Targeted serum proteome profiling reveals nicotinamide adenine dinucleotide phosphate (NADPH)-related biomarkers to discriminate linear IgA bullous disorder from dermatitis herpetiformis.

Linear IgA bullous dermatosis (LABD) and dermatitis herpetiformis (DH) represent the major subtypes of IgA mediated autoimmune bullous disorders. We sought to understand the disease etiology by using serum proteomics. We assessed 92 organ damage biomarkers in LABD, DH, and healthy controls using the Olink high-throughput proteomics. The positive proteomic serum biomarkers were used to correlate with clinical features and HLA type. Targeted proteomic analysis of IgA deposition bullous disorders vs. controls showed elevated biomarkers. Further clustering and enrichment analyses identified distinct clusters between LABD and DH, highlighting the involvement of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Comparative analysis revealed biomarkers with distinction between LABD and DH and validated in the skin lesion. Finally, qualitative correlation analysis with DEPs suggested six biomarkers (NBN, NCF2, CAPG, FES, BID, and PXN) have better prognosis in DH patients. These findings provide potential biomarkers to differentiate the disease subtype of IgA deposition bullous disease.

[Stiff person syndrome associated with dermatitis herpetiformis: a case report]. / Syndrome de la personne raide associé à une dermatite herpétiforme: à propos d'un cas.

Stiff person syndrome (SPS) is a rare disease affecting the central nervous system which can be autoimmune, paraneoplastic or idiopathic in origin. Its typical classic presentation is characterized by progressive stiffness of the trunk and limbs, associated with spasms. The diagnosis is supported by the existence of continuous and spontaneous muscle activity on electroneuromyogram detection, the presence of serum anti-GAD antibodies, and a response to benzodiazepines. We report the case of a 46-year-old patient with a classic form of autoimmune stiff person syndrome associated with dermatitis herpetiformis.

T Cell Response Toward Tissue-and Epidermal-Transglutaminases in Coeliac Disease Patients Developing Dermatitis Herpetiformis.

The reason why only few coeliac patients develop the cutaneous manifestation of the disease, named dermatitis herpetiformis (DH), is still unknown. Epidermal transglutaminase (TG3) has been described as the main autoantigen of humoral immunity in DH but the mechanisms leading to this autoimmune response remain obscure. Here we characterized T cells from skin, gut and peripheral blood of DH and coeliac disease (CD) patients, evaluated the impact of the gluten-free diet on circulating T lymphocytes' phenotype and investigated antigen specific T cell response toward epidermal and tissue transglutaminase (TG2). DH patients showed an increased frequency of skin-derived T cells producing TNFα when compared to CD patients. Moreover, circulating T cells producing TNFα and IL-17A positively correlated with clinical score of skin disease activity and decreased after gluten-free diet. Finally, TG2 and TG3-specific T cells resulted more reactive to antigens stimulation in DH patients and showed cross reactivity toward the two autoantigens in both the group of patients. Our data suggest a role of TNFα and IL-17A producing cells in the development of DH and, for the first time, show the existence of a crossed T cell response toward the two transglutaminases isoforms, thus suggesting new insights on T cells role in skin damage.

Dermatitis Herpetiformis: An Update on Diagnosis and Management.

Dermatitis herpetiformis (DH), presenting with an intense itch and blistering symmetrical rash, typically on the elbows, knees, and buttocks, is a cutaneous manifestation of celiac disease. Though overt gastrointestinal symptoms are rare, three-fourths of patients with DH have villous atrophy in the small bowel, and the rest have celiac-type inflammatory changes. DH affects mostly adults and slightly more males than females. The mean age at onset is about 50 years. DH diagnosis is confirmed by showing granular immunoglobulin A deposits in the papillary dermis. The DH autoantigen, transglutaminase 3, is deposited at the same site in tightly bound immune complexes. At present, the DH-to-celiac disease prevalence is 1:8. The incidence of DH is decreasing, whereas that of celiac disease is increasing, probably because of improved diagnostics. In DH, the treatment of choice for all patients is a gluten-free diet (GFD) in which uncontaminated oats are allowed. At onset, most patients need additional dapsone to rapidly control the rash and itching. Dapsone can be stopped after a mean of 2 years, and a strict lifelong GFD alone is required. Dietary adherence offers an excellent long-term prognosis for patients with DH, with a normal quality of life and all-cause mortality.

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.

TG6 Auto-Antibodies in Dermatitis Herpetiformis.

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of gluten sensitivity, in which an autoimmune response is directed against transglutaminase 3 (TG3), an epidermal transglutaminase. TG2 is the autoantigen in celiac disease (CD), defined by the presence of enteropathy, and TG6 is the autoantigen in neurological manifestations of gluten sensitivity. The interplay between B cell responses to these 3 transglutaminases in developing the clinical spectrum of disease manifestations is not completely understood. Also, the individual or combined diagnostic and predictive value of the respective autoantibodies is not fully explored. We examined the prevalence of TG6 antibodies in a cohort of patients with DH. TG6 positivity was found in 13/33 (39%), with IgA detected in 11 patients, IgG in 3, and both in 1. This was significantly higher compared to what is seen in the classic CD cases (14%) in a Finnish population. TG6 positive baseline samples constituted 60% of DH patients with no enteropathy (n = 10), as opposed to 17% positivity in those with overt enteropathy (n = 12; Marsh IIIB). Repeat testing after adherence to a gluten-free diet for 1 year showed reduced titers for TG6 antibodies in 11/13 (85%), whereby 7 patients were now TG6 antibody-negative. Four patients seroconverted and tested positive for TG6 antibodies at one year, due to the ongoing exposure to gluten. We report another patient who presented with neurological manifestations (encephalopathy) leading to the diagnosis of CD, who was intermittently adhering to a gluten-free diet. Serological testing at baseline showed him to be positive for antibodies to all 3 transglutaminases. Eleven years later, he developed DH. He also subsequently developed ataxia and peripheral neuropathy. Although TG3 and TG6 autoantibodies are linked to certain disease manifestations, TG2, TG3, and TG6 autoantibodies can be present across the spectrum of GRD patients and might develop years before onset of symptoms of extraintestinal manifestations. This is consistent with gluten-dependent adaptive immunity being a necessary but not sufficient pretext to organ-specific damage. TG6 antibodies appear to develop more frequently in patients where tolerance to gluten was broken but, either there was no development of the molecular state driving the tissue destruction at the level of the gut, or perhaps more likely, there was more resistance to developing this phenotype.

Intestinal TG3- and TG2-Specific Plasma Cell Responses in Dermatitis Herpetiformis Patients Undergoing a Gluten Challenge.

Dermatitis herpetiformis (DH), a cutaneous manifestation of coeliac disease, is characterized by transglutaminase (TG) 3-targeted dermal immunoglobulin A (IgA) deposits. The treatment for DH is the same as for coeliac disease, namely a life-long gluten-free diet. DH patients typically have gluten-dependent circulating autoantibodies targeting TG3 and TG2, and plasma cells secreting such autoantibodies have been detected in the small intestinal mucosa. This study investigates the gluten-responsiveness of intestinal TG3 and TG2 antibody-secreting plasma cells in 16 treated DH patients undergoing a gluten challenge. The frequency of both plasma cell populations increased significantly during the challenge, and their frequency correlated with the corresponding serum autoantibody levels at post-challenge. TG3-specific plasma cells were absent in all 18 untreated coeliac disease patients and seven non-coeliac control subjects on gluten-containing diets. These findings indicate that, in DH, both intestinal TG3- and TG2-antibody secreting plasma cells are gluten-dependent, and that TG3-antibody secreting plasma cells are DH-specific.

Current Concepts of Dermatitis Herpetiformis.

Dermatitis herpetiformis (DH) is an autoimmune skin disease that causes itchy, blistering rash, typically on the elbows, knees and buttocks. DH and coeliac disease share the same genetic background, gluten-dependent enteropathy and antibody response against tissue transglutaminase. DH is currently considered a cutaneous manifestation of coeliac disease, and the prevailing hypothesis is that DH develops as a late manifestation of subclinical coeliac disease. The incidence of DH is decreasing contemporarily with the increasing incidence of coeliac disease. The IgA immune response in DH skin is directed against epidermal transglutaminase, while the autoantigen in the gut is tissue transglutaminase. Granular IgA deposition in the papillary dermis is pathognomonic for DH, and is a finding used to confirm the diagnosis. The treatment of choice for DH is a life-long gluten-free diet, which resolves the rash and enteropathy, increases quality of life, and offers a good long-term prognosis.

Dermatitis Herpetiformis: Novel Perspectives.

Dermatitis herpetiformis (DH) is an inflammatory disease of the skin, considered the specific cutaneous manifestation of celiac disease (CD). Both DH and CD occur in gluten-sensitive individuals, share the same Human Leukocyte Antigen (HLA) haplotypes (DQ2 and DQ8), and improve following the administration of a gluten-free diet. Moreover, almost all DH patients show typical CD alterations at the small bowel biopsy, ranging from villous atrophy to augmented presence of intraepithelial lymphocytes, as well as the generation of circulating autoantibodies against tissue transglutaminase (tTG). Clinically, DH presents with polymorphic lesions, including papules, vesicles, and small blisters, symmetrically distributed in typical anatomical sites including the extensor aspects of the limbs, the elbows, the sacral regions, and the buttocks. Intense pruritus is almost the rule. However, many atypical presentations of DH have also been reported. Moreover, recent evidence suggested that DH is changing. Firstly, some studies reported a reduced incidence of DH, probably due to early recognition of CD, so that there is not enough time for DH to develop. Moreover, data from Japanese literature highlighted the absence of intestinal involvement as well as of the typical serological markers of CD (i.e., anti-tTG antibodies) in Japanese patients with DH. Similar cases may also occur in Caucasian patients, complicating DH diagnosis. The latter relies on the combination of clinical, histopathologic, and immunopathologic findings. Detecting granular IgA deposits at the dermal-epidermal junction by direct immunofluorescence (DIF) from perilesional skin represents the most specific diagnostic tool. Further, assessing serum titers of autoantibodies against epidermal transglutaminase (eTG), the supposed autoantigen of DH, may also serve as a clue for the diagnosis. However, a study from our group has recently demonstrated that granular IgA deposits may also occur in celiac patients with non-DH inflammatory skin diseases, raising questions about the effective role of eTG IgA autoantibodies in DH and suggesting the need of revising diagnostic criteria, conceivably emphasizing clinical aspects of the disease along with DIF. DH usually responds to the gluten-free diet. Topical clobetasol ointment or dapsone may be also applied to favor rapid disease control. Our review will focus on novel pathogenic insights, controversies, and management aspects of DH.

Fibrillar-type dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is a pruritic papulovesicular disease that is relatively common in Caucasian populations, and was first reported by Louis Duhring. It is characterized by granular IgA deposition in the dermal-epidermal junction and gluten-sensitive enteropathy (GSE) associated with human leukocyte antigen-DQ2/DQ8 haplotype. In contrast, DH is rare in Japan, and Japanese DH patients occasionally show unique features, including a high frequency of fibrillar IgA deposition in the papillary dermis, and rare occurrence of GSE. We refer to this condition in Japanese patients as "fibrillar-type DH", while the DH that is typically observed in the Caucasian population is referred to as "granular-type DH". In patients with typical fibrillar-type DH, IgA antibodies to epidermal transglutaminase are the only antibodies detected. In addition, Th2-type cytokines, such as interleukin (IL)-4, IL-5 and IL-13, may be important in the development of skin lesions in fibrillar-type DH (especially in the infiltration of tissue by eosinophils), as in granular-type DH. The pathogenesis of fibrillar-type DH may differ from that of granular-type DH, which is dependent on gluten and in which IgA antibodies to tissue transglutaminase (the main antigen in GSE) are detected. We herein review the clinical, histological, and immunological findings of fibrillar-type DH.

Treatment Update of Autoimmune Blistering Diseases.

The treatment of refractory autoimmune blistering diseases (AIBDs) has always been a challenge. Because randomized controlled trials are lacking, treatment has been based on analysis of anecdotal data. The last 2 decades has seen the use of rituximab become a conventional treatment in the therapeutic armamentarium of AIBDs, leading to its Food and Drug Administration indication for pemphigus vulgaris in 2018. We review the current updated data on the use of rituximab including dosing, protocols, and its role in the algorithm of AIBDs. In addition, we discuss several promising novel emerging therapeutic agents for AIBDs.

DNA damage in human skin fibroblasts from patients with dermatitis herpetiformis.

Dermatitis herpetiformis (DH) and celiac disease (CD) are considered to be autoimmune diseases that share a specific trigger (gluten) and a common genetic background (HLA-DQ2/DQ8). However, the pathogenesis of DH is not yet fully understood and no data are available regarding a possible role of fibroblasts in this disease. The aim of this study was to assess baseline DNA damage in fibroblasts in DH-diagnosed patients vs. fibroblasts of controls without DH or CD. Primary fibroblast cultures were derived from dermal biopsies from DH patients and controls (without DH or CD). In vitro genotoxic damage was investigated using the comet assay and ɣH2AX test after different treatments (with 33mer peptide and digested gliadin [DG]) in order to investigate a correlation between oxidative stress (evaluated by reactive oxygen species formation) and glutathione content. Our results demonstrate a difference in baseline DNA damage between cutaneous fibroblasts of controls and DH patients, moreover, DNA damage significantly increased after exposure to gluten (DG and 33mer peptide) in fibroblasts from DH patients. DNA damage in fibroblasts from patients under dapsone treatment was similar to that of the control group. Our data indicate that oxidative stress and DNA damage may be characteristics of fibroblasts from DH patients who are not treated with dapsone, particularly after exposure to gliadin peptides.

[Dermatitis herpetiformis]. / Dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is a genetically determined, gluten sensitive autoimmune bullous dermatosis related to celiac disease in which granular, insoluble aggregates in the papillary dermis of epidermal transglutaminase (TG3), immunoglobulin A (IgA), and fibrinogen are present. Detection of the dermal IgA-TG3 immune complex is the gold standard of diagnosis. DH develops in a subpopulation of patients with gluten sensitive enteropathy, characterized by itching, erythematous, excoriated papules showing characteristic distribution over the knees, elbows and buttocks; vesicles are rarely seen. The primary therapy of DH is a strict, lifelong gluten-free diet, and it may be necessary to temporarily give dapsone in case of severe symptoms.

Clinical, pathologic, and immunologic features of pemphigus herpetiformis: a literature review and proposed diagnostic criteria.

Pemphigus herpetiformis (PH), a rare type of pemphigus, is characterized by immunologic findings consistent with pemphigus but with a unique clinical and pathologic presentation. PH was first described as resembling dermatitis herpetiformis clinically, but because of its variable presentation, it can also resemble linear immunoglobulin A bullous dermatosis and bullous pemphigoid. We reviewed reported cases to analyze the most frequent clinical, pathologic, and immunologic characteristics and to propose corresponding diagnostic criteria. Through a comprehensive review of Medline and PubMed databases, 96 publications and 158 cases were identified. After reviewing the reported characteristics of PH, we suggest the following diagnostic criteria: Clinical: 1) pruritic herpetiform intact blisters with/without erosions; and/or 2) pruritic annular or urticarial erythematous plaques with/without erosions; Pathologic: 1) intraepidermal eosinophils or neutrophils, or both; and/or 2) intraepidermal split with/without acantholysis; Immunologic: 1) direct immunofluorescence showing immunoglobulin G with/without C3 intercellular deposits; and/or 2) indirect immunofluorescence showing immunoglobulin G to epithelial cell surface; and/or 3) detection of serum autoantibodies against desmogleins (1,3) or desmocollins (1,2,3), or both. Diagnosis requires one clinical, one pathologic, and one immunologic feature. We also report three new cases diagnosed at our institution to demonstrate the applicability of the suggested criteria.