Autoantibodies Against the Immunodominant Bullous Pemphigoid Epitopes Are Rare in Patients With Dermatitis Herpetiformis and Coeliac Disease.

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of coeliac disease (CD). Patients with DH have an elevated risk of development of another autoimmune blistering skin disease, bullous pemphigoid (BP). In this study we investigated whether patients with DH and CD (mean age for both 49 years) have circulating autoantibodies against BP180, the major BP autoantigen. ELISA tests showed that only a few DH (3/46) and CD (2/43) patients had BP180-NC16A IgG autoantibodies. Immunoblotting found that more than half of the DH samples contained IgG autoantibodies against full-length BP180. Epitope mapping with 13 fusion proteins covering the BP180 polypeptide revealed that in DH and CD patients, IgG autoantibodies did not target the NC16A or other epitopes typical of BP but recognized other intracellular and mid-extracellular regions of BP180. None of the analyzed DH and CD patients with either ELISA or immunoblotting positivity had IgG or IgA reactivity against the cutaneous basement membrane in indirect immunofluorescence analysis or skin symptoms characteristic of BP. Although only a minority of middle-aged DH patients had IgG autoantibodies against the immunodominant epitopes of BP180, our results do not exclude the possibility that intermolecular epitope spreading could explain the switch from DH to BP in elderly patients.

Mast cells and thymic stromal lymphopoietin (TSLP) expression positively correlates with pruritus intensity in dermatitis herpetiformis.

BACKGROUND: Pruritus is one of the leading symptoms of dermatitis herpetiformis (DH), however, studies on the pathogenesis of pruritus are scarce. Currently, skin mast cells (MCs) have been indicated to play a role in pruritus in autoimmune bullous disease. OBJECTIVE: To study the role of mast cells and related mediators involved in the pathogenesis of pruritus in DH. MATERIALS & METHODS: The number of MCs and expression of histamine and thymic stromal lymphopoietin (TSLP) was investigated in lesions of 29 DH cases and 15 healthy skin donors by immunohistochemistry. Fourteen patients were assessed for severity of pruritus based on the Numeric Rating Scale and Pruritus Grading System. The levels of histamine and TSLP in the serum of 18 DH patients and 15 healthy controls were also investigated. RESULTS: A significant increase in the number of MCs and degranulation was observed in DH lesions, which positively correlated with intensity of pruritus. In addition, skin TSLP but not histamine was shown to correlate with intensity of pruritus. No significant difference in expression of serum TSLP or histamine was observed between DH patients and healthy controls. CONCLUSION: These results suggest that skin MCs and TSLP might be involved in the pathogenesis of pruritus in DH which should be further clarified in future studies.

Celiac-Related Autoantibodies and IL-17A in Bulgarian Patients with Dermatitis Herpetiformis: A Cross-Sectional Study.

Background and objectives: Dermatitis herpetiformis (DH) is a blistering dermatosis, which shares common immunologic features with celiac disease (CD). The aim of the present study was to explore the performance of a panel of CD-related antibodies and IL-17A in Bulgarian patients with DH. Materials and Methods: Serum samples from 26 DH patients at mean age 53 ± 15 years and 20 healthy controls were assessed for anti-tissue transglutaminase (anti-tTG), anti-deamidated gliadin peptides (anti-DGP), anti-actin antibodies (AAA), and IL-17A by enzyme linked immuno-sorbent assay (ELISA), as well as anti-tTG, anti-gliadin (AGA), and anti-Saccharomyces cerevisiae antibodies (ASCA) using immunoblot. Results: The average serum levels of anti-tTG, anti-DGP, AGA, AAA, and the cytokine IL-17A were at significantly higher levels in patients with DH compared to the average levels in healthy persons which stayed below the cut-off value (p < 0.05). Anti-DGP and anti-tTG antibodies showed the highest diagnostic sensitivity and specificity, as well as acceptable positive and negative predictive value. None of the healthy individuals was found positive for the tested antibodies, as well as for ASCA within the DH group. All tests showed good to excellent correlations (r = 0.5 ÷ 0.9, p < 0.01). Conclusions: Although the diagnosis of DH relies on skin biopsy for histology and DIF, serologic testing of a panel of celiac-related antibodies could be employed with advantages in the diagnosing process of DH patients. Furthermore, DH patients who are positive for the investigated serologic parameters could have routine monitoring for gastrointestinal complications typical for the gluten-sensitive enteropathy.

Ex vivo Culture of Duodenal Biopsies from Patients with Dermatitis Herpetiformis Indicates that Transglutaminase 3 Antibody Production Occurs in the Gut.

Coeliac disease and dermatitis herpetiformis (DH) are characterized by autoantibodies targeting transglutaminase (TG)2 and TG3, respectively. Previous studies show that TG2 antibodies are produced in the gut and can be assessed in organ culture of small-intestinal biopsies from patients with coeliac disease. Thus far, no studies have investigated TG3 antibodies in organ culture of biopsies from patients with DH, or exploited the method in DH. The aim of this study was to investigate TG3 and TG2 antibody responses in serum and small-intestinal biopsies from patients with DH with active disease, and from those in remission. The majority of patients with DH were negative for both serum and organ culture medium TG2-targeting antibodies. Surprisingly, patients with active DH secreted TG3 antibodies into the culture medium despite seronegativity. In patients secreting high levels of TG3 antibodies into the culture medium, we also detected TG3-antibody-positive cells in the small-intestinal mucosa. These findings suggest that TG3 antibodies can be investigated in the organ culture system and that their secretion occurs in the small intestine, especially in active DH.

The Role of Intereukin-31 in Pathogenesis of Itch and Its Intensity in a Course of Bullous Pemphigoid and Dermatitis Herpetiformis.

Itch which is one of the major, subjective symptoms in a course of bullous pemphigoid and dermatitis herpetiformis makes those two diseases totally different than other autoimmune blistering diseases. Its pathogenesis is still not fully known. The aim of this research was to assess the role of IL-31 in development of itch as well as to measure its intensity. Obtained results, as well as literature data, show that lower concentration of IL-31 in patients' serum may be correlated with its role in JAK/STAT signaling pathway which is involved in development of autoimmune blistering disease. Intensity of itch is surprisingly huge problem for the patients and the obtained results are comparable with results presented by atopic patients.

The Decreasing Prevalence of Severe Villous Atrophy in Dermatitis Herpetiformis: A 45-Year Experience in 393 Patients.

GOALS: We analyzed from our prospectively collected series of patients with dermatitis herpetiformis (DH) whether small-bowel histologic findings are changing and how serum tissue transglutaminase (TG2) IgA antibodies correlate to mucosal damage. BACKGROUND: DH is an extraintestinal manifestation of celiac disease presenting with itchy blistering rash and pathognomonic IgA deposits in the skin. Prominent gastrointestinal symptoms are rare, and small-bowel findings range from severe villous atrophy (SVA) and partial villous atrophy (PVA) to normal mucosa with inflammatory changes. METHODS: The cohort included 393 patients (214 male and 179 female) with DH having small-bowel biopsies performed at Tampere University Hospital since 1970. The small-bowel findings were calculated in the three 15-year periods, and in the last period they were correlated with serum IgA class TG2 antibody levels measured by enzyme-linked immunosorbent assay. RESULTS: The prevalence of SVA decreased significantly (P=0.032), from 42% in the first study period to 29% in the last study period. A concomitant increase was seen in PVA, from 33% to 41%, and normal villous architecture, from 25% to 30%. The patients with SVA (P<0.001) and PVA (P=0.046) had significantly higher TG2 antibody levels than those with normal villous architecture. CONCLUSIONS: This long-term study in patients with DH disclosed a significant decrease in the occurrence of SVA. Serum IgA TG2 antibody levels correlated to damage in the small bowel. The trend toward milder small-bowel histology in DH suggests that a similar pattern could occur in the pool of undiagnosed celiac disease from which DH develops.

Autoimmunity to heat shock proteins and vitamin D status in patients with celiac disease without associated dermatitis herpetiformis.

Inflammation-induced heat shock proteins (HSPs) and hypovitaminosis D have been reported to impact immune responses and to be associated with autoimmune diseases including celiac disease (CD), a gluten-sensitive enteropathy mediated by autoantibodies against tissue transglutaminase (TG2). Recently, we provided evidence for a role of autoantibodies to HSPs in patients with dermatitis herpetiformis (DH), an inflammatory skin disease induced by underlying latent CD. In this study, we aimed at investigating the humoral autoimmune response to HSPs and vitamin D status in CD patients (n=15) presenting without the cutaneous disease manifestation. In comparison with healthy controls (n=15), circulating autoantibodies against HSP40, HSP60, and HSP90 were increased in these patients, and these autoantibodies, including anti-HSP70, correlated with serum anti-TG2 autoantibodies. Deficient and insufficient vitamin D serum levels were found in 8 out of 15 CD patients and 11 out of 15 healthy controls, and the vitamin D status showed no relationship with levels of circulating anti-TG2 or anti-HSP autoantibodies in the patients. Our results preliminarily suggest a pronounced anti-HSP autoimmune response in CD that is linked to pathophysiological processes in the gut independently of both a potential concomitant disease-related extra-intestinal inflammatory manifestation in the skin and the vitamin D status. Future studies on larger groups of patients are needed to confirm the present data and to further clarify whether autoimmunity towards HSPs is primarily related to underlying CD or skin inflammation in DH patients.

Decreased fibrinolytic potential and morphological changes of fibrin structure in dermatitis herpetiformis.

BACKGROUND: Recently, high prevalence of cryofibrinogenaemia has been observed in plasma of untreated dermatitis herpetiformis (DH) patients, and the pathological IgA and TG3 deposits in the papillary dermis were found to co-localize with fibrin and fibrinogen. OBJECTIVE: To study the fibrinolytic potential in plasma of untreated, dapsone and or/gluten-free diet treated DH patients as well as the in vitro effect of dapsone on the fibrinolytic profile. METHOD: Plasma samples of 23 DH patients, 19 healthy subjects and 5 pemphigus vulgaris patients were investigated by a turbidimetric-clot lysis assay. Out of them 5 DH plasma samples representing different fibrinolytic parameters, and 3 healthy controls were selected for parallel fibrin clot preparation. The clot fibrin structure was examined by scanning electron microscopy (SEM), and the diameters of 900 fibrin fibres were determined in each clot. RESULTS: A significantly prolonged clot lysis time was detected in untreated DH patients. The turbidity values of DH plasma clots indicated an altered fibrin structure that was also confirmed by SEM: significantly thicker fibrin fibers were observed in untreated, TG3 antibody positive DH patients compared to healthy controls, whereas the fiber diameters of dapsone-treated patients were similar or thinner than the control values. In line with the structural changes of fibrin, the fibrinolytic profile of 5 DH patients under dapsone treatment approached the control values. CONCLUSION: This study revealed that the fibrinolytic potential was impaired in the plasma of untreated DH patients, whereas dapsone corrected the fibrinolytic defect. These data suggest a pathogenic role for plasma-derived factors in the development of skin symptoms and add a new aspect to the long-known beneficial, symptomatic effect of dapsone in active DH.

Serum transglutaminase 3 antibodies correlate with age at celiac disease diagnosis.

BACKGROUND: Transglutaminase (TG)2 is the autoantigen in celiac disease, but also TG3 antibodies have been detected in the serum of celiac disease patients. AIMS: To investigate the correlations between serum TG3 antibodies and clinical and histological manifestations of celiac disease and to assess gluten-dependency of TG3 antibodies. METHODS: Correlations between serum TG3 antibody levels measured from 119 adults and children with untreated coeliac disease and the demographic data, clinical symptoms, celiac antibodies, histological data and results of laboratory tests and bone mineral densities were tested. TG3 antibodies were reinvestigated in 97 celiac disease patients after 12 months on a gluten-free diet (GFD). RESULTS: TG3 antibody titers were shown to correlate with the age at celiac disease diagnosis. Further, negative correlation with TG3 antibodies and intestinal γδ+ cells at diagnosis and on GFD was detected. Correlations were not detected with the clinical manifestation of celiac disease, TG2 or endomysial autoantibodies, laboratory values, severity of mucosal villous atrophy, associated diseases or complications. TG3 antibody titers decreased on GFD in 56% of the TG3 antibody positive patients. CONCLUSION: Serum TG3 antibody positivity in celiac disease increases as the diagnostic age rises. TG3 antibodies did not show similar gluten-dependency as TG2 antibodies.

Celiac disease evolving into dermatitis herpetiformis in patients adhering to normal or gluten-free diet.

OBJECTIVE: Dermatitis herpetiformis (DH) is a cutaneous form of celiac disease affecting ∼ 17% of celiac disease patients. The aim was to determine how often celiac disease precedes the development of DH, and what is the impact of gluten-free diet (GFD) in this phenotype change. MATERIAL AND METHODS: Our prospectively collected DH series from 1970 comprised 514 patients. We analyzed all DH patients who at least 2 years earlier had been diagnosed with celiac disease. DH diagnosis was confirmed by showing immunoglobulin A deposits in dermis. Serological and small bowel mucosal findings were analyzed, and the strictness of GFD treatment before and after the diagnosis of DH was evaluated. RESULTS: Twenty (4%) DH patients had a prior diagnosis of celiac disease. The median time interval between celiac disease and DH detection was 9.5 years. Before DH appeared 4 patients had been on a normal gluten-containing diet, 10 had dietary lapses on a GFD, and 6 were on a strict GFD. Celiac autoantibodies were positive in 7 out of 19 patients, and 5 out of 7 undergoing small bowel biopsy had partial villous atrophy. Following DH diagnosis the rash was controlled after a median of 6 months on a strict GFD. CONCLUSIONS: Patients with celiac disease may develop DH by time. This is most often an indicator of poor adherence to GFD, and a rigorous dietary intervention is necessary. In the majority of cases, DH will be detected without prior celiac disease diagnosis, but the physicians should recognize this phenotype alteration.

Regulatory T cells as well as IL-10 are reduced in the skin of patients with dermatitis herpetiformis.

BACKGROUND: Dermatitis herpetiformis (DH) and celiac disease (CD) are considered as autoimmune diseases that share a defined trigger (gluten) and a common genetic background (HLA-DQ2/DQ8). However, the pathogenesis of DH is not fully understood and no data are available about the immune regulation in such a disease. OBJECTIVE: The aim of this study was to assess if alterations in the pattern of the immune response and, in particular, impairments of regulatory T (Tregs) cells may contribute to the phenotypic differences between DH and CD. METHODS: We investigated the presence of Tregs cell markers, in the skin, the duodenum and the blood of patients with DH by immunohistochemistry, confocal microscopy and flow cytometry. As controls, we included patients with bullous pemphigoid, patients with CD without skin lesions, as well as healthy subjects (HS). RESULTS: In the skin of DH patient, we found a significantly lower proportion of FOXP3(+) Tregs and IL-10(+) cells than in HS (p < 0.001 for both cell populations). In duodenal samples, no differences where found in the proportion of Tregs between patients with DH and patients with CD without skin manifestations. Finally, the frequency of CD25(bright)FOXP3(+) cells within the CD4(+) subset was significantly reduced in CD patients either with or without DH with respect to HS (p = 0.029 and p = 0.017, respectively). CONCLUSIONS: Our findings suggested that a reduction of Tregs may play a major role in the skin, leading to a defective suppressive function and thus to the development of the lesions. By contrast, no differences could be detected about Tregs between patients with DH and patients with CD in the duodenum, suggesting that the mechanisms of the intestinal damage are similar in both diseases.