IgA antibodies to gliadin and coeliac disease in psoriatic arthritis

A Critical Appraisal of Gluten in Skin Disorders, the Evidence So Far, and Updated Recommendations

Gluten, a polypeptide hapten, found in many cereals such as barley, wheat, rye, oats, and others, has been recently implicated in a range of cutaneous disorders ranging from chronic plaque psoriasis through psoriatic arthritis, urticaria (chronic as well as paediatric onset), and angioedema to lichen planus, vitiligo, and rosacea. The evidence for them is still not well reviewed. To generate evidence for the causal role of gluten in various dermatological disorders. The Pubmed, MedLine, and EMBASE databases were searched using the keywords "Gluten" and one of the dermatoses, namely, "Atopic Dermatitis", "Vasculitis", "Psoriasis", "Psoriatic Arthritis", "Acne", "Alopecia Areata", and "Immunobullous disorders". All articles published in English for which free full text was available were taken into consideration. The search strategy returned in a total of 1487 articles which were screened for relevance and elimination of duplicates. Ultimately, around 114 articles were deemed suitable. The data were extracted and presented in the narrative review format. A simple and cost-effective solution to many of these chronic and lifelong conditions is to restrict gluten in the diet. However, the dermatologist would do well to remember that in the vast majority of dermatological disorders including the ones listed here, gluten restriction is not warranted and can even lead to nutritional deficiencies. The evidence varied from Grade I for some disorders like psoriatic arthritis to Grade IV to most disorders like acne, vitiligo, vasculitis, and atopic dermatitis. Herein, we review the evidence for each of these conditions and make practical recommendations for gluten restriction in them.

Psoriasis, bone and bowel: a comprehensive review and new insights

Psoriasis is a chronic immune-mediated disorder affecting about 2% of the population worldwide which is associated with significant morbidity. The disease usually presents as raised, well-demarcated erythematous plaques with adherent silvery scales. Psoriasis can appear at any age but it has two peaks occurring at 15–20 and 55–60 years of age. It affects males and females equally. Despite the multitude of investigations about psoriasis and even development of drugs with satisfactory results, its pathogenesis is not fully understood yet and its course is unpredictable. Various environmental triggers, e.g., obesity, stress and drugs may induce disease in genetically susceptible patients. Although psoriasis was considered primarily as a disease of the skin, more investigations have been revealed its systemic nature. Psoriatic arthritis (PsA) may complicate up to one-third of cases of psoriasis vulgaris (PV). Also, the association between psoriasis and a variety of other immune-mediated disorders such as inflammatory bowel disease (IBD) and celiac disease (CD) has been confirmed in various studies. Moreover, a growing body of evidences indicates that psoriasis shares some common histological and phenotypical properties with the spectrum of osteoimmunological diseases such as Paget’s disease of bone (PDB). Thus, exploring the common molecular and genetic mechanisms underlying psoriasis and related disorders is of paramount importance for better elucidating disease pathogenesis and designing more targeted treatments.

Metabolic Disorders and Psoriasis: Exploring the Role of Nutritional Interventions

(1) Background: Psoriasis is a chronic autoimmune disease with a close relationship with metabolic diseases such as obesity, diabetes, and dyslipidemia. The aim of this review was to identify the relationship between psoriasis, metabolic diseases, and dietetic therapies. According to recent findings, there is a strong association between psoriasis and obesity as well as vitamin D and micronutrient deficiencies. (2) Methods: This review was conducted via PubMed, aiming to search for studies involving psoriasis linked with metabolic disorders or with nutritional treatments. (3) Results: Our review shows that a healthy lifestyle can positively influence the course of the disease. The maintaining of a proper body weight together with physical activity and good nutritional choices are associated with an improvement in psoriasis severity. A Mediterranean diet rich in fiber, vitamins, and polyphenols may indeed be a strategy for controlling psoriasis symptoms. The effectiveness of this diet lies not only in its anti-inflammatory power, but also in its ability to favorably influence the intestinal microbiota and counteract dysbiosis, which is a risk factor for many autoimmune diseases. (4) Conclusions: In synergy with standard therapy, the adoption of an appropriate diet can be recommended to improve the clinical expression of psoriasis and reduce the incidence of comorbidities.

Skin gluten-related disorders: new and old cutaneous manifestations to be considered

The term gluten-related disorders (GRD) refer to a spectrum of different clinical manifestations triggered by the ingestion of gluten in genetically susceptible individuals, including coeliac disease (CD), wheat allergy and non-celiac gluten sensitivity (NCGS). GRD are characterized by a large variety of clinical presentations with both intestinal and extra-intestinal manifestations. The latter may affect almost every organ of the body, including the skin. Besides the well-known association between CD and dermatitis herpetiformis, considered as the cutaneous specific manifestation of CD, many other muco-cutaneous disorders have been associated to GRD. In this review, we analyzed the main features of dermatological diseases with a proven association with GRD and those that improve after a gluten-free diet, focusing on the newly described cutaneous manifestations associated with NCGS. Our main hypothesis is that a "cutaneous-gluten sensitivity," as specific cutaneous manifestation of NCGS, may exist and could represent a diagnostic marker of NCGS.

Screening of antigliadin and antitissue transglutaminase antibodies in patients with chronic plaque psoriasis: a case-control study

BACKGROUND

In this study, we aimed to investigate different types of celiac antibodies in psoriasis patients and to see if the presenceof the antibodies was associated with other variables.

METHODS

We included patients with plaque psoriasis who were followed up in our dermatology clinic between February 2019 and February 2021 and added a healthy control group for comparison. The antibodies studied were serum antitissue transglutaminase (tTG)-IgA, tTG-IgG, antigliadin antibody (AGA)-IgA, and AGA-IgG. The patients' records were used to note age, sex, the pattern of psoriasis involvement, psoriasis area and severity index (PASI), presence of hypertension, presence of type 2 diabetes mellitus, use of methotrexate, and use of biologic agents.

RESULTS

Sixty-five psoriasis patients (31 F, 34 M, mean age: 38.9 ± 15.2) and 65 controls (42 F, 23 M, mean age: 40.7 ± 13.2) wereincluded in the study. There was no significant difference in antibody levels between the groups: tTG-IgA (2.4 U/mL vs 3.2 U/mL, p = 0.11), tTG-IgG (2.2 U/mL vs 3.2 U/mL, p = 0.74), AGA-IgA (2.4 U/mL vs 3.5 U/mL, p = 0.068), and AGA-IgG (3.2 U/mL vs 4.2 U/mL, p = 0.15). One patient from the psoriasis group only had borderline positive antibody levels whereas the rest of the psoriasis and control group had negative levels. Hypertensive psoriasis patients had significantly higher AGA-IgA titers compared to normotensive psoriasis patients (4.2 U/mL vs 2.3 U/mL, p = 0.005).

DISCUSSION

There was no increase in the AGA-IgA/IgG and tTG-IgA/IgG levels in psoriasis patients compared to the healthy population. However, hypertensive psoriasis patients had higher AGA-IgA levels compared to normotensive ones.

Overexpression of Transmembrane TNF Drives Development of Ectopic Lymphoid Structures in the Bone Marrow and B Cell Lineage Alterations in Experimental Spondyloarthritis

TNF is important in immune-mediated inflammatory diseases, including spondyloarthritis (SpA). Transgenic (tg) mice overexpressing transmembrane TNF (tmTNF) develop features resembling human SpA. Furthermore, both tmTNF tg mice and SpA patients develop ectopic lymphoid aggregates, but it is unclear whether these contribute to pathology. Therefore, we characterized the lymphoid aggregates in detail and studied potential alterations in the B and T cell lineage in tmTNF tg mice. Lymphoid aggregates developed in bone marrow (BM) of vertebrae and near the ankle joints prior to the first SpA features and displayed characteristics of ectopic lymphoid structures (ELS) including presence of B cells, T cells, germinal centers, and high endothelial venules. Detailed flow cytometric analyses demonstrated more germinal center B cells with increased CD80 and CD86 expression, along with significantly more T follicular helper, T follicular regulatory, and T regulatory cells in tmTNF tg BM compared with non-tg controls. Furthermore, tmTNF tg mice exhibited increased IgA serum levels and significantly more IgA⁺ plasma cells in the BM, whereas IgA⁺ plasma cells in the gut were not significantly increased. In tmTNF tg × TNF-RI^-/- mice, ELS were absent, consistent with reduced disease symptoms, whereas in tmTNF tg × TNF-RII^-/- mice, ELS and clinical symptoms were still present. Collectively, these data show that tmTNF overexpression in mice results in osteitis and ELS formation in BM, which may account for the increased serum IgA levels that are also observed in human SpA. These effects are mainly dependent on TNF-RI signaling and may underlie important aspects of SpA pathology.

Could it be gluten? Additional skin conditions associated with celiac disease

Celiac disease is a multifactorial, inflammatory disorder initiated and sustained by the ingestion of gluten. Occurring across a broad population, the intestinal and extraintestinal manifestations of celiac disease are variable in severity and may be nonspecific in presentation. Given that environmental, genetic, and immune factors involved in the pathogenesis of celiac disease that the digestive tract and skin share many characteristics, and with a prevalence of 0.5-1% in most populations, it is reasonable to consider varying presentations of skin conditions that are linked with celiac disease. The association between celiac disease and skin conditions has been discussed earlier, but new studies have emerged suggesting cutaneous involvement in addition to dermatitis herpetiformis. We review the current literature identifying the relationship and potential mechanisms between celiac disease and various skin conditions.

Association of Psoriasis with Autoimmune Disorders: Results of a Pilot Study

BACKGROUND

Association of psoriasis with other autoimmune diseases remains an ongoing research subject.

OBJECTIVES

To investigate the association of psoriasis with other autoimmune disorders.

MATERIALS AND METHODS

We studied 80 (M: F 57:23) psoriasis patients aged 13-75 years for concurrent autoimmune disorders. After clinical examination, hemogram, fasting blood sugar, HbA1c, thyroid function tests, anti-TPO antibody, rheumatoid factor, anti-tTG antibody, anti-CCP antibody, ANA, anti-dsDNA antibody, anti-Ro antibody, and fecal calprotectin were estimated.

RESULTS

Mild-to-moderate and severe psoriasis was present in 86.3% and 13.8% patients, respectively. Psoriatic arthritis was present in 3.8% patients, all of whom also had severe psoriasis. Only 37 (46.3%) patients had clinical and/or sero-abnormality suggestive of autoimmune disorders; vitiligo in 3.8%, type-1 diabetes mellitus (DM) in 1.3%, and type-2 DM in 6.3% patients. Sero-positivity reflecting subclinical autoimmunity was noted for anti-CCP antibodies (in 2.5%), rheumatoid factor (in 2.5%), hypo- or hyper-thyroidism (in 8.8%), anti-TPO antibodies (in 5.0%), anti-tTG antibody (in 1.3%), ANA (in 5.0%), anti-dsDNA antibody (in 2.5%), and anti-Ro antibody in 11.3% patients. Elevated fecal calprotectin levels suggestive of inflammatory bowel disease (IBD) occurred in 11.2% of 27 patients. Multiple abnormalities happened in 2.5% patients.

CONCLUSION

Apparently psoriasis patients seem to have a predilection for other autoimmune disorders particularly for vitiligo, diabetes mellitus, autoimmune thyroiditis, rheumatoid arthritis, and IBD. However, association between psoriasis and other autoimmune disorders at best remains tenuous for want of strong evidence. Nevertheless, screening for them will improve overall management of these patients. Cross-sectional study design and small number of study subjects remain important limitations.

The association of anti-gliadin and anti-transglutaminase antibodies and chronic plaque psoriasis in Indian patients: Preliminary results of a descriptive cross-sectional study

BACKGROUND

Gluten sensitivity among psoriasis patients and its association with gender, age, disease duration and severity of psoriasis are under studied in Indians.

OBJECTIVE

To examine association among serum levels of anti-tTG and anti-gliadin antibodies and clinical features including gender, age, duration and severity of psoriasis.

METHODS

Serum levels of anti-transglutaminase and anti-gliadin antibodies were measured quantitatively in 80 (M:F 57:23) psoriasis patients aged 15 to 83 years and matched healthy subjects.

RESULTS

Forty-five (56.3%) patients were aged ≥41years, duration of disease was >5years in 43(53.8%) patients, and 22 (27.5%) patients had moderate-to-severe psoriasis. Two (2.5%) patients had arthritis and elevated serum anti-gliadin antibody. Significantly more patients than controls had elevated serum anti-gliadin antibody (67.5% vs. 2.5%) and anti-transglutaminase antibody levels (62.5% vs. 0%). Two patients, each with mild and moderate-to-severe psoriasis, had highly elevated serum anti-gliadin antibody and symptoms akin to coeliac disease. Except for a longer duration of psoriasis in patients with elevated anti-gliadin antibodies, there was no statistically significant difference in gender, age, and severity of psoriasis when compared with patients having normal levels.

CONCLUSION

Significant elevation of serum anti-transglutaminase and anti-gliadin antibodies levels is noted in psoriasis patients reflecting a possible link. However, results need careful interpretation for any significance of gluten sensitivity in pathogenesis of psoriasis/arthritis or as a stand-alone risk factor for chronicity/severity of psoriasis or whether gluten-free diet will be ameliorating. Small number of subjects, cross-sectional study design, lack of pathological/endoscopic diagnosis and follow-up are study limitations.

An update on the cutaneous manifestations of coeliac disease and non-coeliac gluten sensitivity

INTRODUCTION

Coeliac disease is a gluten-induced immune-mediated enteropathy, characterised by the expression of specific genotypes and the production of autoantibodies. The inflammatory process specifically targets the intestinal mucosa, but gastrointestinal and extraintestinal signs and symptoms can also be present. Non-coeliac gluten sensitivity (NCGS) can be diagnosed in individuals who have intestinal and/or extraintestinal symptoms related to the ingestion of gluten, but do not have autoantibodies and do not suffer from lesions in the duodenal mucosa. Among the extraintestinal manifestations, cutaneous manifestations are the most common for both diseases.

PURPOSE

We conducted this review to illustrate the common and uncommon features underlying the association of coeliac disease and NCGS with cutaneous manifestations related to gluten ingestion. Areas covered: The roles of innate and adaptive immunity in the cutaneous appearance of gluten sensitivity will be discussed.

Cutaneous and Mucosal Manifestations Associated with Celiac Disease

Celiac disease (CD) is an immune-mediated, gluten-induced enteropathy that affects predisposed individuals of all ages. Many patients with CD do not report gastrointestinal symptoms making it difficult to reach an early diagnosis. On the other hand, CD is related to a wide spectrum of extra-intestinal manifestations, with dermatitis herpetiformis (DH) being the best characterized. These associated conditions may be the clue to reaching the diagnosis of CD. Over the last few years, there have been multiple reports of the association between CD and several cutaneous manifestations that may improve with a gluten-free diet (GFD). The presence of some of these skin diseases, even in the absence of gastrointestinal symptoms, should give rise to an appropriate screening method for CD. The aim of this paper is to describe the different cutaneous manifestations that have been associated with CD and the possible mechanisms involved.

Digestive system in psoriasis: an update

Psoriasis is a chronic inflammatory immune-mediated disorder associated and often coexisting with many other immune-related clinical conditions including those affecting the gastrointestinal tract. Data obtained from the reviewed literature suggest an association between psoriasis and pathologies of the oral cavity, both psoriasis-specific lesions, as well as non-specific, such as geographic tongue or fissured tongue. These findings show the importance of thorough examination of oral mucosa in psoriatic patients. Inflammatory bowel diseases (IBD) are also linked with psoriasis. Crohn’s disease and ulcerative colitis share a common genetic background, inflammatory pathways and have an evident iatrogenic anti-TNF treatment link, necessitating dermatological or gastroenterological care in patients with IBD or psoriasis, respectively, as well as treatment adjusted to manifestations. The presence of celiac disease-specific antibodies in psoriatic patients and their correlation with the severity of the disease show the association between these disorders. The linking pathogenesis comprises vitamin D deficiency, immune pathway, genetic background and increase in the intestinal permeability, which suggests a potential benefit from gluten-free diet among psoriatic patients. The link between psoriasis and non-alcoholic fatty liver disease implies screening patients for components of metabolic syndrome and lifestyle changes necessity. Some studies indicate increased prevalence of cancer in patients with psoriasis, probably due to negative influence of skin lesion impact on lifestyle rather than the role of psoriasis in carcinogenesis. However, there are no sufficient data to exclude such an oncogenic hit, which is yet to be confirmed. Therefore, all psoriasis-associated comorbidities establish the importance of a multidisciplinary approach in the treatment of these patients.

Disease activity in and quality of life of patients with psoriatic arthritis mutilans: the Nordic PAM Study

OBJECTIVE

To describe the social status and health-related quality of life of patients with psoriatic arthritis mutilans (PAM) in the Nordic countries.

METHOD

Patients with at least one mutilated joint confirmed by radiology were studied. Disease activity involving joints and skin, physician-assessed disease activity, and patient's education and work status were recorded. Data from the 36-item Short Form Health Survey, Health Assessment Questionnaire and Dermatology Life Quality Index questionnaire were gathered and correlated with disease duration, pain, and general well-being (visual analogue scale). The controls were 58 Swedish patients with long-standing psoriatic arthritis sine PAM.

RESULTS

Sixty-seven patients were included. Patients with PAM had a protracted disease history (33 ± 14 years) and disease onset at a relatively early age (30 ± 12 years). Overall inflammatory activity at inclusion was mild to moderate. The mean number of mutilated joints was 8.2 and gross deformity was found in 16% of patients. Forty per cent were treated with biological and 32% with conventional synthetic disease-modifying anti-rheumatic drugs. Forty-two per cent had retired early or were on sick leave. Impaired functional capacity with little or no ability to perform self-care or everyday tasks was reported by 21% of the patients. Patients between 45 and 60 years of age reported the most impaired quality of life in comparison to the control group.

CONCLUSION

PAM seriously affects social functioning. Whether early recognition of PAM and new forms of therapy can improve disease outcome and quality of life remains to be studied.

Diet and psoriasis, part II: celiac disease and role of a gluten-free diet

Patients with psoriasis have been shown to have a higher prevalence of other autoimmune diseases including celiac disease, a condition marked by sensitivity to dietary gluten. A number of studies suggest that psoriasis and celiac disease share common genetic and inflammatory pathways. Here we review the epidemiologic association between psoriasis and celiac disease and perform a meta-analysis to determine whether patients with psoriasis more frequently harbor serologic markers of celiac disease. We also examine whether a gluten-free diet can improve psoriatic skin disease.

Coeliac disease-associated antibodies in psoriasis

Background

The possible relationship between psoriasis and coeliac disease (CD) has been attributed to the common pathogenic mechanisms of the two diseases and the presence of antigliadin antibodies in patients has been reported to increase the incidence of CD.

Objective

The aim of this report was to study CD-associated antibodies serum antigliadin antibody immunoglobulin (Ig)A, IgG, anti-endomysial antibody IgA and anti-transglutaminase antibody IgA and to demonstrate whether there is an increase in the frequency of those markers of CD in patients with psoriasis.

Methods

Serum antigliadin antibody IgG and IgA, antiendomysial antibody IgA and anti-transglutaminase antibody IgA were studied in 37 (19 males) patients with psoriasis and 50 (23 males) healthy controls. Upper gastrointestinal endoscopy and duodenal biopsies were performed in patients with at least one positive marker.

Results

Antigliadin IgA was statistically higher in the psoriasis group than in the controls (p<0.05). Serological markers were found positive in 6 patients with psoriasis and 1 person from the control group. Upper gastrointestinal endoscopy was performed in all these persons, with biopsies collected from the duodenum. The diagnosis of CD was reported in only one patient with psoriasis following the pathological examination of the biopsies. Whereas one person of the control group was found to be positive for antigliadin antibody IgA, pathological examination of the duodenal biopsies obtain from this patient were found to be normal.

Conclusion

Antigliadin IgA prominently increases in patients diagnosed with psoriasis. Patients with psoriasis should be investigated for latent CD and should be followed up.

Psoriatic arthritis

Autoimmune diseases (ADs) are chronic, often debilitating and potentially life-threatening conditions that collectively affect up to 23.5 million Americans, and their incidence is rising.¹ They are heterogeneous in pathology but share common etiopathogenic factors such as intestinal hyperpermeability.² Although up to 100 ADs have been identified, there are likely more.¹ Genetics plays a clear role in the predisposition for the development and phenotype of AD, but various combinations of factors, such as toxins, endogenous hormone imbalances, microbes (including of GI origin), infections, stress and food antigens, are involved in disease expression.^2–5 Standard treatments include NSAIDs, steroids, antineoplastic agents and tumor necrosis factor-alpha antagonists. These tools have potentially devastating side effects and are often applied regardless of the diagnosis. Frequently, they are only modestly effective in relieving symptoms and limiting the advancing disease process. Direct health-care costs of AD are estimated at around 100 billion dollars per year in the United States. By comparison, cancer care costs about 57 billion dollars per year.¹ The rising incidence of this debilitating and costly group of conditions dictates that safe, alternative approaches to treatment be considered now.

Celiac disease and dermatologic manifestations: many skin clue to unfold gluten-sensitive enteropathy

Cutaneous manifestations of intestinal diseases are increasingly reported both in the adult and in the children, and this association cannot longer be considered a simple random. Besides the well-known association between celiac disease (CD) and dermatitis herpetiformis (DH), considered as the cutaneous manifestation of gluten-dependent enteropathy, is more frequently reported also the association with other mucocutaneous diseases. Among these there are both autoimmune, allergic, and inflammatory diseases, but also a more heterogeneous group called miscellaneous. The knowledge about pathogenic, epidemiological, clinical, and diagnostic aspects of CD is increasing in recent years as well as those about DH, but some aspects still remain to be defined, in particular the possible pathogenetic mechanisms involved in the association between both CD and DH and CD and other immunological skin diseases. The aim of this paper is to describe the skin diseases frequently associated with CD, distinguishing them from those which have a relationship probably just coincidental.

IgA transglutaminase levels in children with Juvenile Idiopathic Arthritis

OBJECTIVES

Several studies have indicated that adult patients with spondyloarthritis (SpA) have elevated levels of antibodies associated with celiac disease (CD). This has not been studied in children, and none of the studies corrected for total IgA levels.

METHODS

We measured total IgA and IgA against tissue transglutaminase (TTG) levels in 42 children with Juvenile Idiopathic Arthritis (JIA), of whom 11 had SpA, along with 10 non-inflammatory control subjects.

RESULTS

Median (IQR) TTG IgA levels were elevated among children with ERA (8.8, 4.6 - 21) compared to 'JIA controls' (JIA subgroups other than ERA) (2.8, 1.5 - 5.9) and a healthy non-inflammatory control group (1.5, 0.82 - 12), p = 0.017, Kruskal-Wallis. There was no correlation between TTG IgA levels and measures of disease activity or with medicine use. None of the children were diagnosed endoscopically with celiac disease. Patients with ERA likewise had elevated total IgA level compared to the other groups (p = 0.001), and total IgA levels correlated highly with TTG IgA (r = 0.599, p<0.001).

CONCLUSION

These findings suggest that elevations in TTG IgA may reflect increased polyclonal IgA production, rather than a specific intestinal inflammatory process.

Prevalence of serological markers for celiac disease (IgA and IgG class antigliadin antibodies and IgA class antiendomysium antibodies) in patients with autoimmune rheumatologic diseases in Belo Horizonte, MG, Brazil

CONTEXT

Patients with autoimmune rheumatologic conditions and celiac disease tend to have a variety of autoantibodies, many of which have no clear pathogenic role. The literature contains frequent reports of celiac disease being more prevalent in patients with rheumatologic diseases, although this remains controversial.

OBJECTIVES

To investigate the prevalence of positive serum tests for celiac disease, particularly IgA and IgG antigliadin (AGA) antibodies and IgA antiendomysium antibodies (EmA) in patients with autoimmune rheumatologic diseases. A second aim was to correlate positive serum tests with prednisone and immunosuppressant medication.

METHODS

A total of 190 adults and pediatric patients with a variety of autoimmune rheumatologic diseases (systemic lupus erythematosus, rheumatoid arthritis, juvenile rheumatoid arthritis and spondyloarthrophathies) were evaluated and tested for IgA and IgG antigliadin-antibodies and IgA antiendomysium antibodies. Patients with positive serum tests underwent endoscopic duodenal biopsies for pathology studies.

RESULTS

There were four positive sera (2.1%) for AGA IgA, all of which tested negative for AGA IgG and EmA. Three sera (1.6%) tested positive for AGA IgG; all were negative for AGA IgA and EmA. The EmA test at a 1:2.5 serum dilution tested positive in 94 patients (49.5%); at a 1:5 serum dilution it was positive in 41 patients (21.6%). Eleven subjects tested positive for EmA at 1:40 dilution; and all of these tested negative for IgA tissue antitransglutaminase (tTG) antibodies. Nine of the 11 EmA-positive patients and all 7 patients with positive antigliadin antibodies tests underwent duodenal endoscopic biopsies, and no significant changes were demonstrated in their duodenal mucosa. A positive EmA was associated with elevated optical density AGA IgA readings; however, there was no relationship between positive EmA and AGA IgG optical density readings. Prednisone and immunosuppressant use were unrelated to AGA IgA optical density readings or AGA IgG readings. These drugs were associated with fewer positive EmA tests.

CONCLUSIONS

Positive AGAA, AGAG or EmA results are probably nonspecific for the presence of celiac disease among autoimmune rheumatologic disease patients. The intake of prednisone and immunosuprressant drugs seems to reduce the prevalence of IgA EmA, but it does not interfere with antigliadin antibodies tests.Further studies are required to estimate more accurately the prevalence of this disease in rheumatologic patients.

Psoriasis in a nationwide cohort study of patients with celiac disease

Earlier studies on the association between celiac disease (CD) and psoriasis show contradictory results. The purpose of this study was to assess the risk of psoriasis in patients with biopsy-verified CD. Through 28 pathology departments in Sweden, we identified individuals with CD diagnosed between 1969 and 2008 (Marsh 3: villous atrophy; n = 28,958 unique individuals). We then used Cox regression to compare individuals with CD with 143,910 sex- and age-matched controls regarding their risk of psoriasis. CD was a risk factor for future psoriasis (hazard ratio (HR) = 1.72; 95% confidence interval (CI) = 1.54-1.92; during follow-up, 401 individuals with CD and 1,139 controls had a diagnosis of psoriasis). The absolute risk of future psoriasis in patients with CD was 135/100,000 person-years (excess risk = 57/100,000). In all, 42% of all psoriasis in patients with CD could be attributed to the underlying CD. Moreover, in children we saw a positive association between CD and psoriasis (HR = 2.05; 95% CI = 1.62-2.60). The association between CD and psoriasis seems to be independent of a temporal relationship, as we also found a positive association between CD and psoriasis before CD diagnosis (odds ratio = 1.91; 95% CI = 1.58-2.31). In conclusion, individuals with CD were at increased risk of psoriasis both before and after CD diagnosis.

Celiac disease-associated antibodies in patients with psoriasis and correlation with HLA Cw6

Etiopathology of psoriasis is not completely understood. Patients with psoriasis show elevated sensitivity to gluten. The aim of this study was to see the expression of celiac disease (CD)-associated antibodies gliadin IgA, gliadin IgG, and tissue transglutaminase IgA, and their correlation with HLA Cw6 in patients with psoriasis. The study comprised 56 patients with psoriasis and 60 healthy controls (HC). The levels of antibodies were detected by using ELISA technique and HLA Cw6 typing was carried out by microcytotoxicity method. HLA Cw6 was significantly expressed in psoriasis cases when compared with HC (P<0.05). CD-associated antibodies gliadin IgA/IgG and tissue transglutaminase IgA were significantly higher in the serum of patient with psoriasis when compared with HC (P<0.05, <0.05, and 0.01, respectively). Serum anti tissue transglutaminase IgA (anti tTG IgA) was significantly higher in females when compared with males and expressed more in elderly patients. There was a significant positive correlation among the antibodies (anti gliadin IgA with anti gliadin IgG: r=0.67, P<0.05; anti gliadin IgA with anti tTG IgA: r=0.45, P<0.05, anti gliadin IgG with anti tTG IgA: r=0.26, P<0.05, respectively), whereas insignificant with HLA Cw6. Our study concludes that latent CD or CD-associated antibodies were present in patients with psoriasis and also concludes that HLA Cw6 has no association with expression of these antibodies in patients with psoriasis.

Psoriasis, the liver, and the gastrointestinal tract

Psoriasis is a common chronic inflammatory, immune-mediated skin disease that is frequently associated with comorbidities including psoriatic arthropathy, chronic inflammatory bowel diseases, and cardio-metabolic disorders. In particular, nonalcoholic fatty liver disease affects about half of patients, Crohn's disease 0.5% and celiac disease 0.2-4.3% of patients with psoriasis. Some shared genetic traits as well as common inflammatory pathways may underlie these associations. The presence of comorbidities has important implications in the global approach to patients. In particular, traditional systemic antipsoriatic agents could negatively affect cardio-metabolic comorbidities as well as nonalcoholic fatty liver disease and may have important interactions with drugs commonly used by psoriasis patients. Moreover, patients with psoriasis should be encouraged to drastically correct their modifiable cardiovascular and liver risk factors, in particular obesity, alcohol consumption, and smoking habit, because this could positively affect both psoriasis and their life expectance.

The role of antibodies in inflammatory arthritis

Inflammatory arthritis presents in a variety of diseases, from rheumatoid arthritis to hepatitis. Antibodies to autoantigens or to microbial constituents are commonly associated with these conditions. In some cases, the antibodies have diagnostic and prognostic relevance. It cannot as yet be determined definitively that any of them mediate joint damage, although the evidence from animal models indicates that this mechanism is likely. The purpose of this article is to give an overview of the spectrum of antibodies found in a variety of inflammatory arthritides. The relevant animal models are also discussed.

Prevalence of antigliadin antibodies in patients with psoriasis is not elevated compared with controls

BACKGROUND

Antigliadin antibodies (AGAs) are markers of celiac sprue but may have autoimmune implications in the absence of gastrointestinal disease. There is anecdotal evidence to suggest that gluten sensitivity may play a role in psoriasis, and patients with psoriasis in Europe have been reported to improve on a gluten-free diet.

OBJECTIVE

To assess whether patients with psoriasis in the US have an increased prevalence of elevated AGAs.

METHOD

A US sample of patients with psoriasis (n=100), patients with psoriasis and psoriatic arthritis (n=100), and age-matched control individuals without any personal or family history of autoimmune disorders (n=100) were tested for IgG and IgA AGAs.

RESULTS

No difference in the prevalence of abnormal AGAs among patients with psoriasis (14%), combined psoriasis and psoriatic arthritis (18%), and control individuals (19%) was observed. No significant correlations between AGA positivity and psoriasis severity, joint involvement, or age of onset of psoriasis or arthritis were observed.

CONCLUSION

We found no support for the results of prior studies showing that elevated AGAs occur with increased frequency in patients with psoriasis. Furthermore, the relatively high prevalence of abnormal AGAs in our control population suggests these antibodies may not be associated with autoimmune disease.

Palmoplantar pustulosis and gluten sensitivity: a study of serum antibodies against gliadin and tissue transglutaminase, the duodenal mucosa and effects of gluten-free diet

BACKGROUND

Palmoplantar pustulosis (PPP) is a chronic inflammatory disease affecting mainly smoking women. Some patients also have psoriasis. A subgroup of patients with psoriasis has been shown to have silent gluten sensitivity with relevance for their psoriasis. Nothing is known about gluten sensitivity in PPP.

OBJECTIVES

To find out whether any patients with PPP are gluten-sensitive and whether this might be relevant for the PPP activity.

PATIENTS AND METHODS

One hundred and twenty-three patients (113 women) with PPP participated. Screening for IgA antibodies against gliadin and tissue transglutaminase (tTG) was performed, the duodenal mucosa in patients with and without these antibodies was studied and the effect of a gluten-free diet (GFD) was followed up.

RESULTS

Twenty-two patients (18%) had IgA antibodies against gliadin and nine of 94 (10%) against tTG. Twelve patients with antibodies and 11 without underwent gastro-duodenoscopy. Four displayed villous atrophy, whereas all other specimens were judged as essentially normal at routine staining. However, with immunohistochemistry, the numbers of CD3+ and CD8+ lymphocytes in the epithelium were found to be increased in patients with any type of antibody, although they were most numerous in those with both types of antibodies. Seven of 123 patients (6%) had coeliac disease (three previously diagnosed). Patients with antibodies who adhered to the GFD displayed total or nearly total clearance of the skin lesions and normalization of the antibody levels.

CONCLUSIONS

Patients with PPP should be screened for antibodies against gliadin and tTG. Those with antibodies can be much improved on a GFD regardless of the degree of mucosal abnormalities.

Deamidated Gliadin Peptides as Targets for Celiac Disease‐Specific Antibodies

Celiac disease (CD) is an (auto)immunologically mediated intestinal intolerance against proteins from wheat (gluten) and related cereal proteins. Tissue transglutaminase (tTG) has been identified as the autoantigen in CD. Although ultimate diagnosis is based on histological analysis of small intestinal mucosa obtained via tissue biopsy, assessment of autoantibodies can provide substantial help in the evaluation of CD. Gliadin antibodies are directed against the native disease-provoking cereal proteins. Despite their initial usefulness, these antibodies have lost diagnostic importance due to their poor specificity and sensitivity as CD markers. Recently, it was found, however, that gliadin antibodies from sera of patients with active CD preferentially recognized deamidated gliadin peptides. The use of deamidated gliadin peptides in immunoassays has significantly improved the usefulness of gliadin antibodies in diagnosis of CD to that observed with autoantibody assay methods (endomysium antibodies, antibodies against tTG). The antibody epitopes (B-cell epitopes) reflect substrate specificity of tTG and resemble peptide sequences known to be strongly T-cell stimulatory (T-cell epitopes) in CD. The assay applying deamidated gliadin peptides measures a new species of antibodies, which is different from conventional gliadin antibodies as well as from autoantibodies and will likely provide new information on pathophysiological mechanisms of CD.

Malabsorption in psoriatic patients: cause or consequence?

OBJECTIVE

The etiopathogenesis of psoriasis is still unclear. Associations between gut and skin diseases are well known, since psoriatic patients show a high prevalence of coeliac disease. Small-bowel abnormalities can cause clinical or, more frequently, laboratory alterations that give rise to malabsorption. The aim of the study was to evaluate the prevalence of malabsorption in psoriatic patients.

MATERIAL AND METHODS

Fifty-five (29 M, 26 F, mean age 51+/-8 years) psoriatic patients in the Dermatology Centre of our hospital and 65 healthy controls (36 M, 29 F, mean age 47+/-9 years) were screened for malabsorption using a D-xylose test. Psoriatic subjects who resulted positive were further investigated in order to reach a better characterization of the malabsorption using serum antigliadin, anti-endomysium and anti-transglutaminase antibodies, H2 lactulose breath test, the parasitological faecal test and colonoscopy with retrograde ileoscopy.

RESULTS

Altered D-xylose absorption was found in 60% (33/55) of psoriatic patients and in 3% (2/65) of controls. Of the former, 6% had coeliac disease, 21% had bacterial overgrowth, 3% had parasitic infections and 1 patient presented eosinophilic gastroenteritis.

CONCLUSIONS

Malabsorption was more prevalent among psoriatic patients than among controls. Coeliac disease, bacterial overgrowth, parasitic infestations and eosinophilic gastroenteritis could be possible causes of malabsorption in these patients. Further studies are needed to clarify the pathogenesis and possible causative associations between gut and skin diseases.

Longitudinal follow-up examination of antigliadin antibody positive children and adults

BACKGROUND

We previously investigated the prevalence of asymptomatic celiac disease in 3004 healthy children and 4313 adult blood donors by screening for IgA and IgG class antigliadin antibodies (AGA) and IgA class anti-endomysial antibodies (EmA). In none of the 162 exclusive AGA-positive adults and in only one of the 117 exclusive AGA-positive children could celiac disease be diagnosed. We followed up AGA-positive individuals in respect of the significance of the AGA.

METHODS

All AGA-positive children and adults were invited for a follow-up clinical examination and laboratory investigations including AGA-IgA, AGA-IgG and EmA. Celiac disease-specific antibodies were also determined in stool samples.

RESULTS

Sixty-nine adults and 47 children returned for follow-up. In 26 (37.7%) cases of the 69 adults formerly tested AGA-positive, AGA were still detectable after an average period of 3.7 years. In 21 (44.7%) cases of 47 formerly AGA-positive children, AGA were still detectable after an average period of 4.3 years. None of the 69 adults and 47 children showed seroconversion to EmA. There were no significant abnormalities in the laboratory results or any clinical signs of enteropathy. The appearance of fecal and serum antibodies was compared in 112 subjects but no correlation between fecal and serum antigliadin antibodies was found.

CONCLUSIONS

In both studied populations of adults and children, AGA disappeared in more than 50% of the cases. The appearance of AGA has to be interpreted as a non-specific immunomodulation phenomenon, confirming the low specificity of AGA as a serologic marker for celiac disease.

Psoriasis phenotype at disease onset: clinical characterization of 400 adult cases

Psoriasis is clinically a heterogeneous disease. Detailed evaluation of phenotype at disease onset is lacking. This study is a baseline characterization of 400 adult individuals with first time incidence of psoriasis on non-hairy skin, describing clinical phenotypes and putative environmental triggers at disease onset. In total, 74 patients with guttate and 326 patients with non-guttate phenotype, the majority with plaque psoriasis, were included. Guttate phenotype was associated with younger age and recent infection in 84%, where acute streptococcal pharyngitis was verified in 63%. The predominating factor associated with onset of plaque psoriasis was a recent life crisis (46%). A positive family history for psoriasis was approximately the same in both groups. Psoriasis arthropathy was diagnosed in 5% of guttate and 15% of non-guttate patients, with enthesopathy being the dominant symptom among guttate patients. This study confirms the strong link between onset of guttate psoriasis phenotype and streptococcal throat infection, whereas onset of plaque psoriasis was highly associated with a preceding distinct stressful life event. Longitudinal follow-up of the patients will provide robust information about disease development and response to treatment.

Coeliac disease-associated antibodies correlate with psoriasis activity

BACKGROUND

Antigliadin antibodies (AGA) have been reported in patients with psoriasis.

OBJECTIVES

To determine if AGA and other coeliac disease (CD)-associated antibodies correlate with clinical features and activity in patients with psoriasis.

METHODS

Patients with psoriasis (n = 130) were investigated for serum IgG and IgA AGA, IgA antitransglutaminase antibody and IgA antiendomysial antibody. Disease characteristics and associated bowel and joint symptoms were determined. All patients were invited to undertake endoscopy with duodenal biopsy.

RESULTS

A significantly higher proportion of patients with elevated CD-associated antibody levels was currently on or had previously required systemic immunosuppressants (methotrexate, ciclosporin or etretinate; P = 0.04) or psoralen plus ultraviolet A phototherapy (P = 0.03). One case of CD was diagnosed.

CONCLUSIONS

The presence of CD-associated antibodies in psoriasis patients correlates with greater disease activity.

Assessment of autoimmune responses associated with asbestos exposure in Libby, Montana, USA

Systemic autoimmune responses are associated with certain environmental exposures, including crystalline particles such as silica. Positive antinuclear antibody (ANA) tests have been reported in small cohorts exposed to asbestos, but many questions remain regarding the prevalence, pattern, and significance of autoantibodies associated with asbestos exposures. The population in Libby, Montana, provides a unique opportunity for such a study because of both occupational and environmental exposures that have occurred as a result of the mining of asbestos-contaminated vermiculite near the community. As part of a multifaceted assessment of the impact of asbestos exposures on this population, this study explored the possibility of exacerbated autoimmune responses. Age- and sex-matched sets of 50 serum samples from Libby and Missoula, Montana (unexposed), were tested for ANA on HEp-2 cells using indirect immunofluorescence. Data included frequency of positive tests, ANA titers, staining patterns, and scored fluorescence intensity, all against known controls. Serum immunoglobulin A (IgA), rheumatoid factor, and antibodies to extractable nuclear antigen (ENA) were also tested. The Libby samples showed significantly higher frequency of positive ANA and ENA tests, increased mean fluorescence intensity and titers of the ANAs, and higher serum IgA, compared with Missoula samples. In the Libby samples, positive correlations were found between ANA titers and both lung disease severity and extent of exposure. The results support the hypothesis that asbestos exposure is associated with autoimmune responses and suggests that a relationship exists between those responses and asbestos-related disease processes.

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.

The prevalence of coeliac disease in rheumatoid arthritis

OBJECTIVE

To determine the prevalence of coeliac disease in rheumatoid arthritis.

METHODS

One hundred and sixty patients with seropositive rheumatoid arthritis were tested for the endomysial antibody. Those found positive were studied further with endoscopic small bowel biopsy.

RESULTS

Only one patient was found to have coeliac disease, and that had already been diagnosed. Thus the prevalence of previously undiagnosed coeliac disease in rheumatoid arthritis is 0 (95% CI 0-0.24%) and the overall prevalence of coeliac disease is 0.63% (95% CI 0.1-3.5%). These prevalences are not significantly different from the reported prevalences of coeliac disease in the general population.

CONCLUSIONS

This study does not support an association between coeliac disease and seropositive rheumatoid arthritis or the screening of such patients for coeliac disease.

Current concepts in psoriatic arthritis

This review summarizes articles written about psoriatic arthritis in the past year. It concentrates on clinical and epidemiologic issues, pathogenesis and treatment, and updates the reader regarding new concepts in psoriatic arthritis.

Human immunoglobulin A (IgA)-specific ligands from combinatorial engineering of protein A

Affinity reagents capable of selective recognition of the different human immunoglobulin isotypes are important detection and purification tools in biotechnology. Here we describe the development and characterization of affinity proteins (affibodies) showing selective binding to human IgA. From protein libraries constructed by combinatorial mutagenesis of a 58-amino-acid, three-helix bundle domain derived from the IgG-binding staphylococcal protein A, variants showing IgA binding were selected by using phage display technology and IgA monoclonal antibodies (myeloma) as target molecules. Characterization of selected clones by biosensor technology showed that five out of eight investigated affibody variants were capable of IgA binding, with dissociation constants (K(d)) in the range between 0.5 and 3 microm. One variant (Z(IgA1)) showing the strongest binding affinity was further analyzed, and showed that human IgA subclasses (IgA(1) and IgA(2)) as well as secretory IgA were recognized with similar efficiencies. No detectable cross-reactivity towards human IgG, IgM, IgD or IgE was observed. The potential use of the Z(IgA1) affibody as a ligand in affinity chromatography applications was first demonstrated by selective recovery of IgA protein from a spiked Escherichia coli total cell lysate, using an affinity column containing a divalent head-to-tail Z(IgA1) affibody dimer construct as a ligand. In addition, efficient affinity recovery of IgA from unconditioned human plasma was also demonstrated.