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Biomedical subjects

R S Barnetson

Publications and source records attributed to R S Barnetson.

At least 73 records · Page 4Linked to original sources

IgE-mediated allergy in adults with severe atopic eczema.

A study was carried out of 45 adults with atopic eczema sequentially admitted to the Dermatology wards in the Royal Infirmary, Edinburgh. The clinical course of the eczema, the associated atopic conditions and the possible role of inhalant and food allergens were assessed. Most subjects had developed eczema in early childhood, but nine of the 45 developed it for the first time after the age of 15 yr. Eleven subjects outgrew their eczema around puberty only to experience recrudescence in their late teens. In 18 subjects the eczema was flexural until the late teens, when it became widespread. In this group of severely affected subjects, 25 had a history of asthma, 29 had either seasonal or perennial rhinitis, and 10 had current symptoms of food allergy. All but one had elevated total serum IgE concentrations (range 63-50,000 kU/l). Using dilutions of the subjects' serum in the radio-allergosorbent test, an estimate of the specific IgE to 10 allergens (three inhalants, seven foods) was obtained, where 1 RAST unit is roughly equivalent to 1 IU total IgE. Most of the IgE was produced in response to the inhalant allergens tested (grass pollen, house dust mite and cat epithelium), 32 of the subjects having a RAST score of 3 or 4 to each of the three inhalant allergens, with the remaining 13 having a RAST score of 3 or 4 to at least one. The highest levels were to house dust mite, exceeding 1000 RAST units in 13 subjects. Thirteen subjects had a RAST score of 4 to at least one food allergen, with levels up to 1000 RAST units. Although this usually correlated with a history of allergy to the food (except in the case of wheat), some subjects with a positive RAST to a specific food could eat the food without problem.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Nutritional status in patients with dermatitis herpetiformis.

Nutritional status of 86 patients with dermatitis herpetiformis (DH) was defined by anthropometric measurements and hematological and biochemical laboratory tests to establish prevalence of malabsorption and malnutrition. Anthropometric measurements in DH patients were comparable to normal control patients. Four individuals were of short stature; two had had diarrhea and failed to thrive in childhood. Abnormalities attributable to nutritional deficiency were detected in only 6 of the 86, whereas drug-associated hematological or biochemical changes were present in 36 of 55 subjects treated with dapsone or sulfapyridine. Twenty patients had hemolytic anemia or macrocytosis related to drug therapy. Only two had anemias attributable to malabsorption; one was iron deficient, the other folate deficient. Two other patients were mildly Fe deficient and two had slight folate deficiency; they lacked other stigmata of malabsorption. Drug-induced hematological and biochemical abnormalities were more common than changes that suggest nutritional disease, even though most DH patients had an enteropathy at presentation.

Adolescent↗

Release of highly-sulphated glycosaminoglycans and histamine from human basophils.

A new assay for highly-sulphated glycosaminoglycans (GAGs) has been applied to the study of allergen (Dermatophagoides pteronyssinus)-induced release of GAG from human basophils. Highly-sulphated GAG, which was not heparin, was found only in basophil-containing cellular fractions of whole blood. Its release, like that of histamine, was Ca++-dependent. However, allergen-induced release of GAG from the basophils of atopic individuals exhibited a different time-course and dose-response from that of histamine, and may occur at least in part by a different mechanism.

Adult↗

Clinical, histological and immunological studies in 50 patients with bullous pemphigoid.

Fifty patients with bullous pemphigoid were investigated over periods of up to 7 years. Sequential studies of circulating basement membrane zone (BMZ) antibody titres revealed two groups of patients: 44% had a high initial titre (greater than 1:160) and 56% had a low initial titre (less than 1:160). Subjects with titres greater than 1:160 continued to have high titres, whereas in those with lower titres the BMZ antibodies usually became undetectable after 4 months. The BMZ antibody titres were of no prognostic value. High titres remained high even in patients who were in remission and off treatment, and in these subjects, there was no evidence of a change in the IgG subclass. The initial BMZ IgG antibody titres showed a highly significant correlation with total serum IgE concentrations. A significant correlation also existed between total serum IgE and IgG4 concentrations, although not between the serum IgE and the peripheral blood eosinophil count. No anti-BMZ antibody of IgE class was found, nor specific IgE against inhalants and foods identified, and the significance of the high total serum IgE remains unexplained. The majority of those followed for more than 2 years were able to stop their steroid therapy without further blistering: this confirms that pemphigoid tends to be a self-limiting disease. Nine patients had a recent history of malignant disease, and this is no more than would be expected for this age group of patients: however, 3 patients presented with pemphigoid and figurate erythema and all died of neoplastic disease, suggesting that such patients should be investigated thoroughly for neoplasia.

Adult↗

House dust mite allergy and atopic eczema: a case report.

Sequential measurements were made of total and specific serum IgE concentrations in an adult patient with severe atopic eczema. Initially, the total serum IgE concentration and the concentration of IgE antibody to house dust mite were very high. These concentrations decreased over the next 3 years, following amelioration of her eczema. However, they rose again when her eczema worsened as a result of marital problems and fell once again with amelioration of her eczema after separation from her husband. The IgE concentrations to other common allergens, however, remained stable during this period. These results suggest that large amounts of house dust mite antigen may be scratched into the skin during clinical exacerbations of the eczema, this in turn aggravating the state of the skin because of hypersensitivity to the mite.

Adult↗

Circulating basophil counts in atopic individuals.

Absolute numbers of circulating basophils were measured in 55 atopic and 35 non-atopic individuals, using a flow cytometer for automated cell counting. They were significantly elevated in the atopic group (p less than 0.001), but the total leucocyte count was not significantly different between the two groups. Eosinophil counts, which correlated with the number of basophils for both populations, were also significantly raised in the atopic group (p less than 0.001). Individual variation in absolute basophil counts was not detected in sequential samples taken at daily intervals over 5 days, in 5 atopics and 4 non-atopics. In addition, no significant variation was detected in 6 atopics and 5 non-atopics over a period of up to 20 months.

Adolescent↗

Effects of additional dietary gluten on the small-intestinal mucosa of volunteers and of patients with dermatitis herpetiformis.

In an attempt to confirm the existence of latent coeliac disease--dose-related gluten-sensitive enteropathy--we have increased dietary gluten by 20 g daily for 2 weeks, in 6 healthy adults and 11 patients with dermatitis herpetiformis (DH). Six of the DH patients had entirely normal jejunal morphology on a normal diet. Jejunal biopsy specimens were taken before and at the end of the study. Measurements of crypts, villi, and crypt mitoses were made on microdissected specimens; disaccharidases were assayed, and intraepithelial lymphocyte counts performed. In one of the six adult volunteers, gluten loading produced diarrhoea and jejunal biopsy abnormalities. Five DH patients on a gluten-free diet had deterioration of biopsy pathology after the gluten challenge. Features suggestive of a latent gluten-sensitive enteropathy were found in one of the other six DH patients; he developed disaccharidase deficiencies and villus atrophy when 20 g gluten was added to his usual gluten-containing diet. This study supports previous suggestions that a gluten-sensitive enteropathy may be latent and dose-related.

Adult↗

Male sex hormone status in dermatitis herpetiformis.

In twenty-eight men with dermatitis herpetiformis (DH) the mean serum testosterone levels were within normal limits, but high levels were found in three patients with partial villous atrophy and two who had normal jejunal biopsies. The introduction of a gluten-free diet in patients with villous atrophy produced a statistically significant fall in the testosterone level in those able to discontinue their drug treatment but not in those noticing no change or only a reduction in drug requirements. The serum levels of luteinizing hormone or follicle-stimulating hormone were increased in nine patients; only one of these had a raised testosterone level and six were over 60 years of age. Four out of twenty married males with DH had no children, a figure higher than expected. Three of these men had elevated gonadotrophin levels although none had an increased serum testosterone. Thus, raised levels of testosterone and gonadotrophin were found in only a minority of men with DH, in contrast to the more marked changes previously reported in males with coeliac disease.

Adult↗

Sequential studies of gliadin antibodies in patients with dermatitis herpetiformis.

Sequential studies of circulating gliadin antibodies (IgG, IgA, IgM, IgD) were performed in 24 patients with dermatitis herpetiformis (DH) by an ELISA. Three groups of patients were studied: (a) 14 patients who responded to a gluten-free diet and were able to stop their drug therapy, (b) 5 patients who did not respond to a gluten-free diet, (c) 5 patients with normal jejunal biopsies, who did not receive a gluten-free diet. Most of the serum gliadin antibodies detected were of IgG class, but in several patients IgA gliadin antibodies were found in addition. When the patients were on a normal diet, 63% had elevated IgG gliadin antibody titres (titres which exceeded the maximum titre of the controls by one dilution) and there were no significant differences between the three groups. When the patients were followed up, there was a significant fall in the gliadin antibody titres in those who responded to a gluten-free diet compared to the two other groups of patients. Thus assays of IgG gliadin antibodies might be helpful in some patients in judging the compliance of patients on a gluten-free diet.

Adolescent↗

Junctional epidermolysis bullosa in two siblings: clinical observations, collagen studies and electron microscopy.

Two siblings with junctional epidermolysis bullosa are described: both survived beyond parturition. They were treated with the usual therapeutic doses of phenytoin, dapsone, prednisolone, and zinc supplements without effect. Investigation of the skin of one of the patients showed that his fibroblasts, collagen synthesis and collagenase levels were normal. In view of the normality of the collagenase levels, it is probably not surprising that phenytoin was ineffective. Electron microscopy demonstrated junctional cleavage without pathology in the dermis itself: abnormal hemidesmosomes were seen as described previously, though it is suggested that this is not the primary abnormality which results in the disease process.

Child, Preschool↗

Dermatitis herpetiformis: diagnosis, diet and demography.

We describe a long term study of 76 patients with dermatitis herpetiformis. Unlike patients with coeliac disease, where the peak incidence was during the first and fourth decades, no dermatitis herpetiformis patients presented in the first decade; also, there was a male preponderance in dermatitis herpetiformis which contrasts with the excess of females in coeliac disease. The apparent prevalence of dermatitis herpetiformis was 11 per 100 000 in our population; approximately one fifth of that of coeliac disease. Jejunal villous atrophy was present in 78% of our dermatitis herpetiformis patients, and a single jejunal biopsy was as effective at detecting this as the multiple biopsy technique. A majority of patients were able to stop, or radically reduce their dapsone or sulphapyridine treatment after the institution of a gluten free diet. Spontaneous remission of the skin lesion occurred in only two patients not receiving a gluten free diet. Gastric parietal or thyroid antibodies were detected in 38% of patients, and three cases of thyroid disease and two cases of pernicious anaemia were detected. Lymphoma developed in two patients, one being intestinal in origin. We conclude that a gluten free diet is of therapeutic benefit in dermatitis herpetiformis and that spontaneous remission is uncommon in those not on a diet. Despite patchiness of the enteropathy, a single jejunal biopsy is quite adequate to diagnose the presence of upper intestinal villous atrophy.

Adolescent↗

Total and specific IgG4 antibody levels in atopic eczema.

Total IgG4 and IgG4 antibody levels specific for 10 allergens (three inhaled and seven ingested) were measured by radioimmunoassay of sera taken from three groups of adult patients: (1) 32 cases of atopic eczema, (2) 28 cases of respiratory allergy and (3) 156 normal volunteers. In all three groups IgG4 antibody activity was mainly directed against common foods, and generally the group with atopic eczema had higher total and specific IgG4 levels than the cases of respiratory allergy, who in turn had higher titres than the normal group. There was within each group a tendency for men to have more total IgG4 than women and the difference was statistically significant among the normals. There was evidence of an IgG4 restricted response in atopic eczema because despite the group's elevated total IgG4 its total IgG4 remained within normal limits. Furthermore specific IgG4 was correlated with the corresponding specific IgE level in five of the 10 allergens examined. These results are generally consistent with the view that IgG4 levels are raised in cases of atopic eczema due to prolonged exposure to an allergen which initiated an IgE response.

Adolescent↗

Precipitins to dietary proteins in atopic eczema.

Precipitating antibodies to foods have been assayed in three groups of patients with atopy. Forty-five per cent of patients with atopic eczema and IgE-mediated food allergy had precipitins to foods in their serum compared with only 15% of patients with atopic eczema without evidence of food allergy, and 16% of patients with atopic asthma and/or rhinitis. It is likely that this results from increased intestinal permeability in the group with eczema and food allergy.

Adult↗