Celiac Abstracts 8

© 2011

Gluten ataxia: passive transfer in a mouse model

            (Boscolo, Sarich et al. 2007) Download

Gluten sensitivity is an autoimmune disease that usually causes intestinal atrophy resulting in a malabsorption syndrome known as celiac disease. However, gluten sensitivity may involve several organs and is often associated with extraintestinal manifestations. Typically, patients with celiac disease have circulating anti-tissue transglutaminase and anti-gliadin antibodies. When patients with gluten sensitivity are affected by other autoimmune diseases, other autoantibodies may arise like anti-epidermal transglutaminase in dermatitis herpetiformis, anti-thyroid peroxidase antibodies in thyroiditis, and anti-islet cells antibodies in type 1 diabetes. The most common neurological manifestation of gluten sensitivity is ataxia, the so-called gluten ataxia (GA). In patients with GA we have demonstrated that anti-gliadin and anti-tissue transglutaminase antibodies cross-react with neurons but that additional anti-neural antibodies are present. The aim of the present article is to review the knowledge on animal models of gluten sensitivity, as well as reviewing the role of anti-neural antibodies in GA.

Neurological complications of celiac disease and autoimmune mechanisms: preliminary data of a prospective study in adult patients

            (Briani, Zara et al. 2005) Download

Antibodies to gangliosides and Purkinje cells have been reported in patients with celiac disease (CD) with neuropathy and ataxia, respectively. Whether these antibodies are pathogenic is not clear. The response of neurological symptoms and antibody titers to a gluten-free diet is still controversial. The objective of our study was to assess whether neurological manifestations in CD patients correlate with antibody titers and a gluten-free diet.Thirty-five CD patients (9 males, 26 females, mean age 37.1 +/- 12.6 yrs) were followed prospectively. At initial evaluation, 23 were on a gluten-free diet, 12 were not. At recruitment and during follow-up, patients underwent neurological and electrophysiological evaluation. IgG, IgM, and IgA anti-ganglioside antibodies were assayed by ELISA; anti-neuronal antibodies were assessed by immunohistochemistry and Western blot. Four patients, all males, had electrophysiological evidence of neuropathy; three had been on a gluten-free diet for several months, and one was newly diagnosed. One had reduced tendon reflexes; another complained of distal paresthesias. With regard to anti-ganglioside antibodies, three patients had a moderate increase in antibodies without symptoms or signs of neuropathy. No patients had ataxia or cerebellar dysfunction, although in four patients reactivity to neuronal antigens was found. In 17 patients, an electrophysiological follow-up (mean duration of follow-up, 9 months) showed no changes. In conclusion, the preliminary results of this prospective study indicate that neuropathy, usually subclinical, may accompany CD. Antibody titers do not seem to correlate with neurological symptoms/signs or diet. Ongoing follow-up will help confirm these data and clarify the role, if any, of antibodies in neurological involvement in CD.

Chronic mucocutaneous candidiasis may cause elevated gliadin antibodies

            (Brinkert, Sornsakrin et al. 2009) Download

We present a 4-year-old boy admitted to the hospital due to the typical symptoms of celiac disease with severe dystrophy, anaemia and elevated gliadin IgG antibodies. Upper endoscopy ruled out celiac disease but showed severe Candida esophagitis. Due to an impaired T-cell function especially following Candida antigen stimulation in vitro, plus recurrent Candida infections of the skin, the diagnosis of chronic mucocutaneous candidasis (CMC) was made. Under the treatment with fluconazol, trimethoprim/sulfmethoxazole and IVIG, the child improved impressively. Gliadin antibodies declined steadily. CONCLUSION: The common symptoms growth retardation, anaemia and elevated gliadin antibodies are suggestive for celiac disease but very unspecific. The rare immunodeficiency CMC may cause elevated gliadin antibodies.

Neurological symptoms in patients with biopsy proven celiac disease

            (Burk, Farecki et al. 2009) Download

In celiac disease (CD), the gut is the typical manifestation site but atypical neurological presentations are thought to occur in 6 to 10% with cerebellar ataxia being the most frequent symptom. Most studies in this field are focused on patients under primary neurological care. To exclude such an observation bias, patients with biopsy proven celiac disease were screened for neurological disease. A total of 72 patients with biopsy proven celiac disease (CD) (mean age 51 +/- 15 years, mean disease duration 8 +/- 11 years) were recruited through advertisements. All participants adhered to a gluten-free diet. Patients were interviewed following a standard questionnaire and examined clinically for neurological symptoms. Medical history revealed neurological disorders such as migraine (28%), carpal tunnel syndrome (20%), vestibular dysfunction (8%), seizures (6%), and myelitis (3%). Interestingly, 35% of patients with CD reported of a history of psychiatric disease including depression, personality changes, or even psychosis. Physical examination yielded stance and gait problems in about one third of patients that could be attributed to afferent ataxia in 26%, vestibular dysfunction in 6%, and cerebellar ataxia in 6%. Other motor features such as basal ganglia symptoms, pyramidal tract signs, tics, and myoclonus were infrequent. 35% of patients with CD showed deep sensory loss and reduced ankle reflexes in 14%. Gait disturbances in CD do not only result from cerebellar ataxia but also from proprioceptive or vestibular impairment. Neurological problems may even develop despite strict adherence to a gluten-free diet.

Neurologic presentation of celiac disease

            (Bushara 2005) Download

Celiac disease (CD) long has been associated with neurologic and psychiatric disorders including cerebellar ataxia, peripheral neuropathy, epilepsy, dementia, and depression. Earlier reports mainly have documented the involvement of the nervous system as a complication of prediagnosed CD. However, more recent studies have emphasized that a wider spectrum of neurologic syndromes may be the presenting extraintestinal manifestation of gluten sensitivity with or without intestinal pathology. These include migraine, encephalopathy, chorea, brain stem dysfunction, myelopathy, mononeuritis multiplex, Guillain-Barre-like syndrome, and neuropathy with positive antiganglioside antibodies. The association between most neurologic syndromes described and gluten sensitivity remains to be confirmed by larger epidemiologic studies. It further has been suggested that gluten sensitivity (as evidenced by high antigliadin antibodies) is a common cause of neurologic syndromes (notably cerebellar ataxia) of otherwise unknown cause. Additional studies showed high prevalence of gluten sensitivity in genetic neurodegenerative disorders such as hereditary spinocerebellar ataxia and Huntington's disease. It remains unclear whether gluten sensitivity contributes to the pathogenesis of these disorders or whether it represents an epiphenomenon. Studies of gluten-free diet in patients with gluten sensitivity and neurologic syndromes have shown variable results. Diet trials also have been inconclusive in autism and schizophrenia, 2 diseases in which sensitivity to dietary gluten has been implicated. Further studies clearly are needed to assess the efficacy of gluten-free diet and to address the underlying mechanisms of nervous system pathology in gluten sensitivity.

Coeliac disease and autoimmune thyroid disease

            (Counsell, Taha et al. 1994) Download

A well defined cohort of coeliac patients was studied prospectively to assess the prevalence of coexisting thyroid disease and positive thyroid autoantibodies. Comparison with epidemiological data on the prevalence of coeliac disease in a neighbouring area suggested that few adult coeliac patients had been missed. Overall, 14% of the coeliac patients had thyroid disease: 10.3% were hypothyroid and 3.7% hyperthyroid, both significantly more than expected. There were significantly more coeliac disease patients with thyroid autoantibodies than expected--11% had thyroglobulin antibodies and 15% had thyroid microsomal antibodies. This association is clinically important. Three patients are described in whom the coexistence of coeliac disease and hypothyroidism led to diagnostic difficulties and delay of treatment.

Intolerance of celiac disease patients to bovine milk is not due to the presence of T-cell stimulatory epitopes of gluten

            (Dekking, Koning et al. 2009) Download

Identification of tissue transglutaminase as the autoantigen of celiac disease

            (Dieterich, Ehnis et al. 1997) Download

Celiac disease is characterized by small intestinal damage with loss of absorptive villi and hyperplasia of the crypts, typically leading to malabsorption. In addition to nutrient deficiencies, prolonged celiac disease is associated with an increased risk for malignancy, especially intestinal T-cell lymphoma. Celiac disease is precipitated by ingestion of the protein gliadin, a component of wheat gluten, and usually resolves on its withdrawal. Gliadin initiates mucosal damage which involves an immunological process in individuals with a genetic predisposition. However, the mechanism responsible for the small intestinal damage characteristic of celiac disease is still under debate. Small intestinal biopsy with the demonstration of a flat mucosa which is reversed on a gluten-free diet is considered the main approach for diagnosis of classical celiac disease. In addition, IgA antibodies against gliadin and endomysium, a structure of the smooth muscle connective tissue, are valuable tools for the detection of patients with celiac disease and for therapy control. Incidence rates of childhood celiac disease range from 1:300 in Western Ireland to 1:4700 in other European countries, and subclinical cases detected by serological screening revealed prevalences of 3.3 and 4 per 1000 in Italy and the USA, respectively. IgA antibodies to endomysium are particularly specific indicators of celiac disease, suggesting that this structure contains one or more target autoantigens that play a role in the pathogenesis of the disease. However, the identification of the endomysial autoantigen(s) has remained elusive. We identified tissue transglutaminase as the unknown endomysial autoantigen. Interestingly, gliadin is a preferred substrate for this enzyme, giving rise to novel antigenic epitopes.


The gluten syndrome: a neurological disease

            (Ford 2009) Download

Hypothesis: Gluten causes symptoms, in both celiac disease and non-celiac gluten-sensitivity, by its adverse actions on the nervous system. Many celiac patients experience neurological symptoms, frequently associated with malfunction of the autonomic nervous system. These neurological symptoms can present in celiac patients who are well nourished. The crucial point, however, is that gluten-sensitivity can also be associated with neurological symptoms in patients who do not have any mucosal gut damage (that is, without celiac disease). Gluten can cause neurological harm through a combination of cross reacting antibodies, immune complex disease and direct toxicity. These nervous system affects include: dysregulation of the autonomic nervous system, cerebella ataxia, hypotonia, developmental delay, learning disorders, depression, migraine, and headache. If gluten is the putative harmful agent, then there is no requirement to invoke gut damage and nutritional deficiency to explain the myriad of the symptoms experienced by sufferers of celiac disease and gluten-sensitivity. This is called "The Gluten Syndrome".

Mechanisms underlying celiac disease and its neurologic manifestations

            (Green, Alaedini et al. 2005) Download

The extra-intestinal manifestations of celiac disease (CD), including ataxia and peripheral neuropathy, are increasingly being recognized as the presenting symptoms of this autoimmune disease. Although there is a greater understanding of the pathogenesis of the intestinal lesions in CD the mechanisms behind the neurologic manifestations of CD have not been elucidated. In this article, the authors review the cellular and molecular mechanisms behind the histopathologic changes in the intestine, discuss the presentation and characteristics of neurologic manifestations of CD, review the data on the mechanisms behind these manifestations, and discuss the diagnosis and treatment of CD. Molecular mimicry and intermolecular help may play a role in the development of neurologic complications.

Neurological complications of coeliac disease: what is the evidence?

            (Grossman 2008) Download

Coeliac disease is a chronic immune-mediated disorder that primarily affects the gastrointestinal tract. There is an inflammatory response in the intestine to the ingestion of gluten which improves with a gluten-free diet. Many patients, especially adults, may be asymptomatic or have only extraintestinal symptoms at onset without any of the classical coeliac symptoms. In the last two decades there have been increasing numbers of reports describing neurological complications of coeliac disease, especially ataxia, peripheral neuropathy and epilepsy. This literature has become quite controversial, with disputes over the definition of coeliac disease and gluten sensitivity, whether neurological complications are caused by coeliac disease or are epiphenomena, and whether the proposed complications respond to a gluten-free diet. This review uses an evidence-based approach to critically assess this literature and provides guidelines for the evaluation and management of these patients.

Downbeat nystagmus, ataxia and spastic tetraparesis due to coeliac disease

            (Habek, Hojsak et al. 2011) Download

A 25-year-old female presented to a university neurology clinic with a 1-month history of progressive ataxia, downbeat nystagmus and spastic tetraparesis. Personal history revealed polyarthralgias and weight loss. Family history was negative. Following thorough history, laboratory, neurophysiological and MRI investigations, a diagnosis of cerebellar ataxia due to coeliac disease was done. The patient was treated with strict gluten-free diet and intravenous administration of immunoglobulins. Although there are many controversies about neurological manifestations of coeliac disease, this case pointed to strong association between these two disorders. The findings of elevated protein content in the cerebrospinal fluid with positive oligoclonal bands suggested an immune-mediated process, further supported by positive anti-endomysium antibodies and anti-transglutaminase antibodies in the cerebrospinal fluid.

Clinical, radiological, neurophysiological, and neuropathological characteristics of gluten ataxia

            (Hadjivassiliou, Grunewald et al. 1998) Download

BACKGROUND: Ataxia is the commonest neurological manifestation of coeliac disease. Some individuals with genetic susceptibility to the disease have serological evidence of gluten sensitivity without overt gastrointestinal symptoms or evidence of small-bowel inflammation. The sole manifestation of disease in such patients may be ataxia. We describe the clinical, radiological, and neurophysiological features of this disorder. METHODS: Patients with ataxia attending the neurology outpatient clinics at the Royal Hallamshire Hospital, Sheffield, UK, were screened for gluten sensitivity as shown by the titre of antibody to gliadin. Those with other causes of ataxia were excluded. We carried out clinical, neurophysiological, neuroradiological, and, in two cases, neuropathological examinations. FINDINGS: 28 patients with gluten ataxia were identified. All had gait ataxia and most had limb ataxia. Those with more severe gait ataxia had longer disease duration. No patient had tremor or other extrapyramidal features. 19 patients showed some form of peripheral neuropathy on neurophysiological examination. 16 patients had no gastrointestinal symptoms. Distal duodenal biopsy showed lymphocytic infiltration in two patients, and changes compatible with coeliac disease in 11. Six patients had evidence of cerebellar atrophy on magnetic-resonance imaging. Necropsy was done on two patients who died; there was lymphocytic infiltration of the cerebellum, damage to the posterior columns of the spinal cord, and sparse infiltration of the peripheral nerves. INTERPRETATION: Gluten sensitivity is an important cause of apparently idiopathic ataxia and may be progressive. The ataxia is a result of immunological damage to the cerebellum, to the posterior columns of the spinal cord, and to peripheral nerves. We propose the term gluten ataxia to describe this disorder.

The humoral response in the pathogenesis of gluten ataxia

            (Hadjivassiliou, Boscolo et al. 2002) Download

OBJECTIVE: To characterize humoral response to cerebellum in patients with gluten ataxia. BACKGROUND: Gluten ataxia is a common neurologic manifestation of gluten sensitivity. METHODS: The authors assessed the reactivity of sera from patients with gluten ataxia (13), newly diagnosed patients with celiac disease without neurologic dysfunction (24), patients with other causes of cerebellar degeneration (11), and healthy control subjects (17) using indirect immunocytochemistry on human cerebellar and rat CNS tissue. Cross-reactivity of a commercial IgG antigliadin antibody with human cerebellar tissue also was studied. RESULTS: Sera from 12 of 13 patients with gluten ataxia stained Purkinje cells strongly. Less intense staining was seen in some but not all sera from patients with newly diagnosed celiac disease without neurologic dysfunction. At high dilutions (1:800) staining was seen only with sera from patients with gluten ataxia but not in control subjects. Sera from patients with gluten ataxia also stained some brainstem and cortical neurons in rat CNS tissue. Commercial anti-gliadin antibody stained human Purkinje cells in a similar manner. Adsorption of the antigliadin antibodies using crude gliadin abolished the staining in patients with celiac disease without neurologic dysfunction, but not in those with gluten ataxia. CONCLUSIONS: Patients with gluten ataxia have antibodies against Purkinje cells. Antigliadin antibodies cross-react with epitopes on Purkinje cells.

Multiple sclerosis and occult gluten sensitivity

            (Hadjivassiliou, Sanders et al. 2005) Download


Myopathy associated with gluten sensitivity

            (Hadjivassiliou, Chattopadhyay et al. 2007) Download

Ataxia and peripheral neuropathy are the most common neurological manifestations of gluten sensitivity. Myopathy is a less common and poorly characterized additional neurological manifestation of gluten sensitivity. We present our experience with 13 patients who presented with symptoms and signs suggestive of a myopathy and in whom investigation led to the diagnosis of gluten sensitivity. Three of these patients had a neuropathy with or without ataxia in addition to the myopathy. The mean age at onset of the myopathic symptoms was 54 years. Ten patients had neurophysiological evidence of myopathy. Inflammatory myopathy was the most common finding on neuropathological examination. One patient had basophilic rimmed vacuoles suggestive of inclusion-body myositis. Six patients received immunosuppressive treatment in addition to starting on a gluten-free diet; five improved and one remained unchanged. Among seven patients not on immunosuppressive treatment, four showed clinical improvement of the myopathy with a gluten-free diet. The improvement was also associated with reduction or normalization of serum creatine kinase level. The myopathy progressed in one patient who refused the gluten-free diet. Myopathy may be another manifestation of gluten sensitivity and is likely to have an immune-mediated pathogenesis. A gluten-free diet may be a useful therapeutic intervention.

Autoantibodies in gluten ataxia recognize a novel neuronal transglutaminase

            (Hadjivassiliou, Aeschlimann et al. 2008) Download

OBJECTIVE: Gluten sensitivity typically presents as celiac disease, a chronic, autoimmune-mediated, small-intestinal disorder. Neurological disorders occur with a frequency of up to 10% in these patients. However, neurological dysfunction can also be the sole presenting feature of gluten sensitivity. Development of autoimmunity directed toward different members of the transglutaminase gene family could offer an explanation for the diversity in manifestations of gluten sensitivity. We have identified a novel neuronal transglutaminase isozyme and investigated whether this enzyme is the target of the immune response in patients with neurological dysfunction. METHODS: Using recombinant human transglutaminases, we developed enzyme-linked immunosorbent assays and inhibition assays to analyze serum samples of patients with gluten-sensitive gastrointestinal and neurological disorders, and various control groups including unrelated inherited or immune conditions for the presence and specificity of autoantibodies. RESULTS: Whereas the development of anti-transglutaminase 2 IgA is linked with gastrointestinal disease, an anti-transglutaminase 6 IgG and IgA response is prevalent in gluten ataxia, independent of intestinal involvement. Such antibodies are absent in ataxia of defined genetic origin or in healthy individuals. Inhibition studies showed that in those patients with ataxia and enteropathy, separate antibody populations react with the two different transglutaminase isozymes. Furthermore, postmortem analysis of brain tissue showed cerebellar IgA deposits that contained transglutaminase 6. INTERPRETATION: Antibodies against transglutaminase 6 can serve as a marker in addition to human leukocyte antigen type and detection of anti-gliadin and anti-transglutaminase 2 antibodies to identify a subgroup of patients with gluten sensitivity who may be at risk for development of neurological disease.

Gluten ataxia

            (Hadjivassiliou, Sanders et al. 2008) Download

Gluten ataxia is an immune-mediated disease triggered by the ingestion of gluten in genetically susceptible individuals. It should be considered in the differential diagnosis of all patients with idiopathic sporadic ataxia. Early diagnosis and treatment with a gluten free diet can improve ataxia and prevent its progression. Readily available and sensitive markers of gluten ataxia include antigliadin antibodies. IgA deposits against TG2 in the small bowel and at extraintestinal sites are proving to be additional reliable and perhaps more specific markers of the whole spectrum of gluten sensitivity. They may also hold the key to its pathogenesis.

Sensory ganglionopathy due to gluten sensitivity

            (Hadjivassiliou, Rao et al. 2010) Download

OBJECTIVES: Gluten sensitivity can engender neurologic dysfunction, one of the two commonest presentations being peripheral neuropathy. The commonest type of neuropathy seen in the context of gluten sensitivity is sensorimotor axonal. We report 17 patients with sensory ganglionopathy associated with gluten sensitivity. METHODS: This is a retrospective observational case series of 17 patients with sensory ganglionopathy and gluten sensitivity. All patients had been followed up for a number of years in dedicated gluten sensitivity/neurology and neuropathy clinics. RESULTS: Out of a total of 409 patients with different types of peripheral neuropathies, 53 (13%) had clinical and neurophysiologic evidence of sensory ganglionopathy. Out of these 53 patients, 17 (32%) had serologic evidence of gluten sensitivity. The mean age of those with gluten sensitivity was 67 years and the mean age at onset was 58 years. Seven of those with serologic evidence of gluten sensitivity had enteropathy on biopsy. Fifteen patients went on a gluten-free diet, resulting in stabilization of the neuropathy in 11. The remaining 4 had poor adherence to the diet and progressed, as did the 2 patients who did not opt for dietary treatment. Autopsy tissue from 3 patients demonstrated inflammation in the dorsal root ganglia with degeneration of the posterior columns of the spinal cord. CONCLUSIONS: Sensory ganglionopathy can be a manifestation of gluten sensitivity and may respond to a strict gluten-free diet.

GAD antibody-associated neurological illness and its relationship to gluten sensitivity

            (Hadjivassiliou, Aeschlimann et al. 2011) Download

BACKGROUND: The high prevalence of gluten sensitivity in patients with stiff-person syndrome (SPS) lead us to investigate the relationship between gluten sensitivity and GAD-antibody-associated diseases. METHODS: We used ELISA assays for anti-GAD and for serological markers of gluten sensitivity. Patients were recruited from clinics based at the Royal Hallamshire hospital, Sheffield, UK. Patients with gluten sensitivity were followed up after the introduction of a gluten-free diet and serological testing was repeated. RESULTS: Six of seven (86%) patients with SPS were positive for anti-GAD, mean titre 109 U/ml; This compared with 9/90 (11%) patients with idiopathic sporadic ataxia, mean titre 32 U/ml, 16/40 (40%) patients with gluten ataxia, mean titre 25 U/ml, and 6/10 patients with type 1 diabetes only, mean titre 8 U/ml. None of 32 patients with celiac disease only, and of 40 patients with genetic ataxia were positive for anti-GAD. The titre of anti-GAD reduced following the introduction of a gluten-free diet in patients with SPS who had serological evidence of gluten sensitivity. The same was observed in patients with gluten ataxia and anti-GAD antibodies. This was also associated with clinical improvement. CONCLUSION: These findings suggest a link between gluten sensitivity and GAD antibody-associated diseases.

Neurologic impairment due to vitamin E and copper deficiencies in celiac disease

            (Henri-Bhargava, Melmed et al. 2008) Download

The neurology of coeliac disease in childhood: what is the evidence? A systematic review and meta-analysis

            (Lionetti, Francavilla et al. 2010) Download

AIM: The aim of this article was to review and conduct a meta-analysis of the paediatric literature on the neurology of coeliac disease. METHOD: We conducted a review of paediatric studies published in English assessing neurological illness in coeliac disease identified through a MEDLINE search (1950-2009). Calculation of computed relative risk, odds ratio, and risk difference was performed using the fixed effect method if applicable. RESULTS: Fifteen studies were analysed (11 772 participants). The meta-analysis showed that (1) the relative risk of epilepsy in individuals with coeliac disease, and of coeliac disease in individuals with epilepsy, compared with the general population, was 2.1 and 1.7, respectively, and the risk difference was close to zero, indicating that it was probably a chance association; and (2) the relative risk of headache in individuals with the disease compared with comparison groups was 3.2. In two studies, cerebellar ataxia was documented in 2.7 to 5.4% of participants; in two further studies, the risk of cerebellar dysfunction was zero. Two studies found an association between coeliac disease and peripheral neuropathy. Brain white matter lesions were recorded in two other studies. An association between autism and coeliac disease is disputed. Interpretation Children with coeliac disease are at risk of developing neurological complications, but the risk is lower than in adulthood. The discrepancy might be due to short disease duration, early elimination of gluten from the diet, stricter adherence to diet, or different susceptibility to immune-mediated disorders.

Celiac disease presenting as resistant hypothyroidism

            (McDermott, Coss et al. 2005) Download

The high prevalence of celiac disease in patients with autoimmune hypothyroidism, compared to the general population, has been well documented but screening for celiac disease is not recommended as yet in otherwise asymptomatic hypothyroid patients. In recent years the high prevalence of undiagnosed celiac disease in the general population, largely as a result of the many atypical manifestations of the disease, has become apparent. We report the case of a 58-year-old woman with autoimmune hypothyroidism who was initially suspected of having celiac disease on the basis of apparent resistance to levothyroxine therapy, and who had no other clinical or laboratory clues to suggest the diagnosis. Cases of undiagnosed celiac disease causing levothyroxine malabsorbtion have previously been described, but all previous cases had other obvious manifestations of the disease. We believe that this atypical presentation of celiac disease warrants further attention, and that the diagnosis of celiac disease should always be considered in patients requiring higher than expected doses of thyroid hormone replacement, even in patients with normal bowel habit, and no other apparent manifestations of the disease.

Is Candida albicans a trigger in the onset of coeliac disease?

            (Nieuwenhuizen, Pieters et al. 2003) Download

Coeliac disease is a T-cell-mediated autoimmune disease of the small intestine that is induced by ingestion of gluten proteins from wheat, barley, or rye. We postulate that Candida albicans is a trigger in the onset of coeliac disease. The virulence factor of C albicans-hyphal wall protein 1 (HWP1)-contains aminoacid sequences that are identical or highly homologous to known coeliac disease-related alpha-gliadin and gamma-gliadin T-cell epitopes. HWP1 is a transglutaminase substrate, and is used by C albicans to adhere to the intestinal epithelium. Furthermore, tissue transglutaminase and endomysium components could become covalently linked to the yeast. Subsequently, C albicans might function as an adjuvant that stimulates antibody formation against HWP1 and gluten, and formation of autoreactive antibodies against tissue transglutaminase and endomysium.

Serology of celiac disease in gluten-sensitive ataxia or neuropathy: role of deamidated gliadin antibody

            (Rashtak, Snyder et al. 2011) Download

The role and relevance of deamidated gliadin antibodies specific for celiac disease in gluten-sensitive ataxia/neuropathy is unknown. We investigated the association of celiac-specific serology with gluten-sensitive ataxia/neuropathy, in patients with and without gliadin-induced enteropathy. 51 patients with unexplained ataxia/neuropathy suspected to have gluten sensitivity were included in the study and their serum celiac-specific markers were measured. Deamidated gliadin-IgA (83% vs. 22%), deamidated gliadin-IgG (50% vs. 3%), tissue transglutaminase-IgA (78% vs. 11%), and anti-endomysial-IgA (70% vs. 0%), were significantly more positive in ataxia/neuropathy patients with celiac disease versus those without enteropathy (P<0.001). Our findings suggest that the serological profile of gluten-sensitive ataxia/neuropathy without intestinal involvement lacks the recognition of deamidated gliadin and tissue transglutaminase epitopes.

Positive serum antigliadin antibodies without celiac disease in the elderly population: does it matter?

            (Ruuskanen, Kaukinen et al. 2010) Download

OBJECTIVE: Antigliadin antibodies (AGA) show good sensitivity but low specificity for celiac disease and can also be found in healthy individuals. However, data suggest that AGA positivity might be related to distinct disease entities such as allergy and gluten ataxia. Our aim here is to explore the clinical relevance of positive AGA in the elderly population. MATERIAL AND METHODS: Serum IgA- and IgG-class AGA and IgA-class tissue transglutaminase antibodies (tTGA) were determined in 2815 individuals aged 52-74 years. Equal numbers of AGA- and tTGA-negative participants of similar age and gender, but without known celiac disease, were randomly selected as controls. Information on clinical history was obtained from hospital records in all groups. RESULTS: Altogether 381 persons were positive for IgA/IgG-class AGA; 38 (14%) of them were also positive for tTGA. Out of the biopsied subjects, 34 (100%) in the AGA+ tTGA+ group and five (9%) in AGA+ tTGA- group had celiac disease. Rheumatoid arthritis and depression were found significantly more often in AGA-positives than controls. The significance remained even when tTGA-positive and known celiac disease cases were excluded. No statistical differences were found in the occurrence of neurological diseases, diabetes, allergic and cardiovascular diseases or malignancies. CONCLUSIONS: Although AGA positivity is of clinical relevance only in a subset of elderly people, it seems to be related to rheumatoid arthritis and depression, both conditions linked to celiac disease. Further studies are needed to reveal the mechanisms underlying this. The poor specificity of AGA for celiac disease was here once more in evidence.

Adhesive and mammalian transglutaminase substrate properties of Candida albicans Hwp1

            (Staab, Bradway et al. 1999) Download

The pathogenesis of candidiasis involves invasion of host tissues by filamentous forms of the opportunistic yeast Candida albicans. Morphology-specific gene products may confer proinvasive properties. A hypha-specific surface protein, Hwp1, with similarities to mammalian small proline-rich proteins was shown to serve as a substrate for mammalian transglutaminases. Candida albicans strains lacking Hwp1 were unable to form stable attachments to human buccal epithelial cells and had a reduced capacity to cause systemic candidiasis in mice. This represents a paradigm for microbial adhesion that implicates essential host enzymes.

Transglutaminase 6: a protein associated with central nervous system development and motor function

            (Thomas, Beck et al. 2011) Download

Transglutaminases (TG) form a family of enzymes that catalyse various post-translational modifications of glutamine residues in proteins and peptides including intra- and intermolecular isopeptide bond formation, esterification and deamidation. We have characterized a novel member of the mammalian TG family, TG6, which is expressed in a human carcinoma cell line with neuronal characteristics and in mouse brain. Besides full-length protein, alternative splicing results in a short variant lacking the second beta-barrel domain in man and a variant with truncated beta-sandwich domain in mouse. Biochemical data show that TG6 is allosterically regulated by Ca(2+) and guanine nucleotides. Molecular modelling indicates that TG6 could have Ca(2+) and GDP-binding sites related to those of TG3 and TG2, respectively. Localization of mRNA and protein in the mouse identified abundant expression of TG6 in the central nervous system. Analysis of its temporal and spatial pattern of induction in mouse development indicates an association with neurogenesis. Neuronal expression of TG6 was confirmed by double-labelling of mouse forebrain cells with cell type-specific markers. Induction of differentiation in mouse Neuro 2a cells with NGF or dibutyryl cAMP is associated with an upregulation of TG6 expression. Familial ataxia has recently been linked to mutations in the TGM6 gene. Autoantibodies to TG6 were identified in immune-mediated ataxia in patients with gluten sensitivity. These findings suggest a critical role for TG6 in cortical and cerebellar neurons.

Identification of Rothia bacteria as gluten-degrading natural colonizers of the upper gastro-intestinal tract

            (Zamakhchari, Wei et al. 2011) Download

BACKGROUND: Gluten proteins, prominent constituents of barley, wheat and rye, cause celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and the protease-resistant domains contain multiple immunogenic epitopes. The aim of this study was to identify novel sources of gluten-digesting microbial enzymes from the upper gastro-intestinal tract with the potential to neutralize gluten epitopes. METHODOLOGY/PRINCIPAL FINDINGS: Oral microorganisms with gluten-degrading capacity were obtained by a selective plating strategy using gluten agar. Microbial speciations were carried out by 16S rDNA gene sequencing. Enzyme activities were assessed using gliadin-derived enzymatic substrates, gliadins in solution, gliadin zymography, and 33-mer alpha-gliadin and 26-mer gamma-gliadin immunogenic peptides. Fragments of the gliadin peptides were separated by RP-HPLC and structurally characterized by mass spectrometry. Strains with high activity towards gluten were typed as Rothia mucilaginosa and Rothia aeria. Gliadins (250 microg/ml) added to Rothia cell suspensions (OD(620) 1.2) were degraded by 50% after approximately 30 min of incubation. Importantly, the 33-mer and 26-mer immunogenic peptides were also cleaved, primarily C-terminal to Xaa-Pro-Gln (XPQ) and Xaa-Pro-Tyr (XPY). The major gliadin-degrading enzymes produced by the Rothia strains were approximately 70-75 kDa in size, and the enzyme expressed by Rothia aeria was active over a wide pH range (pH 3-10). CONCLUSION/SIGNIFICANCE: While the human digestive enzyme system lacks the capacity to cleave immunogenic gluten, such activities are naturally present in the oral microbial enzyme repertoire. The identified bacteria may be exploited for physiologic degradation of harmful gluten peptides.


References

Boscolo, S., A. Sarich, et al. (2007). "Gluten ataxia: passive transfer in a mouse model." Ann N Y Acad Sci 1107: 319-28.

Briani, C., G. Zara, et al. (2005). "Neurological complications of celiac disease and autoimmune mechanisms: preliminary data of a prospective study in adult patients." Ann N Y Acad Sci 1051: 148-55.

Brinkert, F., M. Sornsakrin, et al. (2009). "Chronic mucocutaneous candidiasis may cause elevated gliadin antibodies." Acta Paediatr 98(10): 1685-8.

Burk, K., M. L. Farecki, et al. (2009). "Neurological symptoms in patients with biopsy proven celiac disease." Mov Disord 24(16): 2358-62.

Bushara, K. O. (2005). "Neurologic presentation of celiac disease." Gastroenterology 128(4 Suppl 1): S92-7.

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