LPL (HC: p<0.05, Cel: p<0.05) but not of CD3+OX40+ LPL, and CD30 or OX40 positive IEL. CONCLUSIONS: The distinctive control of OX40+ cells with a T regulatory phenotype mediated by the influence of IL-15 comes out as new function of this cytokine in the context of CD. The higher production of IFN-γ by a subpopulation of peripheral CD3+CD30+ cells contributes to the type I biased immune response.Fil: Periolo, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Guillen, Laura Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Arruvito, Maria Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Alegre, Nadia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Niveloni, S. I.. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "dr C.b.udaondo"; ArgentinaFil: Hwang, J. H.. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "dr C.b.udaondo"; ArgentinaFil: Bai, J. C.. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "dr C.b.udaondo"; ArgentinaFil: Cherñavsky, Alejandra Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentin

Reduced dietary omega-6 to omega-3 fatty acid ratio and 12/15-lipoxygenase deficiency are protective against chronic high fat diet-induced steatohepatitis.

Obesity is associated with metabolic perturbations including liver and adipose tissue inflammation, insulin resistance, and type 2 diabetes. Omega-6 fatty acids (ω6) promote and omega-3 fatty acids (ω3) reduce inflammation as they can be metabolized to pro- and anti-inflammatory eicosanoids, respectively. 12/15-lipoxygenase (12/15-LO) enzymatically produces some of these metabolites and is induced by high fat (HF) diet. We investigated the effects of altering dietary ω6/ω3 ratio and 12/15-LO deficiency on HF diet-induced tissue inflammation and insulin resistance. We examined how these conditions affect circulating concentrations of oxidized metabolites of ω6 arachidonic and linoleic acids and innate and adaptive immune system activity in the liver. For 15 weeks, wild-type (WT) mice were fed either a soybean oil-enriched HF diet with high dietary ω6/ω3 ratio (11∶1, HFH), similar to Western-style diet, or a fat Kcal-matched, fish oil-enriched HF diet with a low dietary ω6/ω3 ratio of 2.7∶1 (HFL). Importantly, the total saturated, monounsaturated and polyunsaturated fat content was matched in the two HF diets, which is unlike most published fish oil studies in mice. Despite modestly increased food intake, WT mice fed HFL were protected from HFH-diet induced steatohepatitis, evidenced by decreased hepatic mRNA expression of pro-inflammatory genes and genes involved in lymphocyte homing, and reduced deposition of hepatic triglyceride. Furthermore, oxidized metabolites of ω6 arachidonic acid were decreased in the plasma of WT HFL compared to WT HFH-fed mice. 12/15-LO knockout (KO) mice were also protected from HFH-induced fatty liver and elevated mRNA markers of inflammation and lymphocyte homing. 12/15-LOKO mice were protected from HFH-induced insulin resistance but reducing dietary ω6/ω3 ratio in WT mice did not ameliorate insulin resistance or adipose tissue inflammation. In conclusion, lowering dietary ω6/ω3 ratio in HF diet significantly reduces steatohepatitis

Bone-specific antibodies in sera from patients with celiac disease: characterization and implications in osteoporosis

Osteopenia and osteoporosis are well-known complications detected in celiac disease patients with still obscure pathogenesis. In the present study we investigated the presence of circulating anti-bone autoantibodies in patients with celiac disease and explored their role in the associated bone disease. We evaluated serum samples from 33 patients at the time of diagnosis and from 20 of them after treatment. Sera from patients with inflammatory bowel disease (n = 9), nonceliac osteoporotic (n = 18), and healthy individuals (n = 10) were used as controls. The presence of IgA specific anti-bone antibodies was first investigated using indirect immunofluorescence on cryosections of fetal rat tibia (20-day pregnancy). Furthermore, samples were homogenized and total tissue extracts were subjected to Western blot analysis to confirm immunoreactivity. At diagnosis, sera from 51.5% (17/33) of celiac patients had antibodies that recognized antigenic structures in chondrocytes and the extracellular matrix along mature cartilage, bone interface, and perichondrium of fetal rat bone. Among controls, only two osteoporotic patients showed very low titles of anti-bone autoantibodies. The immunostaining was localized in areas where an active mineralization process occurred and was similar to the distribution of the native bone tissue transglutaminase. The frequency of patients with positive baseline titers of anti-bone antibodies diminished significantly after treatment (P = 0.048). Western blot assays confirmed the presence of autoantibodies in sera from patients with a positive immunofluorescence staining. Autoantibodies recognized a major protein band on tissue extracts with a molecular weight of 77–80 kDa, which could be displaced when sera were preadsorbed with human recombinant tissue transglutaminase. We provide original evidence that patients with celiac disease have IgA-type circulating autoantibodies against intra- and extracellular structures of fetal rat tibia. Our findings suggest that these antibodies recognize bone tissue transglutaminase as the autoantigen, and based on the localization of the immunoreactivity we speculate that they might have an active role in the pathophysiology of celiac disease-associated bone complications.Fil: Sugai, Emilia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; ArgentinaFil: Cherñavsky, Alejandra Claudia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Pedreira, Silvia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; ArgentinaFil: Smecuol, Edgardo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; ArgentinaFil: Vazquez, Horacio. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; ArgentinaFil: Niveloni, Sonia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; ArgentinaFil: Mazure, Roberto. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; ArgentinaFil: Mauriño, Eduardo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; ArgentinaFil: Rabinovich, Gabriel Adrián. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Bai, Julio C.. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología ; Argentin