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1.  Dysbiosis May Trigger Autoimmune Diseases via Inappropriate Post-Translational Modification of Host Proteins 
The gut ecosystem with myriads of microorganisms and the high concentration of immune system cells can be considered as a separate organ on its own. The balanced interaction between the host and microbial cells has been shaped during the long co-evolutionary process. In dysbiotic conditions, however, this balance is compromised and results in abnormal interaction between the host and microbiota. It is hypothesize here that the changed spectrum of microbial enzymes involved in post-translational modification of proteins (PTMP) may contribute to the aberrant modification of host proteins thus generating autoimmune responses by the host, resulting in autoimmune diseases.
PMCID: PMC4742538  PMID: 26903965
microbiome; dysbiosis; intestine; post-translational modification; autoimmune disease
2.  Possible association between celiac disease and bacterial transglutaminase in food processing: a hypothesis 
Nutrition Reviews  2015;73(8):544-552.
The incidence of celiac disease is increasing worldwide, and human tissue transglutaminase has long been considered the autoantigen of celiac disease. Concomitantly, the food industry has introduced ingredients such as microbial transglutaminase, which acts as a food glue, thereby revolutionizing food qualities. Several observations have led to the hypothesis that microbial transglutaminase is a new environmental enhancer of celiac disease. First, microbial transglutaminase deamidates/transamidates glutens such as the endogenous human tissue transglutaminase. It is capable of crosslinking proteins and other macromolecules, thereby changing their antigenicity and resulting in an increased antigenic load presented to the immune system. Second, it increases the stability of protein against proteinases, thus diminishing foreign protein elimination. Infections and the crosslinked nutritional constituent gluten and microbial transglutaminase increase the permeability of the intestine, where microbial transglutaminases are necessary for bacterial survival. The resulting intestinal leakage allows more immunogenic foreign molecules to induce celiac disease. The increased use of microbial transglutaminase in food processing may promote celiac pathogenesis ex vivo, where deamidation/transamidation starts, possibly explaining the surge in incidence of celiac disease. If future research substantiates this hypothesis, the findings will affect food product labeling, food additive policies of the food industry, and consumer health education.
PMCID: PMC4502714  PMID: 26084478
celiac disease; food processing; gluten; microbial transglutaminase; tissue transglutaminase
3.  Nutritional deficiencies in the pediatric age group in a multicultural developed country, Israel 
Nutrient deficiencies are prevalent worldwide. Diseases and morbid conditions have been described to result from nutritional deficiencies. It is essential to address nutrient deficiencies as these may lead to chronic long-term health problems such as rickets, iron deficiency anemia, goiter, obesity, coronary heart disease, type 2 diabetes, stroke, cancer and osteoporosis. In the present review we surveyed the extent and severity of nutritional deficiencies in Israel through a selective and comprehensive Medline review of previous reports and studies performed during the last 40 years. Israeli populations have multiple nutritional deficiencies, including iron, calcium, zinc, folic acid, and vitamins B12, C, D and E, spanning all age groups, several minorities, and specific regions. In Israel, some of the nutrients are mandatorily implemented and many of them are implemented voluntarily by local industries. We suggest ways to prevent and treat the nutritional deficiencies, as a step to promote food fortification in Israel.
PMCID: PMC4023304  PMID: 24868510
Nutrient deficiencies; Type 2 diabetes; Obesity; Israel
4.  The thrombophilic network of autoantibodies in celiac disease 
BMC Medicine  2013;11:89.
Celiac disease is a life-long autoimmune condition, affecting genetically susceptible individuals that may present with thromboembolic phenomena. This thrombophilia represents a puzzle with multiple constituents: hyperhomocysteinemia, B12 and\or folate deficiency, methylenetetrahydrofolate reductase mutations, and protein C and S deficiency due to vitamin K deficiency. However, the well known thrombogenic factors, antiphosphatidylserine/prothrombin and antiprothrombin have never been explored in celiac disease.
The serum autoantibody levels were determined in 248 individuals, classified into three groups. Group 1 comprised 70 children with definitive celiac disease (age: 7.04 ±4.3 years, male to female ratio 1.06) and group 2 comprised 88 normal children (age: 6.7 ±4.17 years, male to female ratio 0.87), representing controls. The pediatric populations were compared to group 3, which included 90 adults who were family members (parents) of group 1 (age: 34.6 ±11.35 years, male to female ratio 1.2). Antibodies were checked by enzyme-linked immunosorbent assay.
Mean optical density levels of serum antiphosphatidylserine/prothrombin immunoglobulin G antibodies were 32.4 ±19.4, 3.6 ±2.5 and 16.1 ±15.8 absorbance units in groups 1, 2 and 3 respectively (P <0.0001), with 45.7%, 0% and 7.8% of groups 1, 2 and 3 respectively positive for the antibody (P <0.01). Mean optical density levels of serum antiphosphatidylserine/prothrombin immunoglobulin M antibodies were 14.2 ±8.7, 6.7 ±6.4 and 12.4 ±15.5 absorbance units in groups 1, 2 and 3 respectively (P <0.0001), with 7.1%, 3.4% and 9.9% of groups 1, 2 and 3 positive for the antibody. Mean optical density levels of serum antiprothrombin and antiphospholipid immunoglobulin G antibodies were higher in groups 1 and 3 compared with 2 (P <0.005) and in groups 1 and 2 compared with 3 (P <0.01), respectively. Groups 1, 2 and 3 were positive for antiphospholipid immunoglobulin G antibodies (groups 1 and 2 compared with 3) . Celiac disease sera harbor a higher antiprothrombin immunoglobulin G level compared with controls.
It is suggested that the intestinal injury, endothelial dysfunction, platelet abnormality and enhanced apoptosis recently described in celiac disease are at the origin of the increased exposure of phospholipids or new epitopes representing autoantigens. Those autoantibodies might play a pathogenic role in the thrombophilia associated with celiac disease and represent markers for potential anticoagulant preventive therapy.
PMCID: PMC3616811  PMID: 23556408
Antiphosphatidylserine/prothrombin; Autoantibodies; Celiac disease; Hypercoagulability; Phospholipid; Prothrombin
5.  A new algorithm for the diagnosis of celiac disease 
Celiac disease (CD) affects at least 1% of the Western population but remains largely unrecognized. In our laboratory, we utilize a novel algorithm to diagnose pediatric CD that offers both high sensitivity and high specificity for diagnosis in an outpatient setting. The aim of the present study was to challenge this algorithm and to test its performance in children and adults suspected of having CD. Using a three-assay algorithm, screening with the most sensitive tissue transglutaminase (tTG) complexed with deamidated gliadin peptide neoepitope immunoglobulin A (IgA)+IgG assay and confirming with the two specific tTG IgA and tTG IgA+IgG assays, we examined the serological results from 112 children aged 0–17 years old and 60 adults in comparison to their respective biopsy results. The algorithm performance was calculated by statistical analysis. The use of the new algorithm enabled us to diagnose CD with 98% sensitivity, 93% specificity and 95% accuracy in the pediatric group and 94% sensitivity, 92% specificity and 93% accuracy in the total population studied. The false-negative cases in the adult group were attributed to previous adherence to a gluten-free diet, and the single false-negative result in a young child became a true positive after 6 months. We have also monitored three celiac patients before and after diagnosis and found that the algorithm may be suitable for disease monitoring. The newly proposed three-assay algorithm for celiac detection is very reliable in both children and adults. Due to the high performance of this assay, the further need for confirmatory intestinal biopsies will be reassessed.
PMCID: PMC4003133  PMID: 21317919
celiac disease diagnosis; intestinal histopathology; sensitivity; specificity; tissue transglutaminase
6.  The Immunohistochemistry Profile of Lymphocytic Gastritis in Celiac Disease and Helicobacter Pylori Infection: Interplay between Infection and Inflammation 
Mediators of Inflammation  2007;2007:81838.
Lymphocytic gastritis (LG) is associated with helicobacter pylori (Hp) and celiac disease (CD). We aimed to clarify the relationship between Hp infection and CD by defining a unique histopathology profile of LG in these two diseases. Forty patients who underwent upper endoscopy were divided into four groups: eight controls, ten active CD patients without Hp, twelve CD negative with Hp, and ten active CD with Hp infection. Antral samples were assessed by immunohistochemical staining for CD20, CD3, CD4, CD8, CD57, CNA42, and Ki67 for lymphoid aggregates, intraepithelial lymphocytes (IELs) number, density of lamina propria (LP) lymphocytes, and inflammatory glandular involvement. Only IELs positive for CD3 and CD8 were increased significantly in CD patients with or without Hp infection. Hp did not contribute to the number of CD8 IELs. In complicated cases with Hp and suspicious for CD, the number of CD8+ IELs hints toward a CD rather than Hp infection.
PMCID: PMC2222270  PMID: 18274643

Results 1-8 (8)