[The clinical study about the serum total and specific IgE levels in Artemisia pollen-induced allergic rhinitis patients]

OBJECTIVE

The aim of our study was to clarify the diagnosis value of total IgE and the relationship between total and specific IgE.

METHOD

Eight-seven Artemisia pollen-sensitive allergic rhinitis patients with obvious autumn onset and 80 nonatopic healthy controls were recruited for this study. Serum levels of total IgE were determined by using the Elecsys IgE reagent kit (Roche). Serum-specific IgE antibodies against Artemisia pollen were measured by using a fluorescent enzyme immunoassay (UniCAP system, Pharmacia and Upjohn Diagnostics).

RESULT

The serum total IgE levels in patients with allergic rhinitis were compared with the controls. The total IgE levels of the patients were much higher than those of the controls(Geometric mean of the patients and the controls were 0. 185 U/L and 0. 050 U/L respectively, P <0.01). The correlation of the serum Artemisia pollen specific IgE and total IgE levels in patients with allergic rhinitis was made. No correlation was found between the total and specific IgE levels ( P >0. 05).

CONCLUSION

There are some reference values for the serum total IgE levels to the diagnosis of the Artemisia pollen-induced allergic rhinitis patients. There are no correlation between the serum Artemisia pollen specific IgE and total IgE levels in patients with allergic rhinitis. Its value is limited to predict the specific value according the total IgE.

[Value of intradermal skin test and serum sIgE detection in diagnosing artemisia pollinosis]

OBJECTIVE

To evaluate the value of intradermal skin test (IDT) and serum sIgE detection in diagnosing Artemisia sensitivity in Chinese patients with autumnal hay fever.

METHODS

1150 patients with autumnal rhinitis or asthma, 504 males and 646 females, aged 5 approximately 77, were evaluated by experienced physicians, then underwent IDT by using 20 kinds of aeroallergen extracts. The concentrations of Artemisia and Ragweed extracts employed in skin test were 1:1000 (W/V) and the concentrations of other aeroallergens were all 1:100 (W/V). Then all patients underwent detection of Artemisia sIgE. Diagnostic standards were established based on the results of IDT and sIgE results respectively. A reference standard was established according to the typical history, symptoms, and an wheal with a diameter >or= 5mm and a sIgE level >or= 0.35 kU(A)/L, an wheal with the diameter >or= 10 mm alone; or a sIgE level >or= 0.70 kUa/L alone.

RESULTS

When using the reference standard as criteria, using IDT had better sensitivity (96.2%), specificity (74.2%), positive predictive value (+PV, 93.5%), negative predictive value (-PV, 85.7%), and efficiency (91.6%) than using sIgE >or= 0.35 kUa/L alone as the criteria of IDT; sIgE detection had better sensitivity (97.6%), specificity (94.9%), +PV (98.7%), -PV (91.1%), and efficiency (97.0%) than using wheal diameter >or= 5 mm alone as the criteria of sIgE detection. The false positive rate of IDT and sIgE detection decreased from 35% and 22.7% to 25.6% and 5.1% respectively when using the wheal diameter >or= 10 mm or sIgE >or= 0.70 kUa/L as a positive criteria.

CONCLUSION

IDT and sIgE detection are correlated with each other well in diagnosing Artemisia pollinosis, both of them have the possibility of being false positive, but IDT has higher false positive rate than sIgE detection. The false positive rates of IDT and sIgE detection can be decreased by increasing the positive criteria to higher grading reaction.

Differential allergen sensitization patterns in chestnut allergy with or without associated latex-fruit syndrome

BACKGROUND

Chestnut allergy has been almost exclusively considered in the context of the latex-fruit syndrome. Chestnut allergens not linked to latex hypersensitivity have not been studied.

OBJECTIVE

We sought to explore whether differences in sensitization patterns between chestnut allergy with or without associated latex-fruit syndrome can be detected.

METHODS

Twelve patients sensitized to chestnut but not to latex and 3 control patients with latex-chestnut allergy were analyzed. A major chestnut allergen was purified and characterized. IgE immunoblotting, specific IgE determination, and skin prick tests with 5 isolated allergens involved in food allergy or latex-fruit syndrome were also performed.

RESULTS

A major 9-kd allergen was detected in chestnut extract, isolated, and identified as lipid transfer protein (LTP) Cas s 8. Specific IgE to this allergen was found in 91% (by means of IgE immunoblotting) and 58% (by means of ELISA) of sera from patients with chestnut but not latex allergy. Moreover, 66% of these patients had positive skin prick test responses to Cas s 8. Additionally, allergenic LTPs from peach fruit and Artemisia vulgaris pollen were also reactive. In contrast, avocado class I chitinase and latex hevein, allergens associated with the latex-fruit syndrome, showed no reaction. The opposite situation was exhibited by patients with latex-chestnut allergy.

CONCLUSIONS

Patients with chestnut allergy with or without associated latex hypersensitivity present different patterns of major allergens (LTPs and class I chitinases, respectively).

CLINICAL IMPLICATIONS

LTPs and class I chitinases can be used as diagnostic tools in patients with chestnut allergy to predict whether an associated latex sensitization and a risk of potential cross-reactivity with other plant foods and pollens exist.

The performance of a component-based allergen-microarray in clinical practice

BACKGROUND

Currently, the diagnosis of IgE-mediated allergy is based on allergen-specific history and diagnostic procedures using natural allergen extracts for in vivo and in vitro tests.

OBJECTIVE

The aim of the study was to comparatively analyse a new component-based allergen-microarray and the 'quasi-standard' ImmunoCAP for their clinical relevance in patients with allergic rhinoconjunctivitis to five aeroallergens [house dust mite (HDM), cat dander, birch, grass and mugwort pollen] in a prospective, double-centre study.

METHODS

We enrolled 120 subjects at the two study centres. Allergic patients were defined as having an allergen-specific history plus a concomitant positive skin-prick test (SPT) to natural allergen extracts and specific serum IgE was measured by both methods. Each allergen was analysed separately.

RESULTS

The microarray performed equally well in receiver-operating characteristic curve (ROC) analyses when compared with the CAP in cat (23 allergic vs 97 non-allergic, ROC area under the curve microarray 0.950 vs CAP 0.894, P = 0.211), birch (31/89, 0.908 vs 0.878, P = 0.483) and grass pollen (47/73, 0.923 vs 0.915, P = 0.770). It was slightly less sensitive in HDM-allergic subjects (26 allergic vs 94 non-allergic, ROC area microarray 0.808 vs CAP 0.911, P = 0.053) and displayed a reduced sensitivity in the mugwort pollen-allergic patients (17/103, 0.723 vs 0.879, P = 0.032).

CONCLUSIONS

Component-based testing and the whole-allergen CAP are equally relevant in the diagnosis of grass-, birch- and cat-allergic patients. Although slightly less sensitive, the microarray is sufficient for the diagnosis of HDM-allergic patients, but needs alternative and/or additional components for detecting mugwort allergy.

Role of Dau c 1 in three different patterns of carrot-induced asthma

OBJECTIVE

To assess the role of Dau c 1 in three patients with carrot induced asthma.

MATERIAL AND METHODS

Patient 1 had asthma when handling raw carrots. Sensitization to pollens wasn't detected. Patient 2 had rhinoconjunctivitis due to grass and olive pollen allergy. She had asthma when handling raw carrots. Patient 3 was diagnosed of rhinoconjunctivitis and asthma due to allergic sensitization to mites, several pollens and cat. She had asthma due to raw carrot ingestion and inhalation. IgE immunobot analysis and ELISA inhibition assay were used to investigate the allergens and specific antibodies.

RESULTS

IgE Immunoblot Analysis: Dau c 1 from carrot extract and the recombinant rDau c 1 were recognized by IgE from patients 1 and 2. Band of Bet v 1 in birch pollen extract wasn't recognized. Patient 3 didn't recognize any of these allergens. Specific IgE to rDau c 1 was measured by ELISA. Specific IgE ELISA-inhibition with carrot as solid phase showed an intermediate inhibition (30 %) between carrot and rDau c 1 in patient 1; and a considerable inhibition (nearly 100 %) between carrot and rDau c 1 in patient 2. No inhibition was found in patient 3. Specific IgE ELISA inhibition between rDau c 1 and rBet v 1, employing rDau c 1 as solid phase was made in patients 1 and 2. Bet v 1 showed less than 40 % of inhibition of rDau c 1 in patient 1; and an intermediate inhibition (> 40 %) between rBet v 1 and rDau c 1 in patient 2.

CONCLUSIONS

Airborne carrot allergens are able to sensitize without the implication of a previous pollen allergy. Dau c 1 was the main allergen in patient 2. In patient 1, there was a band of 30 kd that looks like the predominant allergen. Patients 1 and 2 were sensitized directly from carrot allergens. In patient 3, Dau c 1 isn't related to the carrot allergy. Allergy to carrot in patient 3 seems to be related to her allergy to different pollens; however, it wasn't related to birch pollen. Mediterranean countries didn't show the same patterns of food-related pollen allergy than Nordic countries.

The Spectrum of Allergens in Ragweed and Mugwort Pollen

Ragweed and mugwort are important allergenic weeds belonging to the Asteraceae or Compositae plant family. Pollen of mugwort is one of the main causes of allergic reactions in late summer and autumn in Europe and affects about 10-14% of the patients suffering from pollinosis. Ragweed pollen represents the major source of allergenic protein in the United States, with a prevalence of about 50% in atopic individuals. In Europe, ragweed allergy is now rapidly increasing particularly in certain areas in France, Italy, Austria, Hungary, Croatia, and Bulgaria. Amb a 1 and Art v 1, the major allergens of ragweed and mugwort, respectively, are unrelated proteins. Amb a 1 is an acidic 38-kDa nonglycosylated protein. The natural protein undergoes proteolysis during purification and is cleaved into a 26-kDa alpha chain, which associates noncovalently with the beta chain of 12 kDa. The two-chain form seems to be immunologically indistinguishable from the full-length molecule. Art v 1 is a basic glycoprotein comprising two domains: an N-terminal cysteine-rich, defensin-like domain and a C-terminal proline/hydroxyproline-rich module. The proline/hydroxyproline-rich domain was recently shown to contain two types of glycosylation: (1) a large hydroxyproline-linked arabinogalactan composed of a short beta1,6-galactan core substituted by a variable number (5-28) of alpha-arabinofuranose residues forming branched side chains with 5-, 2,5-, 3,5-, and 2,3,5-substituted arabinoses, and (2) single and adjacent beta-arabinofuranoses linked to hydroxyproline. As described for other pollen, ragweed and mugwort pollen also contain the pan-allergen profilin and calcium-binding proteins, which are responsible for extensive cross-reactivity among pollen-sensitized patients.

Nondiffusional Release of Allergens from Pollen Grains of Artemisia vulgaris and Lilium longiflorum Depends Mainly on the Type of the Allergen

BACKGROUND

Upon contact with a wet surface, mature pollen grains hydrate and release proteins including allergens. Knowledge of the release mechanism of allergens that are mainly localized intracellularly may allow the design of strategies for inhibition of allergen release and the consequent sensitization process.

METHODS

An improved pollen chromatography was performed with Artemisia vulgaris and Lilium longiflorum pollen. Using three elution media of different pH, osmolality and salt concentration mimicking various types of wet surfaces, the time-dependent elution profiles of total protein, a cell wall-bound acid phosphatase activity (acPase), allergenic (profilin, Art v 1) and nonallergenic molecules (14-3-3 protein, actin) were monitored.

RESULTS

The release kinetics of total protein and cell wall-bound acPase followed an exponential decrease in both pollen species indicating a diffusion-based protein release, whereas the elution profiles of profilin, Art v 1 and 14-3-3 protein showed nondiffusion characteristics. No general dependence on pH, osmolality or salt concentration of the elution media was observable in the elution profiles. Under the applied conditions, actin was not released indicating that the pollen grains remained intact during the elution.

CONCLUSION

The elution profiles of pollen allergens indicated that substantial amounts of these proteins do not diffuse from the cell wall or are released from intracellular compartments during imbibitional leakage. Instead, a mechanism seems to operate that involves translocation from the pollen cytoplasm to the extracellular environment by crossing an intact plasma membrane. Such a mechanism would probably allow the use of pharmaceuticals for inhibition of allergen release.

[Sensitization to Castanea sativa pollen and pollinosis in northern Extremadura (Spain)]

BACKGROUND

Castanea sativa pollen allergy has generally been considered to be uncommon and clinically insignificant. In our geographical area (Plasencia, Cáceres, Spain) Castanea sativa pollen is a major pollen.

OBJECTIVE

To determine the atmospheric fluctuations and prevalence of patients sensitized to Castanea pollen in our region and to compare this sensitization with sensitizations to other pollens.

METHODS

Patients with respiratory symptoms attending our outpatient clinic for the first time in 2003 were studied. The patients underwent skin prick tests with commercial extracts of a battery of inhalants including Castanea sativa pollen. Serologic specific IgE to Castanea sativa pollen was determined using the CAP system (Pharmacia and Upjohn, Uppsala, Sweden). Airborne pollen counts in our city were obtained using Cour collection apparatus over a 4-year period (2000 to 2003).

RESULTS

The most predominant pollens detected were (mean of the maximal weekly concentrations over 4 years in pollen grains/m3): Quercus 968, Poacea 660, Olea 325, Platanus 229, Pinus 126, Cupresaceae 117, Plantago 109, Alnus 41, Populus 40, Castanea 32. We studied 346 patients (mean age: 24.1 years). In 210 patients with a diagnosis of pollinosis, the percentages of sensitization were: Dactylis glomerata 80.4%, Olea europea 71.9%, Fraxinus excelsior 68%, Plantago lanceolata 62.8%, Chenopodium album 60.9%, Robinia pseudoacacia 49%, Artemisia vulgaris 43.8%, Platanus acerifolia 36.6%, Parietaria judaica 36.1%, Populus nigra 32.3%, Betula alba 27.6%, Quercus ilex 21.4%, Alnus glutinosa 20.9%, Cupressus arizonica 7.6% and Castanea sativa 7.1%. Fifteen patients were sensitized to Castanea sativa and 14 had seasonal rhinoconjunctivitis and asthma. Ten patients had serum specific IgE to Castanea pollen (maximum value: 17.4 Ku/l). Castanea pollen is present in our area in large amounts from the 23rd to the 28th weeks of the year, with a peak pollen count in the 25th week.

CONCLUSIONS

The most important allergenic pollens in northern Extremadura were Poaceae, Olea europaea and Plantago sp. The prevalence of sensitization to Castanea sativa pollen was very low (7.1%). Most sensitized patients had asthma and polysensitization. Castanea sativa pollen is not a major cause of pollinosis in our area.

Prevalence of sensitization to Artemisia allergens Art v 1, Art v 3 and Art v 60 kDa. Cross-reactivity among Art v 3 and other relevant lipid-transfer protein allergens

BACKGROUND

Artemisia vulgaris is a widespread weed in the Mediterranean area and several allergens have been detected in its pollen. One of them, Art v 3, belongs to the lipid-transfer protein (LTP) family and its prevalence in Artemisia-sensitized patients or its relationship with other LTP allergens is not clear.

OBJECTIVE

To assess the pattern of sensitization to an array of mugwort allergens in a Mediterranean population, and to study the cross-reactivity of Art v 3 with Pru p 3 and Par j 1, relevant LTP allergens in the area.

METHODS

Skin prick test was performed with whole extracts (A. vulgaris, Parietaria judaica and peach) and pure natural allergens Art v 1, Art v 3, Art v 60 kDa and Par j 1 in 24 mugwort-allergic patients from a Mediterranean area. In vitro assays included measurement of specific IgE and ELISA inhibition among LTP allergens.

RESULTS

The three Artemisia allergens elicited a positive skin response in 70-80% of the patients. Seven patients were clearly sensitized to Par j 1 and 11 to Pru p 3. There was no correlation between Par j 1 and Pru p 3 sensitization, but a highly significant correlation was found between peach extract and Art v 3 as regards the skin response. No IgE cross-reactivity was observed between Art v 3/Par j 1 or Pru p 3/Par j 1. In contrast, Art v 3 significantly inhibited the binding to Pru p 3 of IgE from three patients' sera out of six studied, but Pru p 3 was not able to inhibit the IgE binding to Art v 3.

CONCLUSION

Art v 3 is a major mugwort allergen and in some patients with IgE to both Art v 3 and Pru p 3, Art v 3 behaves as the primary sensitizing agent.

Mustard allergy confirmed by double-blind placebo-controlled food challenges: clinical features and cross-reactivity with mugwort pollen and plant-derived foods

BACKGROUND

Mustard IgE-mediated allergy is supposed to be a rare cause of food allergy, and its clinical features and cross-reactivities have not been fully elucidated.

METHODS

A prospective study was carried out, recruiting mustard allergic patients, and paired control subjects. A clinical questionnaire was administered, and skin-prick tests (SPT) with panels of aeroallergens and foods, serum extraction for in vitro tests and double-blind placebo-controlled food challenges (DBPCFC) were performed.

RESULTS

Thirty-eight mainly adult patients, with 10.5% reporting systemic anaphylaxis, were included in the study [age (mean +/- SD): 21.9 +/- 8.6 years]. DBPCFC were performed in 24 patients, being positive in 14 cases (58.3%). Patients with positive outcome showed significantly greater mustard SPT than those with negative outcome (8.2 +/- 3.7 vs 5.3 +/- 2.4 mm, P <0.05), and the receiver-operating characteristic (ROC) curve analysis yielded a cut-off value for mustard commercial SPT of 8 mm, with a specificity of 90% (95% CI, 55.5-98.3), and a sensitivity of 50% (95% CI, 23.1-76.9). A significant association between mustard hypersensitivity and mugwort pollen sensitization was found (97.4% of patients), with partial cross-reactivity demonstrated by UniCAP System inhibition assays. All patients showed sensitization to other members of Brassicaceae family, and cross-reactivity among them was also confirmed. Moreover, significant associations with nut (97.4%), leguminous (94.7%), corn (78.9%), and Rosaceae fruit (89.5%) sensitizations were also shown. Around 40% of these food sensitizations were symptomatic, including food-dependent exercise-induced anaphylaxis in six patients.

CONCLUSIONS

Mustard allergy is a not-uncommon disorder that can induce severe reactions. Significant associations with mugwort pollinosis and several plant-derived food allergies are demonstrated, suggesting a new mustard-mugwort allergy syndrome. A relationship between this syndrome and food-dependent exercise-induced anaphylaxis is also reported.

Allergoid-specific T-cell reaction as a measure of the immunological response to specific immunotherapy (SIT) with a Th1-adjuvanted allergy vaccine

BACKGROUND

Specific immunotherapy (SIT) is believed to modulate CD4+ T-helper cells. In order to improve safety, SIT vaccines are often formulated with allergoids (chemically modified allergens). Interaction between T-cells and allergoids is necessary to influence cellular cytokine expression. There have been few reports on identification the early cellular effects of SIT.

METHOD

Patients allergic to grass and/or mugwort pollen (n= 21) were treated with a 4-shot allergy vaccine (Pollinex Quattro) containing appropriate allergoids (grass/rye and/or mugwort) adsorbed to L-tyrosine plus a Th1 adjuvant, monophosphoryl lipid A (MPL). Fourteen grass-allergic patients served as untreated controls. Using the peripheral blood mononuclear cells of these patients, an optimized lymphocyte transformation test (LTT) was employed to monitor the in vitro proliferative response of T-cells to an allergoid challenge (solubilised Pollinex Quattro) before the first and last injection and then 2 and 20 weeks after the final injection. Control challenges utilised preparations of a similar pollen vaccine without the adjuvant MPL and a tree pollen vaccine with and without MPL.

RESULTS

The LTT showed increased LTT stimulation indices (SI) in 17/20 SIT patients when the solublised vaccine preparation was used as a challenge before the last injection and 2 weeks after, in comparison to pre-treatment levels. Twenty weeks after therapy, the SI decreased to baseline level. A vaccine challenge without MPL gave lower SI levels. A challenge of a clinically inappropriate tree allergoid vaccine gave no response, and a nontreated group also showed no response.

CONCLUSION

Following a short-course SIT adjuvated with MPL, challenges of allergoids were shown to activate allergen-specific T cells in vitro. There was an additional stimulating effect when the challenge was in combination with MPL. There were no non-specific effects of MPL, shown by the tree allergoid/MPL control. The timing of the response was closely correlated to the treatment course; reactivity fell two weeks after the final injection and 20 weeks later it was at baseline level. Thus an immunological response to SIT was detected after very few injections. This methodology could provide a basis for monitoring the immediate progress of allergy vaccinations.

Molecular Characterization of Polygalacturonases as Grass Pollen-Specific Marker Allergens: Expulsion from Pollen via Submicronic Respirable Particles

Grass pollen belong to the most important allergen sources involved in the elicitation of allergic asthma. We have isolated cDNAs coding for Bermuda grass (Cynodon dactylon) and timothy grass (Phleum pratense) pollen allergens, belonging to a family of pectin-degrading enzymes (i.e., polygalacturonases). The corresponding allergens, termed Cyn d 13 and Phl p 13, represent glycoproteins of approximately 42 kDa and isoelectric points of 7.5. rPhl p 13 was expressed in Escherichia coli and purified to homogeneity. Immunogold electron microscopy using rabbit anti-rPhl p 13 Abs demonstrated that in dry pollen group 13, allergens represent primarily intracellular proteins, whereas exposure of pollen to rainwater caused a massive release of cytoplasmic material containing submicronic particles of respirable size, which were coated with group 13 allergens. The latter may explain respiratory sensitization to group 13 allergens and represents a possible pathomechanism in the induction of asthma attacks after heavy rainfalls. rPhl p 13 was recognized by 36% of grass pollen allergic patients, showed IgE binding capacity comparable to natural Phl p 13, and induced specific and dose-dependent basophil histamine release. Epitope mapping studies localized major IgE epitopes to the C terminus of the molecule outside the highly conserved functional polygalacturonase domains. The latter result explains why rPhl p 13 contains grass pollen-specific IgE epitopes and may be used to diagnose genuine sensitization to grass pollen. Our finding that rabbit anti-rPhl p 13 Abs blocked patients' IgE binding to the allergen suggests that rPhl p 13 may be used for immunotherapy of sensitized patients.

[Polyclonal antisera to birch pollen allergen for the air allergen screening]

The cross reactivity of the pollen allergens of birch (Betula pendula), hazel (Corylus avelana), alder (Alnus glutinosa), wormwood (Artemisia absinthium), oak (Quercus robur) and ashtree (Fraxinus excelsior) was studied by the methods of the enzyme immunoassay and gel diffusion with the use of rabbit polyclonal antisera (PAS) prepared against birch pollen allergen. PAS was shown to be greatly related to all above-mentioned allergens with the exception of oak pollen allergen. PAS was found capable of forming precipitates in the layer of agar gel only with birch pollen allergen. A proposal was made to use PAS, in view of the established specific features of its immunochemical properties, in the development of test systems for the ecological monitoring of biotopes.

Primary sensitization to sweet bell pepper pollen in greenhouse workers with occupational allergy

BACKGROUND

In a previous investigation, a high prevalence of allergy to sweet bell pepper pollen was found among exposed horticulture workers. Allergy to plant-derived food is often the consequence of primary sensitization to common pollen allergens.

OBJECTIVE

We therefore investigated the cross-reactivity between sweet bell pepper pollen and pollen from grass, birch or mugwort.

METHOD

We selected 10 sera from greenhouse workers who had, besides specific IgE against sweet bell pepper pollen, also IgE to grass, birch or mugwort pollen. Cross-reactivity was tested by the inhibition of IgE binding to solid-phase coupled sweet bell pepper pollen extract. The 10 sera were also analysed for IgE binding to sweet bell pepper pollen by immunoblotting.

RESULTS

With these sera, no or small inhibition of IgE binding to sweet bell pepper pollen extract was observed with grass, birch and mugwort pollen. With immunoblotting, major IgE-binding structures were seen at 14, 29 and 69 kDa in sweet bell pepper pollen extract.

CONCLUSION

The results of our study demonstrate that sweet bell pepper pollen contains allergens that have no or limited cross-reactivity with common pollen allergens. With sera from the 10 patients tested, sensitization to sweet bell pepper pollen was not the consequence of primary sensitization to common pollen allergens.

HLA class II genotypic frequencies in atopic asthma: association of DRB1*01-DQB1*0501 genotype with Artemisia vulgaris allergic asthma

Different human leukocyte antigen (HLA) class II alleles have been associated with the development of atopic asthma. To determine whether HLA class II alleles are associated with atopic asthma in a population from southeast Spain (Murcia region), 213 atopic asthmatic patients and 150 controls were selected for HLA typing. Significant association of the DRB1*01 and DQB1*0501 alleles was found in Artemisia vulgaris allergic patients (p(c) = 0.00052 and p(c) = 0.00023, respectively). No significant correlation was found in other atopic patients allergic to pollens (Phleum pratense, Olea europaea, and Salsola kali), house dust mites (Dermatophagoides pteronyssinus, D. farinae), molds (Alternaria alternata, Cladosporium herbarum), or animal danders (dog, cat). The results reveal that the DRB1*01-DQB1*0501 genotype is strongly associated with a positive response to Artemisia vulgaris in the population studied.

Specific allergens enhance elastase release in stimulated neutrophils from asthmatic patients

BACKGROUND

The presence of the three forms of IgE receptor - the heterotrimeric high-affinity receptor for IgE (Fc(epsilon)RI), the low-affinity receptor for IgE (Fc(epsilon)RII/CD23) and the Mac-2/IgE-binding protein (epsilonBP) - has been demonstrated on human neutrophils. We have previously shown that specific allergens are able to activate functional responses by neutrophils from allergic patients sensitized to those allergens. Neutrophils are present at the sites of allergic inflammation. The primary (azurophilic) granules of neutrophils contain a variety of enzymes, such as elastase, that might potentiate inflammation. It is not known whether specific allergens are able to elicit elastase release by neutrophils from allergic patients. In addition, we attempted to evaluate the relationship between neutrophil degranulation and lung function of the patients, measured as FEV(1).

METHODS

Neutrophils were challenged in vitro with the specific allergens that produced clinical symptoms in asthmatic patients. The cells were also challenged with allergen to which the patients were not sensitive. Neutrophils from normal subjects were challenged with allergens as control.

RESULTS

The in vitro challenge of neutrophils with allergens to which the patients were sensitive elicited a release of elastase by these cells. The in vitro activation of neutrophils was highly allergen specific; allergens other than those accounting for clinical symptoms did not evoke elastase release, and allergens were ineffective on neutrophils from healthy donors. A significant inverse correlation was observed between elastase release and patients' lung function, measured as FEV(1).

CONCLUSION

An IgE-dependent mechanism might promote elastase release by neutrophils at allergic sites. There is a significant inverse relationship between levels of elastase released by neutrophils from allergic patients and lung function, as assessed by FEV(1).

Native Art v 1 and recombinant Art v 1 are able to induce humoral and T cell-mediated in vitro and in vivo responses in mugwort allergy

BACKGROUND

Mugwort pollen is an important allergen source in hay fever and pollen-related food allergy. Little is known about the clinical relevance of the major mugwort allergen Art v 1 and its importance in allergy.

OBJECTIVE

In this study we aimed to investigate the allergenicity of mugwort extract compared with the allergenicity of native (n)Art v 1 and recombinant (r)Art v 1, one major allergen of mugwort, in vivo and in vitro.

METHODS

Thirty-two patients allergic to mugwort and 10 control subjects were investigated by means of skin prick and nasal provocation testing with different concentrations of mugwort extract, nArt v 1, and rArt v 1. nArt v 1 was purified from aqueous mugwort extract, and rArt v 1 was cloned, expressed in Escherichia coli, and then purified. The in vitro allergenicity was measured by means of ImmunoCAP, ELISA, ELISA-inhibition experiments, and T-cell proliferation assays.

RESULTS

nArt v 1 and rArt v 1 were able to elicit positive in vivo and in vitro reactions. The IgE-binding capacity, as determined by means of ELISA, was slightly higher for nArt v 1 than for rArt v 1, and both allergens were able to induce T-cell proliferation in sensitized patients. However, rArt v 1 elicited a reduced response in skin and nasal provocation tests compared with nArt v 1. Compared with mugwort extract, both nArt v 1 and rArt v 1 showed lower sensitivity in patients with mugwort allergy in vivo.

CONCLUSIONS

Art v 1, either in its native or recombinant form, is able to induce allergic reactions in patients with mugwort allergy. rArt v 1 induced comparable humoral and cell-mediated responses in vitro but showed reduced in vivo allergenicity compared with biochemically purified nArt v 1.

Art v 1, the major allergen of mugwort pollen, is a modular glycoprotein with a defensin-like and a hydroxyproline-rich domain

In late summer, pollen grains originating from Compositae weeds (e.g., mugwort, ragweed) are a major source of allergens worldwide. Here, we report the isolation of a cDNA clone coding for Art v 1, the major allergen of mugwort pollen. Sequence analysis showed that Art v 1 is a secreted allergen with an N-terminal cysteine-rich domain homologous to plant defensins and a C-terminal proline-rich region containing several (Ser/Ala)(Pro)2-4 repeats. Structural analysis showed that some of the proline residues in the C-terminal domain of Art v 1 are posttranslationally modified by hydroxylation and O-glycosylation. The O-glycans are composed of 3 galactoses and 9-16 arabinoses linked to a hydroxyproline and represent a new type of plant O-glycan. A 3-D structural model of Art v 1 was generated showing a characteristic "head and tail" structure. Evaluation of the antibody binding properties of natural and recombinant Art v 1 produced in Escherichia coli revealed the involvement of the defensin fold and posttranslational modifications in the formation of epitopes recognized by IgE antibodies from allergic patients. However, posttranslational modifications did not influence T-cell recognition. Thus, recombinant nonglycosylated Art v 1 is a good starting template for engineering hypoallergenic vaccines for weed-pollen therapy.

[Association of hypersensitivity to wormwood pollen in patients with allergic rhinitis with HLA alleles polymorphism]

OBJECTIVE

Our purpose was to determine whether alleles at one or more HLA loci are associated with hypersensitivity to wormwood pollen in patients with allergic rhinitis.

METHOD

By using PCR-SSP(sequence-specific primer polymerase chain reaction), we tested the frequency distribution of HLA-DQA1, DQB alleles in 41 patients with allergic rhinitis(AR) and 41 healthy controls from Beijing.

RESULT

The frequency of HLA-DQA1* 0201, DQB1 * 0602 was lower in AR than in controls(24.39%, 4.88% vs 46.34%, 26.83%), and the frequency of DQA1 * 0302 was increased among patients(58.54% vs 14.63%).

CONCLUSION

HLA-DQA1 * 0201, DQB1 * 0602 alleles might confer protection against AR, and DQA1 * 0302 may be a susceptibility factor for hypersensitivity to wormwood pollen.

The T cell response to Art v 1, the major mugwort pollen allergen, is dominated by one epitope

Mugwort (Artemisia vulgaris) pollen allergens represent the main cause of pollinosis in late summer in Europe. At least 95% of sera from mugwort pollen-allergic patients contain IgE against a highly glycosylated 24- to 28-kDa glycoprotein. Recently, this major allergen, termed Art v 1, was characterized, cloned in Escherichia coli, and produced in recombinant form. In the present study we characterized and compared the T cell responses to natural (nArt v 1) and recombinant Art v 1 (rArt v 1). In vitro T cell responses to nArt v 1 and rArt v 1 were studied in PBMC, T cell lines (TCL), and T cell clones (TCC) established from PBMC of mugwort-allergic patients. Stimulation of PBMC or allergen-specific TCL with either nArt v 1 or rArt v 1 resulted in comparable proliferative T cell responses. Eighty-five percent of the TCC reactive with rArt v 1 cross-reacted with the natural protein. The majority of the CD4(+)CD8(-)TCR alphabeta(+) Art v 1-specific TCC, obtained from 10 different donors, belonged to the Th2 phenotype. Epitope mapping of TCL and TCC using overlapping peptides revealed a single immunodominant T cell epitope recognized by 81% of the patients. Inhibition experiments demonstrated that the presentation of this peptide is restricted by HLA-DR molecules. In conclusion, the T cell response to Art v 1 is characterized by one strong immunodominant epitope and evidently differs from the T cell responses to other common pollen allergens known to contain multiple T cell epitopes. Therefore, mugwort allergy may be an ideal candidate for a peptide-based immunotherapy approach.

The influence of a residual group in low-molecular-weight allergoids of Artemisia vulgaris pollen on their allergenicity, IgE- and IgG-binding properties

BACKGROUND

Reaction of epsilon-amino groups of lysine with potassium cyanate, maleic, or succinic anhydride leads to allergoids of low molecular weight. No study has been performed to compare their properties and investigate the influence of a residual group on allergenicity and human IgE- and IgG-binding of these derivatives.

METHODS

Allergoids of a pollen extract of Artemisia vulgaris were obtained by means of potassium cyanate, and succinic and maleic anhydride. Biochemical properties were investigated by determination of amino groups, enzyme activity, isoelectric focusing IEF and SDS-PAGE. IgE- and IgG-binding was determined using immunoblots and ELISA inhibition. Allergenicity was investigated by skin prick tests (SPT) on a group of 52 patients, of which 6 were control subjects, 30 were patients with no previous immunotherapy (IT), and 16 were patients undergoing immunotherapy.

RESULTS

The same degree of amino-group modification (more than 85%), residual enzyme activity (less then 15%), IEF, and SDS-PAGE pattern were noted. In the immunoblots of IgE-binding, there was more pronounced reduction in the succinyl and maleyl derivatives than in the carbamyl one. IgG-binding was less affected by carbamylation than by acid anhydride modification. The SPT showed that the succinylated derivative had the most reduced allergenicity (98% showed a reduced wheal diameter when tested with the succinyl derivative, 87% with the maleyl allergoid, and 83% with the carbamyl allergoid). The most significant difference among allergoids could be seen in the group of patients with high skin reactivity (83% of patients showed no reaction to the succinyl derivative when compared to the value of 28% for the carbamyl derivative or 22% for the maleyl derivative).

CONCLUSIONS

According to our results, all three modification procedures yielded allergoids with a similar extent of modification. No single biochemical parameter investigated in the study could predict the degree of reduced allergenicity in vivo. The most reduced allergenicity was seen in the succinyl derivative while the preservation of IgG binding epitopes was of the highest degree for the carbamyl derivative.

Identification of an allergen related to Phl p 4, a major timothy grass pollen allergen, in pollens, vegetables, and fruits by immunogold electron microscopy

Group 4 grass pollen allergens represent 60 kDa glycoproteins recognized by 70% of patients sensitive to these pollens. An antiserum against purified Phl p 4 from timothy grass pollen was used to investigate various pollens, fruits, and vegetables for Phl p 4-related allergens by immunogold electron microscopy. In timothy grass, mugwort, and birch pollens, allergens were located in the wall, and in timothy grass and birch pollens additionally in the cytoplasm. In peanut, apple, celery root, and carrot root, only cytoplasmic areas were labeled. Group 4-related allergens thus occur in pollens of unrelated plants and in plant food and may therefore contribute to crossreactivities in patients allergic to various pollens and plant food.

Patterns of reactivity to lipid transfer proteins of plant foods and Artemisia pollen: an in vivo study

BACKGROUND

Lipid transfer proteins (LTPs) are major allergens of Rosaceae fruits in the Mediterranean area. IgE-cross-reactivity has been demonstrated in vitro among LTPs from peach, apple, chestnut and Artemisia pollen. The aim of this study was to evaluate the reactivity to LTPs from peach, apple, chestnut and Artemisia pollen by means of skin prick tests (SPTs).

METHODS

Forty-seven patients allergic to peach (peach group), 20 patients sensitized to Artemisia pollen with no food allergies (Artemisia group), and 12 control subjects were skin tested with fresh peach, as well as with whole extracts and purified LTPs of peach, apple, chestnut and Artemisia pollen.

RESULTS

The rates of positive SPTs for peach, apple, chestnut and Artemisia LTPs were, respectively, 91, 77, 23, and 36% in the peach group, and 30, 5, 15 and 40% in the Artemisia group. No response was observed in the control subjects. SPTs with peach LTP strongly correlated with SPTs conducted with fresh peach. In the peach group, the most frequent pattern of reactivity to LTPs was the combination peach-apple (45%), followed by peach-apple-Artemisia-chestnut (21%). Significant correlations were found between peach and apple LTPs, and between Artemisia and chestnut LTPs. Positive SPTs to chestnut LTP were only observed in patients with positive SPTs to Artemisia LTP. All the patients with positive case histories to chestnut reacted to chestnut LTP.

CONCLUSIONS

LTPs are plant panallergens with different patterns of cross-reactivity. They are major allergens of Rosaceae fruits and seem to be involved in allergic reactions to unrelated foodstuffs such as chestnut, probably through sensitization to the cross-reactive Artemisia LTP. Rosaceae LTPs could be useful tools for in vivo diagnosis of Rosaceae fruit allergy.