A convenient and sensitive allergy test: IgE crosslinking-induced luciferase expression in cultured mast cells

Background

For the detection of allergen-specific IgE in sera, solid-phase IgE-binding assays like the CAP test are commonly used. Although such immunochemical methods are very sensitive, they frequently produce false positives. Degranulation of the human IgE receptor (FcεRI)-transfected rat mast cell (RBL) lines seems to be a possible indicator for human IgE, but spontaneous mediator release from these cells in the presence of human sera is not negligible.

Methods

The nuclear factor of activated T-cells (NFAT)-responsive luciferase reporter gene was stably transfected into human FcεRI-expressing RBL-SX38 cells. One established clone (RS-ATL8) was sensitized with 1 : 100 dilution of sera from patients with egg white allergy and then stimulated with purified or a crude extract of egg white allergen.

Results

Sensitization with 15 pg/ml IgE was sufficient to detect IgE crosslinking–induced luciferase expression (EXiLE) by anti-IgE stimulation. Allergen-specific EXiLE was elicited by as little as 1 fg/ml of egg white protein without cytotoxicity. There was a good correlation between results with EXiLE and oral food challenge tests on patients with egg allergy (P = 0.001687, Fisher's exact test). The measured values of EXiLE and the CAP test also correlated well (R = 0.9127, Spearman's test).

Conclusion

The EXiLE test using RS-ATL8 cells is a promising in vitro IgE test to evaluate the biological activity of the binding between IgE and allergens.

Hyper IgM syndrome and complement Clq deficiency in an individual with systemic lupus erythematosus-like disease

Many immunedeficiency syndromes are associated with autoimmune disorders. We here report on a girl with a systemic lupus erythematosus-like disease who suffered from both hyperimmunoglobulin M syndrome (HIGMS) and C1q deficiency. Despite severe central nervous system-lupus like disease, probably due to C1q deficiency, kidney function was relatively spared. IgM autoantibody might play a protective role against lupus-glomerulonephritis.

State of the art and new horizons in the diagnosis and management of egg allergy

Egg allergy is one of the most frequent food allergies in children below the age of three. Common symptoms of egg allergy involve frequently the skin as well as the gut and in more severe cases result in anaphylaxis. Non-IgE-mediated symptoms such as in eosinophilic diseases of the gut or egg-induced enterocolitis might also be observed. Sensitization to egg white proteins can be found in young children in absence of clinical symptoms. The diagnosis of egg allergy is based on the history, IgE tests as well as standardized food challenges. Ovomucoid is the major allergen of egg, and recent advances in technology have improved the diagnosis and follow-up of patients with egg allergy by using single allergens or allergens with modified allergenic properties. Today, the management of egg allergy is strict avoidance. However, oral tolerance induction protocols, in particular with egg proteins with reduced allergenic properties, are promising tools for inducing an increased level of tolerance in specific patients.

Allergen-specific helper T cell response in patients with cow's milk allergy: Simultaneous analysis of proliferation and cytokine production by carboxyfluorescein succinimidyl ester dilution assay

BACKGROUND

The role of antigen-specific T cells in the allergic reaction to cow's milk or in tolerance induction is not yet fully understood.

OBJECTIVE

This study was designed to analyse both cow's milk protein (CMP)-specific T cell proliferation and cytokine production simultaneously in children with cow's milk allergy (CMA) in comparison with subjects with various allergic backgrounds.

METHODS

Carboxyfluorescein succinimidyl ester was used to detect cow's milk-specific T cells by flow cytometry. The intra-cytoplasmic cytokine production of these antigen-specific T cells was also analysed.

RESULTS

Significant differences of both CMP-specific CD4+ cell proliferation and cytokine production between CMA and non-allergic children were observed. While the proliferative responses of children who recently outgrew CMA were not significantly different from those of patients, the patterns of cytokine production were similar to those of non-allergic children.

CONCLUSION

These results suggest that the presence of CMP-specific T cell clones per se does not produce CMA, but that the T-helper type 2-skewed pattern of those T cells is associated with adverse reactions. Although it is not possible to distinguish between individual patients with and without CMA on the basis of CFSE assays, these results contribute to the understanding of the pathogenesis and tolerance induction of CMA.

Assessment of cross-reactivity between Japanese cedar (Cryptomeria japonica) pollen and tomato fruit extracts by RAST inhibition and immunoblot inhibition

BACKGROUND

An association between pollinosis and sensitivity to fruits and vegetables has been reported. Although Japanese cedar (Cryptomeria japonica) pollinosis is one of the most widespread diseases in Japan, there have been no reports demonstrating cross-reactivity between Japanese cedar pollen and other plant food.

OBJECTIVE

The aim of this study was to demonstrate cross-reactivity between Japanese cedar pollen and tomato fruit (Lycopersicon esculentum) using RAST inhibition and immunoblot inhibition.

METHODS

The RAST and immunoblot inhibition were performed using sera from patients with oral allergy syndrome (OAS) after ingesting fresh tomatoes. We identified some proteins that took part in cross-reactive IgE by the determination of N-terminal amino acid sequences and a homology search through the SWISS-PROT database.

RESULTS

In the RAST inhibition, the bindings of IgE from the sera from four out of five (4/5) subjects to Japanese cedar pollen discs were inhibited by more than 50% by preincubation of the serum with tomato fruit extracts. Likewise, the IgE bindings to tomato fruit discs were inhibited more than 50% by Japanese cedar pollen extracts in 3/5 sera. In immunoblot inhibition, IgE binding activities of some protein bands on both membranes were decreased by heterologous inhibitors. However, the combinations of these protein bands involved in cross-reactivity were different between patients.

CONCLUSION

We have demonstrated cross-reactivity between Japanese cedar pollen and tomato fruit using RAST inhibition and immunoblot inhibition.

Identification and characterization of the allergens in the tomato fruit by immunoblotting

BACKGROUND

Although the tomato fruit (Lycopersicon esculentum) has been widely investigated for breeding purposes, there have been few studies on tomato allergenicity. We attempted to identify the tomato fruit allergens and to compare the concentrations of IgE-binding proteins among the different growth stages with sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting.

METHODS

An immunoblot experiment on tomato fruit extracts was performed using sera from 11 patients with oral allergy syndrome (OAS) to tomatoes. Bands reacting with IgE from more than half of the OAS patients' sera were excised and subjected to determination of N-terminal amino acid sequences using the automated Edman degradation method. Moreover, we compared the concentrations of these proteins at each growth stage of the tomato fruit with SDS-PAGE and immunoblotting.

RESULTS

Four proteins binding with IgE from more than half of the OAS patients' sera were determined to be polygalacturonase 2A (PG2A), beta-fructofuranosidase, superoxide dismutase (SOD) and pectinesterase (PE). The concentrations of PG2A, beta-fructofuranosidase and PE were highest in the red ripening stage with both SDS-PAGE and immunoblotting.

CONCLUSION

The concentrations of 3 of 4 tomato allergens increased during ripening.

A 33-kDa allergen from rice (Oryza sativa L. Japonica). cDNA cloning, expression, and identification as a novel glyoxalase I

Cereal proteins are known to cause allergic reactions such as Baker's asthma and severe atopic dermatitis to certain populations. In rice allergy, proteins with molecular masses of 14-16, 26, 33, and 56 kDa have been demonstrated to be potentially allergenic. In this study, to identify and characterize the 33-kDa allergen, designated Glb33, this protein was first purified to homogeneity, and its cDNA clone was isolated. When expressed in Escherichia coli, the recombinant Glb33 was shown to be as reactive as the native Glb33 with mouse IgG and patients' IgE antibodies to Glb33. The Glb33 cDNA coded for a protein of 291 amino acids with two 120-amino acid residue repeats, and the amino acid sequence showed similarity to glyoxalase I from various organisms, including human, plant, yeast, and bacterium. As expected, both native Glb33 purified from rice seeds and the recombinant protein had glyoxalase I activity that catalyzes condensation of methylglyoxal and glutathione into S-lactoylglutathione. However, Glb33 had a higher sequence identity to the bacterial glyoxalase I rather than to known plant and yeast enzymes. Both the Glb33 transcript and the protein were detected not only in maturing seeds of rice but also in its stem and leaf. Taken all together, the rice allergen, Glb33, was identified to be a novel type of plant glyoxalase I that is expressed in various plant tissues, including maturing seeds.

IgE-binding activity to enzyme-digested ovomucoid distinguishes between patients with contact urticaria to egg with and without overt symptoms on ingestion

BACKGROUND

We occasionally see egg-allergic children who develop contact urticaria to hen's egg despite the absence of the overt symptoms on ingestion. The mechanisms remain to be elucidated.

METHODS

Twenty-one subjects with positive reactions to 20-min patch tests for egg-white antigens were divided into subgroups with positive (n = 10) and negative (n = 11) results to oral challenge tests by the same antigens. We measured IgE antibody for egg white and its components, and IgE-binding activities to digestive enzyme-treated ovomucoid by RAST inhibition.

RESULTS

There were no significant differences in IgE antibody titers to egg white (positive vs negative: 30.3% vs 15.3%, P=0.130), ovomucoid (21.5% vs 10.2%, P= 0.078), ovotransferrin (9.9% vs 3.7%, P = 0.105), and lysozyme (3.4% vs 2.9%, P=0.944), except ovalbumin (16.8% vs 5.6%, P=0.024), between the positive and negative subjects in the provocation tests. In contrast, the concentration (1.93 microg/ml) of pepsin-treated ovomucoid needed for 50% RAST inhibition in the challenge-positive subjects was significantly (P=0.0003) lower than that (114.9 microg/ml) of negative subjects. Similar but less significant differences were obtained when ovomucoid fragments treated with chymotrypsin (0.91 microg/ml vs 6.86 microg/ml, P=0.014) and trypsin (0.75 microg/ml vs 4.67 microg/ml, P= 0.041) were used as inhibitors.

CONCLUSIONS

We suggest that IgE antibodies from subjects showing contact urticaria despite the absence of reactions to the ingestion of egg white recognize the epitope(s) unstable to digestive enzymes.

Clinical significance of IgE-binding activity to enzymatic digests of ovomucoid in the diagnosis and the prediction of the outgrowing of egg white hypersensitivity

BACKGROUND

We frequently encounter subjects without overt symptoms despite high IgE antibodies to egg white and its components. The measurements of these antibodies are not necessarily efficient for the diagnosis or the prediction of the outcome of egg allergy in children.

METHODS

Specific IgE antibodies to egg white and its components, including ovomucoid, ovalbumin, ovotransferrin and lysozyme, were measured by direct RAST assays. IgE-binding activity to ovomucoid degraded by pepsin, trypsin and chymotrypsin was examined by RAST inhibition. Thirty subjects were divided into two groups with positive (n=18; mean age +/- SD = 42 +/-25 months) and negative (n=12; mean age +/- SD = 48 +/-31 months) oral challenge tests with egg white antigens. The individuals with positive results to the first challenge tests were given the second provocation tests at mean intervals of 32 months. IgE-binding activity of the sera collected on the first challenge to these ovomucoid fragments was compared between subjects with positive and negative reactions to the follow-up challenge tests.

RESULTS

There were no significant differences in IgE antibody titers to egg white and its components between the positive and negative groups at the first and the second challenge tests. IgE-binding activity to ovomucoid digests after treatments with pepsin (p = 0.000008) and trypsin (p=0.037), except chymotrypsin (p=0.062), were significantly higher in subjects with positive challenge tests than in those with negative results. The difference was most remarkable in the IgE-binding to pepsin digests; the average concentrations (mean - SD and mean + SD) needed for 50% RAST inhibition in the positive group and in the negative group were 2.6 microg/ml (0.3 and 25) and 94.2 microg/ml (24.7 and 358.7), respectively. A significant difference was still observed in the inhibition tests using filtrates of pepsin digests with a membrane with MW 10,000 (p=0.014) and 3,000 (p=0.042) of cutoff. The concentration (mean= 0.8, mean - SD=0.2, mean + SD=3.4; microg/ml) of pepsin-treated ovomucoid required for 50% RAST inhibition in the subjects with positive second challenge results was significantly (p=0.033) lower than that (mean=6.8, mean-SD=0.6, mean + SD=73.9) of the negative group.

CONCLUSION

IgE-binding activity to pepsin-digested ovomucoid was of diagnostic value to distinguish the challenge-positive subjects from the negative subjects. Subjects with high IgE-binding activity to pepsin-treated ovomucoid are unlikely to outgrow egg white allergy.

[Respiratory symptoms by oral challenge tests with egg white antigens in egg-allergic children]

One hundred and ninety one subjects showing histories of immediate hypersensitive response to egg white ingestion and/or positive IgE antibody titers specific for egg white were enrolled in double-blind placebo-controlled oral challenge with freeze and dried, heated or heated and ovomucoid-depleted egg white antigens. Seventy seven were male and 114 female, and their ages ranged from 11 month to 10 years 5 month; 118 of them had atopic dermatitis, seven had asthma and 33 had both atopic dermatitis and bronchial asthma and 33 had urticaria. One hundred four children developed 147 positive symptoms including 131 immediate reactions and 16 non-immediate reactions by oral challenge tests. Respiratory symptoms were observed in 25 cases (17%) including cough alone in 12 cases (8.2%), and both wheezing and cough in 13 cases (8.8%). These were all observed as immediate reactions and accompanied with dermal symptoms. Frequency of respiratory symptoms correlated with specific IgE antibody titers for egg white. Heated and ovomucoid-depleted egg white was more hypoallergenic that heated or freeze and dried egg white with respect to respiratory symptoms as well as other symptoms. We concluded that respiratory symptoms were provoked through oral challenges with egg white in a part of egg-allergic children.

[Assessment of allergenic activity of heated and ovomucoid-depleted egg white]

We investigated allergenic activity of heated and ovomucoid (OM)-depleted egg white by RAST inhibition tests, skin tests and and oral challenge tests. Freeze-dried egg white, OM and ovalbumin (OA) were coupled with CNBr-activated paper discs. Freeze-dried, heated, and heated and OM-depleted egg white antigens were used as inhibitors in RAST inhibition tests. Freeze-dried egg white significantly inhibited the IgE-binding to freeze-dried egg-white-, OM- and OA-discs. Heated egg white showed a significant inhibition against only OM-disc, but heated and OM-depleted egg white didn't effectively suppress IgE-binding to all discs. Fifty-six patients were subjected for skin tests and 27 patients for oral challenge tests with freeze-dried egg white, heated egg white and heated and OM-depleted egg white. Eighteen of 25 subjects with positive prick tests results to freeze-dried egg white showed negative results to heated egg white. Four of 7 cases with positive prick test results to heated egg white gave negative results to heated and OM-depleted egg white. 20-minutes patch tests showed almost similar results to prick tests. Four of 8 subjects showing positive oral challenge tests with freeze-dried egg white were negative to heated egg white. All of 4 with positive oral challenge tests by heated egg white were negative results to heated and OM-depleted egg white. These evidence indicated that heated and OM-depleted egg white was more hypoallergenic than heated egg white.

Allergenic activity of heated and ovomucoid-depleted egg white

BACKGROUND

No egg white products have been clearly proven to be hypoallergenic. The role of egg white proteins in allergic reactions to eggs is still debatable.

OBJECTIVE

This study was designed to determine the importance of ovomucoid, an egg white protein, in the development of allergies to egg white.

METHODS

We performed a double-blind, placebo-controlled food challenge in subjects with high levels of IgE antibodies for egg white to compare the allergenicities of heated and ovomucoid-depleted egg white, freeze-dried egg white, and heated egg white. Levels of IgE antibodies for egg white, ovomucoid, ovalbumin, ovotransferrin, and lysozyme were measured in serum by RAST.

RESULTS

Twenty-one of 38 subjects with positive challenge responses to freeze-dried egg white had negative challenge responses to heated egg white, whereas 16 of 17 subjects (94.1%) with positive responses to heated egg white did not respond to the heated and ovomucoid-depleted egg white challenge. The subjects with positive challenge responses to freeze-dried egg white tended to have higher IgE antibody values to ovomucoid than those with negative responses. IgE antibody levels to ovomucoid were significantly higher in subjects with positive responses to a challenge with heated egg white than in those with no response. There were no significant differences in the levels of IgE antibodies to the other proteins, except ovomucoid, in the negative-response and positive-response groups in challenge tests with freeze-dried and heated egg white.

CONCLUSION

The heated and ovomucoid-depleted egg white preparation was less allergenic than heated or freeze-dried preparations. Ovomucoid has a more important role in the pathogenesis of allergic reactions to egg white than other proteins in egg white.

A case retaining contact urticaria against egg white after gaining tolerance to ingestion

A girl, 5.7 years old, gained tolerance to egg white ingestion in spite of high immunoglobulin E (IgE) antibody titers to egg white but retained contact urticaria against egg white. She developed atopic dermatitis on her face at 2 months of age and showed high IgE antibody titers to egg white and cow's milk. Accidental ingestion of egg products initiated immediate symptoms such as wheezing, urticaria, erythema and edema of the eyelids and conjunctiva three times. These symptoms were confirmed by challenge tests using boiled egg white at 3.9 years of age. She also reacted positively to a 20 min patch test on her volar arm with raw egg white. However, there were no reactions to the oral challenge test by boiled egg and freeze-dried egg white at 5.1 and 5.7 years of age, respectively. This non-responsiveness was confirmed by a double-blind, placebo-controlled food challenge using freeze-dried egg white. Nevertheless, she showed positive reactions to a 20 min patch test with freeze-dried egg white. Her IgE antibody titers to the egg white components including ovomucoid, ovalbumin, ovotransferrin and lysozyme as well as egg white were high from 2.9 to 5.7 years old. Her IgE antibody titers for the ovomucoid fragments digested by pepsin, chymotrypsin and trypsin were not lower than those of positive control subjects. The binding activity of IgE antibody to ovomucoid, however, decreased from 2.9 to 5.6 years as shown by radioallergosorbent test (RAST) inhibition assays. The IgE antibody showed weaker binding activity to pepsin- and chymotrypsin-digested ovomucoid that were filtered through cut-off 10,000 filter at the age of 2.1 and 5.7 years. We speculated that the maturation of secretion of digestive enzymes was involved in the mechanisms of the acquisition of tolerance to egg white ingestion in spite of the persistence of contact urticaria.

Primary structure and allergenic activity of trypsin inhibitors from the seeds of buckwheat (Fagopyrum esculentum Moench)

The complete amino acid sequences of two trypsin inhibitors BWI-2a and BWI-2b from the seeds of buckwheat (Fagopyrum esculentum Moench) were determined. BWI-2b consists of 51 amino acid residues containing two disulfide bonds. BWI-2a shares all amino acids with BWI-2b except for the C-terminal tripeptide: BWI-2a lacks Glu-Gly-Asn and ends with the Asp residue, making a total of 48 residues in the chain. The two disulfide bonds connect Cys11 to Cys32 and Cys15 to Cys28. BWI-2b shows no relatedness to the other buckwheat trypsin inhibitor reported [Belozersky et al. (1995) FEBS Lett. 371, 264-266]. Sequence comparison of BWI-2b with those of the other proteins included in PIR showed that BWI-2b is significantly homologous to the N-terminal region of storage proteins classified in the vicilin family. Furthermore, the allergenic activity of BWI-2b and the other buckwheat trypsin inhibitor BWI-1 was examined using the radioallergosorbent test. The result indicated that both inhibitors BWI-2b and BWI-1 have IgE binding activity, albeit to a low extent, suggesting that they might be minor allergenic proteins in buckwheat seeds.

Immediate hypersensitive reactions to buckwheat ingestion and cross allergenicity between buckwheat and rice antigens in subjects with high levels of IgE antibodies to buckwheat

BACKGROUND

Immediate hypersensitive reactions induced by buckwheat ingestion are considered to be IgE-mediated. Some subjects, however, develop no immediate adverse reactions after buckwheat ingestion despite high levels of buckwheat-specific antigens IgE. The mechanism is unknown.

OBJECTIVE

To investigate the mechanisms.

METHODS

RAST for buckwheat and rice and RAST inhibition between these antigens were performed using sera from 23 buckwheat-sensitive subjects and 30 buckwheat-tolerant subjects who had IgE antibodies for both buckwheat and rice.

RESULTS

RAST values for buckwheat and rice were significantly correlated with each other (P < .01) in the buckwheat-tolerant group, but not in the buckwheat-sensitive group. This suggests the IgE antibodies from the subjects without any overt symptoms after buckwheat ingestion recognize the cross-reactive epitope between buckwheat and rice, whereas the IgE antibodies from those with immediate reactions to buckwheat ingestion do not. RAST inhibition assays were performed to evaluate this. RAST inhibition of heterogeneous combination of inhibitor and disc antigen such as rice and buckwheat was significantly smaller than that of homologous combination of rice and rice or buckwheat and buckwheat in the group with immediate symptoms after buckwheat ingestion. There was no significant difference in RAST inhibition between homologous and heterogeneous combinations in the group without the symptoms.

CONCLUSIONS

There was cross-reactivity with IgE antibodies between buckwheat and rice and IgE antibodies from the buckwheat-tolerant subjects with high levels of IgE antibodies from the buckwheat might recognize the epitopes on buckwheat antigens which cross-react with rice antigens, whereas IgE antibodies from the buckwheat-sensitive subjects might bind to buckwheat-specific epitopes.

[Immediate hypersensitive reactions to the ingestion of egg white and IgE binding to the egg white components]

IgE is considered to be involved in immediate hypersensitive reactions (IHR) following egg ingestion. IgE antibody levels to egg-white (EW) antigens in the IHR-positive group (n = 19, mean age +/- SD = 5.2 +/- 4.5 yr) were higher than those in the IHR-negative group (n = 13, mean of age +/- SD = 3.6 +/- 2.2 yr). However, even in the IHR-negative group, some patients showed high IgE to EW. RAST inhibition tests with heat-treated (100 degrees C, 5, 10, and 30 min) egg-white antigens were performed on 13 serum samples from subjects with IHR and 9 serum samples from subjects without IHR. Heat treatment decreased the IgE-binding activity of egg white and it was speculated that IgE from IHR-negative subjects bound to relatively heat-unstable sites of egg-white antigens. Furthermore, we selected IHR-negative subjects (n = 8, mean of age +/- SD = 3.0 +/- 1.7 yr) with higher IgE antibody levels than the lowest limit of IgE to EW of the IHR-positive group and compared IgE to ovomucoid (OM), ovalbumin (OA), conalbumin (CA), and lysozyme (Ly) between these IHR-negative and positive groups. IgE-binding activities to egg-white components, including OA, CA, and Ly but not OM, were significantly decreased with heat treatment. The IHR-negative group showed significantly lower IgE to OM (untreated, 5, 10, 30 min treatment) and 5 min treated OA alone than the IHR-positive group, while no difference was found in IgE to other components between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Specific IgE antibodies and serum eosinophil cationic protein in children with atopic dermatitis alone

Both eosinophils and specific immunoglobulin E (IgE) to foods and mites have been considered involved in the pathogenesis of atopic dermatitis (AD). The relationship between eosinophils and specific IgE, however, remains to be elucidated. Blood eosinophil counts, serum eosinophil cationic protein (ECP) and IgE to egg white, cow's milk, soybean, rice and Dermatophagoides pteronyssinus (Dp) were measured in subjects with AD alone or bronchial asthma (BA) alone. Subjects with positive IgE titers (Pharmacia radioallergosorbent test (RAST) units > 0.7) of one or more items were defined as RAST-positive. Immunoglobulin E titers to egg white, cow's milk and soybean of subjects with AD were high in early childhood and declined with aging, whereas the titers of subjects with BA were negative or low. Immunoglobulin E titers to Dp were elevated after 1 year of age in both disease groups. Eosinophil cationic protein (ECP) levels and blood eosinophil counts in the AD and BA groups were significantly higher than those of non-atopic controls. No difference in ECP levels or blood eosinophil counts were observed between RAST-positive and negative groups. It is concluded that IgE to foods such as egg white, cow's milk and soybean might have a role in the pathogenesis of AD of young children, while IgE to mites might be involved in older children. Eosinophils may also participate in AD. However, different mechanisms may be responsible for the rise in specific IgE and high ECP levels and blood eosinophil counts.

[Cross-allergenicity between rice and buckwheat antigens and immediate hypersensitive reactions induced by buckwheat ingestion]

Immediate hypersensitive reactions (IHR) induced by buckwheat ingestion are considered to be IgE-mediated. However we found 28 subjects without IHR to buckwheat ingestion out of 46 subjects who had positive RAST values for both buckwheat and rice antigens. The IHR-positive group showed significantly higher RAST values for buckwheat antigens (p < 0.01) but lower RAST values for rice antigens (p < 0.01) than did the IHR-negative group. RAST values for buckwheat and rice were significantly correlated with each other (p < 0.01) in the IHR-negative group, but not in the IHR-positive group. An effective dose-dependent inhibition was obtained in a RAST inhibition assay between homologous combinations of inhibitor and disc antigens such as rice and rice or buckwheat and buckwheat. The IHR-positive group showed no significant RAST inhibition between heterogeneous combinations of rice and buckwheat antigens. In contrast, the IHR-negative group showed a significant decrease in IgE binding even in the RAST inhibition assay between heterogenous combinations. These results led to the conclusion that there is cross-reactivity with IgE antibodies between buckwheat and rice and that IgE antibodies from IHR-negative subjects might recognize the epitopes on buckwheat antigens which cross react with rice antigens, whereas IgE antibodies from IHR-positive subjects might bind to buckwheat-specific epitopes.

Varicella-zoster virus replication site in internal organs of an otherwise healthy child with varicella and sudden death

Pathological findings of an otherwise healthy 17 month old boy who was exposed to Varicella-zoster virus (VZV) in his family and unexpectedly died 3 days after onset of varicella are reported. They showed a disseminated VZV infection with involvement of skin, lung, liver, spleen, gastrointestinal tract and other organs where VZV antigen was detected by the enzyme-immunoassay with monoclonal antibodies to VZV. Since the subject was the full-term product of an uncomplicated pregnancy, who grew and developed normally, and had no symptoms or laboratory findings suggestive of immunodeficiency until his death, these findings suggest that many organs are involved as major internal sites of viral replication before or during infection of skin with VZV in the immunocompetent host.

[Allergen analysis of buckwheat by the immunoblotting method]

Inhalation or ingestion of very small amounts of buckwheat allergen can initiate severe symptoms including wheezing, rhinorrhea, urticaria, vomiting and anaphylactic shock in patients with hypersensitivity against buckwheat. However, few studies of the immunological properties of buckwheat allergen have been made. The aim of the present investigation was to analyze the allergen in buckwheat antigen using the immunoblotting method, radioallergosorbent test (RAST) and RAST inhibition assay. Buckwheat 24 kilodalton protein (BW24KD) was shown by immunoblotting analysis to be the most frequently recognized allergenic component, binding to IgE antibodies from 100% of the patients' sera. There was a significant positive correlation (p < 0.001) between % bindings for BW24KD and buckwheat. In the RAST inhibition assay using patients' sera which showed positive IgE antibodies to buckwheat and BW24KD, there was effective inhibition in a dose-dependent manner between inhibition in a dose-dependent manner between BW24KD and buckwheat. These data indicated that BW24KD was a major allergen in buckwheat antigens. The experiments of SDS-PAGE using digestion buffer with or without 2-mercaptoethanol suggested that BW24KD was a component of heterodimer and the paired components had different molecular weights.

Nucleotide sequence of a cDNA clone encoding a major allergenic protein in rice seeds. Homology of the deduced amino acid sequence with members of alpha-amylase/trypsin inhibitor family

A cDNA clone of rice major allergenic protein (RAP) was isolated from a cDNA library of maturing rice seeds. The cDNA had an open reading frame (486 nucleotides) which coded a 162 amino acid residue polypeptide comprising a 27-residue signal peptide and a 135-residue mature protein of M(r) 14,764. The deduced amino acid sequence of RAP showed a considerable similarity to barley trypsin inhibitor [1983, J. Biol. Chem. 258, 7998-8003] and wheat alpha-amylase inhibitor [1981, Phytochemistry 20, 1781-1784].

[The involvement of rice protein 16KD in cross-allergenicity between antigens in rice, wheat, corn, Japanese millet, Italian millet]

Cross-reactivity between rice, wheat, corn, Japanese millet and Italian millet in Poaceae family were studied by absorption test, radioallergosorbent test (RAST), and RAST inhibition assay. In absorption test using Phadebas RAST discs, more than 50% absorption of IgE antibodies was observed between rice, wheat and corn. There were significant correlations of RAST values for cereal grains including rice, wheat, corn, Japanese millet and Italian millet. RAST inhibition assay between every combinations of these cereals showed dose-dependent decrease in IgE-binding. These data indicated cross-reactivity with IgE antibodies between the five cereals in Poaceae family. RAST values for RP16KD significantly correlated with those for Italian millet as well as rice but not with those for corn and wheat. There was a trend of positive correlation between RAST values for RP16KD and Japanese millet. In RAST inhibition assay using sera with positive RAST for these five cereal grains and RP16KD, RP16KD inhibited IgE-binding to these all cereal discs in dose-dependent manner. Similarly, all of five cereal grain extracts showed an effective diminution in IgE-binding to RP16KD disc. These results indicated possible participation of IgE-binding structure on RP16KD in cross-reactivity between these cereal grains in Poaceae family.

[Relationship between immediate hypersensitive reactions by buckwheat ingestion and specific IgE for rice in subject with positive IgE-RAST for buckwheat]

IgE-mediated mechanisms are important in immediate hypersensitive reactions (IHR) to buckwheat. However, a part of subjects with high IgE for buckwheat show no IHR to buckwheat ingestion. Inspite of cross-allergenicity between buckwheat and rice, rice ingestion rarely induces IHR even in subjects with high IgE for rice unlike buckwheat-induced IHR. We speculated that there were some relationships between the presence of IHR to buckwheat and recognition of cross-allergenic determinants on buckwheat components with rice components. We examined IgE-RAST for rice in 58 subjects with positive IgE-RAST for buckwheat. IgE-RAST for Dermatophagoides pteronyssinus (Dp), egg white and cow's milk as unrelated antigens with rice were also assessed for a comparison. Subjects (n = 33) without IHR to buckwheat showed higher IgE-RAST values for rice than those (n = 25) with IHR, whereas there were no differences in IgE-RAST values for Dp, egg white and cow's milk between two groups with and without IHR. IgE-RAST values for buckwheat showed significant close correlations to those for rice in subjects without IHR to buckwheat but not in those with IHR. There were no significant correlations between IgE-RAST values for buckwheat and for Dp, egg white or cow's milk in both groups with and without IHR. These results suggested that the IgE from subjects without IHR to buckwheat recognized cross-allergenic determinants with rice on the buckwheat components.

Rice protein 16KD--a major allergen in rice grain extract

The allergenic activity of Rice protein 16 KD (RP16KD) isolated from water soluble rice proteins was examined by radioallergosorbent test (RAST), RAST inhibition and histamine release assay. All of the 31 sera which showed positive RAST values for rice grain extract were positive for RP16KD RAST. Furthermore, there was a significant correlation (r = 0.56, p less than 0.01) between these RAST values. PR16KD effectively inhibited IgE binding to the rice grain extract disc in RAST inhibition assays using 4 sera with positive RAST values for both antigens. In 17 subjects with positive RAST values for rice grain extract, a significant positive correlation (r = 0.53, p less than 0.05) was found between the maximum percent histamine releases from their leukocytes by rice grain extract and RP16KD. These data strongly suggest that RP16KD is one of the major allergens of rice grain.

16-kilodalton rice protein is one of the major allergens in rice grain extract and responsible for cross-allergenicity between cereal grains in the Poaceae family

Cross-allergenicity between five cereal grains including rice, wheat, corn, Japanese millet (Panicum crus-galli L. var. frumentaceum Trin.) and Italian millet (Setaria italica Beauv. var. germanica schrad.) was examined by radioallergosorbent test (RAST) and RAST inhibition assay. There were significant close correlations between every combinations of RAST values for the five cereal grain extracts. RAST inhibition assay of each extract against RAST discs coupled with other cereal grain extracts indicated marked cross-reactivity of IgE binding between these cereal grain extracts. Rice protein 16KD (RP16KD) was shown to be one of major allergens in rice grain extracts by immunoblotting analysis, histamine release assay from human leukocytes and RAST inhibition. Next, the involvement of RP16KD in the cross-allergenicity between these cereals was investigated. RAST values for RP16KD significantly correlated with that for Italian millet as well as rice but not with those for corn and wheat. There was a trend of positive correlation between RAST values for RP16KD and Japanese millet. In the RAST inhibition assay using sera with positive RAST for these five cereal grain extracts and RP16KD, RP16KD inhibited IgE binding to these all cereal discs in a dose-dependent manner. Similarly, all of the five cereal grain extracts showed an effective decrease in IgE binding to the RP16KD disc. These results indicated possible participation of IgE binding structure on RP16KD in cross-allergenicity between these cereal grain extracts in the Poaceae family.

[Inhibitory action amlexanox on interleukin-3-induced enhancement of histamine releasability of human leukocytes]

Amlexanox, an anti-allergic drug, showed a concentration-dependent inhibition against hrIL-3-induced enhancement of in vitro histamine release from human leukocytes by anti-IgE. The significant inhibitory action of amlexanox was observed in one out of nine and six out of nine allergic subjects at concentrations of 10(-5) M and 10(-4) M, respectively. This means that the inhibitory effect of amlexanox varied from patient to patient. Post-treatment as well as simultaneous treatment with amlexanox produced an inhibitory action on the enhancing effect of hrIL-3, suggesting that hrIL-3-induced enhancement of releasability is a reversible reaction. AA-861, OKY-046, superoxide dismutase and prostaglandin E2 showed no effects on the hrIL-3-induced enhancement of histamine releasability. The inhibitory action of amlexamox to the hrIL-3-induced enhancement of histamine releasability may be a new anti-allergic mechanism, details of which remains unclear.

[Allergic individuals to Japanese cedar or orchard grass consist of two subgroups based on the sensitization to Dermatophagoides pteronyssinus]

One hundred and twenty-six allergic subjects were divided into three groups based on the RAST results for Dermatophagoides pteronyssinus (D.p) and Japanese cedar (J.C.). We compared sex, age of examination for RAST, serum IgE, family history of allergic diseases, prevalence rate of bronchial asthma (BA) and allergic rhinitis (AR), and onset of AR among three groups. No significant difference in the other variables except serum IgE and prevalence rate of BA was found between the group with D.p-positive and J.C.-positive RAST and the group with D.p-positive and J.C.-negative RAST. The group with positive RAST for D.p and J.C. showed lower age of the examination, higher serum IgE, higher incidence of allergic family history, higher prevalence rate of BA, and lower onset age of AR than the group with negative RAST for D.p and positive RAST for J.C. We suggested that in J.C. RAST-positive group there might be two different subgroups distinguished by RAST result for D.p Similar results were obtained from the assessment of RAST for Orchard grass instead of J.C.

[Histamine release from human leukocytes by human recombinant interleukin-3]

Human recombinant interleukin-3 (hrIL-3) released histamine from human leukocytes in vitro. The histamine release by hrIL-3 significantly correlated with those by anti-IgE, thrombin, and f-met. peptide, but not by A23187. Histamine release by hrIL-3 was a Ca2(+)-dependent reaction, as was that by anti-IgE, although the time course of histamine release by hrIL-3 was slower than that by anti-IgE. Pre-treatment of leukocytes with hrIL-3 decreased the histamine release by hrIL-3 itself, but enhanced the histamine releases by anti-IgE, f-met. peptide, thrombin and A23187. These results suggested that the mechanism of hrIL-3-induced histamine release was different from those of anti-IgE, f-met. peptide, thrombin, and A23187. There was no significant difference between hrIL-3-induced histamine release of leukocytes from asthmatics and healthy controls.

[A clinical study of two cases with immediate hypersensitivity to apple-pulp and an investigation of cross-allergenicity between apple-pulp allergen and some other pollen allergens]

In Japan there are no case reports of immediate hypersensitivity to apple-pulp. Here, we report on two patients: a 23-year-old woman and a 14-year-old girl with 3-year and 7-year histories, respectively, of anaphylactic reactions to apple-pulp. In the first patient, eating raw apples immediately elicited itching and tingling of the lips and mouth with severe edema of the lips and tongue, irritation of the throat and slight colic in the upper abdomen. In the second, nausea and vomiting occurred after ingestion of apples. In skin prick tests, they showed positive reactions to apple-pulp extract prepared by the method of Björkstén et al. and to fresh apple juice. In addition, IgE antibody to the apple-pulp extract was detected in the sera of both patients. They also possessed IgE antibodies to some other species of both pollens and fruits/vegetables in their sera. In the present study, cross-allergenicity between apple-pulp and five pollen species, which consisted of birch, Japanese cedar, orchard grass, mugwort and ragweed pollen, was investigated by RAST inhibition. The apple-pulp extract effectively inhibited RASTs to all the pollens except Japanese cedar pollen. These results suggested that the four pollens might have shared allergen with the apple-pulp extract.

[Allergenic and antigenic activities of the osmophilic fungus Wallemia sebi asthmatic patients]

Recently large amounts of Wallemia sebi, a species of osmophilic fungi, have been detected in house dust by low water activity media. The allergenic activity of W. sebi was examined by skin prick tests and radioallergosorbent tests (RAST) in 74 asthmatic patients (mean age 11.7, range 6-32). Aspergillus fumigatus and house dust were used for comparison. In the skin prick tests, W. sebi extract, A. fumigatus extract and house dust extract elicited positive reactions in 4 (5.4%), 4 (5.4%) and 51 (68.9%) patients, respectively. RAST showed positive results in 14 subjects (18.9%) for W. sebi extract, in 8 (10.8%) for A. fumigatus extract and in 59 (79.7%) for house dust extract. These results indicated that some asthmatic individuals showed immediate type hypersensitivity to W. sebi, which means this fungal species may be important as a causative agent in atopic diseases. Additionally, the authors measured W. sebi-specific IgG by enzyme-linked immunosorbent assay in asthmatic (n = 28) and non-atopic patients (n = 28). W. sebi-specific IgG was found in sera from all subjects in each group. W. sebi-specific IgG in asthmatics (mean +/- SD = 0.686 +/- 0.160) was significantly higher than that in non-atopics (mean +/- SD = 0.572 +/- 0.188) (p less than 0.01).

Studies on the osmophilic fungus Wallemia sebi as an allergen evaluated by skin prick test and radioallergosorbent test

Recently, Wallemia sebi, a species of osmophilic fungi, has been abundantly detected in house dust using low water activity media. In this study, allergenic activity of W. sebi was assessed by skin prick test and radioallergosorbent test (RAST) in 74 asthmatic patients ranging from 6 to 32 years of age. Aspergillus fumigatus and house dust were used for comparison. In skin prick test, W. sebi extract, A. fumigatus extract and house dust extract elicited positive reactions in 4 (5.4%), 4 (5.4%) and 51 (68.9%) patients, respectively. RAST showed positive results in 14 subjects (18.9%) for W. sebi extract, in 8 (10.8%) for A. fumigatus extract and in 59 (79.7%) for house dust extract. These results indicated that some asthmatic individuals showed immediate-type hypersensitivity to W. sebi, and which means this fungal species may be of importance to atopic diseases as a causative agent.

Purification and characterization of serotype 6 fimbriae from Bordetella pertussis and comparison of their properties with serotype 2 fimbriae

Fimbriae were removed from Bordetella pertussis (serotype 1.3.6) by mechanical shearing and purified by precipitation with ammonium sulfate, pH-dependent precipitation at pH 7.4, followed by two successive extractions of the precipitated fimbriae with 4 M urea. By electron microscopy, the precipitated fimbriae appeared as aggregated bundles of long, relatively straight filaments which were disaggregated to individual flexuous filaments at pH 10.5. These purified fimbriae were identified as serotype 6 agglutinogens, since antibody to the purified fimbriae agglutinated B. pertussis strains serotyped as 1.3.6, 1.2.3.6, or 1.2.3.4.6 but did not agglutinate strains of serotype 1.2.3.4, 1.2.3, or 1.3. In contrast, antibody to serotype 2 fimbriae only agglutinated B. pertussis strains containing serotype 2 agglutinogen. Purified type 6 and 2 fimbriae were found to be weakly cross-reactive by enzyme-linked immunosorbent assay, using polyclonal antibody to each type of fimbria. In an immunoblot assay, polyclonal antibodies to a 22,000-dalton subunit of fimbriae from B. bronchiseptica reacted strongly with the type 2 fimbrial subunit of B. pertussis, but only weakly with the type 6 subunit. When subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protein subunit of the type 6 fimbriae migrated with a molecular weight of 21,500, whereas the type 2 fimbrial subunit had a molecular weight of 22,000. The two types of subunits had similar amino acid compositions and showed amino-terminal sequence homology in 15 of 21 amino acids. The amino-terminal amino acid sequences of the B. pertussis fimbriae were distinct from those reported for fimbriae from other gram-negative bacteria. Neither the type 6 nor the type 2 fimbriae caused hemagglutination when assayed with several types of erythrocytes.

Filamentous hemagglutinin has a major role in mediating adherence of Bordetella pertussis to human WiDr cells

[35S]methionine-labeled Bordetella pertussis adhered to monolayers of WiDr cells, an epitheliumlike cell line from a human intestinal carcinoma. Adherence was proportional to the density of the WiDr cells and to the concentration of B. pertussis in the assay. Adherence of virulent phase I strains Tohama phase I, 114, and BP338 was much greater than adherence of avirulent strains Tohama phase III and 423 phase IV. Mutants deficient in the production of the filamentous hemagglutinin (FHA) were hemagglutination negative and adhered to WiDr cells much less efficiently than the parent strains. Preincubation of B. pertussis cells with FHA increased their hemagglutination activity and adherence to WiDr cells. Goat antibody to FHA inhibited, in a dose-dependent manner, the adherence of strain Tohama I but not the adherence of FHA-deficient mutant Tohama 325. At similar protein concentrations, normal goat antibody, goat antibody to pertussis toxin, or the Fab fragments of goat antibody to serotype 2 fimbriae had no effect on adherence. Also, an FHA-positive strain without fimbriae showed high adherence, while a fimbriated FHA-deficient mutant adhered poorly. Our data indicate that FHA plays a major role in adherence of B. pertussis to human WiDr cells. Fimbriae do not appear to mediate attachment of B. pertussis to WiDr cells.