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Biomedical subjects

M Viander

Publications and source records attributed to M Viander.

At least 37 records · Page 2Linked to original sources

Airborne birch pollen antigens in different particle sizes.

Two particle samplers for ambient air, situated together: a static size-selective bio-aerosol sampler (SSBAS) and a Burkard pollen and spore trap were compared in sampling intact birch pollen grains through one flowering period of Betula (a total of 44 days). The SSBAS trapped pollen grains three times more efficiently than the Burkard trap, but the variations in pollen counts were significantly correlated. In contrast, birch pollen antigenic activity and the pollen count in the Burkard samples were not closely correlated. The antigenic concentration was occasionally high both before and after the pollination period. There was a high birch pollen antigenic activity in particle size classes where intact pollen grains were absent, even on days when the pollen count was very low. Correspondingly, on days with high birch pollen counts in the air, pollen antigenic activity was on several occasions low, indicating that pollen grains were empty of antigenic material. The small particle size classes are especially important to allergic patients because they are able to penetrate immediately into the alveoli and provoke asthmatic reactions. Therefore, aerobiological information systems based on pollen and spore counts should be supplemented with information concerning antigenic activities in the air.

Air Pollutants↗

Avidity of Aspergillus umbrosus IgG antibodies in farmer's lung disease.

Farmer's lung disease (FL), the commonest form of allergic alveolitis caused by repeated inhalation of mouldy hay, is associated with exposure to the fungus Aspergillus umbrosus among Finnish farmers. The antigen-binding avidity of A. umbrosus-specific IgG antibodies was measured in 12 FL patients in acute phases of initial and recurrent attacks and during 1 year follow up as well as in 12 healthy farmers and five healthy urban controls. The farmers' groups were further divided into two subgroups: subjects with short exposure (< 7 years) and subjects with long exposure (> 25 years). During the first acute phase FL patients with long exposure exhibited a high avidity of A. umbrosus-specific IgG antibodies that remained high during the 1 year follow up, although the A. umbrosus-specific IgG antibody titre decreased. A re-exposure to mouldy hay leading to a recurrence further enhanced the maturation of the antibody avidity, so that an even higher A. umbrosus-specific IgG avidity with a less significant increase of antibody titre occurred than during the first acute attack. Notably higher IgG antibody avidity was observed in FL patients with long exposure than in healthy farmers or in healthy controls.

Antibody Affinity↗

IgG and IgA subclass antibodies against Aspergillus umbrosus in farmer's lung disease.

Fifty patients with farmer's lung disease (FL), 20 asymptomatic exposed farmers, and 18 healthy controls were investigated for total IgG and total IgA, as well as subclass antibody levels against Aspergillus umbrosus, the most common fungus to which FL patients in Finland have been exposed. Enzyme-linked immunosorbent assay (ELISA) revealed significantly elevated levels of specific total IgG and IgA antibodies in the sera of patients during the acute phase of the disease. Both IgG1 and IgG2 subclass antibodies and both IgA1 and IgA2 subclass antibodies were significantly associated with the disease. The antibody levels decreased during the first 3 months, when mould exposure was avoided and when an oral 6-week steroid treatment was administered. During the next 12 month follow-up, the mean antibody levels continued to decrease, even though re-exposure might have occurred. The results (with sensitivity 94% and specificity 95%) imply that in addition to the measurement of A. umbrosus-specific IgG, determination of both A. umbrosus-specific IgG1 and IgA might also be useful in the serodiagnosis of acute stage of FL.

Antibodies, Fungal↗

Candida albicans and atopic dermatitis.

The role of sensitization and exposure to Candida albicans in atopic dermatitis (AD) was studied with skin-prick tests, yeast cultures and immunoblotting in 156 young adults with AD attending the Department of Dermatology, University of Turku, during 1983-89. Eighteen patients with allergic rhinitis without eczema and 39 non-atopics were included as controls. Parameters associated with severe AD were simultaneous anti-C. albicans IgE and saprophytic C. albicans growth. A statistically significant correlation between C. albicans sensitization (specific IgE antibodies) and AD symptoms was observed only in patients with saprophytic C. albicans exposure. No correlation between C. albicans-specific IgE and AD severity was shown in patients without gastrointestinal growth. Furthermore, severe eczema was seldom seen in patients without saprophytic C. albicans growth. The most important IgE-binding components of C. albicans in immunoblotting were 27 and 46 kD proteins and mannan, a polysaccharide. IgG and IgA antibodies to C. albicans, mainly towards C. albicans mannan, were found in practically all 70 sera studied. These results suggest a continuous exposure and induction of IgE antibodies by C. albicans in AD patients. Severe phases of AD in colonized patients are associated with IgE synthesis against C. albicans. These findings suggest a role for C. albicans in the exacerbations of AD but the clarification of this subject needs double-blind placebo-controlled treatment trials.

Adolescent↗

Characterization of Aspergillus umbrosus carbohydrate antigens by biotinylated lectins and IgG response to mannan/mannoprotein antigens in patients with farmer's lung.

Twenty-one different biotinylated lectins were used to recognize the carbohydrates of Aspergillus umbrosus, one of the most common microbes that patients with farmer's lung in Finland are exposed to. The glycoprotein fraction of A. umbrosus was bound especially well by Concanavalin A and consisted mainly of carbohydrates mannose and glucose. The carbohydrate fraction of A. umbrosus antigens were isolated from the crude extract of A. umbrosus with Con A-Sepharose affinity chromatography. Serum IgG antibodies to A. umbrosus mannoprotein fraction were determined in 57 patients with farmer's lung, 10 asymptomatic exposed farmers and 10 healthy controls by enzyme linked immunosorbent assay. Candida albicans and Saccharomyces cerevisiae mannan were used as controls. Patients had high levels, whereas asymptomatic exposed farmers showed moderate, and health controls low levels, of IgG antibodies to the A. umbrosus mannan/mannoprotein fraction. There were no significant differences in the mean antibody levels between the patients and controls against C. albicans or S. cerevisiae mannose fraction although in all groups more antibodies were detected against C. albicans than S. cerevisiae.

Animals↗

Prevalence of coeliac disease in diabetic children and adolescents in Sweden.

The aim of this study was to determine the minimum prevalence of coeliac disease in a group of 459 diabetic children and adolescents. Six patients were already known to have coeliac disease. A total of 436 patients with type 1 diabetes mellitus aged 2-21 years and with age at onset at 2 months to 17 years at three paediatric departments agreed to participate in the study. All patients were tested for gliadin IgA antibodies with a commercial kit (Pharmacia Gluten IgA EIA). Later, serum was tested for reticulin IgA/IgG antibodies. Nineteen patients had elevated gliadin IgA levels (> 25 AU). Eighteen underwent jejunal biopsy. Ten had total or subtotal villous atrophy. These 10 patients were reticulin IgA-positive. Of 417 gliadin IgA-negative patients, 408 were reticulin IgA/IgG-negative. Of 6 reticulin IgA-positive patients, 3 had total or subtotal villous atrophy. All 3 had become gliadin IgA-positive at the time of biopsy. Among 3 reticulin IgG-positive patients with IgA deficiency, 2 had total villous atrophy: 1 was not willing to be biopsied. Patients with total or subtotal villous atrophy were judged as having coeliac disease and were recommended a gluten-free diet. Within 2 months, gliadin IgA levels were normal in patients adhering to the diet. Five patients have gone through a second jejunal biopsy to date with normal histology in all 5. The 15 newly diagnosed patients with coeliac disease plus 6 already known patients with coeliac disease and type 1 diabetes mellitus gave a minimum prevalence of coeliac disease in diabetic children and adolescents of 21/459 = 4.6%.

Adolescent↗

Stability of Candida albicans allergens during storage.

Stability of Candida albicans allergens was studied under various storage conditions. Lyophilized extract was reconstituted with human serum albumin (NSA) diluent, glycerol-free and in the presence of 10% or 50% glycerol and stored at various temperatures for different time periods. All extracts were tested at the same time with immunoblotting using C. albicans allergic patient sera and galactosidase-labelled anti-IgE. The highest number of detected allergens in the immunoblotting pattern was found in the presence of 50% glycerol at +6 degrees C. The most important allergen of C. albicans, the 46 kD protein allergen was stable up to 10 weeks at +6 degrees C in the presence of 50% glycerol but thereafter began to lose its IgE-binding capacity. After 30 weeks more than 50% of the IgE binding had disappeared. The 27 kD protein, another important allergen, was also labile but retained the allergenicity better than the 46 kD one. The 29 kD protein allergen was stable at all storage conditions, except +37 degrees C tested even after one year. More than 6 months storage at +6 degrees C or higher temperature is, however, unacceptable even in the presence of the 50% glycerol. These findings have particular importance in the diagnosis and treatment of allergic diseases.

Allergens↗

Rheumatic complaints as a presenting symptom in patients with coeliac disease.

Twenty-three cases of coeliac disease were found after a small bowel biopsy had been carried out on seventy patients with various rheumatic complaints. The prevalence of coeliac disease in patients with rheumatic disorders was estimated to be 1 in 243. The majority (19) of these cases were found by screening patient sera with a reticulin antibody test. Sjögren's syndrome was the most frequent rheumatic diagnosis, with a total of six cases. Coeliac disease may occur concomitantly with various rheumatic complaints, and serological screening is advisable.

Adult↗

Serological markers and HLA genes among healthy first-degree relatives of patients with coeliac disease.

Coeliac disease may remain undiagnosed because of the non-specific nature of the presenting symptoms. Several antibody tests are claimed as markers for this condition but a direct comparison of the available tests has not been reported. The probands and healthy first-degree relatives of 42 families with coeliac disease were studied. Histological examination of biopsy specimens revealed jejunal mucosal villous atrophy compatible with coeliac disease in 13 of 122 relatives. Reticulin-antibody-positive relatives with or without jejunal mucosal atrophy were genetically similar to the probands of the families (DR3 gene frequencies 55.3%-60.0%). Gliadin-antibody-positive relatives with normal mucosa were genetically different from the probands (DR3 gene frequency 16.7% versus 55.3%). IgA reticulin and endomysium antibodies detected 92.3% of subjects with silent coeliac disease. The only case that was missed had selective IgA deficiency and was positive for IgG-class reticulin antibodies. By contrast, gliadin antibodies detected only half of the cases. Follow-up of the 7 reticulin-antibody-positive relatives with normal mucosa revealed 2 further cases of coeliac disease and 1 of dermatitis herpetiformis during the next three years. Our family study shows that healthy reticulin-antibody-positive first-degree relatives of coeliac disease patients, irrespective of the state of the jejunal mucosa, are genetically similar to known coeliac disease patients. Reticulin-antibody positivity is an indicator of both silent and latent coeliac disease.

Antibodies↗

Use of the extended Phadebas RAST panel in the diagnosis of mould allergy in asthmatic children.

The clinical significance of mould allergens in Phadebas RAST panel was investigated in 121 asthmatic children. They were selected from a total population of 1649 patients. The patients were distributed into four groups, based on the combination of positive or negative skin prick tests (SPT) together with symptoms suggestive or not of mould sensitivity. Mould-specific IgE antibodies were investigated using the original RAST panel (Alternaria, Aspergillus, Candida, Cladosporium, Mucor and Penicillium) and a set of 10 additional mould-allergen discs (Aureobasidium, Botrytis, Curvularia, Epicoccum, Fusarium, Helminthosporium, Phoma, Rhizopus, Stemphylium and Trichoderma). The set of additional RAST discs revealed patients with mould-reaginic antibodies not found with the original RAST panel. This occurred in four of 49 (8.2%) RAST positive (class greater than or equal to 2) patients. The allergens most frequently positive were Cladosporium (in 28% of the patients), Candida (28%) and Helminthosporium (26%). A remarkable degree of simultaneous reactivity to almost all moulds tested was observed. Patients with multiple (greater than or equal to 7) mould sensitization were effectively pinpointed using any duplicate combination of Aureobasidium, Botrytis, Candida, Cladosporium, Helminthosporium, Penicillium and Stemphylium.

Adolescent↗

IgE, IgA and IgG antibodies and delayed skin response towards Candida albicans antigens in atopics with and without saprophytic growth.

Immunoblotting and RAST were used to analyse IgE, IgA and IgG responses to antigens of Candida albicans. These were compared with the delayed skin response and C. albicans carriage in 40 atopic subjects. The majority of the atopic patients showed a strong IgG and IgA antibody response towards mannan, a carbohydrate, but only occasionally to proteins. Altogether 22 of the 40 patients showed specific IgE towards C. albicans by immunoblotting. The IgE response was mainly towards proteins, particularly to ones with molecular weights of 29 kD and 46 kD, and only in eight out of 22 IgE-positive subjects towards mannan. The IgG and IgA responses to mannan and the total IgE response towards C. albicans assessed by RAST showed an association with C. albicans carriage, whereas the delayed skin response showed an inverse relationship. The immunological parameters characteristic of C. albicans carriage were found to be C. albicans-specific depressed delayed skin response and elevated IgE, IgA and IgG responses. This situation in the atopics presenting such parameters may favour simultaneous sensitization and exposure by colonization. The degree of sensitization may be sufficiently high to produce symptomatic allergy, such as asthma, in some individuals during occasional overgrowth of C. albicans, e.g. due to antibiotic therapy.

Adolescent↗

Immunoblotting analysis of concanavalin A-isolated allergens of Candida albicans.

The carbohydrate-containing fraction of Candida albicans was isolated from the crude extract with ConA Sepharose affinity chromatography and studied by IgE-immunoblotting with individual and pooled sera from C. albicans-allergic subjects. In the ConA-bound fraction there was a diffuse IgE binding in the high molecular weight area which also gave a carbohydrate stain (PAS). A distinct band corresponding to a molecular weight of 70 kD bound specific IgE antibodies. This glycoprotein, presumably a mannoprotein, gave a weak carbohydrate staining and a strong protein staining. Further biochemical studies are needed to reveal the exact nature of the epitopes in the ConA-bound mannose-containing fraction of C. albicans.

Allergens↗

Distribution of watersoluble antigens and allergens of Candida albicans in blastospore cell extract fractions.

Watersoluble antigens of Candida albicans were sequentially extracted from intact and disrupted yeast cells grown on protein-free agar, and analysed on immunoblots after SDS-PAGE. Washing of the cells in saline before proper extraction resulted in loss of 47.2% of the total carbohydrate and 1.5% of the total protein. The protein fraction contained 14 antigenic bands when analysed with hyperimmune rabbit antisera. Four of these bound IgE when probed with a RAST-positive serum pool and beta-galactosidase-labelled anti-IgE. Extraction of the disrupted cells resulted in 15% of the total carbohydrate and 94% of the total protein. The cytoplasmic protein fraction showed 69 antigenic bands, 13 of which bound IgE. The carbohydrate fraction contained mannan, which was found in the washing solutions and in the surface extract as well as in the cytoplasmic extract. Allergens found in washing solutions were also present in cytoplasmic fraction. This study suggests that the rapid release of allergens from saprophytic C. albicans cells on mucous membranes of the body may cause continuous exposure and result in sensitization.

Allergens↗

IgE-, IgA- and IgG-antibody responses to carbohydrate and protein antigens of Candida albicans in asthmatic children.

Analysis of IgE, IgA and IgG antibodies directed against Candida albicans antigens in 28 asthmatic children was performed with immunoblotting after SDS-PAGE. Analysis with the purified cytoplasmic protein fraction revealed a major protein allergen with an MW of 46 kD. In addition to the major allergen, 15 other antigenic bands with molecular weights between 16 and 135 kD bound IgE. Ten of 13 anti-C. albicans IgE-positive children had IgE towards the 46 kD major allergen. None of the subjects in the study group or in the non-atopic controls had IgA or IgG antibodies towards this protein. Analysis of the crude surface extract showed that mannan, a carbohydrate, was an intermediate allergen contrary to being the major antigen in IgA and IgG antibody responses.

Adolescent↗

Atypical coeliac disease found with serologic screening.

Eighteen patients with coeliac disease were found by screening for reticulin antibodies of unselected sera at the time when determination of various tissue antibodies was requested. Joint disease, allergic and pulmonary disorders, and diabetes were particularly observed. IgA class reticulin antibody, in particular, proved to be specific for coeliac disease. Most patients with coeliac disease also had positive serum gliadin antibodies. Abdominal symptoms and signs of malabsorption were slight and infrequent. In most patients a gluten-free diet resulted in the improvement of jejunal mucosal histology, and serum reticulum and gliadin antibody titres decreased simultaneously, reflecting the appropriateness of the diet. Coeliac disease often has mild and atypical symptoms, and, particularly in certain disease groups, screening with reticulin antibody test seems to be appropriate.

Adult↗

Circulating immune complexes during immunotherapy in allergy to dog.

Circulating immune complexes (CIC) were determined from dog-allergic asthmatic children (n = 35) receiving immunotherapy with dog dander and hair extract. The results from CIC are expressed in SDU (standard deviation units) and presented as follows: pretreatment results (n = 20), rush results (n = 11), mid-schedule results (n = 20), maintenance results (n = 15) and the results of the placebo-treated group (n = 12). The results of the placebo-treated group (n = 12) and those of the untreated atopic (n = 12) and non-atopic (n = 14) were controls. CIC levels were analysed by means of KgB-ELISA (conglutinin binding enzyme linked immunosorbent assay), C1qB-ELISA (C1q-binding enzyme linked immunososrbent assay), RFb-ELISA (rheumatoid factor binding enzyme linked immunosorbent assay) and by PIPA (platelet 125J-labelled staphylococcal protein-A test). The CIC level determined by KgB-ELISA in dog-allergic asthmatic children was higher than that of the atopic controls (P less than 0.05) already before the onset of the hyposensitization. During conventional hyposensitization with dog dander and hair the CIC level remained the same as before treatment. On day 5 of rush hyposensitization the mean level of CIC showed no increase when compared with the pretreatment values. A statistically significant correlation (P less than 0.01) was observed between the dog dander and hair-specific IgG antibodies and the CIC level measured by KgB-ELISA during the maintenance period of conventional immunotherapy. The samples of sera to measure this correlation were collected before the injection of allergen and after 2 weeks of injection during maintenance treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Postpubertal gluten challenge in coeliac disease.

Altogether 38 postpubertal children with coeliac disease were rebiopsied. Mucosal abnormality in nine (24%) of them indicated poor adherence to the diet. Gluten challenge with a diet containing a normal amount of gluten was performed in those 29 patients with a normal mucosa. During challenge, rebiopsy was done when reticulin antibodies turned positive (mean 0.6 years, range 0.2-2.0) or at the end of the two year study. Histologically a clear relapse into coeliac disease was seen in all 23 patients who were positive for reticulin antibodies. At this time gliadin antibodies were positive in all but two. Sixteen (70%) of those who relapsed were completely asymptomatic. Three girls and one boy did not relapse within two years, indicating the possible recovery from coeliac disease to be 11%. All four had undergone gluten challenge earlier in childhood, after initial diagnosis and mucosal recovery, and this had resulted in mucosal relapse. To establish definite postpubertal recovery from coeliac disease in cases with normal mucosa at two years from challenge, further follow up studies of reticulin antibodies and later rebiopsy are needed. The reticulin antibody test seems to be suitable for prediction of mucosal relapse in coeliac disease.

Adolescent↗