Maintenance of tolerance to cow''s milk in atopic individuals is characterized by high levels of specific immunoglobulin G4

BACKGROUND: The central role of specific IgE in cow's milk allergy (CMA) is well documented. However, less is known about the function of other immunoglobulin isotypes in allergy and tolerance to cow's milk proteins (CMPs). OBJECTIVE: To determine differences in the antibody responses that are associated with allergy and tolerance to cow's milk in allergic, atopic and non-atopic individuals of different age groups. METHODS: Nineteen infants (<1 year), 18 children (6-14 years) and 41 adults (21-68 years) were included. Each age group was comprised of subjects with CMA, atopic individuals without a history of CMA and non-atopic subjects. Levels of specific IgE, IgG4, IgG1 and IgA to whole cow's milk and the six most abundant individual CMPs were determined in plasma by ELISA. For comparison, specific IgE and IgG4 were measured to ovomucoid and house dust mite (HDM) in individuals allergic for the respective allergens, and in atopic and non-atopic subjects without allergy. RESULTS: In infants and children with CMA, alphas1-casein and beta-lactoglobulin induced the highest specific IgE response, whereas alphas1-casein was the most allergenic CMP in adult patients. Specific IgG4 and IgG1 responses were the highest to alphas1-casein and beta-lactoglobulin in all age groups, while kappa-casein and alpha-lactalbumin induced the highest levels of IgA. CMP-specific IgG4 was higher in atopic children and adults without CMA, as compared with non-atopic individuals. A similar difference between tolerant atopic and non-atopic subjects was observed for IgG4 specific to ovomucoid, whereas HDM-specific IgG4 was not detectable in these subjects. CONCLUSION: Maintenance of tolerance to cow's milk in atopic children and adults without CMA is associated with elevated levels of specific IgG4, in combination with low specific IgE. The up-regulation of specific IgG4 in tolerant atopic individuals may be related to the type of allergen and its regular dose of exposure.     

Serum antibodies against native, processed and digested cow's milk proteins in children with cow's milk protein intolerance

Children with or without cow's milk protein intolerance were investigated for serum antibodies to native cow's milk proteins, processed cow's milk proteins and native- and pepsin-digested β-lactoglobulin. Antibodies of IgG and IgA isotypes were determined with ELISA and those of IgE isotype with RAST. Children who exhibited slowly appearing untoward reactions to cow's milk feeding had significantly higher titres of IgG antibodies against both native and digested β-lactoglobulin than children with an immediate type of reaction or no intolerance. The IgG antibodies to pepsin-digested β-lactoglobulin were efficiently inhibited by native β-lactoglobulin even at low concentrations, which suggests that there were no antibodies specific for the degraded proteins. The children with slow reactions to cow's milk also tended to have higher antibody levels of the IgG and IgA isotypes to both native and processed cow's milk. Antibodies to this mix of antigens discriminated less well, however, than the antibodies to isolated β-lactoglobulin between the groups of children with slowly appearing reactions, with immediate reactions and the controls. Seven out of nine children with an immediate type of reaction to cow's milk protein had IgE antibodies against cow's milk protein determined with the RAST, while this type of antibodies could not be demonstrated in any child in the two other groups. Using processed or digested protein as antigen did not increase the sensitivity of the antibody determinations.     

C3-containing IgE immune complexes in asthmatic patients.

Higher levels of IgE-containing immune complexes (IC) have been reported in sera from patients with allergic diseases than in sera from controls. To evaluate the possibility of an IC-mediated mechanism in the pathogenesis of bronchial asthma, we measured circulating C3-containing IgE IC (C3-IgE IC) using anti-C3 ELISA from 20 house dust mite (HDM)-sensitive asthmatics, 20 non-atopic asthmatics, and 14 non-atopic controls. C3-IgE IC levels were significantly higher in HDM-sensitive asthmatics (mean +/- S.D.: 12.2 +/- 7.8 AU/ml) than in non-atopic asthmatics (6.5 +/- 7.5 AU/ml) or controls (5.8 +/- 4.4 AU/ml). C3-IgE IC levels were significantly correlated with HDM-specific IgE levels (r = 0.50, p < 0.05), but not with total IgE levels (r = 0.36, p > 0.05) in HDM-sensitive atopic asthmatics. C3-IgE IC levels in sera did not significantly change during HDM-bronchoprovocation test in six HDM-sensitive asthmatics who showed positive reaction. Part of C3-IgE IC could be precipitated by protein G coupled beads. In conclusion, C3-IgE IC levels were elevated in sera from HDM-sensitive asthmatics; moreover IgG antibodies might be a component of C3-IgE IC. Our results suggest that an IgE IC-mediated mechanism could be involved in the pathogenesis of atopic asthma.     

Clinical associations with serum allergen-specific IgG4 antibodies

Serum total and allergen-specific IgE and IgG4 antibodies, were measured in eighty-seven atopic and nineteen non-atopic asthmatics. The allergens studied were: Dermatophagoides pteronyssinus, grass pollens, cat dander, dog dander, milk and egg. Sixty-eight atopic asthmatics and fourteen non-atopic asthmatics were found to have allergen-specific IgG4 antibodies, to at least one of the allergens tested. IgG4 antibodies to milk and egg were common in both groups of asthmatics, and to animal danders in the non-atopic asthmatics. Skin prick tests were always negative when allergen-specific IgG4 antibodies occurred alone, but in such cases, intradermal skin tests were positive. Seventy-five per cent ofa group of patients with normal levels of serum total IgG4, were found to have at least one positive IgG4 RAST.     

Relationship between antigen-specific IgE antibody (RAST) and total serum IgE levels.

Although the total serum IgE level is generally higher in atopic than in non-atopic individuals, high total serum IgE levels and atopic diseases are not invariably associated. In 42 atopic patients with the total serum IgE levels less than 100 U/ml, 27% of RAST against 14 allergens were positive whereas in 45 atopic patients with the total serum IgE levels greater than 500 U/ml, 57% of RAST against 14 allergens were positive. The mean RAST values against four grass antigens expressed as a percentage of antigen-disc bound radioactivities were significantly lower in the group with the lower total serum IgE levels. Low or normal total serum IgE levels are likely to be found in atopic patients who are allergic to a relatively few grass antigens.     

Isotypic analysis of antibody response to a food antigen in inflammatory bowel disease

We studied the class-specific antibody response to the cow's milk antigen beta-lactoglobulin (beta-LG) in sera from patients with ulcerative colitis and Crohn's disease. IgG and IgM to beta-LG were significantly higher in patients when compared to healthy non-atopic controls, whereas IgA values were similar, and specific IgE absent in all groups. No correlation between IgG- or IgM-containing immune complexes was found with the corresponding isotype of antibody to beta-LG; however, IgM complexes correlated with serum total IgM in ulcerative colitis. In these patients, IgG antibodies were higher in active cases, whereas IgM increased in patients without signs of disease activity. Antibody titers did not correlate with disease duration or administration of antiinflammatory drugs. This pattern of anti-beta-LG reactivity suggests that the presence of intestinal lesions may be revealed by the selective increase of some antibody isotypes to orally administered antigens. Enhanced mucosal permeability may be studied by this type of serological analysis.     

Circulating IgG autoantibodies to IgE in atopic syndromes

Sera from nonatopic healthy donors and patients with hyper-IgE syndrome, allergic respiratory disease, i.e., allergic rhinitis and asthma, and atopic dermatitis were assayed for the presence of IgG and IgM antibodies to IgE. The assay used was based on an ELISA method that measured the binding of IgG or IgM in test sera to myeloma IgE (PS)-coated microtiter wells. The levels of IgG anti-IgE but not of IgM anti-IgE were elevated in patient sera of all three categories tested. The same sera failed to demonstrate increased levels of IgG anti-IgM or IgG anti-IgA. Significant IgG anti-IgE activity remained after absorption of patient sera over pooled human IgG F(ab')2 Sepharose. The IgG anti-IgE activity appeared to be directed toward the Fc portion of IgE because absorption of positive sera over IgE (ADZ) Sepharose but not over myeloma IgG Sepharose completely removed their reactivity with IgE (PS) and because sera from atopic individuals but not from normal subjects contained IgG anti-IgE activity against the protein backbone of the Fc portion of IgE synthesized from a fragment of the cloned gene of human myeloma IgE (ND) heavy chain. Regression analysis demonstrated a weak but significant correlation (r = 0.31; p less than 0.05) between serum IgE levels and IgG anti-IgE activity. Fractionation of sera from the three patient categories by gel filtration over Sepharose 6B revealed that IgG anti-IgE activity was present both as monomeric IgG and in IgE containing immune complexes (IC). Intermediate molecular size IC (between 7S and 19S) were present in all three patient groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Variable binding affinities for allergen suggest a 'selective competition' among immunoglobulins in atopic and non-atopic humans

Atopy is a persistent, aberrant humoral response to certain classes of proteins (allergens) characterized by the presence of allergen-specific IgE. Yet, in both atopic and non-atopic individuals, allergen-specific responses involving the IgA and IgG subclasses have been observed, which evidence does not support models suggesting inherited differences in sensitivity to certain protein classes. Using the major ragweed component Amb a 1 as a model allergen, we assessed the humoral responses in three groups of unrelated donors: (A) atopic, ragweed sensitive; (B) atopic, but not ragweed sensitive; (C) non-atopic. As expected, Amb a 1-specific IgE was present in group A only. However, there were essentially no differences in the relative proportions of Amb a 1-specific IgA(1,2) and IgG(1-4) among the groups. We also determined the Amb a 1 binding affinities for IgG(1) and IgG(4) in the three groups, and compared these to Amb a 1-specific IgE binding affinities in group A. Group A donors' Amb a 1-IgE had extremely high affinities (10(8) to 10(11)M(-1)), but their Amb a 1-IgG(1) and Amb a 1-IgG(4) affinities were significantly lower (10(7) to 10(10)M(-1)). The average IgG(4) binding affinities in groups B and C were slightly higher than that of IgG(4) in group A, although not statistically significant. However, the IgG(1) affinity for Amb a 1 among group C, non-atopic donors was significantly elevated and comparable to the IgE affinity observed in group A, ragweed atopics. Inhibition studies with allergen-specific IgE-free serum showed that all isotypes recognized the major epitopes seen by IgE. These results suggest that there may be a "selective competition" among isotypes for allergens that is driven by the ability to produce high affinity, allergen-specific immunoglobulins.     

Immunoglobulin response to intrapulmonary immunization of asthmatics.

Atopic asthmatics, compared to non-atopic individuals, exhibit an increased amount of serum antigen-specific IgE and IgG4 antibody directed toward many aeroallergens. We tested the hypothesis that this difference between atopics and non-atopics extends to the response to intrapulmonary deposition of a neoantigen, keyhole limpets haemocyanin (KLH). We immunized nine atopic asthmatics and nine non-atopic controls with 500 micrograms KLH instilled into a subsegment of the lingula and examined serum anti-KLH, IgG1, IgG2, IgG3, IgG4, IgA1, IgA2, and IgM and specific antibody production by peripheral blood mononuclear cells for 25 days. We also determined specific antibody in bronchoalveolar lavage fluid (BALF) in both the immunized and a non-immunized lobe 11 days after immunization. We found specific serum antibody in all immunized subjects with no difference between atopics and normals in the amount or kinetics of anti-KLH IgG1, IgG2, IgG3, IgA1, IgA2 and IgM. However, the atopics exhibited more anti-KLH IgG4 than the normal controls. Specific anti-KLH antibody-producing cells were detected in peripheral blood in most subjects at day 8 to 12 after immunization with no difference between atopics and normals. Specific IgA1, IgA2, IgG1 and IgM antibodies were detected in BALF from the immunized lobes but not from the non-immunized lobes of both groups of subjects with no difference between atopics and normals. We conclude that atopic asthmatics respond to intrapulmonary KLH with more serum anti-KLH IgG4 than normal controls, consistent with a bias toward a Th2 response to intrapulmonary exposure to antigen.     

Total serum IgD is increased in atopic subjects

We have developed a sandwich-type ELISA system for measuring total IgD levels in the serum of atopics and non-atopic controls. In this ELISA system, affinity purified goat anti-human IgD was used for capture. Results were superior to those obtained with monoclonal anti-human IgD antibody. No cross-reactivity could be demonstrated to IgG, IgM, IgA or IgE. The assay showed minimal non-specific binding even with initial serum dilutions of 1:2. The results obtained were reproducible among replicates (Mean CV +/- SEM = 0.03 +/- 0.002; n = 251), between dilutions (CV = 0.08 +/- 0.006; n = 108), and between assays (CV = 0.05 +/- 0.12; n = 5). We used routine radioimmunoassay for measuring total serum IgE. Using these assays total serum IgD and IgE levels were measured in 75 atopic patients and 33 normal subjects. None of the atopics had recent immunotherapy. As expected, the geometric mean serum IgE in atopics (373 ng/ml) was significantly higher than that in normal subjects (49 ng/ml) (P less than 0.01). However, geometric mean serum IgD was also significantly higher in atopics (20.3 micrograms/ml) than that in normal subjects (8.4 micrograms/ml) (P less than 0.02). In both atopic and normal groups, mean serum IgD level did not differ significantly on the bases of age, sex or asthmatic status. Furthermore, total serum IgD was not significantly correlated with total serum IgE (r = 0.14; P = 0.14; n = 108), indicating that immunoregulatory control of the basal levels of the two isotypes is not linked.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical correlations between long-term (IgE) and short-term (IgG S-TS) anaphylactic antibodies in atopic and 'non-atopic' subjects with respiratory allergic disease

The sera of atopic and non-atopic persons with allergic pulmonary disorders were examined for long-term sensitizing, IgE and short-term sensitizing heat-stable (S-TS) antibodies which were present separately or together in the sera of some patients sensitive to antigens such as budgerigar serum proteins and Aspergillus fumigatus. In fourteen atopic patients with extrinsic asthma, six had both types of antibody to common allergens, and of nine non-atopic patients with cryptogenic (intrinsic) asthma, four had only heat-stable short-term sensitizing antibodies. The sera of atopic subjects with type I prick test reactions and positive RAST's, showed specific IgE antibody by baboon PCA tests to budgerigar serum proteins, A. fumigatus, Timothy grass pollen extract and hen egg extract, and not to Dermatophagoides farinae, possibly because of naturally occurring mite antibodies in the baboon. The sera of non-atopic asthmatics, who had given negative prick test but positive immediate, dual or late intracutaneous tests, and only late asthmatic reactions, contained precipitins in most cases and gave little or no RAST reaction. On baboon PCA these sera contained either, S-TS antibody alone, or S-TS plus long-term sensitizing antibody, or long-term sensitizing antibody alone. Some of the sera with long-term sensitizing antibody contained blocking antibody which could diffuse away in the 24 hr delay for the baboon PCA test and could also be responsible for the negative RAST. Tests with insoluble anti-IgE immuno-adsorbents on two sera from persons sensitive to aspergillus confirmed that the S-TS activity was not due to IgE, and on two sera with negative RAST and negative prick tests to budgerigar serum antigens confirmed that the 24 hr monkey PCA responses were due to IgE.     

Specific antibodies in infants with gastrointestinal intolerance to cow's milk protein

Antibodies of various immunoglobulin classes against cow's milk proteins were studied in infants and children with cow's milk protein intolerance, gluten-sensitive enteropathy and acute gastroenteritis. Their IgE, IgG, IgM and IgA antibody levels determined with the enzyme-linked immunosorbent assay (ELISA) and the IgE antibodies also determined with RAST, were compared with reference groups of children and adults. IgE, IgT or IgA antibodies against unseparated cow's milk proteins, alpha-lactalbumin, beta-lactoglobulin, alpha-casein and beta-casein were present in many of the studied samples, but did not discriminate between the individuals with and without intolerance symptoms. As a group, the infants with late reactions to cow's milk showed increased levels of IgE and IgG antibodies detected with the ELISA, while patients with gluten-sensitive enteropathy had significantly increased levels of IgG and IgA antibodies of cow's milk proteins compared to the reference group. By combining the findings of antibody increases in various immunoglobulin classes, an individual discrimination could be reached. Thus, 8 of 9 of the patients with late reactions to cow's milk had increased levels of IgE or IgG + IgA antibodies as compared to 3 of 22 in the reference group. Serodiagnosis with the ELISA may, therefore, be of some use in patients with a suspicion of cow's milk protein intolerance.     

The investigation of asthmatic children by multiple factor analysis. II. The influence of 17 allergic factors on atopic dermatitis and allergic rhinitis in asthmatic children

We investigated possible influence of 17 allergy-associated factors on atopic dermatitis and allergic rhinitis using Multiple factor analysis in 150 asthmatic children. Atopic dermatitis was complicated in ninety-seven cases and allergic rhinitis in ninety-seven cases. 17 allergy-associated factors were as follows: 1) sex, 2) age, 3) onset age of asthma, 4) family history of allergy, 5) peripheral eosinophil counts, 6) IgE RIST, 7) IgE RAST score to egg white, 8) IgE RAST score to milk, 9) IgE RAST score to soybean, 10) IgG4 antibody titers to egg white, 11) IgG4 antibody titers to milk, 12) IgG4 antibody titers to soybean, 13) IgE RAST score to house dust, 14) IgE RAST score to Dermatophagoides farinae, 15) severity of asthma, 16) exercise-induced asthma, 17) atopic dermatitis or allergic rhinitis. We concluded as follows: 1) Factors which more strongly influenced both atopic dermatitis and allergic rhinitis were IgE RAST score to D.f., positive family history of allergy, IgE RIST and eosinophil counts. 2) Combination with high levels of IgG4 antibody to 3 food allergens such as egg-white, milk and soybean and IgE RAST to egg-white has a strong influence on atopic dermatitis, but high levels of IgG4 antibody to 3 food allergens except high level of IgG4 antibody to soybean have a weak influence on allergic rhinitis.     

Clinical and immunological responses to enzymes of Bacillus subtilis in factory workers and consumers

Skin (prick) and serological tests were made with enzyme preparations of Bacillus subtilis in exposed factory workers and potential ‘consumers’. Prick tests with these materials at 10 mg/ml gave positive immediate reactions in twenty-six out of sixty-five factory workers. Eighteen of the factory workers were classified as atopic because of allergy to common allergens and fifteen gave positive reactions to the enzymes compared with eleven out of forty-seven non-atopic workers. A group of eleven of the factory workers had consistent ventilatory impairment on repeated examination; all were prick test positive and seven were atopic, and four non-atopic. Of 2500 patients attending for investigation of respiratory allergy, 40% were highly atopic, 40% moderately atopic and 20% non-atopic. 80% were consumers of biological detergents. Only two gave weak, not clinically relevant, prick test reactions to the enzyme preparations. In radioallergosorbent (RAST) tests for specific IgE antibody against the enzyme preparations, counts in the present investigation of 600/30 sec or more corresponded best with prick test positivity, such values being found in twelve of the fifteen prick test positive atopics and in eight of the eleven workers with ventilatory impairment. Comparison of the RAST counts on sera from cord blood and from the patients who included non, light and heavy consumers showed increasingly higher specific IgE counts in these groups, although these counts were almost all below the level of 600/30 sec, which corresponded with skin test reactions and clinical relevance. Radioimmunodiffusion (RID) and radioimmunoelectrophoretic (RIEP) tests with enzyme preparations gave positive reactions only in the factory workers, of whom forty-three had IgG and twenty-one IgA antibody, none having only IgE antibody.     

Subclass distribution and IgE responses after treatment in human schistosomiasis

The IgG and IgA subclass distribution of specific antibodies as well as the distribution of total and specific IgE in 15 patients with schistosomiasis was determined in consecutive samples before and after initiation of treatment. An adult worm antigen preparation and a soluble egg antigen preparation were used as antigens in the ELISA assays. After initiation of treatment a rise was noted in certain subclasses and a correlation was found for specific IgG1 and IgG4 serum levels in the egg-excreting patients against adult worm antigen and for specific IgG4 and IgE levels in sera from the eight patients with a chronic disease. They also had a rise of the specific IgA1 titre and six of them also of specific IgA2. Members of eosinophilic granulocytes reached a peak after 2 weeks in seven of the eight patients. The increase of eosinophils was an early event as opposed to the incidence of peak of the determined specific isotypes. The associated rise in IgG1, IgG4 and IgE antibody concentrations and eosinophils may suggest a causal relation possibly induced by common interleukins.     

Development of a reverse enzymoallergosorbent test (REAST) to detect timothy-specific IgE antibodies. Comparison with RAST

Radioallergosorbent test (RAST) for the measurement of IgE antibodies has been introduced more than 15 years ago and a number of technical modifications have since improved its sensitivity and reproducibility. The test has been applied to the diagnosis of allergy and to determine changes in the levels of IgE antibodies following immunotherapy. However, specific IgG antibodies are raised during such a therapy and can interfere with the RAST. We have developed a reverse enzymoallergosorbent test (REAST) where microtiter plates are first coated with a purified polyclonal anti-IgE antibody, then with the serum to test and finally with peroxidase-labeled antigen. This assay is antigen specific as shown by the significant inhibition of binding of the labeled antigen in presence of unlabeled specific antigen (greater than 95%) and the absence of inhibition in presence of irrelevant antigens. The values found in atopic patients (85 subjects) were significantly higher than in the non-atopic donors (35 subjects) (1.14 U +/- 1.20 vs. 0.01 U +/- 0.02, P less than 0.0005) and there was a good correlation with the Pharmacia RAST (P less than 0.0005). The levels of specific IgE by both REAST and RAST correlated well with the clinical symptomatology.     

An assay to measure antigen-specific immune complexes in food-allergy patients

An allergen- and isotype-specific assay to quantify the presence of serum immune complexes is described. This assay is based on a two-site recognition system so that only molecular complexes containing both antigen and antibody are counted. In this study affinity-purified antibodies to egg and milk whey were used on paper discs in conjunction with a soluble, labeled anti-immunoglobulin (IgE or IgG specific). To evaluate the assay, immune complexes were prepared in vitro by mixing antigen at different concentrations with serum from a patient with high levels of antibody. Complexes were detectable over a 5 log range of antigen concentration. The lower limit of sensitivity of the assay was estimated to be 5.8 ng of complexed IgE per milliliter of patient serum. To determine if the assay could detect natural in vivo-formed complexes, sera from patients with positive RAST scores to egg white or milk were selected for a preliminary study. Three of the nine egg white-positive sera and two of the nine milk-positive sera were found to contain significant levels of IgE immune complexes. The versatility and sensitivity of the assay should now make it feasible to design experiments to elucidate the role, if any, of circulating immune complexes in the etiology of food allergy.     

Assessment of skin reactivity and specific antibody to egg and milk proteins in patients with atopic dermatitis: comparison with responses to the house dust mite antigen

Sixty patients with atopic dermatitis attending an allergy clinic were assessed for evidence of skin sensitivity and serum antibodies to egg and milk proteins. Prick skin test responses to egg were found in 23 patients and in 74% of these positive egg radioallergosorbent test (RAST) was demonstrable. Positive prick test for milk were present in 10 patients, but only 30% gave a positive milk RAST. Quantitative intradermal skin testing, RAST, and a double antibody antigen binding radioimmunoassay confirmed the presence of IgE antibody to egg proteins but indicated that the levels were very low when compared to those seen to the house dust mite antigen in sensitive patients. In contrast, IgG antibody to purified egg and milk proteins was present in large amount in most patients, the levels being significantly higher than in non-allergic controls.     

Evaluation of antigen specific IgE responses in Japanese asthmatics and non-asthmatics]

BACKGROUND: An increase in the prevalence of asthma does not seem to be comparable to the dramatic increase of atopy for the last two decades in Japan. Atopy is considered an important risk factor for asthma. It is, however, suggested that asthma itself may be responsible for the increased overall IgE responsiveness. We examined the significance of IgE responsiveness in asthma. METHODS: We studied 265 healthy controls and 275 patients with asthma. Total serum IgE levels and levels of antigen-specific IgE antibody to mite (D. farinae), cat, dog, timothy, and Candida spp. were determined. We defined atopy by positive RAST (>0.35UA/ml) or MAST scores (>1.0 lumicount) to at least one inhaled allergen. Frequencies of atopic subjects and frequencies of subjects sensitized to each allergen in atopic subjects were compared between the asthmatics and controls. All comparisons were made in younger (<41 yrs) and older (> = 41 yrs) groups, separately. RESULTS: In younger non-asthmatics, 76.5% (104/136) were atopic. The frequency of atopy was significantly higher in asthmatic subjects compared to non-asthmatics in both younger and older groups. In atopic subjects, older asthmatics were sensitized to animals more frequently than older controls. Although the frequency of subjects sensitized to mite did not differ between asthmatics and controls both in younger and older atopic subjects, asthmatics sensitized to mite had higher titers of specific IgE antibody to mite compared to those of controls sensitized to mite. Even non-atopic asthmatics had higher levels of total IgE compared to non-atopic controls. CONCLUSION: Our data may indicate that sensitization to animals and severer sensitizations to mite are risk factors for asthma. However, given the high prevalence of atopy in younger healthy controls, and increased levels of total serum IgE even in non-atopic asthmatics, our findings may reflect the increased overall IgE responsiveness that is inherent in asthma.     

Detection of IgE anti-parvovirus antibodies in human breast milk

Breast milk is a complex fluid, rich in nutrients and non-nutritional bioactive components, including antimicrobial factors, immunoglobulins, cytokines, and anti-inflammatory substances. Although IgE is implicated in viral immunity, its role in breast milk in parvovirus B19 immunity has not been studied. Total immunoglobulin levels of IgE, IgG, and IgE anti-parvovirus B19 antibodies were determined by ELISA and Western blot analysis in breast milk and in sera from a mother and her nursing infant (female, 10 mo). For specific IgE protein determination, breast milk was fractionated by chromatography on G-100 Sephadex; 3 peaks were collected and separated by SDS PAGE. The levels of total IgE in breast milk and its fractions were low (<2.4 ng/ml), and those of maternal and infant serum were negligible (18 and 4.3 IU/ml, respectively). Nevertheless, the breast milk and maternal and infant sera contained IgE anti-parvovirus B19 antibodies, even though the infant was never infected with parvovirus B19. Total serum levels of maternal IgG were within the normal range and those of infant IgG were low (473 mg/dl); total IgG in breast milk was not determined. Maternal serum contained some detectable IgG anti-parvovirus antibodies that were not present in infant serum or breast milk. Total maternal and infant serum levels of IgM and IgA were within the normal ranges. The presence of IgE anti-parvovirus B19 antibodies in breast milk suggests that IgE anti-viral antibodies are transmitted in breast milk and may provide protective responses in nursing children.