Eeva Vainio

IgA ANTIGLIADIN ANTIBODIES: A MARKER OF MUCOSAL DAMAGE IN CHILDHOOD COELIAC DISEASE

Antigliadin antibodies in serum samples of 31 children with coeliac disease were measured by an enzyme-linked immunosorbent technique. In young patients (less than 2 years) tested before gluten withdrawal IgA antigliadin antibody levels were invariably above the levels of 36 controls. The titres fell rapidly when gluten was eliminated from the diet and rose on its reintroduction. The titres were not always greater than the control level in older untreated patients. IgA antigliadin antibodies seem to be a good marker of the immune reaction in the jejunum triggered by gluten. In 2 IgA-deficient patients gluten challenge caused an increase in IgM antigliadin antibodies, and at the same time the number of IgM-containing cells increased in the jejunal mucosa. Rising IgG antigliadin antibody levels after gluten elimination were seen in 6 patients, 5 of whom had very low complement C3 levels before gluten elimination.

Antigliadin IgE--indicator of wheat allergy in atopic dermatitis.

Background: Cereal grains are recognized as the cause of adverse reactions in some patients exposed to grain or flour by either inhalation or ingestion. Cereal‐related diseases, such as celiac disease and bakers asthma, have been well studied and the causative cereal proteins have been characterized. Although cereals form an essential part of daily nutrition, the allergenic proteins causing symptoms on ingestion in atopic dermatitis (AD) have remained obscure. In this study, we have investigated the allergenic fraction of wheat in AD.

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

SummaryA sensitive and technically simple enzymelinked 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.

IgA anti-endomysial antibodies in dermatitis herpetiformis: correlation with jejunal morphology, gluten-free diet and anti-gliadin antibodies

Circulating IgA‐class anti‐endomysium antibodies (EmA) can be detected by indirect immunofiuorescence on monkey oesophagus sections. We found EmA in 22 (76%) of 29 patients with dermatitis herpetiformis (DH) on a normal, gluten‐containing diet. The highest frequency (100%) of EmA was observed in patients with sub‐total villous atrophy. IgA‐class antigliadin antibodies (AGA) were found using an ELISA method in 59% of 29 DH patients and in 86% of those with sub‐total villous atrophy. There was a significant correlation between EmA litres and AGA levels in individual patients.

Antigliadin and antireticulin antibodies in children with dermatitis herpetiformis

The serum samples of 27 children with dermatitis herpetiformis (DH) were examined for the presence of antigliadin (AGA) and antireticulin (ARA) antibodies. AGA were determined with an enzyme-linked immunosorbent assay (ELISA) and ARA with an immunofluorescence method. Increased IgA or IgG class AGA levels were found in four of ten children on a normal diet, in two of 25 on a gluten-free diet (GFD), and in two of four children on gluten challenge. The corresponding figures for ARA were nine of ten, two of 25, and four of four, respectively. All nine patients with ARA on a normal diet had either subtotal or partial villous atrophy, whereas the patient negative for ARA had a normal jejunal mucosa. ARA were mostly of IgA class, and after gluten withdrawal, increased levels fell to normal range. Four children were challenged with gluten, and they all developed subtotal villous atrophy and demonstrated IgA class ARA. These results suggest that in childhood DH, ARA is a more sensitive indicator of gluten-sensitive enteropathy than AGA, but both antibody determinations can be used in monitoring adherence to GFD treatment.

Immunoblotting Analysis of Antigliadin Antibodies in the Sera of Patients with Dermatitis herpetiformis and Gluten-Sensitive Enteropathy

Antigliadin antibodies (AGA) were analyzed by immunoblotting from the sera of 30 patients with dermatitis herpetiformis (DH) and of 13 patients with gluten-sensitive enteropathy (GSE). The results were correlated to the jejunal morphology and to the serum AGA values as quantified with an enzyme-linked immunosorbent assay (ELISA). Immunoblotting analysis disclosed a distinct pattern of AGA which was similar in patients with DH and GSE. In both diseases individual variation in IgG class AGA patterns was large, suggesting that several antigenic determinants are involved in the AGA response. The IgA class AGA pattern was clearly more homogeneous. The sera with several bands in immunoblotting had the highest AGA levels in ELISA. Strong staining in the main gliadin area (bands from 31 to 38 kd) indicated severely damaged intestinal mucosa whereas the serum of DH patients with partial villous atrophy or normal mucosa showed usually weaker staining. The immunoblotting pattern of sera from healthy controls was even weaker but was directed against the same polypeptides as in the patients suggesting a quantitative rather than qualitative difference between healthy and diseased subjects. This difference was, however, more obvious in the IgA than in the IgG class AGA pattern possibly indicating a more fundamental defect in the regulation of synthesis of IgA isotype in DH and GSE.

Antibody Response against Wheat, Rye, Barley, Oats and Corn: Comparison between Gluten-Sensitive Patients and Monoclonal Antigliadin Antibodies

The antibody response of patients with gluten-sensitive enteropathy and dermatitis herpetiformis against alcohol-soluble prolamines of wheat, rye, barley, oats and corn assessed by immunoblotting was compared to the staining patterns produced by monoclonal antigliadin antibodies. Both monoclonal antibodies (MAbs) and patient serum reacted with wheat, rye, barley and oats, the patient serum showing individual variation both in IgA and IgG stainings. A broad reactivity with polypeptides from 30 to 68 kD was, however, typical for patient serum and comparable to the reactivity of two broadly reacting antigliadin MAbs. This kind of broad reactivity of the MAb may suggest that it binds to glutamine-repeating sequences of highly homologous gliadin polypeptides. Glutamine- and proline-containing motifs Pro-Ser-Gln-Gln and Gln-Gln-Gln-Pro are also included in the peptides toxic to the celiac small intestinal mucosa. Our study indicates that the humoral response of the patients may detect similar structures, in oat prolamines as well. Patient serum and one of the MAbs also reacted with a 22-kD polypeptide of corn extract. The meaning of this reactivity is not known, and further characterization of the antigenic epitopes of different cereals will be important.

IgA and IgG Binding Components of Wheat, Rye, Barley and Oats Recognized by Immunoblotting Analysis with Sera from Adult Atopic Dermatitis Patients

IgA and IgG antibody response of adult atopic dermatitis patients against neutral/ acidic fractions of wheat, rye, barley and oats was analyzed utilizing an immunoblotting method. Moreover, the antibody response against ethanol-soluble fraction of wheat was examined with serum pools of healthy donors, atopic dermatitis patients and patients with dermatitis herpetiformis or adult celiac disease. All patient sera revealed polymorphic IgA and IgG binding to cereal peptides with molecular weights of 11-97 kD. The antibody staining was essentially identical with atopic dermatitis patients and controls. Patients with dermatitis herpetiformis or celiac disease showed more intensive staining with the ethanol extract of wheat and showed more IgA-stained bands in immunoblotting. It seems that the presence of IgA and IgG antibodies to different cereal antigens is a result of natural exposure and in atopic dermatitis displays little diagnostic significance, in contrast to antigliadin antibody response in dermatitis herpetiformis and celiac disease.

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.