Cereal pollen sensitisation in pollen allergic patients: to treat or not to treat?

Pollen allergens of the Poaceae family comprise one of the main causes of pollinosis worldwide. Although most of cereals are included in this family, certain pollination characteristics and aerobiological features differentiate them from common wild grass pollen. Cereal pollen grains cannot be easily characterised as potential sources of aero allergens, because of their pollination mode (most of them are autogamous plants), the consecutive low numbers of pollen they produce and their pollen's large volume and consequent high weight which further prevent dispersion and pollen transport. However, various epidemiologicalstudies concluded in comparable sensitisation patterns between common grass and cereal pollen. This fact can be attributed to the common epitopes shared between grass and cereal pollen allergens, which are responsible for the high cross reactivity observed not only in vitro but also in vivo. Therefore, the sensitisation patterns do not usually reflect a genuine, cereal-specific IgE recognition. On the contrary, genuine cereal sensitisation and allergy are referred to only in rare cases of occupational exposure to high amounts of these pollen grains (farmers and field workers) or in patients staying in the vicinity of cereal fields. Thus, cautious considerations should be taken into account when diagnostically approaching patients in which cereal pollen allergy could be considered in the differential diagnosis.     

Identification of peroxidase-1 and beta-glucosidase as cross-reactive wheat allergens in grass pollen-related wheat allergy

BackgroundSome patients with wheat-dependent exercise-induced anaphylaxis (WDEIA) or wheat allergy showed negative ω-5 gliadin-specific IgE test and high level of grass pollen-specific IgE. It was presumed that these patients developed allergic reaction upon cross-reaction of their IgE antibodies raised against grass pollen allergens to wheat allergens. This study aimed to clarify clinical characteristics and wheat allergens of this phenotype of WDEIA/wheat allergy, which were tentatively diagnosed as grass pollen-related wheat allergy (GPWA).MethodsA total of six patients with GPWA were enrolled, and controls were 17 patients with grass pollen allergy but no episode of wheat allergy, and 29 patients with other wheat allergies: 18 with conventional WDEIA and 11 with hydrolyzed wheat protein allergy. Sensitization to wheat proteins was determined by basophil activation test (BAT). IgE-binding proteins in wheat flour were identified by immunoblotting followed by mass spectrometry. Wheat allergen-specific IgE tests were established by CAP-FEIA system.ResultsAll the six patients with GPWA were sensitized to water-soluble wheat proteins in BAT and IgE-immunoblotting, and peroxidase-1 (35 kDa) and beta-glucosidase (60 kDa) were identified as specific IgE-binding wheat proteins. The binding of patient IgE to these proteins was inhibited by pre-incubation of patient sera with grass pollen. The peroxidase-1- and beta-glucosidase-specific IgE tests identified three and four of six patients with GPWA, respectively, but only two of 29 controls, indicating high specificity of these tests.ConclusionsPeroxidase-1 and beta-glucosidase are specific wheat allergens for GPWA among grass pollen allergy and other types of wheat-induced food allergies.     

Allergy to Salsola Kali in a Salsola Incanescens-rich Area: Role of Extensive Cross Allergenicity

BackgroundPollens from the Salsola spp. are an important source of respiratory allergy in tropical countries. Our aim was to characterize the IgE binding proteins of S. incanescens pollen extract and study its cross-reactivity with S. kali pollen allergens.MethodsPrick tests with S. kali and S. incanescens pollen extracts were performed on eight respiratory allergy patients from Mashhad, Northeast Iran. The antigenic profiles and IgE-binding patterns of S. kali and S. incanescens pollen extracts were compared by SDS-PAGE and Western blotting, using individual sera from the salsola pollen-sensitive patients. Cross-reactivity of proteins in the two weeds was assessed by IgE- immunoblotting inhibition.ResultsS. kali and S. incanescens pollen extracts showed similar IgE-binding profiles in Western blotting. The IgE binding components of 39, 45, 66 and 85 kDa were detected in both pollen extracts. Furthermore, inhibition of the immunoblots revealed extensive inhibition of IgE binding to proteins and a close relationship between these two weeds allergens.ConclusionsS. incanescens pollen is a potent allergen source with several IgE binding components that shows a close allergenic relationship with S. kali. Our results suggest that in S. incanescens-rich areas, S. kali pollen extracts could be used as a diagnostic reagent for allergic patients to S. incanescens pollen.     

IgE reactivity to profilin in Platanus acerifolia pollen-sensitized subjects with plant-derived food allergy.

BACKGROUND: The presence of profilin-specific IgE antibodies is a cause of cross-reactivity between botanically-unrelated allergen sources. Recently, the association between Platanus acerifolia pollinosis and plant-derived food allergy has been described. The aim of this study was to ascertain whether the P. acerifolia profilin is involved in such cross-reactivity. METHODS: Twenty-three patients suffering from Platanus acerifolia pollinosis and plant-derived food allergy were evaluated in an allergy department. Specific IgE levels to P. acerifolia pollen, P. acerifolia profilin and food extracts were measured. Molecular masses of IgE-binding proteins were calculated by Western blotting and cross-reactivity studies among P. acerifolia profilin and different food extracts were evaluated by Enzyme AllergoSorbent Test (EAST)-inhibition assays. Also, EAST-inhibition assays with the two known P. acerifolia allergens, Pla a 1 and Pla a 2, were performed. RESULTS: Surprisingly, a high IgE-binding prevalence (90%) of P. acerifolia profilin was found. EAST-inhibition showed high inhibition values when Platanus acerifolia pollen extract was used as free phase and plant-derived food extracts as solid phase, whereas the other way round showed low inhibition values. IgE reactivity to profilin was studied using a pool of patient sera, by EAST-inhibition assays with hazelnut, apple peel, peanut, chickpea and peanut extracts as solid phase and no inhibition was obtained when P. acerifolia profilin was used as inhibitor phase. The same results were obtained when purified Pla a 1 and Pla a 2 were also used as inhibitor phase. CONCLUSIONS: The clinical association observed between Platanus acerifolia pollen and plant-derived food could be explained by the in vitro IgE cross-reactivity detected by EAST-inhibition. However, it appears that neither P. acerifolia profilin nor the two major allergens described (Pla a 1 and Pla a 2) can explain such a strong cross-reactivity.     

Parietaria pollinosis in an Atlantic area: clinical and palynological data.

BACKGROUND: Parietaria pollen is considered as one of the most common causes of allergic respiratory symptoms in the Mediterranean area but its presence is limited in the Atlantic area. Some leading patients from Muros, a small town on the Spanish Atlantic coast, complaining of nearly all year round respiratory symptoms happened to be allergic to Parietaria pollen. AIM OF THE STUDY: To evaluate the prevalence of Parietaria sensitization among patients from this Atlantic town, and its correlation with aerobiological data (concentration of Urticaceae pollen). PATIENTS AND METHODS: Eighty-nine patients suffering from rhinoconjunctivitis and/or asthma from the area of Muros between January 1998 and January 1999 were included. Skin prick tests and serum-specific IgE (CAP Pharmacia) to Parietaria judaica and a battery of perennial or seasonal allergens were performed. Information about the seasonal and hourly rhythm of symptoms was obtained in each patient sensitized to Parietaria pollen. Atmospheric pollen was collected, using a Hirst-type volumetric pollen sampler, during 1998. RESULTS: Parietaria allergy was detected in 22 patients (25%) and represented the second most important aeroallergen after mites and along with grass pollen. The total atmospheric pollen recorded in Muros during the study period was 27,515 pollen grains, Urticaceae being the most important one (18,554 grains, 67% of the total). The proportion of Urticaceae pollen found in Muros was the highest among all samplers belonging to the Spanish Aerobiology Network. Maximum values of Urticaceae pollen were recorded during May and June. Intradiurnal variation of pollen counts showed maximum values between 11 a.m. and 1 p.m. A parallelism was observed between the rate of symptomatic patients and Parietaria type grain pollen count. CONCLUSION: The prevalence of Parietaria pollen sensitization seems to be very important in this Atlantic area. The presence of very high levels of this pollen in its atmosphere explains this fact. Such sensitization should be taken into account concerning specific diagnostic tests.     

Allergy to laxative compound (Plantago ovata seed) among health care professionals.

BACKGROUND: The seeds of Plantago ovata (psyllium, ispaghula) used in the manufacture of bulk laxatives are known to be the cause of occupational allergy (rhinitis, asthma) in health care and pharmaceutical workers. OBJECTIVE: We studied the prevalence of P ovata seed allergy among health care workers in geriatric care homes and compared it with a group of health care professionals not exposed to P ovata seed. Cross reactivity with Plantago lanceolata pollen was also studied. METHODS: Two groups of health professionals were recruited: 58 health care workers from geriatric care homes who were exposed daily to laxatives containing P ovata and 63 nonexposed health care professionals. The prevalence of allergy and sensitization to P ovata seed was determined based on clinical history, skin prick test, and analysis of specific immunoglobulin (Ig) E. IgE immunoblotting was performed to calculate the molecular weights of the P ovata seed allergens. Cross reactivity to P lanceolata pollen was studied by enzyme allergosorbent test (EAST) and immunoblot inhibition techniques. RESULTS: The prevalence of sensitization and clinical allergy to P ovata seed in the exposed group was 13.8% and 8.6%, respectively. No sensitization was observed in the nonexposed group. IgE-binding proteins of 17, 20, 25, 32-34, 54, 73-77, and > 97 kDa were identified. EAST inhibition and immunoblot inhibition demonstrated the existence of cross reactivity between P ovata seed and P lanceolata pollen extracts. CONCLUSIONS: The rate of sensitization to P ovata seed is high among health care workers in geriatric care homes (13.8%). A mild cross reactivity between P ovata seed and P lanceolata pollen was observed.     

An aerobiological perspective in allergy and asthma

Allergic diseases are amongst the most common chronic disorders worldwide. Today, more than 300 million of the population is known to suffer from one or other allergic ailments affecting the socio-economic quality of life. Major causative agents implicated are pollen grains, fungal spores, dust mites, insect debris, animal epithelia, etc. Several aerobiological studies have been conducted in different parts of the world to ascertain aerial concentration and seasonality of pollen grains and fungi. Especially from clinical point of view, it is important to know the details about the pollen season and pollen load in the atmosphere. The flowering time of higher plants are events that come periodically in each season, but the time of blooming may differ from year to year, in different geographic locations. Based on differences recorded in several years of observations in airborne pollen, pollen calendars are drawn as an aid to allergy diagnosis and management. This review article emphasises on various aerobiological parameters of environmental pollen from different parts of the world with special emphasis from India. The role of aerobiology in the diagnosis and management of allergic diseases is reviewed briefly in this article.     

Phoenix sylvestris Roxb pollen allergy: a 2-year randomized controlled trial and follow-up study of immunotherapy in patients with seasonal allergy in an agricultural area of West Bengal, India.

BACKGROUND: Although the efficacy of allergen immunotherapy has been demonstrated in seasonal pollen allergy, there is no report of a double-blind placebo-controlled trial with standardized pollen extract in seasonal respiratory allergy from India. In the agricultural area of eastern India, Phoenix sylvestris Roxb or date sugar palm is grown or cultivated and seasonal allergic rhinitis is common during the pollen season. OBJECTIVE: The objective of the present study was to observe the clinical and immunological changes during a 2-year double-blind placebo-controlled trial of immunotherapy with standardized P sylvestris pollen extract in respiratory patients sensitive to pollen from this wild date palm. Thirty-five subjects with typical seasonal allergic rhinitis with or without bronchial asthma were selected. A symptom-medication score (based on a questionnaire and diary) was correlated with pollen counts as recorded in a Burkard sampler. Eighteen subjects were randomized to a specific immunotherapy (SIT) group receiving regular injections containing standardized allergen extract and 17 to a placebo control group. Changes in the level of specific immunoglobulin (Ig) E, IgG1, and IgG4 were recorded at 3-month intervals. Measurement of wheal diameter, total IgE level and forced expiratory volume in 1 second (FEV1) were performed before starting and a month after finishing therapy. RESULTS: The SIT group showed decreases of 33.5% and 57% from the baseline symptom-medication scores during the first and second treatment season, respectively. This group showed significant decreases in skin-reactivity to P sylvestris pollen extract and in specific IgE levels, and significant increases in FEV,, specific IgGI (1.95-3.2 times higher) and IgG4 (21.24-30.83 times higher). There were no significant changes in total IgE levels. The control group showed no significant changes for any parameter except the development of new sensitization in 2 cases (to Saccharum officinarum pollen grain and Alternaria species spores). The rate of local adverse reactions was 0.024%. CONCLUSION: After a 2-year study, allergen immunotherapy with standardized P sylvestris pollen extract was found to be effective in seasonal respiratory allergic subjects susceptible to P sylvestris pollen with a narrow range of sensitization.     

Further characterization of IgE-binding antigens in kiwi, with particular emphasis on glycoprotein allergens.

Fruit allergy is frequently associated with birch pollinosis. The aim of this study was to investigate which kiwi allergens were involved in subjects allergic to fruit alone and in patients allergic to both fruit and birch pollen. Sera of nine patients (five with both kiwi and birch pollen allergy and four with isolated kiwi allergy) were studied by immunoblot of kiwi extract. Eight of the nine sera reacted with the 30 kDa protein. Furthermore, IgE-binding proteins were seen at approximately 23 kDa (detected by five sera), 43 kDa and 80 kDa (four sera), and > 80 kDa (two sera). One serum showed no IgE binding to any kiwi allergen. The 30 kDa is the major allergen in kiwi and was purified by anion-exchange chromatography and characterized by isoelectrofocusing and amino acid sequencing. The comparison of its partial amino acid sequence with data from the Swiss Protein Bank revealed that this protein is actinidine. The carbohydrate structures in kiwi and birch pollen extracts were investigated with seven lectins. On kiwi blot, Aleuria aurantia agglutinin showed strong reactivity (indicating fucose residues) to the components of 35 to 92 kDa, while concanavalin A (indicating mannose, glucose or N-acetylglucosamine residues) showed weak binding at 67 kDa. In contrast, strong binding of Galanthus nivalis agglutinin (indicating mannose residues) and concanavalin A was found on birch pollen blots. The presence of IgE against carbohydrate structures was determined by means of enzyme-linked immunosorbent assay (ELISA) after periodate treatment of kiwi extract. The IgE binding was reduced by periodate treatment of kiwi coated microtiter plates, but not by sera reacting exclusively with the 30 kDa protein. Furthermore, selected sera were treated with proteinase K-digested kiwi and birch pollen extracts as the sources of crossreactive carbohydrate determinants. In accordance with the results of sodium periodate treatment, significant levels of anti-cross-reactive carbohydrate determinant IgE were found in sera from patients allergic to both kiwi and birch pollen. Our results show that the major allergen for kiwi allergy is the 30 kDa protein and additionally that the cross-reaction between kiwi and birch pollen allergy is mainly due to carbohydrate moieties.     

Juniperus ashei: the gold standard of the Cuppressaceae

The non-standardized Cupressus sempervirens allergen extract currently available for the diagnosis of cypress allergy has a low level of activity. The search for an active material consisted of in vitro and in vivo comparison of three Cupressaceae pollen extracts: Cupressus sempervirens (Cs), Cupressus arizonica (Ca) and Juniperus ashei (Ja) (synonyms: Juniperus sabinoides and Mountain Cedar). These 3 trees belong to the same botanical family of Cupressaceae. While Cs and Ca are commonly encountered in Mediterranean regions, Ja is only present in Europe in the Balkans, but is a major cause of allergy in the USA. In vitro, with a similar protein content, the allergenic properties of Ja extract are 20-Fold higher than those of Cs and 11-fold higher than those of Ca. IgE immunoblotting revealed 14, 42 and 70 kDa allergens common to all 3 extracts. The inhibition curves of the 3 extracts were more than 88% parallel. A significant correlation was observed between serum specific IgE titres for Ja and Cs in 23 patients (r = 0.916; p < 0.001). In vivo, in 23 patients with cypress allergy, the mean diameter of the prick test papule at 1/20 W/V of Ja (8.3 mm) was greater than that of the Cs papule (6.3 mm) (p = 0.001) and the Ca papule (6.7 mm) (p < 0.001). Correlations between cutaneous responses to Cs and Ja (r = 0.629; p = 0.002), and to Cs and Ca (r = 0.75; p = 0.001) were significant. These results demonstrate the intense cross-reactivity between Cs, Ca and Ja. The allergenic potency of the Ja extract is superior to that of Cs and Ca extracts, both in vitro and in vivo. This superiority is correlated with a high concentration of the major allergen, Jun a 1. The non-standardized The now standardized extract of in vitro ashei pollen therefore represents an effective and documented solution for identification, and probably for treatment, of Cupressaceae pollen allergy.     

Cross-reactivity between Parietaria species using the major rParj1 and rParj2 allergens.

Parietaria pollen is one of the most important outdoor allergenic sources in all the Mediterranean countries, with a large number of subjects showing a positive skin prick test to both P. judaica and P. officinalis pollen extracts. A cross-reactivity between the two species has been already reported although few data are known at the molecular level. Twenty-five consecutive patients with Parietaria pollen allergy were selected on the basis of their clinical history. Skin prick test to P. judaica and officinalis extracts was performed. In vitro IgE measurement to both allergenic sources was performed by using a quantitative assay. ELISA inhibition experiments were made by using the rParj1 and rParj2 allergens. All the patients showed a positive skin prick test to both Parietaria species. Quantitative IgE measurement showed similar antibody concentration for P. judaica and P. officinalis extracts. ELISA inhibition experiments demonstrated that the cross-reactivity between the two species was due to the presence of the Parj1 and Parj2 allergens in the extracts with a high conserved IgE epitopes content. We conclude that P. judaica and P. officinalis pollens contain highly cross-reactive species-specific major allergens useful for the diagnosis and therapy of both allergenic sources.     

Prevalence of cypress pollen sensitization and its clinical importance in Izmir, Turkey, with cypress allergy assessed by nasal provocation.

BACKGROUND AND OBJECTIVE: Pollens from the Cupressaceae family are considered important allergens in the Mediterranean area, though reports of the prevalence of allergic symptoms have ranged from 1.04% to 35.4%. Our aim was to detect the prevalence of cypress pollen sensitization and determine its clinical importance in patients with seasonal respiratory allergy. METHODS: We used skin prick tests (SPT) and serum specific IgE assays to reveal sensitization to cypress pollen. In patients who showed positive results to cypress pollen, a nasal provocation test (NPT) with pollen extract was used to assess the target organ response. RESULTS: Sixty-five (14.3%) of 455 patients showed positive SPT responses to Cupressus sempervirens extract. Only 1 patient was monosensitized while 64 patients were polysensitized. Among those, 2 pollen cosensitizations were found to be significant (86% were cosensitized to grasses and 72% were cosensitized to olive (P < .001). Serum specific IgE to cypress pollen was measured in 50 of the 65 patients; findings were positive for 37. When these 37 patients underwent NPT with C sempervirens allergen extract, only the single monosensitized patient had a positive NPT. CONCLUSION: A positive SPT to cypress pollen may not reflect the true prevalence of sensitization. We assume that in the absence of a positive NPT, positive SPT results might be related to the presence of cross-reactivity between pollen species.     

Immunoblot studies in birch pollen-allergic patients with and without fruit hypersensitivity: part I: antibody pattern for birch pollen extract.

About 40-70% of birch pollen allergic patients show allergic symptoms after ingesting or handling raw fruits. Several investigations have indicated a partial immunological identity between birch pollen and stone fruit. To further clarify this association, we investigated 59 patients with allergic symptoms (conjunctivitis, rhinitis, and asthma during the birch pollen season) and 18 nonatopic controls by skin prick test (SPT) and RAST with birch pollen, fresh apple, cherry, and peach as well as freshly prepared fruit extracts. According to a questionnaire dealing with symptoms after ingestion of raw fruits, the subjects were divided into groups with (35 FH+) and without (24 FH-) fruit hypersensitivity. IgE, IgG, IgG1, IgG4, IgA, and IgM binding patterns to birch pollen extracts were performed with 33 sera (12 FH+, 11 FH-, and 10 nonatopic controls) using the immunoblot-technique. Patients with FH+ expressed a significantly stronger sensitization to birch pollen than patients without FH-, as measured by RAST and SPT. Native fruits induced stronger SPT reactions than fruit extracts, and patients with FH+ showed a significantly higher skin index with all fruits and fruit extracts tested. Specific IgE, IgG, IgG1, IgG4, IgM and IgA to birch pollen extracts could be detected by immunoblot in all groups, albeit with different frequencies and intensities. From this data we conclude that fruit hypersensitivity is related more to the 17 kd and 67-85 kd than to the 26-28 kd or 36 kd protein bands of the birch pollen extract. The relationship of specific IgE > IgG > IgM to a single protein band seems to be associated with the development of symptomatic type I allergy.     

Diagnostic biologique de l'allergie respiratoire : évaluation du réactif Vidas Stallergy genévrier dans l'allergie au cyprès

Cypress allergy is an important health issue in Mediterranean areas but its diagnosis is still difficult in some cases. The fact that cypress and juniper tree pollens share a number of allergens, together with the higher allergenic protein contents of the latter have recently led allergologists to use juniper pollen extracts while testing for cypress allergy. In the present study we have evaluated a new Vidas bioMérieux reagent, Stallergy ST6, designed for the detection and quantification of anti-juniper serum IgE, when applied to cypress allergy diagnosis. In thirty-one Respiratory Diseases Department outpatients clinically suspected of cypress pollen allergy, Stallergy ST6 results were compared to those of prick tests and of serum IgE quantification using the CAP System (Phadia). There is a good class concordance between IgE results yielded by the two methods. We conclude that Stallergy ST6 provides a sensitive and specific reagent for cypress allergy diagnosis.     

Immune complexes IgE/IgG in airborne allergy: increase during pollen season.

In the present study we addressed the question of IgE/IgG immune complex serum level in 92 patients with respiratory allergy in relation to their clinical status. Twenty patients with allergy to insect stings and 22 healthy volunteers were also investigated. IgE/IgG immune complexes and IgG anti-IgE antibodies were estimated using double antibody solid-phase immunoassays in IgG serum fractions isolated by protein A affinity chromatography or in fractions obtained by Sephacryl S-300 gel filtration. Three people (14%) from the control group, two patients (10%) with insect allergy and 41 patients (45%) from the group with airborne allergy exhibited an increased serum level of IgE/IgG immune complexes (chi2, p <0.05). IgG anti-IgE serum level was also significantly higher in the examined group of patients with airborne allergy than in the control group. None of the factors analyzed, including the kind of allergic disease, the type of inhalant allergen (pollen or house dust antigens), the severity of allergy judged from the frequency and intensity of symptoms for 1 year preceding blood sampling and the symptoms exhibited during blood sampling, showed a statistically significant relation to the level of IgE/IgG immune complexes or IgG anti-IgE, when the whole group of patients with respiratory allergy was analyzed. A distinct difference between patients investigated during and outside of the pollen season was found in patients with isolated pollen allergy. The latter exhibited an increase of IgE/IgG immune complexes (57% vs. 29%) significantly more often, which indicates the possible involvement of IgE/IgG immune complexes in the pathogenesis of pollen allergy.     

Immunoglobulin E and G antibody profiles to grass pollen allergens during a short course of sublingual immunotherapy.

BACKGROUND: Various studies have shown the clinical efficacy of sublingual immunotherapy in grass pollen-induced rhinoconjunctivitis. However, even short-term treatment with grass extracts might cause sensitizations to formerly unrecognized antigens. OBJECTIVE: To determine whether the antibody profiles are changing in patients receiving a defined grass pollen extract prior to and during the grass pollen season. METHODS: A randomized, double blind, placebo-controlled, multicenter phase I/I111 trial was started prior to the commencement of the grass pollen season. Patients with grass pollen allergy were randomly allocated to four groups, and received daily a standardized tablet at different doses. Treatment was started 8 weeks prior to the beginning of the pollen season and stopped at the end of the season. Blood samples were taken at the beginning of the study, at the beginning and the end of the pollen season, and one year after commencement of the study. RESULTS: At the beginning of the study, all patients tested positive for the major grass pollen allergens, but negative to the minor antigens. In all patients, the degree of antibody reactivity rose considerably after starting active treatment and fell back to the initial values within one year. Immunoglobulin (Ig) E antibodies to the minor antigens remained negative, independent of treatment and seasonal exposure. In contrast to IgE, specific IgG antibodies to all allergens tested revealed no specific trend. CONCLUSIONS: Immunotherapy with grass allergen tablets was accompanied by an increase in grass-specific IgE antibodies, which further increased during pollen exposure, followed by a post-treatment drop in patient- and disease-specific antibodies. During this short course of treatment, no patient developed any additional sensitizations.     

IgE cross-reactivity between meadow fescue pollen and kiwi fruit in patients' sera with sensitivity to both extracts.

BACKGROUND: The presence of IgE reactivity to kiwi fruit and grass pollen allergens which could be caused by cross-reactivity has been detected in many patients with allergy. Proper identification of allergens as well as cross-reactive components is essential for understanding fruit- and pollen-associated hypersensitivity. METHODS: Using the sera from the polysensitized patients with specific IgE to grass pollen and kiwi fruit we tested reactivity to both allergen sources. IgE reactivity was exhibited in 8 serum samples by immunoblot. A serum pool formed by 8 individual sera was used for the investigation of IgE crossreactivity. SDS-PAGE immunoblot-inhibition assay was performed by preincubation of the sera with meadow fescue pollen, kiwi fruit extract, and isolated 24 kDa kiwi protein. To determine the allergens of kiwi fruit extract, we performed 2D PAGE immunoblot. In order to detect the crossreactive components between two allergen sources, a specific IgE for the 24 kDa kiwi allergen was purified. RESULTS: SDS-PAGE immunoblot meadow fescue pollen showed allergens ranging from 94 to 16 kDa, and kiwi fruit had 12 allergens ranging from 94 to 17 kDa. 2D-PAGE analysis revealed at least 15 spots in the kiwi extract and about 10 allergens. The most prominent allergen in 2D PAGE immunoblot was protein with 24 kDa and pI 9.4-9.5. Using an affinity-purified specific IgE we found that the 24 kDa kiwi allergen shared IgE-reactive epitopes with the meadow fescue group 4 and allergen about 36 kDa. Crossreactivity between isolated 24 kDa kiwi allergen and Fes p 4 was confirmed by anti-grass group 4 moab 2D8. CONCLUSION: Our findings showed that fescue meadow pollen cross-sensitize to kiwi fruits. A 24 kDa kiwi glycoprotein represent potential major allergen, which share common epitopes with Fes p 4 and 36 kDa meadow fescue allergen.     

In vitro and in vivo biological activities of old and fresh Cupressus arizonica pollen.

BACKGROUND: Respiratory allergy to the pollen of Cupressaceae is becoming more and more common every year in the Mediterranean area. OBJECTIVE: The purpose of this study was to see whether the allergenic potency of Cupressus arizonica pollen diminished after a 6-year period (1994-2000). MATERIALS AND METHODS: Among the Cupressaceae, we selected the pollen of C arizonica. The mode of sampling in 1994 and in 2000 was the same and the pollen was collected on the same tree and stored at room temperature. To compare its biological and allergenic activities data was collected with the following methods: cytohistology of Alexander, 2,3,5-triphenyltetrazolium chloride enzyme staining, skin testing, nasal provocation test, radioallergosorbent test (RAST), RAST inhibition, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and immunoblotting to detect protein content. Thirty-eight patients with respiratory allergy to Cupressaceae were selected. RESULTS: We found no decrease in the allergenic potency of the pollen, but did find that viability and germinating power had disappeared completely after 30 to 40 days. Moreover, the amount of protein in the old pollen was half the amount found in the fresh one. Skin prick testing showed identical results with the old and the fresh pollens. CONCLUSIONS: The allergenic in vivo and in vitro activity of cypress pollen is retained for years after its collection. This activity seems to be independent of the viability of pollen grains and of the total protein content. This may explain the presence of clinical symptoms in patients out of the pollen season.     

Assessment of allergenicity to Mallotus phillipensis pollen in atopic patients in India: a new allergen.

OBJECTIVE: Pollen grains of the Euphorbiaceae family are well known causative agents of respiratory allergies in India, European countries and USA. Mallotus phillipensis belongs to the same family and may have some common allergenic properties. It has thus been evaluated for the first time in Indian population for its pollinosis causing properties. METHODS: Pollen antigen of Mallotus phillipensis (MP) was extracted and characterized for its protein components by biochemical methods. Pollinosis potency of crude extract of MP pollen was evaluated by skin prick test on population residing in different parts of India. Specific IgE binding characteristics of the extract were determined by ELISA and Immunoblot. RESULTS: Marked skin reactivity in 5.7% atopic population was recorded and subjects constituting 23.8% of the total patients tested showed skin sensitivity to the MP pollen antigen. Significantly raised specific IgE against MP pollen were recorded in 50% of the skin test positive patients. A number of protein bands were detected in a wide Molecular weight range as well as in acidic pI range, by SDS-PAGE and IEF, respectively. A total 11 protein fractions were detected by the specific IgE antibodies on immunoblotting with patient's sera and were considered allergenic. CONCLUSION: Patients from different geographical regions have shown sensitization to MP pollen antigen. Many proteins have similar molecular weights and pI as other allergenic members of the family (Ricinus communis and Putranjiva roxburghii) found in India, which constitutes a good reason for studying cross reactivity among the members of family Euphorbiaceae, in the future.     

Allergie respiratoire aux protéines de feuilles, implication d’un nouvel allergène

Symptoms of subjects presenting with rhinitis, conjunctivitis or contact urticaria when exposed or in contact with grass are usually attributed to allergy to grass pollen or to certain airborne molds. The four cases described in the present report presented with allergic symptoms when mowing their lawn. The suspicion of allergy to grass leaves was confirmed by skin prick tests with native leaves. An extract of rye grass leaves was made and its allergens were analyzed by SDS-PAGE and immunoblotting. Three of the four patients were found to have IgE specific for a single 56 kDa molecule. It was shown to be a major leaf protein and identified as a subunit of ribulose 1,5 diphosphate carboxylase/oxydase, a major plant kingdom enzyme involved in photosynthesis. This protein is widely present in leaves and is, in addition, used as a non-allergenic model in investigation of the allergenicity of food proteins. In fact, it is degraded instantaneously by digestive enzymes, in contrast to the known principal food allergens. In conclusion, respiratory allergy to grass leaf proteins was demonstrated in this study of four patients, who were or were not allergic or sensitized to grass pollen.