The Oslo definitions for coeliac disease and related terms

OBJECTIVE

The literature suggests a lack of consensus on the use of terms related to coeliac disease (CD) and gluten.

DESIGN

A multidisciplinary task force of 16 physicians from seven countries used the electronic database PubMed to review the literature for CD-related terms up to January 2011. Teams of physicians then suggested a definition for each term, followed by feedback of these definitions through a web survey on definitions, discussions during a meeting in Oslo and phone conferences. In addition to 'CD', the following descriptors of CD were evaluated (in alphabetical order): asymptomatic, atypical, classical, latent, non-classical, overt, paediatric classical, potential, refractory, silent, subclinical, symptomatic, typical, CD serology, CD autoimmunity, genetically at risk of CD, dermatitis herpetiformis, gluten, gluten ataxia, gluten intolerance, gluten sensitivity and gliadin-specific antibodies.

RESULTS

CD was defined as 'a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals'. Classical CD was defined as 'CD presenting with signs and symptoms of malabsorption. Diarrhoea, steatorrhoea, weight loss or growth failure is required.' 'Gluten-related disorders' is the suggested umbrella term for all diseases triggered by gluten and the term gluten intolerance should not to be used. Other definitions are presented in the paper.

CONCLUSION

This paper presents the Oslo definitions for CD-related terms.

Epidermal transglutaminase (TGase 3) is the autoantigen of dermatitis herpetiformis

Gluten sensitivity typically presents as celiac disease, a common chronic small intestinal disorder. However, in certain individuals it is associated with dermatitis herpetiformis, a blistering skin disease characterized by granular IgA deposits in the papillary dermis. While tissue transglutaminase has been implicated as the major autoantigen of gluten sensitive disease, there has been no explanation as to why this condition appears in two distinct forms. Here we show that while sera from patients with either form of gluten sensitive disease react both with tissue transglutaminase and the related enzyme epidermal (type 3) transglutaminase, antibodies in patients having dermatitis herpetiformis show a markedly higher avidity for epidermal transglutaminase. Further, these patients have an antibody population specific for this enzyme. We also show that the IgA precipitates in the papillary dermis of patients with dermatitis herpetiformis, the defining signs of the disease, contain epidermal transglutaminase, but not tissue transglutaminase or keratinocyte transglutaminase. These findings demonstrate that epidermal transglutaminase, rather than tissue transglutaminase, is the dominant autoantigen in dermatitis herpetiformis and explain why skin symptoms appear in a proportion of patients having gluten sensitive disease.

Celiac disease

Celiac disease (CD) is a common autoimmune disorder, induced by the intake of gluten proteins present in wheat, barley and rye. Contrary to common belief, this disorder is a protean systemic disease, rather than merely a pure digestive alteration. CD is closely associated with genes that code HLA-II antigens, mainly of DQ2 and DQ8 classes. Previously, it was considered to be a rare childhood disorder, but is actually considered a frequent condition, present at any age, which may have multiple complications. Tissue transglutaminase-2 (tTG), appears to be an important component of this disease, both, in its pathogenesis and diagnosis. Active CD is characterized by intestinal and/or extra-intestinal symptoms, villous atrophy and crypt hyperplasia, and strongly positive tTG auto-antibodies. The duodenal biopsy is considered to be the "gold standard" for diagnosis, but its practice has significant limitations in its interpretation, especially in adults. Occasionally, it results in a false-negative because of patchy mucosal changes and the presence of mucosal villous atrophy is often more severe in the proximal jejunum, usually not reached by endoscopic biopsies. CD is associated with increased rates of several diseases, such as iron deficiency anemia, osteoporosis, dermatitis herpetiformis, several neurologic and endocrine diseases, persistent chronic hypertransami-nasemia of unknown origin, various types of cancer and other autoimmune disorders. Treatment of CD dictates a strict, life-long gluten-free diet, which results in remission for most individuals, although its effect on some associated extraintestinal manifestations remains to be established.

Recognition and management of the cutaneous manifestations of celiac disease: a guide for dermatologists

In celiac disease, the ingestion of gluten-containing cereals, such as wheat, rye, and barley, results in small-bowel mucosal inflammation and villous atrophy with crypt hyperplasia. The prevalence of the condition may be as high as 1% in the adult population. The disease can also embrace various extraintestinal manifestations, of which dermatitis herpetiformis is the best known. Earlier, dermatitis herpetiformis was considered a skin disease occurring often concomitantly with celiac disease. At present, a body of evidence shows that dermatitis herpetiformis is a cutaneous manifestation of celiac disease, and affects approximately 25% of patients with celiac disease. Both conditions can appear in the same family and are closely linked to HLA class II locus in chromosome 6; 90% of patients have HLA DQ2 and, almost all the remainder, HLA DQ8. All patients with dermatitis herpetiformis have at least some-degree of mucosal inflammation or lesion consistent with celiac disease. The etiology of celiac disease in not fully understood, but tissue transglutaminase seems to be the predominant autoantigen both in the intestine and the skin. Serum antibodies against tissue transglutaminase can be used in the serologic screening and follow-up of dietary compliance of patients with celiac disease. Gluten-free diet is essential in the treatment of both conditions, and oral dapsone is usually needed in newly detected dermatitis herpetiformis in order to alleviate symptoms. Oral mucosal lesions, alopecia areata, and vitiligo probably occur more frequently in patients with dermatitis herpetiformis than in the general population. By contrast, the reported association of celiac disease with psoriasis seems to be coincidental.

Coeliac disease in the elderly

Of 228 patients with adult coeliac disease, 42 (19%) were diagnosed aged 60 years or over. In this series, of 35 patients who did not have dermatitis herpetiformis, 15 had attended family doctors and hospital outpatient departments for an average of 28 years with unexplained symptoms or abnormalities in blood tests but the diagnosis of coeliac disease had been missed. This is unsatisfactory because these patients can both manage and respond to a gluten free diet. Thirty eight patients complied strictly with the diet with resolution of symptoms. Significant improvement in weight, haemoglobin, albumin, calcium, and alkaline phosphatase values after a year on the diet also occurred. Clinicians should be alert to the possibility of coeliac disease in the elderly particularly in patients with non-specific complaints in the presence of unexplained anaemia.

Coeliac disease: a cause of various associated diseases?

Deposition in other organs of immune complexes originating from the small-intestinal musosa is suggested as a possible reason, in some patients, for the described association between coeliac disease and a range of "autoimmune" diseases.

The pathogenesis of dermatitis herpetiformis: recent advances

Over the last two decades a rapid expansion of our knowledge regarding dermatitis herpetiformis has occurred, including the discovery of IgA in the skin, the discovery of an associated gluten-sensitive enteropathy, the noting of an increased prevalence of the human lymphocyte antigens (HLA)-B8 and -DRw3, and the documentation that the skin disease of many dermatitis herpetiformis patients can be controlled by a gluten-free diet. It has also been noted that two distinct forms of dermatitis herpetiformis occur, those with granular deposits of IgA at the dermoepidermal junction (85%-95% of dermatitis herpetiformis patients) and those with linear IgA deposits (10%-15% of dermatitis herpetiformis patients). These findings are reviewed with particular emphasis on the form of dermatitis herpetiformis associated with granular IgA deposits. The current findings regarding the nature and origin of the cutaneous IgA deposits, the role of the gluten-sensitive enteropathy, and the spectrum of both the immunologic and the nonimmunologic abnormalities associated with dermatitis herpetiformis are presented, and from these data pathophysiologic mechanisms are proposed that may be involved in dermatitis herpetiformis.

Internal disorders associated with bullous disease of the skin. A critical review

Acquired bullous dermatoses, including pemphigus, bullous pemphigoid (BP), dermatitis herpetiformis (DH), and porphyria cutanea tarda (PCT), have been reported in association with multiple internal disorders. These associations, as well as those cases of bullous lesions in specific systemic disorders, may prove to be important markers of internal disease. Patients with acquired bullous disorders may require specialized evaluation or follow-up. Pemphigus is associated with thymoma and/or myasthenia gravis; however, the course of disease is rarely affected. Pemphigus, pemphigoid, and DH are associated with other autoimmune disorders. Particularly important are the associations of pemphigoid and rheumatoid arthritis (RA) and DH and thyroid disorders. PCT may occur with cutaneous lupus erythematosus (LE). Malignancy is rarely associated with bullous dermatoses except coincidentally, with the exception of porphyria and hepatic tumors, and DH and lymphoma of the gastrointestinal tract.

Extraintestinal manifestations of celiac disease

Celiac disease is an autoimmune disorder that occurs in genetically predisposed individuals as the result of an immune response to gluten. It is present in approximately 1% of the population. Diarrhea has become a less common mode of presentation (<50% of cases) than it once was. Other presentations include iron-deficiency anemia, osteoporosis, dermatitis herpetiforme, and neurologic disorders, mainly peripheral neuropathy and ataxia. Arthritis is commonly found in patients with celiac disease when systematically sought. Overall, autoimmune diseases occur more frequently (three to ten times more) in those with celiac disease than in the general population. A gluten-free diet is the standard of treatment, although its effect on some of the extraintestinal manifestations remains to be determined.

Coeliac disease and oats: a systematic review

A systematic review of the literature related to the inclusion of oats in the gluten-free diet for patients with coeliac disease to assess whether oats can be recommended. A computerised literature review of multiple databases was carried out, identifying 17 primary studies, 6 of which met the criteria for inclusion in this review. None of the six studies found any significant difference in the serology between the oats and control groups. Two studies, however, identified a significant difference (p<0.001; p = 0.039) in intraepithelial lymphocyte counts between the oats and control groups. Oats can be symptomatically tolerated by most patients with coeliac disease; however, the long-term effects of a diet containing oats remain unknown. Patients with coeliac disease wishing to consume a diet containing oats should therefore receive regular follow-up, including small bowel biopsy at a specialist clinic for life.

The widening spectrum of celiac disease

Celiac disease is a permanent intolerance to ingested gluten that results in immunologically mediated inflammatory damage to the small-intestinal mucosa. Celiac disease is associated with both human leukocyte antigen (HLA) and non-HLA genes and with other immune disorders, notably juvenile diabetes and thyroid disease. The classic sprue syndrome of steatorrhea and malnutrition coupled with multiple deficiency states may be less common than more subtle and often monosymptomatic presentations of the disease. Diverse problems such as dental anomalies, short stature, osteopenic bone disease, lactose intolerance, infertility, and nonspecific abdominal pain among many others may be the only manifestations of celiac disease. The rate at which celiac disease is diagnosed depends on the level of suspicion for the disease. Although diagnosis relies on intestinal biopsy findings, serologic tests are useful as screening tools and as an adjunct to diagnosis. The treatment of celiac disease is lifelong avoidance of dietary gluten. Gluten-free diets are now readily achievable with appropriate professional instruction and community support. Both benign and malignant complications of celiac disease occur but these can often be avoided by early diagnosis and compliance with a gluten-free diet.

Clinical features of celiac disease today

The clinical spectrum of celiac disease has widened over the past decades. The condition is no longer a severe malabsorption syndrome. Instead, a typical celiac disease patient today has merely mild abdominal symptoms. Malabsorption can be subclinical or absent, and there is usually only moderate, if any, loss of weight. Simultaneously, the current prevalence has increased from 1:1,000 to 1:300 inhabitants, or even higher. Clinically silent celiac disease cases are being detected in increasing numbers since the introduction and widespread use of serologic screening tests. Symptoms of celiac disease can appear outside the intestine, a typical example being dermatitis herpetiformis. Gluten intolerance is no longer limited to overt villous atrophy. Inflammation without villous damage may be observed in genetically susceptible individuals. The term latent celiac disease is applied in situations where the patient has normal villous architecture while on a gluten-containing diet, but later develops small bowel villous atrophy compatible with celiac disease.

A comparison of histocompatibility antigens in dermatitis herpetiformis and adult coeliac disease

The incidence of histocompatibility antigens HL-A, 4a and 4b was studied in thirty-eight patients with dermatitis herpetiformis (DH) and thirty-six patients with adult coeliac disease (ACD). The 4b antigen was found in all the DH and ACD patients. HL-A 8 was found in 89% of patients with ACD--similar to the incidence reported in previous studies--and in 79% of patients with DH, a higher incidence than in previous studies which may be due to stricter criteria being used here to diagnose DH. There was no significant difference in the incidence of HL-A 8 between those patients with DH whose small intestinal biopsies appeared macroscopically abnormal and those with a normal macroscopic appearance. These findings suggest that patients with DH form a single disease group and do not support the concept previously postulated that there are two groups of patients with DH, one with an increased incidence of HL-A 8 antigen similar to that in ACD who have a gluten sensitive enteropathy (GSE), and another with a normal incidence of HL-A 8 antigen and without enteropathy.

Dermatitis herpetiformis is associated with atrophic but not with goitrous variant of Hashimoto's thyroiditis

BACKGROUND

Dermatitis herpetiformis (DH) is a gluten-sensitive skin disease that is associated with a variety of autoimmune disorders. Several investigations demonstrated an association between DH and autoimmune thyroid disease. However, it has not been shown if DH is associated with atrophic or goitrous variant of Hashimoto's thyroiditis.

MATERIALS AND METHODS

We investigated a cohort of 41 DH patients (18 male, 23 female) and a control group (11 male, 19 female; sex and age matched healthy volunteers) to find out which variant of Hashimoto's thyroiditis is associated with DH. All patients had thyroid hormones and antibodies measured. In addition to that, thyroid sonography as well as detailed history-taking of previous thyroid disease were performed.

RESULTS

In the control group no individual with elevated levels of thyroid antibodies nor abnormal thyroid hormones nor thyroid atrophy was found. Median thyroid volume in the control group was 11 mL (range 4.8-24.7 mL). However, in nine DH patients (22%) elevated levels of antithyroid microsomal (TM) antibodies were seen (P < 0.01). Three of them had abnormal thyroid hormones (7%). In the group of DH patients a significantly smaller thyroid volume was found (median 8 mL, range 1. 6-25.2 mL; P < 0001). Thyroid atrophy (volume < 4.4 mL) was found in 10 DH patients (24%) of whom 9 were females. All patients with elevated levels of TM antibodies or abnormal thyroid hormones and all patients with a history of previous hypothyroidism had a thyroid volume < 7 mL. Goitrous variant of Hashimoto's thyroiditis was not seen in any of the DH patients.

CONCLUSIONS

Our findings demonstrate that DH is associated with atrophic but not with goitrous variant of Hashimoto's thyroiditis.

The neurology of gluten sensitivity: separating the wheat from the chaff

Coeliac disease is the prototypical gluten-sensitive disease. Clinico-pathological features heal on a gluten-free diet and relapse when gluten is reintroduced. An immunopathology is suspected. A number of neurological syndromes may be associated with coeliac disease but it is unclear whether these are directly or indirectly caused by gluten ingestion. It has been proposed that idiopathic ataxias and central nervous system white matter disease are gluten-sensitive syndromes. This is an exciting hypothesis because it offers new therapeutic possibilities including simple exclusion diets. However, interpretation is difficult because occult sub-clinical coeliac disease occurs commonly and background prevalence needs to be accounted for in population-based studies. This review will attempt to summarize the pertinent literature on this fascinating topic.

Thyroid diseases and skin autoimmunity

The skin is the largest organ of the body, at the boundary with the outside environment. Primarily, it provides a physical and chemical barrier against external insults, but it can act also as immune organ because it contains a whole host of immune-competent cells of both the innate and the adaptive immune systems, which cooperate in eliminating invading pathogens following tissue injury. On the other hand, improper skin immune responses lead to autoimmune skin diseases (AISD), such as pemphigus, bullous pemphigoid, vitiligo, and alopecia. Although the interplay among genetic, epigenetic, and environmental factors has been shown to play a major role in AISD etiology and progression, the molecular mechanisms underlying disease development are far from being fully elucidated. In this context, epidemiological studies aimed at defining the association of different AISD with other autoimmune pathologies revealed possible shared molecular mechanism(s) responsible for disease progression. In particular, over the last decades, a number of reports have highlighted a significant association between thyroid diseases (TD), mainly autoimmune ones (AITD), and AISD. Here, we will recapitulate the epidemiology, clinical manifestations, and pathogenesis of the main AISD, and we will summarize the epidemiological evidence showing the associations with TD as well as possible molecular mechanism(s) underlying TD and AISD pathological manifestations.

Antipeptide antibodies to adenovirus E1b protein indicate enhanced risk of celiac disease and dermatitis herpetiformis

The relationship between adenovirus type 12 (Ad12), celiac disease (CD) and dermatitis herpetiformis (DH) was evaluated by enzyme-linked immunosorbent assay (ELISA). Diagnostic phase serum samples from 44 children with CD, 16 children with DH and 60 matched controls were studied for serum antibodies to synthetic peptides derived from an early E1b protein of Ad12 and A gliadin. Both the patient groups had significantly (p < 0.001) higher IgG antibody levels to the Ad12 E1b peptide than the controls. The difference was especially pronounced for girls (p < 0.005). Antipeptide IgG antibodies to Ad12 E1b and A gliadin posed a synergistic increase in the CD and DH risk suggesting that infection with Ad12 is associated with CD and DH.

Coeliac disease: the great imitator

Coeliac disease (CD) is caused by a complex immunological response provoked by grain protein in susceptible people. The majority of people with CD are symptom-free adults; the remainder are prone to a bewildering variety of signs and symptoms, ranging from infertility to type 1 diabetes. Many patients with undiagnosed CD spend years seeking help for complaints such as chronic tiredness or mild abdominal symptoms. In primary care, an appropriate target group to test for CD is people with anaemia (especially women), chronic tiredness, non-specific abdominal symptoms (including so-called "irritable bowel syndrome"), or a family history of CD. The response to an appropriate gluten-free diet is often life-transforming for symptomatic patients. Positive serological tests for CD require confirmation by duodenal biopsy and, if confirmed, referral to a dietitian and a coeliac society, followed by a life-long gluten-free diet.