Allergens from plantain (plantago lanceolata). Studies with pollen and plant extracts

There has been unjustified neglect of dicotyledonous (dicot; 'weed') pollens in research directed at isolating pure allergens, since dicot pollens are widespread and frequently important in provoking immediate allergic reactions. Sera from patients who showed positive skin prick test reactions to plantain pollen generally also reacted in the radioallergosorbent test (RAST) with at least one other species of dicot pollen. Fractionation of plantain pollen extracts by ultrafiltration and molecular sieving and examination of the fractions by the RAST revealed a spread of allergenic activity. Using crossed immunoelectrophoresis, at least 16 different antigens were detected in plantain pollen and at least 6 of these antigens may be allergenic. Allergenic glycoproteins that react with concanavalin A were isolated and their complexity examined by electrophoresis and electro-focusing. IgE-binding components were found widely distributed in plantain plants and not confined to the pollen.     

Detection of allergens in plantain (Plantago lanceolata) pollen

BACKGROUND: Allergens in Plantago lanceolata have not been characterized yet. The objective was to characterize some plantain-pollen allergens and to investigate the cross-reactivity between plantain and grass pollens. METHODS: Sera from four patients monosensitive to plantain pollen and from eight grass-pollen-allergic patients showing strong skin reactivity to plantain pollen in the skin prick test (SPT) underwent immunoblot analysis with both Plantago and grass mix extract. Moreover, immunoblot inhibition experiments were done with grass mix extract as inhibitor. RESULTS: All four sera from plantain-allergic patients reacted to two distinct bands at 17 and 19 kDa, and 2/4 sera showed further reactivity to a 40-kDa protein, which in one case represented the most prominent IgE-binding allergen. Plantain-monosensitive subjects did not show any reactivity to grass-pollen extract, and preabsorption of their sera with grass-pollen extract did not cause any loss of reactivity to plantain pollen. Sera from all eight grass-pollen-allergic controls reacted to a 30-kDa protein in plantain pollen, and some sera showed cross-reactivity to higher and lower molecular-weight structures as well. In all cases, plantain reactivity was totally abolished by preabsorption of sera with grass-pollen extract. A preliminary investigation by immunoblot showed that polyclonal IgG anti-Phl p 5 (but not polyclonal Phl p 1) from rabbit reacted to a 30-kDa protein in plantain pollen. CONCLUSIONS: Three specific allergens (of 17, 19, and 40 kDa, respectively) have been detected in plantain pollen. Further studies on a larger number of patients will determine whether these proteins may be considered major allergens. Cross-reactivity between grass and plantain pollen is mainly caused by a 30-kDa protein in plantain pollen. Group 5 grass-pollen allergen is probably responsible for most grass/plantain cross-reactivity.     

Mercurialis annua pollen: a new source of allergic sensitization and respiratory disease.

Sensitization to Mercurialis annua pollen in 13 patients admitted for allergy study of asthma, rhinitis, or rhinoconjunctivitis is described. Twelve of these patients were also sensitized to other common aeroallergens. In five patients, a relationship was found between exposure to M. annua pollen and elicitation of symptoms. All patients were prick test and RAST positive to an extract of M. annua pollen. Nasal provocation test proved positive in 10 of 12 patients, and bronchial provocation test was positive in the only patient in whom it was performed. Two late responses were recorded. Immunoblotting of the 13 sera revealed two different groups of relevant allergens; one of isoelectric point 10.2, reacting with 12 of the 13 sera, and the other allergen of isoelectric point 5.0 to 5.5, reacting with 11 of the 13 sera. M. annua pollen is able to induce both sensitization and clinical disease in atopic patients. Since sensitization to this pollen accounts for 8.5% of total positive skin tested patients in the same period, we believe M. annua pollen should be considered as a relevant allergen and thus included in skin test batteries. Some patients labeled as having "intrinsic" asthma or rhinitis might be sensitized to this and other previously unknown allergens.     

Relationship of Allergen-Specific IgE Antibodies, Skin Prick Tests and Allergic Disorders in Unselected Adolescents

The relationship between serum levels of allergen-specific IgE (RAST) and skin prick test reactivity and allergic disorders was evaluated in 137 subjects randomly selected from an adolescent population. All subjects were prick tested with six common allergens, interviewed and physically examined. In addition, serum was collected for RAST analysis with three to six allergens. At least one positive RAST result (score 1-4) was observed in 40% and at least two positive RASTs in 22% of the subjects. Boys experienced more RAST reactions and generally with higher scores than girls. For instance, 26% of boys but only 11% of girls were RAST positive to timothy grass pollen. The correlation between prick test and RAST results was better with pollens than with house dust and animal epithelia. When the test results were discordant, the skin test was usually positive and RAST negative. Many of the small skin reaction (weal diameter 3-4 mm) were accompanied by a negative RAST. Respiratory allergy was closely connected with both positive skin test and RAST reactivity, while atopic dermatitis was less related. In 17% of the adolescents positive skin tests and in 14% positive RASTs occurred in the absence of any allergic symptoms. We conclude that a positive RAST score 3-4 to inhaled allergens is a strong indicator of clinical allergy but low scores 1-2 are frequently found in healthy young people.     

Investigation of the Involvement of Echium plantagineum (Paterson's Curse) in Seasonal Allergy

The possible allergenicity of an insect pollinated weed, Echium plantagineum , was investigated in a rural area of Australia. Sixty-one subjects with respiratory allergy were studied. Positive skin test reactions to defatted ammonium bicarbonate extract of pollen were found in over 60% of subjects, and positive RAST tests in a similar number. The question of cross-reactivity between weed pollens is discussed. The pollen of E. plantagineum was shown to reach the atmosphere in significant amounts about 1 month before the peak grass pollinating period. Evidence that the pollen of E. plantagineum becomes airborne and elicits an IgE response suggests that further attention should be directed to weed pollens as potential allergens.     

Two-spotted spider mite allergy: immunoglobulin E sensitization and characterization of allergenic components.

BACKGROUND AND OBJECTIVE: Previous investigations demonstrated that two-spotted spider mite (TSM) inhalation causes allergic asthma in agricultural workers. This work investigates whether TSM causes similar problems in the urban population. We determined the sensitization rate to TSM. We also identified immunoglobulin (Ig)E-binding components and evaluated their relationship with house-dust mite (HDM) allergens. METHODS: We carried out skin prick test (SPT) with TSM in 1,806 respiratory allergy patients over 1 year. TSM-IgE was detected by enzyme-linked immunoadsorbent assay (ELISA). TSM-sensitized patients were classified into two groups: patients who were skin test-positive to both TSM and HDM were included in group A and patients who were skin test-positive to TSM only were included in group B. ELISA inhibition test using sera from group A and B were conducted. IgE-immunoblotting was used to identify major allergens. These were purified by 2-dimensional electrophoresis and blotted onto polyvinylidene difluoride, and N-terminal sequences were identified. RESULTS: SPT (> or = 2+ of allergen/histamine) was positive in 358 (19.8%) patients. Twelve (6.6%) showed positive response to TSM only, and 54.5% had positive specific IgE. ELISA inhibition test using sera from two groups showed significant inhibition by TSM with minimal inhibition by HDM. Amino acid sequence of three major allergens was not homologous with any previously characterized allergens. CONCLUSION: IgE-sensitization rate to TSM was 19.8% in respiratory allergy patients. Eleven IgE-binding components and three major allergens were identified. The pIs and amino acid sequences of the major allergens were determined.     

Pollinosis to Ricinus communis (castor bean): an aerobiological, clinical and immunochemical study

BACKGROUND: Ricinus communis (castor bean) is a species included into the Euphorbiaceae family, common to all the warm regions of the world. Although the allergenicity of its seed is well known, references are scarce regarding the role played by its pollen as a pneumo-allergen. OBJECTIVES: To carry out an aerobiological study of this pollen in the Málaga area (southern Spain); describe the physicochemical characteristics of its most relevant allergens; and to demonstrate the existence of patients with respiratory allergy due to this pollen. METHODS: A Burkard spore trap was used for the aerobiological study from 1992 to 1996. Skin prick tests with castor bean pollen extract were performed to 1946 patients with rhinitis and/or asthma. Specific IgE levels were measured in castor bean-positive SPT patient sera. Immunochemical characterization of the most relevant allergens was performed using electrophoretic techniques. In vitro cross-reactivity studies using positive patient sera were carried out. Nasal challenge tests were done in 32 subjects randomly selected from the sensitized patient group. RESULTS: Castor bean is a perennial pollen with total annual pollen levels never exceeding 1%. One hundred and eighteen (7.7%) patients showed positive prick test (74 rhinitis, 36 rhinitis and asthma, eight asthma). Nine were monosensitized. Specific IgE levels were > or =0.35 PRU/mL in 39 (33%) of patient sera. Nasal challenge test: 10 subjects presented non-specific nasal hyperactivity, 15 were positive and seven negative. The molecular masses and isoelectric points of the main IgE-binding proteins, ranged from approximately 67-15.5/14.5 kDa and approximately 4.5-5.5, respectively. Profilin of the extract was purified by poli-L-proline-Sepharose chromatography and it appeared as one of the most frequent allergens. CONCLUSION: Castor bean pollen is an allergen which causes respiratory (mainly nasal) symptoms.     

Sensitivity to tomato and peanut allergens in children monosensitized to grass pollen

Possible associations between allergy to grass pollen and positive skin tests to food allergens were studied in 102 children monosensitized (as to inhalant allergens) to grass pollen, and in 117 children monosensitized (as to inhalant allergens) to Dermatophagoides. Thirty-two foods were tested by an epicutaneous method. Positive skin tests to food allergens were more frequent in children with allergy to grass pollen (59.8%) than in children with allergy to Dermatophagoides (9.4%). A considerably high frequency of positive reactions to tomato (39.2%), peanut (22,5%), green pea (13.7%), and wheat (11.7%) was observed in children with allergy to grass pollen. Positive skin tests to peanut closely correlated with positive RAST results and nasal provocation tests, whereas in children with skin test positivity to tomato a close correlation with nasal provocation tests but a 45% correlation with a positive RAST result were observed. RAST inhibition experiments were carried out, and the results may suggest the presence of cross-reacting IgE to grass pollen, tomato, and peanut antigens. Clinical implications of these findings are discussed in the light of histories of food hypersensitivity, urticaria-angioedema, and atopic dermatitis in children with allergy to grass pollen.     

Anaphylaxis to camomile: clinical features and allergen cross-reactivity

BACKGROUND: Medicinal remedies of plant origin became very popular in recent years, and allergic reactions to these are on the rise, accordingly. Camomile has been reported as a potential trigger of severe anaphylaxis. The allergens responsible for camomile allergy have not been characterized as yet. OBJECTIVE: The present study aims at reviewing the clinical symptomatology of immediate-type reactions in a series of patients sensitized to camomile and at characterizing the responsible allergens. METHODS: Fourteen patients with a history of allergy either to camomile or to spices or weeds, and a positive skin prick test/RAST to camomile were investigated for related allergic reactions to food, pollen and others. IgE-binding patterns were determined by immunoblotting, inhibition tests and deglycosylation experiments. RESULTS: Ten of 14 patients had a clinical history of immediate-type reactions to camomile, in some cases life threatening. Eleven subjects were also sensitized to mugwort in prick or RAST, eight to birch tree pollen. Using a polyclonal rabbit anti-Bet v 1 antibody, a homologue of the major birch pollen allergen Bet v 1 was detected in two camomile blots. In four cases a group of higher molecular weight allergens (23-50 kDa) showed IgE-binding to camomile. All allergens proved heat stable. Binding was inhibited in variable degrees by extracts from celery roots, anize seeds and pollen from mugwort, birch and timothy grass. Deglycosylation experiments proved the presence of carbohydrate determinants in camomile which were not responsible for IgE-binding, though. Profilins (Bet v 2) were not detected in our camomile extracts. CONCLUSION: Incidence and risk of type I allergy to camomile may be underestimated. Concurrent sensitization to mugwort and birch pollen is not infrequent. Bet v 1 and noncarbohydrate higher molecular weight proteins were found to be eliciting allergens and are responsible for cross-reactivity with other foods and pollen.     

Allergenic components of Candida albicans identified by immunoblot analysis

Allergenic components of Candida albicans fractionated by SDS-polyacrylamide gel electrophoresis (PAGE) and transferred to nitrocellulose membranes were identified using sera from 30 asthmatic patients who showed positive skin test and RAST (radio-allergosorbent test) to C. albicans. The IgE-binding yeast components in the complex antigen preparation were then detected by reaction with enzyme-labelled anti-human IgE antibodies. They were confirmed by Coomassie blue R-250 staining of the membrane to visualize all protein bands after reaction with the enzyme substrate. The IgE-binding patterns of the sera tested were heterogeneous, displaying a total of 16 identifiable components with molecular weights ranging from 20 to 94 kD. A 40 kD component showed the highest IgE-binding frequency, being recognized by 23 (77%) of the 30 sera examined. The other 15 allergenic components identified were recognized by less than 25% of the sera tested. Only two of the 30 serum samples contained IgE antibodies reactive with seven to eight allergenic components. Ten of the 30 sera reacted with only one allergenic component, and the remaining serum samples recognized two to five of the 16 identified allergens. Results described in this study are applicable to allergen standardization work and provide a basis for further study on the role of C. albicans in clinical allergy.     

Analysis of IgE binding proteins of mesquite (Prosopis juliflora) pollen and cross-reactivity with predominant tree pollens

Pollen from the mesquite tree, Prosopis juliflora, is an important source of respiratory allergy in tropical countries. Our aim was to partially characterize the IgE binding proteins of P. juliflora pollen extract and study cross-reactivity with prevalent tree pollen allergens. Intradermal tests with P. juliflora and five other tree pollen extracts were performed on respiratory allergy patients from Bikaner (arid) and Delhi (semi arid). Prosopis extract elicited positive skin reactions in 71/220 of the patients. Sera were collected from 38 of these 71 patients and all demonstrated elevated specific IgE to P. juliflora. Immunoblotting with pooled patients' sera demonstrated 16 IgE binding components, with components of 24, 26, 29, 31, 35, 52, 58, 66 and 95 kDa recognized by more than 80% of individual patients' sera. P. juliflora extract is allergenically potent requiring 73 ng of self-protein for 50% inhibition of IgE binding in ELISA inhibition. Cross-inhibition assays showed close relationship among P. juliflora, Ailanthus excelsa, Cassia siamea and Salvadora persica. IgE binding components of 14, 41, 52 and 66 kDa were shared allergens whereas 26 and 29 kDa were specific to P. juliflora. The findings suggest that purification of cross-reactive allergens will be helpful for diagnosis and immunotherapy of tree pollen allergic patients.     

Evaluation of a capsulated hydrophilic carrier polymer (the ImmunoCAP) for measurement of specific IgE antibodies

The Pharmacia CAP System is a new assay for serum specific IgE, utilising a solid phase capable of binding more antigen than conventional systems. The CAP System has been evaluated in 69 consecutive patients referred to one allergy clinic in relation to skin prick test (SPT), radioallergosorbent test (Phadebas RAST) and specific allergy diagnosis for five inhalant allergens, D.pteronyssinus, timothy grass pollen, cat epithelium/dander, Cladosporium and Alternaria. Good correlation was obtained between RAST and CAP for all allergens, e.g. r = 0.974 for D.pteronyssinus and r = 0.964 for grass pollen. When sensitivity and specificity were examined for both CAP and RAST versus SPT, CAP was usually found to be of greater sensitivity than RAST, and of similar or slightly lower specificity. SPT gave more positive reactions than either in vitro test, but CAP gave more positives than RAST. Twenty-two of 336 (6.6%) tests were CAP positive/RAST negative, whereas a negative CAP with a positive RAST occurred in only 2/336 (0.6%) tests. Of patients with any test (SPT or RAST or CAP) for specific IgE positive, up to 20-30% did not have clinical allergy, confirming the importance of the history in interpreting these tests. Our results suggest that, for the allergens tested, the Pharmacia CAP System is more sensitive than the RAST, identifying more positive tests and approximating more closely to the SPT. It offers the additional advantages of speed and efficiency.     

Possible relationship between systemic side effects and sensitization to rPar j 2 in allergic patients submitted to an ultra-rush (20 min) sublingual immunotherapy and selected by component resolved diagnosis

BACKGROUND: The pollen of Parietaria spp., a weed of the Urticaceae family, is a major cause of respiratory allergy in the Mediterranean area, where the most common species are Parietaria judaica and Parietaria officinalis. In this study, we evaluated the specific serum IgE-binding profiles to individual P. judaica pollen recombinant major allergen, and Phleum pratense cytoskeletal profilin and a 2-EF-hand calcium-binding allergen homologous to cross-reactive Parietaria pollen allergens, in patients allergic to pollen with positive skin test towards Parietaria spp. extract. METHODS: The present observation included 220 patients from the province of Cuneo, north-west Italy, all suffering from rhino-conjunctivitis and/or asthma selected on the basis of skin test positive to P. judaica extract. The sera were evaluated for specific IgE reactivity to P. judaica pollen major recombinant(r) allergen Par j 2, Phleum pratense pollen allergens rPhl p 7 (2-EF-hand calcium binding protein) and rPhl p 12 (profilin), both identified as cross-reactive Parietaria spp. allergens, using Pharmacia CAP System. Out of 220 patients, 37 patients with IgE reactivity to rPar j 2 and 105 patients sensitized to at least one timothy pollen major allergen (i. e. rPhl p 1, rPhl p 2, natural Phl p 4 and rPhl p 6) were submitted to an ultra-rush protocol of sublingual immunotherapy (SLIT). The occurrence of adverse reactions were evaluated in both groups. RESULTS: All 220 patients with pollinosis and positive in vivo skin prick tests had in vitro positive CAP results to P. judaica natural extract. On the contrary, in these patients the prevalence of Par j 2-specific IgE was only 33.2% (73/220). In fact, 116/220 (52.7%) patients with serum specific IgE to crude Parietaria pollen extract had specific IgE to Phl p 12, 18/220 (8.1%) subjects with specific IgE to rPhl p 12 also exhibited specific IgE to Phl p 7 and 26/220 (11.8%) subjects had specific IgE against rPhl p 7. Particularly, geometric mean (25th-75th percentile) of specific IgE to rPar j 2 were as follows: 2.87 kUA/l (1.005-7.465). Out of 73 patients with specific IgE to rPar j 2, 7 subjects (9.6%) had also specific IgE to rPhl p 7, 12 (16.4%) had specific IgE to rPhl p 12 and 4 (4.1%) patients had specific IgE to both recombinant allergens. Of 37 patients under an ultra-rush protocol of SLIT, 3 subjects (8.1%) experienced generalized urticaria, and 1 of them also had diarrhea 3 h after the last dose of Parietaria judaica extract oral-vaccine administration. On the contrary, no systemic reactions were observed in 105 patients after Phleum pratense extract oral intake after a similar ultra-rush SLIT protocol (p = 0.0046). CONCLUSIONS: In the light of present findings, allergen extract-based diagnosis, in vivo and in vitro, cannot discriminate allergic patients that are genuinely sensitized to Parietaria spp. major allergens or to other major allergens to which current immunotherapeutic allergy extracts are standardized. Therefore, in vitro component resolved diagnosis is the unique tool to define the disease eliciting molecule(s). Finally, during sublingual immunotherapy, not only the dose of allergen, but also the biochemical characteristic of the major allergen administered may be an important factor in determining possible systemic reactions.     

Allergenicity of the cat flea (Ctenocephalides felis felis)

Adult fleas, spent and unspent culture media were extracted and the radio-atlergosor-bent test (RAST) performed with sera of 48 cat flea skin test-positive individuals from the Tampa Bay area of Florida. Sixteen sera (33.6%) had a positive RAST to the cat flea extract prepared in our laboratory [1.7-11.4% of the total counts (TC) added]. Six of the 16 sera (12.5%) also contained specific IgE to allergens in thespent medium (0.8-3.3% TC). The allergen composition and strength were studied by RAST inhibition of two commercial cat flea extracts and compared with our in-house flea extract. The results demonstrated similar allergen compositions and different potencies. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the in-house flea extract showed several Coomassie blue-stained bands (10–85 kD). SDS-PAGE immunoblols revealed five IgE-binding bands at 34, 35, 39, 54 and 60 kD. Flea allergens were quantified in eight house dust samples using RAST inhibition assays and expressed as RAST inhibition units; five of these samples contained detectable levels. Cat flea allergens may contribute to the allergenicity of house dust in areas of heavy llea infestation.     

Banana allergy in patients with immediate-type hypersensitivity to natural rubber latex: Characterization of cross-reacting antibodies and allergens

Background: An association between allergy to latex and banana has been reported. Even though cross-reacting IgE antibodies have been demonstrated, in no study has the existence of structurally similar allergens been confirmed. In the present study banana allergy was studied in a large series of patients with latex allergy. Specific IgE antibodies were characterized for cross-reactivity and compared with pollen RAST results. Latex and banana extracts were investigated for common antigens and allergens. Methods: Latex-, banana-, and pollen-specific (birch, timothy, mugwort) IgE were measured in 47 sera from patients with latex allergy. Thirty-one patients were skin prick tested with banana and questioned for possible reactions after eating bananas. Several RAST inhibition and immunospot inhibition studies were used to characterize cross-reacting IgE antibodies. Structurally similar antigens and allergens were evaluated with crossed-line immunoelectrophoresis and crossed-line radioimmunoelectrophoresis, respectively. Results: Latex RAST results were positive in 31 (66%) and banana RAST results were positive in 26 (55%) of the 47 sera. Of the 31 latex RAST–positive sera, 25 (81%) were also banana RAST–positive. Results from latex RAST correlated significantly with results from banana RAST (p < 0.001), but not with those from pollen RAST (p > 0.05). Banana skin prick test results were positive in 11 (35%) of the 31 patients tested. Symptoms after eating bananas were reported by 16 (52%) of the 31 patients. In inhibition studies the binding of IgE antibodies to solid-phase banana and to several latex preparations was inhibited by latex and banana, respectively. In crossed-line immunoelectrophoresis at least one antigen from banana fused with an antigen from latex, which also bound IgE antibodies in autoradiography (crossed-line radioimmunoelectrophoresis). Conclusions: Patients with latex allergy have symptoms caused by banana and show positive skin test and specific IgE test results. Cross-reacting IgE antibodies were confirmed by several inhibition techniques. For the first time, a structurally similar antigen/allergen was demonstrated. (J ALLERGY CLIN IMMUNOL 1994;93:990-6.)     

Evidence for the genetic control of immunoglobulin E reactivity to the allergens of Alternaria alternata

BACKGROUND: The fungus Alternaria alternata contains potent allergens, and sensitization to these allergens is associated with a high risk of respiratory disease. The influence of genetic regulation on sensitization to Alternaria is unknown. OBJECTIVE: To determine the influence of genetic factors on IgE responses to specific allergens of Alternaria. METHODS: The concordance of skin prick test (SPT), radioallergosorbent test (RAST) and IgE-binding profiles of sera were examined from a large cohort of monozygotic and dizygotic twins. RESULTS: Casewise concordance for a positive SPT response was monozygous (MZ) 66%: dizygous (DZ) 40% (P = 0.002). Logistic regression confirmed that casewise concordance was significantly stronger between MZ than DZ pairs. Immunoblotting against an Alternaria extract revealed 19 allergenic bands. The differences in concordance between the different bands were not significant for either the MZ (P = 0.97) or DZ (P = 0.84) groups. The pooled MZ : DZ difference in concordance was just significant (P = 0.049), suggesting an overall genetic effect on the response to Alternaria. This was reinforced by the comparison of the MZ and DZ correlations for total number of bands recognized (MZ r = 0.65; DZ r = 0.37, P = 0.015). Overall, there was a moderate correlation between the individual SPT weal size and RAST score (r(2) = 0.41) and a substantial correlation between the number of immunoblotted bands and RAST scores (r(2) = 0.79). CONCLUSION: There is a strong genetic influence on IgE response to the mixture of Alternaria allergens and a lesser effect on IgE response to individual allergens.     

Immunologic evaluation of shrimp-allergic individuals

Thirty-three individuals with a history of immediate hypersensitivity reactions after shrimp ingestion and 29 nonshrimp-sensitive control subjects were evaluated for evidence of crustacea-specific immunity by skin prick test titration end point, RAST, and ELISA, with extracts of shrimp, crab, crayfish, and lobster. Individuals were categorized as either atopic or nonatopic on the basis of history and skin test reactivity to common inhalant allergens. Most (28/33) shrimp-sensitive subjects had positive skin prick tests to shrimp extract, whereas skin tests were negative in 27/29 control subjects. Eighty-one percent of atopic and 41% of nonatopic shrimp-sensitive subjects had elevated shrimp-RAST ratios. The RAST ratios of atopic individuals were significantly higher than ratios of nonatopic individuals, and there was a significant correlation between shrimp-RAST ratios and historical clinical symptom scores. RAST determinations of all control subjects were negative. Shrimp-sensitive subjects also had significantly elevated serum levels of shrimp-specific IgG and IgA as compared to control individuals. Both IgG and IgA shrimp-specific reactivity demonstrated a significant positive correlation with shrimp-RAST ratios. These studies indicate that IgE-mediated, type I mechanisms, detected by positive shrimp skin tests and RASTs, appear to be operative in crustacea-sensitive individuals, particularly those with concurrent respiratory allergy. Although the role of shrimp-specific IgG and IgA antibodies in the immunopathogenesis of crustacea allergy remains unclear, such antibodies appear to represent increased immunologic recognition of shrimp allergens/antigens in shrimp-sensitive subjects.     

Comparative studies on tree pollen allergens. VIII. Immunological properties of the alder (Alnus incana) pollen extract

The immunological properties of the aqueous crude alder pollen extract (AI crude) and gel filtration fractions AI 3, AI 4 and AI 34 (pool of fractions AI 3 and AI 4) were examined by immuno- and radioimmuno-electrophoretic techniques, RAST titration, RAST inhibition and skin prick tests (SPT). In CIE, the AI crude extract and AI 34 displayed reference precipitate patterns consisting of 27 and 24 visible Coomassie brilliant blue stained lines, respectively. The CRIE allergogram performed by incubation with 18 individual reaginic sera detected three IgE-binding antigens characterized by different IgE-binding properties. Antigen No. 7 (Ag 7) was demonstrated to be the major IgE antibody-binding antigen of alder pollen, while Ag 1 and Ag 11 were classified as intermediate allergens. The allergens of alder pollen were located in fractions AI 3 and AI 4 of the gel filtration chromatogram. Ag 7 was present in both fractions as demonstrated by FRIE with autoradiography (FRIEWA) on the gel filtration fractions and tandem-CRIE of AI 3 and AI 4. The CRIE allergogram, RAST, RAST inhibition and SPT demonstrated fraction AI 34 to be allergenically representative of the AI crude extract both qualitatively and quantitatively. Thus, fraction AI 34 was considered an optimal purified allergen extract of alder pollen, a suitable material for further biochemical characterization and trials on purification of the allergenic reactive antigens.     

Platanus acerifolia pollinosis and food allergy

BACKGROUND: In Mediterranean areas, oral allergy syndrome (OAS) occurs independently of an associated birch pollinosis; moreover, on occasions it presents with no other associated pollinosis. The aim of this study was to assess the possible association of OAS with Platanus acerifolia pollinosis. METHODS: We evaluated consecutive patients seen for pollinosis in an allergy department. Seven hundred and twenty patients were selected on the basis of seasonal or perennial rhinitis, or asthma, or both. Respiratory and food allergies were studied in all patients. Clinical history was recorded and examinations and skin prick tests were performed with a battery of available common inhalant allergens and plant-derived food allergens. Specific IgE levels to P. acerifolia pollen extract and food allergens tested were measured. Molecular masses of the IgE-binding proteins and cross-reactivity among the P. acerifolia pollen and different food extracts were also determined. RESULTS: Of the 720 patients evaluated, 61 (8.48%) were sensitized to P. acerifolia pollen. Food allergy was observed in 32 (52.45%) of the 61 patients sensitized to P. acerifolia pollen. Food allergens most frequently implicated were hazelnuts, peach, apple, peanuts, maize, chickpea and lettuce. Enzyme allergosorbent (EAST)-inhibition showed high inhibition values when P. acerifolia pollen extract was used as free phase. On the contrary low inhibition was observed when plant-derived food allergens were used as free phase and P. acerifolia pollen extract as solid phase. CONCLUSIONS: Cross-reactivity was observed among P. acerifolia pollen and plant-derived foods. OAS in these patients may have been caused by primary respiratory sensitization.     

Skin test and RAST responses to wheat and common allergens and respiratory disease in bakers

Interrelationships between skin and humoral tests for immediate hypersensitivity to wheat and indicators of respiratory disease were examined in 176 male bakers. Skin tests were assessed by measuring the diameter of the weal resulting from prick innoculation of allergen extract and circulating allergen-specific IgE by radioallergosorbent test (RAST). Fifteen per cent of subjects showed positive skin-prick test responses to wheat extracts. These subjects demonstrated an increased prevalence of respiratory symptoms and of measurable bronchial responsiveness to methacholine. Thirty per cent of subjects had positive skin test responses to common allergens but negative responses to whole wheat. Compared to subjects with no positive skin test responses they had an increased prevalence of bronchial responsiveness to methacholine but a similar prevalence of respiratory symptoms. There was a significant association between skin test responses to whole wheat and skin test responses to common allergens suggesting that bakers with pre-existing sensitivity to common allergens are at increased risk of developing wheat flour sensitization. There was no significant difference between skin-prick test and RAST responses to wheat, water-soluble wheat protein and common allergens. Both tests showed similar relationships with indices of respiratory disease. The associations between skin test and RAST responses to wheat extracts and indices of respiratory disease was stronger for the water-soluble wheat proteins than for other wheat grain extracts. These results suggest that immediate hypersensitivity to wheat flour is important in the development of non-specific bronchial hyperreactivity in bakers and that the water-soluble fractions of wheat flour are the most important allergenic components. It agrees with in vitro results showing that water-soluble wheat proteins bind IgE in sensitive bakers more closely than other grain extracts.