Small-bowel changes in dermatitis herpetiformis

[Dermatitis herpetiformis. An update of the pathogenesis]

The multifactorial pathogenesis of dermatitis herpetiformis is reviewed in light of current experimental data. Genetic background, gluten consumption, and abnormal immune and autoimmune reactions are the most important pathogenetic factors, but other agents also participate in the disease development. The predisposing and inducing factors are summarized, while the pathophysiological steps leading to the development of skin symptoms are detailed.

A long‐term gluten‐free diet as an alternative treatment in severe forms of dermatitis herpetiformis

BACKGROUND

A long-term gluten-free diet (GFD) as a first-choice treatment for dermatitis herpetiformis (DH) has been used successfully. The aim of the present study is to evaluate the possibility of treating all severe skin manifestations of DH by a GFD only.

METHODS

Seventy-two patients with DH were subdivided in two groups: group A (18 patients) underwent a GFD and received dapsone; group B (54 patients) underwent a GFD. Patients were subdivided into slight, moderate and severe forms.

RESULTS

A total of 88.9% of patients treated with dapsone and a GFD (group A) had remission of skin manifestations and the remaining 11.1% were improved. In group B, 87% of patients showed complete remission of skin manifestations after 18 months of a GFD; 13% showed improvement. With regard to severe forms, after an 18-month treatment, 70.4% of patients in group B; 66.6% in group A.

CONCLUSION

Our study shows that a GFD, if administered steadily and for a long period, can be a valid treatment for severe forms of DH. Dapsone can be useful to control the inflammatory phase of the disease.

Celiac disease and myointimal proliferation: a possible correlation?

Celiac disease (CD) is an autoimmune disorder of the small bowel that occurs in genetically predisposed people of all ages, from middle infancy, and is caused by a reaction to gliadin, a gluten protein. Some patients are diagnosed with symptoms related to the decreased absorption of nutrients or with various symptoms which, although statistically linked, have no clear relationship with the malfunctioning bowel. Classic symptoms of CD include diarrhea, weight loss, and fatigue; bowel symptoms may be limited or even absent. In this article we describe the case of a young woman with CD who presents with myointimal proliferation. However multiple cases of vessel thrombosis have been reported in patients with CD. Despite the fact that no definitive relationship between these diseases could be explained, we think this association must be remembered especially in cases of young and tenuous women with these vascular abnormalities.

Autoantibodies in gluten ataxia recognize a novel neuronal transglutaminase

OBJECTIVE

Gluten sensitivity typically presents as celiac disease, a chronic, autoimmune-mediated, small-intestinal disorder. Neurological disorders occur with a frequency of up to 10% in these patients. However, neurological dysfunction can also be the sole presenting feature of gluten sensitivity. Development of autoimmunity directed toward different members of the transglutaminase gene family could offer an explanation for the diversity in manifestations of gluten sensitivity. We have identified a novel neuronal transglutaminase isozyme and investigated whether this enzyme is the target of the immune response in patients with neurological dysfunction.

METHODS

Using recombinant human transglutaminases, we developed enzyme-linked immunosorbent assays and inhibition assays to analyze serum samples of patients with gluten-sensitive gastrointestinal and neurological disorders, and various control groups including unrelated inherited or immune conditions for the presence and specificity of autoantibodies.

RESULTS

Whereas the development of anti-transglutaminase 2 IgA is linked with gastrointestinal disease, an anti-transglutaminase 6 IgG and IgA response is prevalent in gluten ataxia, independent of intestinal involvement. Such antibodies are absent in ataxia of defined genetic origin or in healthy individuals. Inhibition studies showed that in those patients with ataxia and enteropathy, separate antibody populations react with the two different transglutaminase isozymes. Furthermore, postmortem analysis of brain tissue showed cerebellar IgA deposits that contained transglutaminase 6.

INTERPRETATION

Antibodies against transglutaminase 6 can serve as a marker in addition to human leukocyte antigen type and detection of anti-gliadin and anti-transglutaminase 2 antibodies to identify a subgroup of patients with gluten sensitivity who may be at risk for development of neurological disease.

No increase in risk of fracture, malignancy or mortality in dermatitis herpetiformis: a cohort study

BACKGROUND

Dermatitis herpetiformis forms part of the same spectrum of gluten-sensitive disorders as coeliac disease yet may have different risks of morbidity and mortality.

AIMS

To quantify the risks of fracture, malignancy and mortality in people with dermatitis herpetiformis compared with the general population.

METHODS

Using the General Practice Research Database, we identified 846 people with dermatitis herpetiformis and 4225 age-, gender- and practice-matched controls. We used Cox regression to estimate hazard ratios.

RESULTS

Comparing people with dermatitis herpetiformis to the general population, the overall hazard ratio for any fracture was 1.1 (95% CI: 0.77-1.52). The overall hazard ratio for any malignancy was 1.0 (95% CI: 0.73-1.49); there was no increased risk of gastrointestinal (HR: 1.6; 95% CI: 0.67-3.67) or lymphoproliferative cancers (HR: 1.6; 95% CI: 0.44-6.06). A reduction in risk of breast cancer was not statistically significant (HR: 0.19; 95% CI: 0.03-1.39). The hazard ratio for all-cause mortality was 0.93 (95% CI: 0.70-1.23).

CONCLUSIONS

Unlike the fivefold increase in risk seen in coeliac disease, we found no increased risk of lymphoproliferative cancer and no increase in fracture, malignancy or mortality in people with dermatitis herpetiformis compared with the general population. It is not clear whether differences in degree of intestinal inflammation or other reasons account for this. Like coeliac disease, dermatitis herpetiformis may protect against breast cancer.

The Immunology of Gluten Sensitivity beyond the Intestinal Tract

Celiac disease and gluten-sensitive enteropathy are terms that have been used to refer to a disease process affecting the small bowel. However, evidence has been accumulated in literature demonstrating that gluten sensitivity or celiac disease can exist even in the absence of enteropathy, but affecting many organs. Based on overwhelming evidence, immunological pathogenesis has been demonstrated in the joint, the heart, thyroid, bone, and, in particular, the brain cerebellum and neuronal synapsin I. When blood samples of patients with celiac disease are tested against gliadin and different tissue antigens, in addition to gliadin antibody, a significant percentage of them exhibit elevation in antibodies against transglutaminase, heat shock protein, collagen, thyroid, myosin, endothelial cell, bone antigen (transglutaminase), myelin basic protein, cerebellar and synapsin. This elevation of autoantibodies in patients with celiac disease may result in neuroimmune disorders. In fact, in comparison to the general population, the incidence of various autoimmune disorders, including gluten ataxia, is increased up to 30-fold in patients with celiac disease. Therefore, immune evaluation of patients with gluten sensitivity or celiac disease, in addition to gliadin and transglutaminase, should include antibody measurement against thyroglobulin, thyroid peroxidase, heat shock protein, bone transglutaminase, myelin basic protein, cerebellar peptide and synapsin. This novel laboratory approach to gluten sensitivity and autoimmunity may enable clinicians to detect markers of autoimmune diseases. Early identification of gluten sensitive and celiac disease patients and implementation of a gluten-free diet may result in significant improvement and control of associated diseases.

Clinical, pathologic, and immunopathologic features of dermatitis herpetiformis: review of the Mayo Clinic experience

BACKGROUND

Dermatitis herpetiformis (DH) is a cutaneous manifestation of gluten sensitivity, occasionally associated with other autoimmune disorders, and reportedly associated with an increased risk of lymphoproliferative disorders. We describe a series of patients with DH, focusing on associated disorders (particularly celiac disease), incidence of lymphoma, histopathology, and sensitivity of direct immunofluorescence (DIF) testing and serologic testing with antiendomysium antibodies for the diagnosis of DH.

METHODS

The medical records of 264 patients with DH diagnosed between 1970 and 1996 were reviewed retrospectively. In addition, the records of six patients evaluated before the advent of DIF testing between 1932 and 1969 were reviewed.

RESULTS

Established celiac disease was present in 12.6% of patients with DH, autoimmune systemic disorders in 22.2%, malignant neoplasms in 10.4%, sarcoidosis in four patients, and ulcerative colitis in six patients. Lymphoproliferative disorders were found in seven patients. The histopathologic examinations showed a marked predominance of neutrophils in the inflammatory infiltrate. DIF testing was positive in 92.4% of the patients tested. Indirect immunofluorescence assay indicated circulating antiendomysial antibodies in the sera of 40 of the 63 patients tested (63.5%).

CONCLUSIONS

In this large series of patients with DH from a single institution, patients had a low incidence of symptomatic gluten-sensitive enteropathy, low risk of lymphoproliferative disorders, and associations with other systemic autoimmune disorders. The value of DIF testing in the diagnosis of DH was confirmed. The detection of antiendomysial antibodies by indirect immunofluorescence was less sensitive than indicated by other reports.

Immunopathology and molecular diagnosis of autoimmune bullous diseases

Autoimmune bullous diseases are associated with autoimmunity against structural components maintaining cell-cell and cell matrix adhesion in the skin and mucous membranes. Pemphigus diseases are characterized by autoantibodies against the intercellular junctions and intraepithelial blisters. In pemphigoid diseases and epidermolysis bullosa acquisita, sub-epidermal blistering is associated with autoantibodies targeting proteins of the hemidesmosomal anchoring complex. The autoantigens in autoimmune blistering diseases have been extensively characterized over the past three decades. In general, the pathogenicity of autoantibodies, already suggested by clinical observations, has been conclusively demonstrated experimentally. Detection of tissue-bound and circulating serum autoantibodies and characterization of their molecular specificity is mandatory for the diagnosis of autoimmune blistering diseases. For this purpose, various immunofluorescence methods as well as immunoassays, including immunoblotting, enzyme-linked immunosorbent assay and immunoprecipitation have been developed. This review article describes the immunopathological features of autoimmune bullous diseases and the immunological and molecular tests used for their diagnosis and monitoring.

Malignancies and mortality in patients with coeliac disease and dermatitis herpetiformis: 30-year population-based study

BACKGROUND AND AIM

To assess the long-term risks of malignant diseases and mortality in patients with coeliac disease and dermatitis herpetiformis in a centre, where the prevalence of these diseases is high. The risks have probably been overestimated, as patients with subtle forms have earlier remained undetected.

PATIENTS

The study comprised 17,245 person-years of follow-up in 1147 patients.

METHODS

The observed numbers of malignancies and causes of deaths were assessed, and compared to those expected, and standardised incidence ratio and standardised mortality ratio given.

RESULTS

The occurrence of all malignant conditions was equal to that in the population both in coeliac disease and dermatitis herpetiformis: standardised incidence ratios of 1.2 (95% confidence intervals 0.9-1.5) and 1.0 (0.6-1.5), respectively. Five patients with coeliac disease and seven with dermatitis herpetiformis had developed non-Hodgkin lymphoma; standardised incidence ratios of 3.2 (1.0-7.5) and 6.0 (2.4-12.4), respectively. Four patients with coeliac disease and one with dermatitis herpetiformis had enteropathy-associated T-cell lymphoma, associated with inadequate dietary compliance. Mortality was increased (standardised mortality ratio 1.26; 1.00-1.55) in coeliac disease, but decreased in dermatitis herpetiformis (standardised mortality ratio 0.52; 0.36-0.72).

CONCLUSION

The overall prognosis in our patients was good. Non-Hodgkin lymphoma emerged in patients with undiagnosed or poorly treated coeliac disease. The mortality rate in dermatitis herpetiformis was even lower than in the population. Our data support the early diagnosis and dietary treatment of these conditions.

Cutaneous manifestations in celiac disease

Celiac disease (CD) is an autoimmune gluten-dependent enteropathy characterized by atrophy of intestinal villi that improves after gluten-free diet (GFD). CD is often associated with extra-intestinal manifestations; among them, several skin diseases are described in CD patients. The present review reports all CD-associated skin manifestations described in the literature and tries to analyze the possible mechanisms involved in this association. The opportunity to evaluate the possible presence of CD in patients affected by skin disorders is discussed.

Signaling through up-regulated C3a receptor is key to the development of experimental lupus nephritis

Signaling of the C3a anaphylatoxin through its G protein-coupled receptor, C3aR, is relevant in a variety of inflammatory diseases, but its role in lupus nephritis is undefined. In this study, we show that expression of C3aR was significantly increased in prediseased and diseased kidneys of MRL/lpr lupus mice compared with MRL/+ controls. To investigate the role of C3aR in experimental lupus, a small molecule antagonist of C3aR (C3aRa) was administered continuously to MRL/lpr mice from 13 to 19 wk of age. All 13 C3aRa-treated mice survived during the 6-wk treatment compared with 9 of 14 (64.3%) control animals given vehicle (p = 0.019). Relative to controls, C3aRa-treated animals were protected from renal disease as measured by albuminuria (p = 0.040) and blood urea nitrogen (p = 0.021). In addition, there were fewer neutrophils, monocytes, and apoptotic cells in the kidneys of C3aRa-treated mice. C3aRa treatment also led to reduced renal IL-1beta and RANTES mRNA and phosphorylated phosphatase and tensin homologue deleted on chromosome 10 protein, whereas the mass of phosphorylated protein kinase B/Akt was increased by C3aRa. Thus, C3aR antagonism significantly reduces renal disease in MRL/lpr mice, which further translates into prolonged survival. These data illustrate that C3aR is relevant in experimental lupus nephritis and may be a target for therapeutic intervention in the human disease.

Intraepithelial lymphocytes and coeliac disease

The diagnosis of coeliac disease is easy in cases with symptoms and unequivocal small intestinal villous atrophy. However, patients often suffer from only subtle if any symptoms. Borderline villous shortening is common, making the histologic diagnosis difficult. The increase in intraepithelial lymphocytes is typical even in early-stage untreated coeliac disease. Unfortunately, this finding is unspecific. In coeliac disease, the relative density of gammadelta+ intraepithelial lymphocytes is increased. The presence of IgA class anti-endomysium or anti-tissue transglutaminase antibodies clearly increases the likelihood of the disease. Coeliac disease is closely linked to HLA DQ2 and DQ8, and their absence speaks strongly against the condition, whereas a positive finding is virtually of no diagnostic value. In borderline cases, the gluten-dependency of symptoms or mucosal inflammation should be shown by gluten-free diet or gluten challenge. No single test is efficient enough to distinguish unspecific increase in intraepithelial lymphocytes from early coeliac disease; clinical history, histology, serology and gluten-dependency should be taken into account in the diagnostic work-up.

Coeliac disease presenting as dermatitis herpetiformis in infancy

The incidence of reporting and diagnosis of coeliac disease (CD) in children is increasing with the improvement in sensitivity and specificity of screening markers. This in turn has led to an increasing awareness of gluten-sensitive enteropathy and associated disorders. We report the unusual case of an 8-month-old child presenting to his general practitioner with pruritic skin lesions, subsequently proven to be dermatitis herpetiformis (DH) as the first sign of gluten-sensitive disease. This infant is the youngest child presenting with DH who could be identified from published report dating from 1966 onwards. Dermatitis herpetiformis is the commonest associated pathology of CD, although rare in infancy, it should be considered in any child presenting with failure to thrive and atypical, chronic rash not responding to simple measures.

Permeability, zonulin production, and enteropathy in dermatitis herpetiformis

BACKGROUND & AIMS

Dermatitis herpetiformis (DH) is characterized by variable degrees of enteropathy and increased intestinal permeability. Zonulin, a regulator of tight junctions, seems to play a key role in the altered intestinal permeability that characterizes the early phase of celiac disease. Our aim was to assess both intestinal permeability and serum zonulin levels in a group of patients with DH having variable grades of enteropathy.

METHODS

We studied 18 DH patients diagnosed on the basis of characteristic immunoglobulin (Ig)A granular deposits in the dermal papillae of noninvolved skin. Results were compared with those of classic celiac patients, patients with linear IgA dermatosis, and healthy controls.

RESULTS

According to Marsh's classification, 5 patients had no evidence of enteropathy (type 0), 4 patients had type II, 2 patients had type IIIb damage, and 7 patients had a more severe lesion (type IIIc). Intestinal permeability (lactulose/mannitol ratio [lac/man]) was abnormal in all patients with DH. Patients with more severe enteropathy had significantly greater permeability ( P < .05). The serum zonulin concentration (enzyme-linked immunosorbent assay) for patients with DH was 2.1 +/- .3 ng/mg with 14 of 16 (87.5%) patients having abnormally increased values. In contrast, patients with linear IgA dermatosis had normal histology, normal intestinal permeability, and negative celiac serology.

CONCLUSIONS

Increased intestinal permeability and zonulin up-regulation are common and concomitant findings among patients with DH, likely involved in pathogenesis. Increased permeability can be observed even in patients with no evidence of histologic damage in biopsy specimens. Patients with linear IgA dermatosis appear to be a distinct population with no evidence of gluten sensitivity.

Retinoic acid reduces autoimmune renal injury and increases survival in NZB/W F1 mice

Retinoic acids, a group of natural and synthetic vitamin A derivatives, have potent antiproliferative and anti-inflammatory properties. Recently, retinoic acids were reported to inhibit Th1 cytokine production. We investigated the effects of retinoic acid on lupus nephritis in a model of NZB/NZW F(1) (NZB/W F(1)) mice. Three-month-old NZB/W F(1) mice were separated into two groups: one treated with all-trans-retinoic acid (ATRA; 0.5 mg i.p., three times weekly for 7 mo) and one with saline as a control. Compared with controls, ATRA-treated mice survived longer and exhibited a significant reduction of proteinuria, renal pathological findings including glomerular IgG deposits, and serum anti-DNA Abs. Splenomegaly was less marked in the treated mice than in controls. Transcripts encoding IFN-gamma, IL-2, and IL-10 in splenic CD4(+) T cells were significantly reduced in treated mice compared with controls. We conclude that treatment with ATRA in SLE-prone NZB/W F(1) mice significantly alleviates autoimmune renal disorder and prolongs survival; this may thus represent a novel approach to the treatment of patients with lupus nephritis.

Neutrophil CD11b, L-selectin and Fc IgA receptors in patients with dermatitis herpetiformis

BACKGROUND

The skin lesions found in patients with dermatitis herpetiformis (DH) are characterized by the presence of neutrophils at the dermal papillary tips in areas where the diagnostic cutaneous IgA deposits are found. Although the presence of the skin lesions of DH is known to be associated with gluten-sensitive enteropathy, the mechanisms that control the development of skin lesions are not known.

OBJECTIVES

To determine if circulating neutrophils from patients with DH have evidence of priming as shown by increased expression of CD11b, decreased expression of L-selectin and increased function of neutrophil Fc IgA receptor.

METHODS

Neutrophils from 12 normal subjects and 10 DH patients with active, ongoing disease and 14 DH patients with quiescent disease activity were examined by fluorescence-activated cell sorter for expression of cell surface CD11b, L-selectin expression, Fc IgA expression (CD89) and for the function of the Fc IgA receptor by determining the binding capacity of neutrophils for monoclonal human IgA.

RESULTS

Neutrophils from patients with active, ongoing DH had increased expression of CD11b when compared with patients with inactive DH or normal subjects [mean net geometric mean channel fluorescence (GMCF): active DH, 403.3; inactive DH, 237.8; normal subjects, 290.5; P < 0.05]. L-selectin expression in both groups of DH patients was significantly lower than that seen in normal subjects (mean net GMCF: active DH, 363.2; inactive DH, 375.2; normal subjects, 432.7; P < 0.05). No difference in CD89 expression was seen in any of the groups; however, the function of Fc IgA receptor was increased in patients with active DH when compared with patients with inactive DH and normal subjects.

CONCLUSIONS

Neutrophils from patients with active, ongoing DH show an increased expression of CD11b, decreased expression of L-selectin and increased ability to bind IgA, consistent with a pattern of priming of the neutrophils. This priming may occur in the gut as a result of the ongoing mucosal immune response that is present in patients with DH on a gluten-containing diet and may predispose neutrophils to localize in the skin of patients with DH.

Characterization of a subgroup of patients with dermatitis herpetiformis with nonclassical histologic features

Dermatitis herpetiformis (DH) is an autoimmune disease mediated by IgA antibodies. The diagnosis of DH is based on clinical presentation, biopsy for hematoxylin and eosin, and direct immunofluorescence. The chief hematoxylin and eosin finding is a subepithelial blister with neutrophils in dermal papillae. The direct immunofluorescence findings are deposition of IgA and sometimes C3 at the basement membrane with accentuation in dermal papillae. Immunofluorescence is thought to be a sensitive and specific assay in DH, and there are no other known diseases with this pattern of immunofluorescence. The aim of this project was to determine the prevalence of nonclassical histologic findings in DH. We studied 24 cases of DH received at our institution. All cases had clinical findings of DH as well as positive direct immunofluorescence with IgA. We found that 9 of 24 cases (37.5%) had nonspecific H&E findings of a lymphocytic infiltrate only with fibrosis in the dermal papillae and ectatic capillaries. The remaining 15 cases had classic findings of multilocular neutrophilic microabscesses in the dermal papillae. These findings were reproduced on step sectioning. These findings suggest that routine histology may be quite nonspecific in DH and direct immunofluorescence or other more specific immunologic assay is an essential adjunct to diagnosis.

Cutting edge: reversal of murine lupus nephritis with CTLA4Ig and cyclophosphamide

Cyclophosphamide (CTX) prevents progression of nephritis and prolongs survival in (NZB x NZW)F(1) (B/W) mice and is used to treat humans with lupus nephritis. To compare the efficacy of CTLA4Ig with CTX and determine whether there is an incremental benefit to combining CTLA4Ig with CTX, we treated B/W mice with CTX, CTLA4Ig, or both agents. In mice with mild renal disease, treatment delayed the onset of proteinuria and prolonged survival in all groups. In mice with advanced renal disease, treatment with both agents reduced proteinuria in 71% of mice, whereas mice treated with either agent alone had no such improvement. Survival was also markedly improved among mice treated with both agents. Thus, combination treatment with CTX and CTLA4Ig is more effective than either agent alone in reducing renal disease and prolonging survival of B/W mice with advanced nephritis. This striking reversal of proteinuria is unprecedented in animal models of SLE.

A case of dermatitis herpetiformis with IgA endomysial antibodies but negative direct immunofluorescent findings

A patient with clinical findings of dermatitis herpetiformis (DH), negative direct immunofluorescent (DIF) findings for junctional IgA deposits in 2 biopsy specimens, and positive for IgA endomysial (AEmA) and tissue transglutaminase (tTG) antibodies responded initially to dapsone. After dapsone had to be discontinued because of side effects, a gluten-free diet and supportive therapy controlled the disease; the AEmA and tTG antibodies became negative. Our data on 10 consecutive DH cases examined by DIF and by serum studies for AEmA and antibodies to tTG, point to frequencies of 90% DIF positive and 70% AEmA and tTG positive cases. The use of both DIF and serum tests for AEmA and tTG reveals DH cases not detected by DIF alone that respond to gluten-free diet. Findings on autoantibodies to tTG, an enzyme that metabolizes gliadin, points to a role of tTG in the immunopathology of gluten-sensitive enteropathy and helps to explain the need for a gluten-free diet in the management of DH cases.

Current concepts of celiac disease pathogenesis

Our knowledge of celiac disease pathogenesis has recently made rapid progress. The disorder is now considered the result of a complex interplay of intrinsic (genetic) and variable extrinsic (environmental) factors that explain the wide spectrum of clinical manifestations ranging from asymptomatic to severe malabsorption. Gluten peptides are efficiently presented by celiac disease-specific HLA-DQ2- and HLA-DQ8-positive antigen-presenting cells, and thus drive the immune response, predominantly in the connective tissue of the lamina propria. Tissue transglutaminase, which has been identified as the highly specific endomysial autoantigen, is released from cells during inflammation. It may potentiate antigen presentation by HLA-DQ2 and HLA-DQ8 by deamidating or cross-linking gluten peptides. The result is lamina propria T-cell activation and mucosal transformation by activated intestinal fibroblasts. In the future, manipulation of the gut-associated lymphoid tissue may allow reduced sensitivity or even generate oral tolerance to gluten. Long-standing untreated celiac disease, even if clinically silent, predisposes for other autoimmune diseases. Therefore, population screening for immunoglobulin A antibodies to tissue transglutaminase seems justified.

Dermatitis herpetiformis effectively treated with heparin, tetracycline and nicotinamide

We report a patient with severe dermatitis herpetiformis (DH) who was intolerant of dapsone, sulphapyridine, systemic steroids, and azathioprine. He was treated effectively with a combination of heparin, tetracycline and nicotinamide.

Dermatitis Herpetiformis: a review of fifty-four patients

A review of 54 patients with dermatitis herpetiformis presenting between 1984-1993 to The Regional Centre of Dermatology, Mater Misericordiae Hospital was undertaken. All patients had skin lesions clinically and histologically typical of dermatitis herpetiformis. Deposition of granular IgA at the dermoepidermal junction on direct immunofluorescence was present in each case. The average age of onset was 41.8 yr, patients having symptoms for an average of 1.6 yr before diagnosis. Six patients had a prior history of coeliac disease. Two patients had a family history of dermatitis herpetiformis, a father and son who were both propositi in this study. Small bowel biopsy was performed on 35 patients, 71.4 per cent of them showing evidence of villous atrophy. All patients were controlled on a gluten free diet or by dapsone or a combination of these. None of the patients experienced serious adverse effects of therapy, nor did any develop lymphoma of the small bowel with a mean follow up period of 4.2 yr (range 1-10 yr).

HLA class II region genes and susceptibility to dermatitis herpetiformis: DPB1 and TAP2 associations are secondary to those of the DQ subregion

Classical dermatitis herpetiformis (DH) is associated with similar HLA class I, II and III polymorphisms to coeliac disease (CD). The two diseases share distinctive pathological changes to the small intestinal mucosa which reverse on withdrawal of dietary gluten. In order to determine the locus primarily associated with DH, and to examine whether there is a common genetic link predisposing to the enteropathy seen in both DH and coeliac disease, HLA-DR, DQ and DP subregion associations were investigated by HLA genotyping in 23 DH patients and 64 healthy controls. We also studied polymorphisms of the TAP2 locus, which is located between the DP and DQ subregions. Genotyping was carried out by PCR of genomic DNA with allelic assignment by sequence-specific oligonucleotide (SSO) hybridization or amplification refractory mutation system (ARMS). The strongest associations in the patient group were with HLA DRB1*0301 (91% vs 22% of controls), HLA DQB1*02 (100% vs 32% of controls) and DPB1*0101 (39% and 14%). These associations are similar to those described for CD. 100% of DH patients were positive for the DQA1*0501/DQB1*02 dimer in cis or trans and, by analogy with CD, this is probably responsible for presenting gliadin peptide implicated in the disease process. Homozygosity for DQ2 was significantly increased in the CD patient group compared to the DH patient group (65% versus 39%), and so differences in dosage of HLA class II genotypes between DH and CD may be responsible for the milder gastrointestinal symptoms characteristic of DH.

[Dermatitis herpetiformis occuring in patients with celiac disease in childhood]

BACKGROUND

Dermatitis herpetiformis (DH) is a chronic papulovesicular immune-mediated disorder associated with gluten-sensitive enteropathy. We report eight cases in which DH appeared many years after celiac disease (CD) in child.

PATIENTS AND METHODS

The diagnosis of CD was based on histological features of total or subtotal villous atrophy, full remission after withdrawal of gluten from the diet, and eventually circulating antibodies (IgA gliadin, antireticulin and antiendomysium) at the time of diagnosis and their disappearance under gluten-free diet. The diagnosis of DH was made from clinical findings, histological examination of the involved skin and direct immunofluorescence microscopy of normal or perilesional skin. HLA class II typing was performed in five patients. DRB1, DQA1, DQB1 and DBP1 alleles were studied.

RESULTS

DH appeared between 3 and 22 years after the initial diagnosis of CD. Five patients did not show at that time any digestive symptoms. In three cases, a break in the gluten-free diet or a recent revival of the normal diet preceded the rash. In only one case, DH appeared while the patient was under gluten-free diet. In three patients, the rash appeared many years after the gluten-free diet had been stopped. Phenotype DR3 and/or DR7 of the celiac disease could be found in four of the five patients studied; three of them were found to bear DQW2. The DR2 allele was not found in any of the five tested patients.

DISCUSSION

These eight cases illustrate the absence of precise nosological barrier between gluten-sensitive enteropathy of the DH and that observed in CD. The presence of the DR7 allele, and especially the absence of the DR2 allele, could explain the particularly severe and symptomatic course of the enteropathy in these patients. The delay in the appearance of DH, after a very variable period of normal diet, could correspond to the necessary time for progressive accumulation of IgA (or immune complex IgA-gluten) in the skin after a digestive sensitization to gluten. The preventive role of gluten-free diet is thus probable.

CONCLUSION

CD and DH likely correspond to two different stages of the same disease, thus requiring a prolonged follow-up of both digestive and skin tissues. Long-term eviction of gluten to prevent eventual DH must be balanced with the demand and the cost of such a diet.

Coeliac disease in childhood

Coeliac disease usually presents in infancy or early childhood with diarrhoea, vomiting and interference with weight gain and growth. Withdrawal of dietary gluten is followed by resolution of the symptoms and signs and restoration of normal weight gain and growth; the characteristic subtotal villous atrophy of the jejunal mucosa also recovers. Later re-introduction of dietary gluten will lead to a return of the jejunal mucosal abnormality in the majority and to clinical relapse in many but not all. The severity and timing of both are variable and 5% of children initially considered on clinical, biopsy and gluten response evidence to have coeliac disease appear to develop permanent tolerance to gluten, although mucosal relapse may occur years after the re-introduction of dietary gluten in a minority, emphasizing the need for long-term follow-up. Although a diagnostic and subsequent follow-up jejunal biopsy are necessary to confirm the diagnosis, anti-gliadin IgA and IgG, anti-reticulum and anti-endomysium antibodies are now almost totally reliable in identifying children who have coeliac disease and are valuable in monitoring the adequacy of gluten withdrawal. Dietary compliance is frequently poor and regular supervision by a paediatric dietitian is needed; indeed, lifelong supervision to ensure gluten withdrawal is essential to reduce the chance of developing later gastrointestinal malignancy.

Gamma/delta T-cell receptor expression in the jejunal epithelium of patients with dermatitis herpetiformis and coeliac disease

The density of jejunal intra-epithelial T cells expressing the gamma/delta form of the T-cell receptor is known to be increased in coeliac disease, the significance of which remains a mystery. The expression of the gamma/delta T-cell receptor in the jejunum of patients with dermatitis herpetiformis, coeliac disease, treated and untreated, and controls were studied. Expression of the gamma/delta T-cell receptor was significantly increased in patients with dermatitis hepetiformis (P < 0.0005) and in both untreated (P < 0.0005) and treated coeliac patients (P < 0.05) compared with controls. There were significant correlations between the indices of enteropathy, enterocyte height (P < 0.005) and villous height/crypt depth ratio (P < 0.0001), and expression of the gamma/delta T-cell receptor in the jejunum of all the patients. This argues against the hypothesis that gamma/delta T-cells have a fundamental role in the aetiology of gluten-sensitive enteropathy. It suggests that gamma/delta T cells may be involved in the effector arm of the mucosal immune response to cereal peptides in susceptible individuals.

Immunoglobulin and HLA-DP genes contribute to the susceptibility to juvenile dermatitis herpetiformis

HLA-DQ genes and gluten diet are the main factors involved in the pathogenesis of Dermatitis Herpetiformis (DH), as well as Coeliac Disease (CD). However other genetic factors are probably relevant, since about 10% of the patients with DH and CD lack the DQA1*0501/B1*0201 heterodimer while the majority of individuals presenting this genotype and also being exposed to gluten diets did not suffer from these diseases. To evaluate the role of other genes, 36 Northern Italian children with DH were analysed for DNA polymorphisms at HLA-DP and immunoglobulin (Ig) heavy chain loci. DPA1*0201 and DPB1*1301 frequencies were higher in patients than in controls (Pc = 0.0357 and Pc = 0.0273). With respect to immunoglobulin heavy chain restriction fragment length polymorphisms (RFLP), the 4.6 kb SacI RFLP at the switch alpha 2 gene was more frequent in patients (0.13) than in controls (0.019; Pc = 0.036). Moreover, rare alleles or duplications in the switch regions occurred more frequently in the patients than in the controls. These results support the hypothesis of a multifactorial inheritance of DH, the HLA and Ig constant heavy chain genes being some of the loci contributing to the susceptibility. In accordance with previous CD studies, these data also confirm that DP subregion is probably involved in the pathogenesis of DH.

Cutaneous manifestations of gastrointestinal disorders. Part II

The cutaneous manifestations of inflammatory bowel disorders, vascular disorders of the gastrointestinal tract, celiac disease, and bowel-associated dermatosis-arthritis syndrome are reviewed. The significance of these signs, guidelines for their management, and investigations are discussed.

Comparison of the intestinal and serum antibody response in patients with dermatitis herpetiformis

Dermatitis herpetiformis (DH) is an intensely pruritic, blistering skin disease characterized by cutaneous IgA deposits and an associated, most often asymptomatic, gluten-sensitive enteropathy. When patients with DH are placed on a gluten-free diet both the intestinal abnormality and the cutaneous manifestations of the disease are controlled, suggesting that a mucosal immune response is important in the pathogenesis of DH. Although patients with DH continue to ingest gluten only 40-50% have evidence of an ongoing mucosal immune response in their serum. In order to investigate directly the mucosal immune response in patients with DH the antibody response to dietary antigens was analyzed in intestinal secretions and compared to that found in the serum. Intestinal secretions from six patients with DH and five normal subjects were collected using an intestinal lavage solution and analyzed for total IgA, IgG, IgM, and IgA subclasses, and for IgG, IgA, and IgM antibodies against the dietary antigens bovine beta-lactoglobulin and gliadin. Intestinal secretions from patients with DH contained more IgA than those from normal subjects (mean total IgA: DH = 2.3 mg/ml; normal subjects (NL) = 0.143 mg/ml, P = 0.017). This increase in IgA in intestinal secretions from patients with DH was composed primarily of IgA1 (intestinal IgA: 86% IgA1, 14% IgA2; NL gut secretions: IgA1 = 54%; IgA2 = 46%). Increased IgA antibodies directed against beta-lactoglobulin and gliadin were detected in gut secretions of two of six patients with DH and in none of the normal subjects. Serum IgA antibodies against beta-lactoglobulin and gliadin were detected only in the two subjects who had detectable IgA antibodies in their intestinal secretions. Serum and intestinal IgA anti-beta-lactoglobulin antibodies had similar isoelectric spectrotypes (pI 5.0-6.5), IgA subclass composition, and antigenic reactivity by immunoblot analysis, demonstrating the close relationship between the serum and intestinal IgA antibodies. These data demonstrate that in patients with DH an ongoing mucosal immune response is present in the gut as evidenced by a significantly increased concentration of IgA, predominately IgA1. The strong correlation between detectable serum and intestinal IgA antibodies against dietary antigens demonstrates that the lack of serum IgA antibodies against dietary antigens in some patients with DH is not due to the presence of "blocking" IgA anti-dietary antigen antibodies in intestinal secretions.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of an elemental diet with and without gluten on disease activity in dermatitis herpetiformis

Elemental diets are reported to decrease activity of patients with dermatitis herpetiformis. We tested the hypothesis that gluten, given in addition to an elemental diet, is responsible for the intestinal abnormalities, cutaneous immunoreactant deposition, and skin disease activity in dermatitis herpetiformis. At entry eight patients with dermatitis herpetiformis, who were consuming unrestricted diets, were stabilized on their suppressive medications at dosage levels that allowed individual lesions to erupt. Six patients were then given an elemental diet plus 30 of gluten for 2 weeks, followed by the elemental diet alone for 2 weeks. Conversely, two patients received an elemental diet alone for 2 weeks followed by an elemental diet plus gluten during the final 2 weeks. Small bowel biopsies, skin biopsies, and clinical assessments were done at 0, 2, and 4 weeks. Suppressive medication dose requirement decreased over the 4 weeks by a mean of 66%. Six of eight subjects significantly improved clinically during the gluten-challenge phase of the elemental diet and all were improved at the end of the study. The amount of IgA in perilesional skin did not change significantly, but the amount of C3 increased in five of seven evaluable subjects after gluten challenge. Circulating anti-gluten and anti-endomysial antibodies were not significantly affected by the diets. All subjects completing evaluable small bowel biopsies (seven of seven) demonstrated worsening of their villus architecture (by scanning electron microscopy and intraepithelial lymphocyte counts) during gluten challenge and improvement (six of six subjects) after 2 weeks of elemental dietary intake. We conclude that 1) there is a significant improvement in clinical disease activity on an elemental diet, independent of gluten administration, 2) small bowel morphology improves rapidly on an elemental diet, and 3) complement deposition but neither IgA deposition nor circulating antibody levels correlate with gluten intake. It seems likely that dietary factors other than gluten are important in the pathogenesis of the skin lesions in dermatitis herpetiformis.