Gluten-free diet in dermatitis herpetiformis. II. Morphological and immunological findings in the skin and small intestine of 12 patients and matched controls

The Long-Term Safety and Quality of Life Effects of Oats in Dermatitis Herpetiformis

The treatment of choice for dermatitis herpetiformis (DH), a cutaneous manifestation of coeliac disease, is a life-long gluten-free diet (GFD). In a GFD, wheat, rye and barley should be strictly avoided, but the role of oats is more controversial. This study aimed to investigate the safety and long-term quality of life and health effects of oat consumption in 312 long-term treated DH patients. Baseline data were gathered from patient records and follow-up data from questionnaires or interviews, and validated questionnaires were used to assess quality of life. We found that altogether 256 patients (82%) were consuming oats as part of their GFD at the follow-up. Long-term follow-up data showed that there were no differences in the presence of long-term illnesses, coeliac disease complications or the usage of medication between those consuming and not consuming oats. However, oat consumers had a better quality of life and reported ongoing gastrointestinal symptoms less frequently (4% vs 19%, p = 0.004) at the follow-up than those not consuming oats. The study established that oats are safe for DH patients and in the long-term seem to improve the quality of life of DH patients.

Serum IL-8 in Patients with Dermatitis Herpetiformis is Produced in Response to Dietary Gluten

Patients with dermatitis herpetiformis (DH) have a gluten-sensitive enteropathy and while on gluten-containing diets have elevated levels of serum IL-8. We hypothesized that the mucosal immune response to gluten is responsible for the elevated serum IL-8. Six DH patients were studied while on a gluten-free diet (GFD), whereas four continued on a normal diet. Patients were followed for a mean 2.2 years and serum IL-8 was analyzed. Small bowel biopsies from five DH patients on normal diets, two DH patients on GFD, and six subjects with no small bowel abnormalities were analyzed for IL-8 mRNA. Serum IL-8 levels normalized in five of six patients on GFD and decreased in one, whereas serum IL-8 levels showed no statistically significant change in DH patients on normal diets. Small bowel biopsies from DH patients on normal diets had increased expression of IL-8 mRNA compared to normal subjects, whereas patients on a GFD showed no significant increase in small bowel mRNA. No significant IL-8 mRNA was detected in normal skin biopsies from patients with DH. These observations suggest that the IL-8 in the serum of patients with DH originates from the small bowel as a mucosal immune response to gluten ingestion.

Cutaneous Endothelial Cell Activation in Normal Skin of Patients with Dermatitis Herpetiformis Associated with Increased Serum Levels of IL-8, sE-Selectin, and TNF-α

The mechanisms that lead to the development of skin lesions in patients with dermatitis herpetiformis (DH) are not known. We hypothesized that an ongoing immune response in the gut of patients with DH would result in an increase in circulating cytokines and be associated with endothelial cell activation, creating a proinflammatory environment in the skin. Skin biopsies from the normal-appearing inner arm of 11 DH patients, with no active skin lesions, and 12 normal subjects were analyzed for E-selectin (E-sel) and ICAM-1 mRNA. DH patients' skin expressed markedly increased levels of E-sel mRNA. Mean E-sel mRNA expression in DH skin was 1,271 (range 63.78-5861) times greater than that of a control, normal skin (P<0.001) with no significant increased expression of ICAM-1 mRNA. Serum levels of soluble E-selectin (sE-sel), IgA anti-tissue transglutaminase antibodies, and serum IL-8 levels were significantly increased in patients with DH. These studies demonstrate that patients with DH have evidence of endothelial cell activation in the skin and systemic manifestations of the ongoing inflammation associated with the mucosal immune response. Endothelial cell activation may play a critical role in the development of skin lesions in patients with DH and may represent a common mechanism for cutaneous manifestations of inflammatory gastrointestinal diseases.

Intraepithelial lymphocytes bearing the gamma/delta receptor in the oral and jejunal mucosa in patients with dermatitis herpetiformis

Lymphocytes bearing T cell receptor (TcR) gamma/delta are increased in the jejunal mucosa of patients with dermatitis herpetiformis (DH) and coeliac disease. In this study, we examined whether increased numbers of gamma/delta TcR positive lymphocytes occur in the oral mucosa of patients with DH. Oral and jejunal mucosal biopsies were taken from 13 newly diagnosed and 13 gluten free diet (GFD)-treated patients with DH. Monoclonal antibodies and avidin-biotin peroxidase method was used for staining, and TcR positive cells were counted from the buccal and jejunal epithelium. Very few gamma/delta TcR positive lymphocytes were seen in the buccal epithelium of untreated or GFD-treated DH patients (median 0.4 and 0.3 cells/mm2), whereas alpha/beta TcR positive lymphocytes were frequent in both groups of DH patients (154 and 250 cells/mm2) and healthy controls (135 cells/mm2). The numbers of gamma/delta TcR positive intraepithelial lymphocytes were significantly increased in the jejunum of both untreated (43 cells/mm) and GFD-treated (27 cells/mm) DH patients compared to control patients (2.2 cells/mm). The present study did not, therefore, disclose any evidence for active recruitment of gamma/delta TcR positive lymphocytes in the oral epithelium, but showed substantial amounts of intraepithelial alpha/beta TcR positive lymphocytes both in DH patients and healthy controls.

The pathogenesis of dermatitis herpetiformis: recent advances

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

Serum antibodies to wheat germ agglutinin and gluten in patients with dermatitis herpetiformis

It has been speculated that gluten may play a role in the pathogenesis of dermatitis herpetiformis (DH) because it can act as a lectin. The lectin activity of gluten preparations was recently identified as wheat germ agglutinin (WGA). IgG and IgA serum antibodies to WGA and gluten were therefore measured in patients with DH and coeliac disease (CD) by an enzyme-linked immunosorbent assay (ELISA). Compared with healthy controls, both patients categories had increased IgG and IgA activities to WGA and gluten, the CD group showing the highest antibody levels. DH patients with subtotal villous atrophy tended to have higher activities than those with no villous changes or only minor changes. No significant difference in the gluten-to-WGA ratio of IgA or IgG antibodies was found when DH patients were compared with CD patients. If WGA plays a pathogenetic role in DH, then DH patients must have dermal characteristics, as yet undefined, that explain the initiation of their skin disease.

HLA antigens, jejunal morphology and associated diseases in children with dermatitis herpetiformis

Forty-five Hungarian and Finnish children from 1.5 to 15 years with dermatitis herpetiformis were studied for HLA antigens, jejunal morphology on gluten-containing diet and associated diseases in the patients and their relatives. A strong association with HLA-B8 was found in patients of both nationalities, the relative risks were 12.8 and 9.6, respectively. The Hungarian patients were also typed for HLA-DR locus, and an association with DR3 but not with DR7 was observed. Patients with subtotal villous atrophy had slightly more often HLA-B8 and DR3 than those with milder intestinal lesions. Atopic eczema occurred in 20% of the patients and family history of atopy seemed to have an inverse correlation with HLA-B8 and DR3.

IgA deposits in the oral mucosa of patients with dermatitis herpetiformis and linear IgA disease

The oral mucosa of seven patients with dermatitis herpetiformis (DH) and one with linear IgA disease was studied. None of the patients with DH showed any macroscopic oral lesions, but direct immunofluorescence (IFL) examination of the buccal mucosa revealed granular IgA deposits in all patients. IgA deposits were found just below the basement membrane zone or slightly deeper in the connective tissue, i.e. a deposition pattern which is pathognomonic to DH. In three patients C3 deposits occurred in the same area as IgA. The patient with linear IgA disease had small white erythematous patches, nonspecific both clinically and histologically, on the palatal mucosa. However, oral IFL specimens showed heavy linear IgA deposits in the basement membrane zone, indicating that the oral mucosa is also involved in this rare disease. Buccal mucosal biopsy specimens were stained with four FITC-conjugated lectins (Ulex europaeus I, soybean, peanut and lentil). The lectin staining was similar in patients with DH and linear IgA disease and did not markedly differ from normal oral mucosa. Our results show that buccal IFL examination is a useful diagnostic aid in both DH and linear IgA disease.

Dermatitis herpetiformis: jejunal findings and skin response to gluten free diet

Fifty seven children with dermatitis herpetiformis, 18 from Finland and 39 from Hungary, were studied. Diagnostic criteria included the finding of granular IgA deposits in the skin of all patients. The mean age at onset of the rash was 7 X 2 years and favoured sites were the elbows, knees, and buttocks. Symptoms suggesting small intestinal disease were rare but in 35 (61%) of the children subtotal villous atrophy and in 16 (28%) partial villous atrophy were found on jejunal biopsy. Eighteen children underwent a second biopsy after a mean of 21 months on a gluten free diet; villous height was found to be increased and the intraepithelial lymphocyte count decreased in all these patients. Gluten challenge caused a reversal in the two children who underwent a third biopsy. The effect of the gluten free diet on the rash was examined in Finnish children by observing the daily requirements of dapsone, a drug used to control the rash at the beginning of the diet. Eight (67%) of the 12 children were able to stop taking dapsone after a mean of 11 months on the diet and all three patients treated with diet alone became asymptomatic after three to 6 months on the diet. These results confirm that most children with dermatitis herpetiformis have jejunal villous atrophy, though they rarely have gastrointestinal symptoms. The central role of gluten in childhood dermatitis herpetiformis is evidenced by the fact that a gluten free diet helps the damaged jejunal mucosa to recover and controls the rash even in those children who do not have an abnormal jejunal biopsy.

Renal involvement and circulating immune complexes in dermatitis herpetiformis

A fine-needle kidney biopsy was performed on eleven patients with dermatitis herpetiformis (DH) who had no previous signs or symptoms of renal disease. Of the eight patients whose biopsy specimens were representative, electron microscopic examination showed mesangial deposits in five. A subsequent conventional renal biopsy was obtained from one of these five, and immunofluorescence microscopy revealed IgA and complement deposits in the glomeruli. Renal involvement was not related either to the degree of jejunal villous atrophy or to the deposition of IgA and complement in the skin. Glomerular deposits, however, were associated with a high frequency of circulating IgA and IgG class immune complexes and IgA class antigliadin and antireticulin antibodies. These results suggest that, in DH, immune complexes or antibodies derived from the gut can be deposited in the kidney.

Circulating IgA- and IgG-class antigliadin antibodies in dermatitis herpetiformis detected by enzyme-linked immunosorbent assay

A sensitive and technically simple enzyme-linked immunosorbent assay (ELISA) was developed to demonstrate circulating IgA- and IgG-class antibodies to gliadin, a component of wheat gluten. Serum samples from 24 patients with dermatitis herpetiformis (DH), 5 with coeliac disease (CD) and 75 normal controls were analysed. Antigliadin antibodies (AGA) of the IgA class were detected in 71% of DH patients, all of the CD patients and 19% of the controls. IgG-AGA was found in over 90% of DH patients and controls and in all of the CD patients. The mean ELISA values of both IgA- and IgG-class AGA were significantly higher in DH patients than in the controls. The occurrence of circulating IgA-class AGA is compatible with the hypothesis that these antibodies can be deposited in the skin, e.g. as immune complexes, or due to cross-reactivity of gliadin and dermal reticulin.

Long term follow-up of dermatitis herpetiformis with and without dietary gluten withdrawal

Seventy-eight patients with dermatitis herpetiformis have been followed up for periods ranging from 3 to 14 years (mean 7.4). Forty-two patients were treated with gluten-free diet (GFD) and thirty-six took a normal diet (ND). Thirty of the forty-two (71%) taking the GFD were able to discontinue drugs previously needed to control their rash compared with five (14%) of the thirty-six patients taking a ND. The mean time taken to reduce drug requirements for patients taking a GFD was 8 months (range 4-30), and for stopping drugs, 29 months (range 6-108). The incidence of macroscopic abnormality of the small intestine decreased from 69 to 15%, and the mean intra-epithelial lymphocyte count decreased significantly in those patients taking a GFD, whereas there was no significant change in patients taking a ND. The improvement in the skin and intestinal lesions was related to the strictness of the GFD.

Inflammatory cells, IgA, C3, fibrin and fibronectin in skin lesions in dermatitis herpetiformis

Skin lesions were produced by application of 50% potassium iodide to twelve patients with dermatitis herpetiformis (DH). Perivascular cellular infiltrates were found to be characteristic of developing lesions. The cells were mainly round cells; alpha-naphthyl acetate esterase staining revealed that in 24-h lesions the mean percentage of T-lymphocytes was 43%, that of mononuclear phagocytes 6% and that of non-T/non-M cells (mainly B-lymphocytes) 44%. The percentage of the latter was highest (mean 81%) in 6-h specimens, suggesting that these cells are participating in the early stages of lesion formation. The infiltrating cells in dermal papillae and within subepidermal vesicles were predominantly polymorphonuclear leukocytes (mean 86%) with some mononuclear phagocytes and non-T/non-M cells. Immunofluorescence examination confirmed that fibrin deposition is characteristic of the initial lesions of DH and showed that the same is true of fibronectin. Seven out of eight patients had fibronectin deposits in dermal papillae. IgA was found in all and C3 in most of the specimens and, with the exception of papillary vesicles and blister cavities, the intensity of IgA and C3 fluorescence showed no marked alterations during the development of lesions.

Celiac disease or dermatitis herpetiformis in three patients with porphyria

Celiac disease was diagnosed in one patient with variegate porphyria, and dermatitis herpetiformis in two patients, one with acute intermittent porphyria and the other with erythropoietic protoporphyria. The probability that celiac disease or dermatitis herpetiformis should occur in three patients with porphyria in Finland is less than 0.2%. Neither a consistent HLA pattern nor any other explanation can be offered for the association between these diseases.

Jejunal mucosal morphometry in children with and without gut symptoms and in normal adults

Nineteen diagnostic peroral biopsy specimens from 18 children without diarrhoea, vomiting, or abdominal pain ('control' children) were compared with those taken from 23 children with diarrhoea of varying aetiology to establish the morphometric characteristics of jejunal mucosa in childhood. Comparison was also made with normal jejunal mucosa from adults. Statistical analysis of each characteristic individually showed no significant difference between the 'control' children and those with diarrhoea, but there were significant differences between the mucosae of 'control' children and those of adults; the villi tended to be shorter and the crypts longer in children. Thirty-seven per cent of specimens from the 'control' children showed a partial villous atrophy, that is, they were abnormal by adult criteria. Discriminant analysis of the features measured showed effective separation of the following groups: normal histology from partial villous atrophy in children, healthy adults from 'control' children, and normal histology in adults from normal histology in children.

Wheat grain immunofluorescent antibodies as an indication of gluten sensitivity?

An immunofluorescence method using whole sections of wheat grains as the substrate was applied to detect circulating antibodies to wheat gluten in dermatitis herpetiformis patients and in controls. Only IgG class antibodies were detected. From dermatitis herpetiformis patients 22% had these antibodies as had 22% of the atopic dermatitis group. Among the controls who had no skin problems 12% were faintly positive. It is evident that the test as such is non-specific and does not have diagnostic significance in dermatitis herpetiformis.

The potassium iodide patch test in the dermatitis herpetiformis in relation to treatment with a gluten-free diet and dapsone

The potassium iodide patch test was studied in twenty-six patients with dermatitis herpetiformis. Histological assessment was found more sensitive than clinical. All of five patients with active disease and not on treatment had a positive test, whereas only two of six patients taking a gluten-free diet (GFD) and one of eight taking dapsone were positive. In another two patients taking a GFD, but in whom the diet had not been strict, the test was positive. All three patients in remission and both patients with the linear pattern of IgA (but with active disease) were negative. Immunofluorescence studies showed no difference in the presence, quantity, or distribution of immunoglobulin, complement or fibrinogen between the patch test site and uninvolved skin, or in the uninvolved skin between patients with and without active lesions.

A comparison of IgA positive and IgA negative dapsone responsive dermatoses

A study of thirty-three patients with a clinical diagnosis of dermatitis herpetiformis (DH) referred to our DH clinic over the las 11 years is reported. Twenty-six were referred by other consultant dermatologists. The diagnosis had been made by the clinical features and response of the rash to dapsone. Seventeen patients were found to have IgA in the uninvolved skin (IgA positive) and in sixteen no IgA was found (IgA negative). The duration of the rash prior to referral to the DH clinic was 3 months to 19 years (mean 5.0 years) for the IgA negative patients and 2 months to 22 years (mean 5.2 years) for the IgA positive group. The length of follow-up was 3 months to 11 years (mean 5.0 years) for the IgA negative, and 2--11 years (mean 5.6 years) for the IgA positive group. During follow-up the rash cleared completely and required no treatment in seven of the sixteen IgA negative patients. Thirteen of these sixteen patients no longer required dapsone, but six patients were receiving alternative treatment. In the three patients still taking dapsone IgA has not been found on subsequent biopsy. Of the seventeen IgA positive patients only three were able to stop dapsone during follow-up and in these three the IgA was still detected in the skin. Small intestinal mucosa was abnormal in eight of eleven IgA positive patients, but was normal in all thirteen IgA negative patients in whom jejunal biopsies were performed. An alternative diagnosis to DH has subsequently been made in thirteen of the sixteen IgA negative patients. Although the significance of IgA in the skin in DH is not known it appears to be part of the disease process. Patients who have a rash suggestive of DH and which is dapsone responsive, but in whom IgA is not found in the uninvolved skin, usually turn out to have a dermatosis other than dermatitis herpetiformis. Referral to a unit with expertise in immunofluorescence techniques of skin biopsies would appear to be helpful.

Juvenile dermatitis herpetiformis: an immunoelectron microscopic study

Three children with persistent maculopapular and urticarial lesions and vesicles at the predilection sites of dermatitis herpetiformis (DH) were shown to exhibit typical granular, papillary IgA and C3 deposits in the tips of the dermal papillae, as demonstrated by direct immunofluorescence. By immunoelectron microscopy, the IgA deposits were associated with the microfibrils of the elastic fibres as has been described in DH of the adult. C3 deposits were scattered throughout the papillary dermis. Despite the similarity of the clinical appearance, history with regard to gluten sensitive enteropathy (GSE) varied in these three cases. In one child, the skin lesions appeared following faults in the gluten free diet on which he was kept for coeliac disease. Another child developed the skin lesions during a gluten free diet which was not strictly followed; no recurrences of gastrointestinal symptoms accompanied the eruption of DH. In the third case, no evidence for GSE in patient's history or in jejunal biopsies was present at the time of onset of DH.

Comparison of immunoglobulin and complement deposition in multiple biopsies from the uninvolved skin in dermatitis herpetiformis

The distribution of immunoglobulins and C3 component of complement (C3) in the skin of twenty-four patients with dermatitis herpetiformis was studied. Skin biopsies were taken from three sites, the extensor surface of the elbow, the flexor surface of the forearm and from the thigh. Twenty-two (90%) patients showed variation in deposits of immunoglobulins and C3 at the three sites. IgA was present in all patients, but differed in quantities deposited at the three sites in nineteen (80%) patients. Similar variation between sites was observed with IgG, IgM and C3. There was variation within three biopsies, IgA being absent from some sections and present in others. Three patients had a continuous pattern of IgA deposition. One had both continuous and papillary deposits within a single section. There was no difference in the incidence or quantity of immunoglobulin and C3 between the elbow, forearm and thigh. There was observed to be a diminution in quantity of IgA and incidence of C3 in patients taking a gluten-free diet. Deposition of IgA, IgM, IgG and C3 is not uniform throughout the skin and conclusions drawn from the quantity of immunoglobulin and C3 in a single biopsy may not be reliable.

Absence of cutaneous IgA in coeliac disease without dermatitis herpetiformis

Skin biopsies from 17 patients with coeliac disease, but without dermatitis herpetiformis, were examined by direct immunofluorescence. In none of them was IgA detectable. In contrast, IgA was present in dermal papillae and/or in relation to the dermo-epidermal junction in 80 out of 83 patients with dermatitis herpetiformis. These findings confirm that cutaneous deposition of IgA at these sites is a very characteristic feature of dermatitis herpetiformis and is unrelated to coeliac disease itself.