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Biomedical subjects

S Husby

Publications and source records attributed to S Husby.

At least 55 records · Page 3Linked to original sources
PubMed1988

A prospective study of cow's milk allergy in exclusively breast-fed infants. Incidence, pathogenetic role of early inadvertent exposure to cow's milk formula, and characterization of bovine milk protein in human milk.

A cohort of 1,749 newborns in the municipality of Odense were followed prospectively for the development of cow's milk allergy (CMA) during their first year of life. Altogether 39 fulfilled the criteria for CMA (2.2%). Out of the 39 infants, 17 developed symptoms of CMA during breast-feeding, in all cases before the age of 3 months. Nine of these were solely breast-fed at the time of diagnosis, giving a one year incidence of CMA in exclusively breast-fed infants of 0.5% (9/1,749) in a study population with a frequency of exclusive breast-feeding of 52% at 3 months of age. None of the infants had signs of CMA in the neonatal period. Review of records from the newborn nursery revealed that all 9 infants had been exposed to cow's milk formula in amounts corresponding to approximately 0.4-3.0 g of beta-lactoglobulin (BLG) during the first three days of life. Human milk samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for the content of bovine BLG. Detectable amounts (0.5-45 ng/ml) were found in 3/9 samples of human milk against which the infants reacted clinically. Analysis of the size distribution by high pressure liquid gel permeation chromatography in combination with ELISA indicated a molecular weight of BLG corresponding to that of monomeric BLG (18 kD). Possibly early inadvertent and occasional exposure to cow's milk proteins may initiate sensitization in predisposed neonates. Subsequent exposure to minute amounts of bovine milk proteins in human milk may act as booster doses eliciting allergic reactions.

Animals↗
PubMed1988

ELISA analysis of IgA subclass antibodies to dietary antigens. Elevated IgA1 antibodies in children with coeliac disease.

Enzyme immunoassays for the quantitation of IgA1 and IgA2 antibodies to dietary antigens were developed. Serum IgA1 antibodies to bovine serum albumin (BSA) were detectable in 2/30 healthy adults, in 3/26 healthy children, and at high levels in 8/11 children with coeliac disease, without relation to gluten exposure. IgA1 antibodies to ovalbumin (OA) and beta-lactoglobulin (BLG) at high titers were seen in one coeliac child but were otherwise low or absent. IgA2 antibodies to BSA were detectable in 28/48 healthy subjects and in 8/11 coeliac children. IgA2 antibodies to OA and BLG were measurable in a few samples from each group. IgA1 antibodies to the gluten component glycgli were found at low levels in 15/56 normal sera, and anti-glycgli antibodies of the IgA2 subclass in 14/48 sera from healthy persons, also at low levels. IgA1 anti-glycgli antibodies were measurable in 5/11 sera from CD patients on a gluten-free diet. Elevated levels of IgA1 anti-glycgli antibodies were detected in all sera from CD patients challenged with gluten, except in 1 patient with a markedly reduced serum IgA level. In contrast, the IgA2 anti-glycgli antibody levels were unaffected. Thus, increased levels of IgA antibodies to dietary protein antigens in childhood coeliac disease were observed only within the IgA1 isotype.

Adolescent↗
PubMed1988

Dietary antigens: uptake and humoral immunity in man.

This thesis is based on 9 papers on the uptake of dietary antigens and on the humoral immune responses to dietary antigens, in healthy subjects and in patients with coeliac disease or atopic eczema. Work in experimental animals have indicated that dietary antigens are taken up in amounts, which are nutritionally insignificant, but may be of immunological importance. Local or systemic antibodies may retard the uptake, but in addition may increase the uptake of unrelated antigens. In humans the uptake of intact dietary antigen, free or in immune complexes, was reported in studies in healthy subjects and in patients with immune deficiency or atopy. We investigated the uptake of dietary antigen in 8 healthy subjects after a test meal, using ELISA methods and high performance liquid chromatography (HPLC) for the fractionation of serum samples. A significant finding was that ovalbumin (OA) was taken up as intact antigen or as a high MW immune complex constituent in all the 8 subjects. IgG was the only isotype demonstrable in the OA-containing aggregates, which were detected in particular in the subjects with high anti-OA antibody levels. The antigen was measurable in serum in up to 48 h after the meal. We studied with the same methods the uptake of OA and beta-lactoglobulin (BLG) in children with coeliac disease on a gluten-free diet and after gluten challenge, and in controls with a normal gut mucosa. Both OA and BLG was mostly present in high MW fractions of the sera, presumably as immune complexes. The levels of antigens in serum did not differ between the children with coeliac disease and the controls. However, in 4/5 coeliac children the uptake of both antigens was increased after gluten challenge, indicating increased antigen uptake in coeliac disease. Increased gut permeability has been suggested as a pathogenic factor in food allergy. At present, there is in this condition no direct evidence for altered uptake of dietary antigens. Dietary antigens have been detected in the mother's milk and may be important for the development of normal immunity to dietary antigens and in particular of cow's milk allergy in the infant. Antibodies to dietary antigens have previously been detected in a major proportion of healthy subjects. In a limited number of sera from normals, analysed by electrophoretic techniques, we detected antibodies to bovine serum albumin and OA predominantly in the IgG class. Interestingly, these antibodies were restricted to the IgG subclasses IgG1, IgG2 and IgG4.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

A method for the blocking of endogenous immunoglobulin on frozen tissue sections in the screening of human hybridoma antibody in culture supernatants.

Endogenous immunoglobulin in tissue sections pose a problem in immuno-histochemical techniques employing homologous antibody as primary reagents and enzyme-labelled anti-immunoglobulin for the development. A method for the blocking of endogenous immunoglobulin in human tissue sections by incubation with monomeric pepsin fragments (Fab') of rabbit anti-human immunoglobulin before applying monoclonal antibody was evaluated for the screening of human monoclonal antibody. It was initially demonstrated that Fab' rabbit anti-human IgM and anti-IgG could block endogenous immunoglobulin in human IgM and IgG producing tumors thereby abolishing the binding of subsequently applied peroxidase-labelled anti-IgM or anti-IgG. Frozen sections of human colo-rectal adenocarcinomas show a variable background staining caused by the endogenous immunoglobulin. The background completely disappeared in the IgM system by preincubation with Fab' anti-IgM while the background was clearly reduced but not abolished in the IgG system. A human hybridoma supernatant containing IgM reactive with colo-rectal adenocarcinoma could easily be screened on frozen sections using this method. This approach should be generally useful for the screening of human antibody on human tissue sections.

Antibodies, Monoclonal↗
PubMed1987

Passage of dietary antigens into the blood of children with coeliac disease. Quantification and size distribution of absorbed antigens.

The uptake of ovalbumin (OA) from egg and beta-lactoglobulin (BLG) from cow's milk into the blood was investigated for seven hours after a test meal in five children with coeliac disease on a gluten free diet and after gluten challenge, and in five children with normal jejunal mucosa. Ovalbumin was detectable by ELISA in three of five coeliac children (maximal concentrations 8-178 ng/ml serum) and in five of five controls (maximal 4-91 ng/ml serum). Beta-lactoglobulin was detected in three of five coeliac children (maximal 0.6-6 ng/ml serum) and in two of five controls (maximal 0.5 and 50 ng/ml serum). No clear relationship was seen between maximal antigen concentrations and titres of serum IgG or IgA antibodies determined by ELISA, or as percentage antigen binding in a Farr type radioimmunoassay. Ovalbumin and beta-lactoglobulin was seen in serum of all coeliac patients and controls by HPLC fractionation in combination with ELISA, either in high MW fractions, or at the Mr of native OA and BLG, respectively. In one control degradation products (about 17 kD) of BLG were detectable in serum. The serum concentrations of OA and BLG were increased on gluten challenge in four or five coeliac children, indicating increased macromolecular passage through the gut mucosa in untreated coeliac disease.

Antibodies↗
PubMed1986

Passage of undegraded dietary antigen into the blood of healthy adults. Further characterization of the kinetics of uptake and the size distribution of the antigen.

The molecular weight distribution of ovalbumin (OA) absorbed into the blood in eight healthy adults after a test meal was analysed by high pressure liquid gel permeation chromatography (HPLC) followed by ELISA for OA. OA was found either as free OA or as aggregates of a size mainly below 700 kD. The addition of OA in vitro to an antibody-containing serum resulted in OA-containing immune complexes (OA-IC) of similar size. The size distribution of serum OA-IC was more heterogeneous late than early in the 7-h observation period. Free OA disappeared at an equal or higher rate than OA-IC when both entities were present in the same individual. The presence of OA-IC was related to the serum IgG antibody levels. IgG, but not IgA or IgM, could be detected in OA-IC (in three individuals) by ELISA. The kinetics of OA appearance was followed for 48 h after a test meal in three individuals. In one person, serum OA reached peak values at 24 h and detectable amounts persisted for 48 h after the test meal. In the other test persons the OA levels peaked earlier. The present study indicates that in healthy adults dietary antigens are absorbed and circulate regularly in minute amounts apparently as native protein and/or as small immune complexes, mostly containing IgG antibodies.

Adult↗
PubMed1986

Humoral immunity to dietary antigens in atopic dermatitis. I. Biotin-avidin amplified ELISA-analysis for serum IgG antibodies.

Enzyme-linked immunosorbent assays (ELISA) employing a biotin-avidin amplification step are described for the quantification of human serum IgG antibodies to the dietary antigens ovalbumin (OA) and beta-lactoglobulin (BLG). The analytical quality of these assays was acceptable. Antibodies were measured in 16 patients with mild or moderate atopic dermatitis (AD), in 31 patients with a history of AD, and in closely matched controls. Levels of serum anti-OA antibodies did not differ in patients and controls, whereas anti-BLG antibodies tended to be higher in patients with mild or moderate AD than in controls (P less than 0.05).

Adolescent↗
PubMed1986

Humoral immunity to dietary antigens in atopic dermatitis. II. Analysis of IgE and IgG subclass antibodies.

IgG subclass antibodies to two dietary antigens, ovalbumin (OA) and beta-lactoglobulin (BLG) were measured with quantitative ELISA-techniques in 16 patients with atopic dermatitis (AD) (6-21 years old) and closely matched controls. In addition, IgE-antibodies to OA, BLG and milk were determined with RAST. IgG subclass antibodies were frequently detected in IgG1 and IgG4 for both AD-patients and controls, quantitatively dominated by IgG4. The IgG4 anti-BLG antibody levels were significantly higher (P less than 0.001) in AD-patients (median: 1.1 microgram/ml, range: 0-24.0 microgram/ml) than in controls (median: 0.05 microgram/ml, range: 0-1.05 microgram/ml). No relation was found between IgG4 anti-BLG antibody levels, levels of IgE antibodies to milk or BLG, or severity of disease.

Adolescent↗
PubMed1986

Relationship between levels of rheumatoid factor isotypes and complement component C3 conversion in blood from patients with rheumatoid arthritis.

Conversion of complement component C3 in plasma from rheumatoid arthritis patients was measured by two different methods. One of the methods gives an estimation of C3 conversion by ELISA measurement of neodeterminants present on the C3d moiety; the other method measures C3 split products expressing D, but not C, epitopes by rocket immunoelectrophoresis (RIE) with intermediate anti-C3c gel. Results from 20 RA patients obtained by the two methods did not correlate significantly (R = 0.52, 0.02 less than p less than 0.05). The results were compared to the level of rheumatoid factors (RFs) of IgG, IgM, and IgA class in serum. A significant correlation was found between the concentration of C3d measured by RIE and level of IgG RFs, whereas neither IgM nor IgA RFs showed correlation to complement activation. The results of the ELISA estimation of C3 activation showed no correlation with the RF level.

Arthritis, Rheumatoid↗
PubMed1986

Autoreactive lymphocytes in thyroid disorders. II. Comparison of anti-thyroglobulin antibody production by plaque-forming cell, radio-immunological and enzyme-linked immunosorbent assays.

Blood mononuclear cells (MNC) from 9 randomly selected patients with autoimmune thyroiditis were stimulated in vitro with pokeweed mitogen (PWM), a polyclonal B lymphocyte activator. The secretion of immunoglobulins (Ig) and anti-thyroglobulin antibodies (TgAb) was assayed by means of haemolytic plaque-forming cell (PFC) assays, radio-immune assay (RIA) and enzyme-linked immunosorbent assays (ELISA). Total Ig and TgAb production was maximal using MNC cultured at 1.0 X 10(6)/ml as estimated by PFC, RIA and ELISA. The Ig and TgAb production as measured by RIA and ELISA was 1.5 - 3 times higher after 12 days' culture compared to 6 days' culture. Ig and TgAb production measured by PFC-assays at day 6 correlated positively to the results obtained by RIA and ELISA at day 12. PWM-induced TgAb secretion correlated positively to TgAb titres in serum. As judged by PFC, TgAb production was found in 8/9 patients; about 5% (range 0 - 7.9%) of the total PWM-stimulated IgG-secreting cells were involved in TgAb secretion. TgAb production as measured by ELISA and RIA was found in 6/9 patients. By reference to an affinity-purified human TgAb preparation, the TgAb secretion was about 0.7% (range 0 - 21.3%) of the total PWM-induced IgG secretion.

Antibody Formation↗
PubMed1986

Serum IgG subclass antibodies to gliadin and other dietary antigens in children with coeliac disease.

IgG subclasses of antibodies to the dietary antigens gliadin, glycgli (a gluten component), ovalbumin (OA) and beta-lactoglobulin (BLG) were quantified in children with coeliac disease (CD), nine on a gluten-containing diet, 15 on a gluten-free diet, and in appropriate controls. In addition, total serum IgG subclasses were measured. IgG1 and IgG3 antibodies to gluten and glycgli were detected in 9/9 and 8/9 CD-patient on a gluten-containing diet, respectively, and in 4/15 and 6/15 patients on a gluten-free diet. None of the controls had appreciable levels of IgG1 antibodies and only 1/22 of the controls had IgG3 antibodies to gliadin and glycgli. IgG2 and IgG4 antibodies to the same antigens were found in a few coeliacs and controls. Consecutive samples from coeliac children (8 patients) showed a clear relation between the exposure to gluten and a rise in IgG1 (8/8) and IgG3 antibody levels (7/8). In contrast, IgG antibodies to OA and BLG were almost exclusively of the IgG1 and IgG4 subclasses. The highest levels were found in children with CD, but the differences between the groups were not significant. Total serum IgG subclasses did not differ between the groups, but the IgG2 and IgG4 levels in most coeliac children were low. The production of IgG1 and IgG3 antibodies to gluten components may be an important precondition for the development of coeliac disease in susceptible individuals.

Adolescent↗
PubMed1985

ELISA quantitation of IgG subclass antibodies to dietary antigens.

The IgG subclasses of human antibodies against 2 dietary antigens, ovalbumin (OA) and beta-lactoglobulin (BLG), were studied by ELISA using monoclonal anti-human IgG subclass antibodies. Under the assay conditions used, the anti-IgG subclass antibodies were subclass specific. Quantitative estimates of the subclass antibodies were obtained by reference to a 'capture' assay using F(ab')2 anti-light chain antibody as ligand and IgG myelomas as standards. The validity of these estimates was supported by antibody quantitation using the Farr assay. In healthy adults with serum anti-OA or anti-BLG antibodies, anti-OA antibodies were found mainly in the IgG1 (9/11) and IgG4 (6/11) subclasses, whereas 5 sera showed high levels of IgG2 antibodies. In contrast, the IgG subclass distribution of anti-BLG antibodies was predominantly IgG4 (10/10).

Adult↗
PubMed1985

Increased non-specific binding of heat-treated proteins to plastic surfaces analyzed by ELISA and HPLC-fractionation.

Heat-treatment of proteins from human sera and bovine serum albumin caused an increase in their binding to microplates in a temperature-dependent manner. Quantitative data were obtained for 125I-labelled human IgG, with binding of up to 400 ng of 56 degrees-treated IgG per untreated well. However, only a minor increase in available antibody activity of adsorbed rabbit antibody was found upon pretreatment at 56 degrees. The increased binding to microplates as a result of pre-incubation at raised temperatures was by high pressure liquid gel permeation chromatography demonstrated to be accompanied by polymerization. Inhibition of the direct binding of the proteins to plastic surface was achieved most efficiently by coating with non-interfering proteins followed by non-ionic detergent (Tween 20), which should also be present in the wash buffer.

Animals↗
PubMed1985

Investigation of TSH dependency, circulating thyroid autoantibody, and morphological features of recurrent nontoxic goitre.

Pathogenetical factors possibly responsible for recurrence of nontoxic goitre in a nonendemic area are evaluated. A group of 22 female patients admitted for surgical treatment of recurrent nontoxic goitre was compared with a control group of 86 female nontoxic goitrous patients not operated upon before. Preoperative serum baseline thyrotrophin levels in the recurrent goitre group were low normal and did not differ significantly from those in the control group. Circulating thyroid microsomal autoantibodies, thyroglobulin antibody titers, and the densities of lymphocytic aggregation in goitrous tissue did not differ significantly in the two groups. Thus, none of the parameters studied were likely explanations of regrowth of goitre.

Autoantibodies↗
PubMed1985

Passage of undegraded dietary antigen into the blood of healthy adults. Quantification, estimation of size distribution, and relation of uptake to levels of specific antibodies.

The absorption into the blood of ovalbumin (OA) and beta-lactoglobulin (BLG) was investigated in eight healthy adults. Enzyme immunoassays showed up to 10.5 ng OA/ml serum in seven out of eight individuals 2-3 h after a test meal, whereas no BLG was demonstrated. The apparent size distribution of the absorbed OA was investigated by high-pressure liquid gel permeation chromatography fractionation, followed by enzyme-linked immunosorbent assay, which in the fractionated sera showed OA in all eight individuals. OA was found at the elution volume of intact OA and, in addition, was present in high molecular weight fractions, as part of the immune complexes. The serum concentrations of OA could not be clearly correlated to levels of serum and secretory anti-OA antibodies. No significant alterations of the levels of circulating immune complexes could be demonstrated by two antigen-nonspecific assays. The presented data indicate that, for certain dietary proteins, low-grade absorption of apparently undegraded protein into the blood occurs regularly in healthy adults.

Absorption↗
PubMed1985

Analysis of rheumatoid factors by a biotin-avidin based isotype-specific ELISA.

A one day enzyme immunoassay for the detection of rheumatoid factors of the IgG, IgM, and IgA class is described. The assay utilizes rabbit IgG as solid-phase reactant and the biotin-avidin interaction for the coupling of enzyme to indicator antibody. Three different indicator antibodies discriminated effectively between rheumatoid arthritis patients and normal subjects. F(ab')2 fragments of goat antibodies were found best suited for the test. Rheumatoid factor activity was expressed in U/ml by comparing samples to an internal standard, which was related to the WHO international reference serum for rheumatoid arthritis. Rheumatoid factor activity (U/ml) in the IgM-specific assay showed a close correlation to the latex agglutination titer. Avidity indices estimated from the slopes of the dose response curves of test sera were significantly higher for rheumatoid arthritis patients than for a group of healthy persons, indicating a higher avidity of the rheumatoid factors in the patients' sera.

Adult↗
PubMed1985

Humoral immunity to dietary antigens in healthy adults. Occurrence, isotype and IgG subclass distribution of serum antibodies to protein antigens.

The occurrence of antibodies to five dietary protein antigens in the sera from 21 healthy adults was investigated by a modified Farr assay. Antibody to ovalbumin (OA) occurred most frequently (90%) whereas only 24% had antibodies to alpha-lactalbumin (ALA). No correlation was noted between the titer of antibodies against bovine serum albumin (BSA) and OA in the single individual. The avidity constants (10(8)-10(9) l/mol) and cross-reactivities against other albumins of anti-BSA antibodies in two human sera were comparable to that of the antibodies in pooled hyperimmune rabbit antiserum. Crossed radioimmunoelectrophoresis showed serum anti-BSA and anti-OA antibodies to be predominantly of the IgG class (13/13, 10/10), occasionally of the IgA- (6/13, 1/10) and rarely of the IgM class (1/13, 0/10). Analysis by radioelectroimmunoassay (rocket immunoelectrophoresis) of the IgG subclass distribution of anti-BSA and anti-OA antibodies showed total absence of IgG3. In contrast, antibodies of the IgG4 subclass were frequently present even in sera with very low levels of total IgG4.

Adult↗