Measurement of IgE and IgG4 antibodies against purified grass pollen allergens (Phl p 1, Phl p 2, Phl p 5 and Bet v 2) and natural extracts after short-term grass immunotherapy

We wanted to define allergen-specific antibodies that change due to specific immunotherapy. We conducted a study with grass pollen-allergic patients and compared allergen-specific IgE and IgG4 before and 5 months after the onset of immunotherapy. Twenty-seven patients were treated with a mixture of two grass species: Phleum pratense and Dactilis glomerata. Sera of patients were tested for IgE and IgG4 against four recombinant allergens (RA): rPhl p 1, 2, 5 and rBet v 2. Specific IgE and IgG4 to timothy and olive pollen were also evaluated. No change in total and specific IgE levels to RA was seen, except to rPhl p 5. We found a decrease in specific IgE levels to olive after immunotherapy. Ten of 10 patients with specific IgE against a single recombinant allergen or two RA showed the same pattern of sensitization before and after 5 months of immunotherapy and the administration of 4000 U/mL allergen extract. Interestingly, we found a significant increase in specific IgG4 to rBet v 2 and olive after grass immunotherapy. These results indicate that application of two grass species in immunotherapy may be sufficient to induce an IgE and IgG4 response to RA, grass and olive extracts. The observations in the present study indicate that monitoring of antibodies against RA is necessary to evaluate patients' pattern of sensitization and emphasize the need of component-resolved immunotherapy.     

Prevalence of IgE antibodies to an extract from rubber tree (Hevea brasiliensis) latex and recombinant pollen allergens (Phl P 1, Phl P 2, Phl P 5, Bet v 1 and Bet v 2) in the sera of Italian atopic patients

BackgroundPrevious studies have reported cross-reactivity between latex and grass allergens. Inhibition studies have indicated cross-reactivity of IgE with latex and grass pollen proteins. A panel consisting of a few recombinant allergens, namely rPhI p 1, rPhl p 2, rPhl p 5 and profilin, was sufficient to diagnose grass pollen allergy in patients allergic to grass pollen.MethodsSerum samples from 528 consecutive outpatients with IgE antibodies towards at least one allergen (IgE level > 0.35 kAU/L) were selected for this retrospective study. Total and specific serum IgE to rPhl p 1, rPhl p 2, rPhl p 5, rBet v 1, rBet v 2, latex, birch, hazel, mugwort, wall pellitory, Dermatophagoides pteronissinus, Alternaria tenuis, cat and apple were measured by the immunoenzymatic capsulated hydrophilic carrier polymer (CAP) FEIA system (Pharmacia & Upjohn).ResultsOf 123 polysensitized patients with antilatex Ig1E, 12 (9.76%) had symptoms after latex exposure. Ten of 12 subjects monosensitized to latex had symptoms after latex exposure. Symptomatic patients had higher IgE levels to latex than symptomless patients (P = 0.046). A higher prevalence of antilatex IgE was seen in sera containing specific IgE to rPhl p 1, rPhl p 5 and rBet v 2. A good correlation (Spearman's r = 0.52; P = 0.001) between high levels of antilatex IgE and total serum IgE was found.ConclusionsThe findings of the present study may support the concept that a high proportion of sera containing IgE to rBet v 2, rPhl p 1 and rPhl p 5 simultaneously contain antilatex IgE. Therefore, patients with specific IgE to these recombinant allergens with no history of current latex exposure may need additional evaluation.     

IgE profiles of Bermuda grass pollen sensitised patients evaluated by Phleum pratense allergens Phl P 1, 2, 4, 5, 6 , 7, 11, 12.

BACKGROUND: Despite the difference in geographical dominance of certain grasses, a high degree of allergenic similarity or cross-reactivity between Bermuda grass pollen (BGP) and timothy grass pollen (TGP) has been previously demonstrated. The aim of the present study was to ascertain the sensitisation to TGP in 411 patients known for their reactivity to BGP extracts by analysing their reactivity to crude timothy pollen extract and timothy pollen purified allergens, establishing their specific IgE-profiles. METHODS: Using the immunoenzymatic CAP method we evaluated IgE-specific antibodies for BGP- and TGP- extracts and the timothy recombinant (r) and natural (n) allergens rPhl p 1, rPhl p 2, nPhl p 4, rPhl p 5, rPhl p 6, rPhl p 7, rPhl p 11, and rPhl p 12. RESULTS: BGP-IgE positive patients (median = 8.0 kUA/l, 2.8-22.2 kUA/l 25th-75th percentile) simultaneously had IgE positive results for TGP (100% of subjects)(median = 48.9 kUA/l, 19.8- > 100 kUA/l 25th-75th percentile) and high prevalence of sensitization to 6/8 Phleum pratense allergens (Phl p 1, 2, 4, 5, 6, 11, markers of genuine sensitisation to TGP) other than profilin and calcium binding protein. More than 72% of BGP allergic patients were co-sensitised to rPhl p 1, rPhl p 2, nPhl p 4, rPhl p 5, rPhl p 6. A decrease of total and specific IgE with patients' age was observed. CONCLUSIONS: Our data show that all BGP-allergic patients simultaneously exhibit higher IgE antibody levels to recombinant and natural P. pratense allergens as well as to crude TGP extract. This suggests that when choosing an immunotherapeutic regimen for BGP-sensitised patients (after establishing their IgE profile via purified TGP-allergens), subcutaneous or sublingual TGP-extract vaccines in appropriate doses, in order to influence T epitope specificity, might be beneficial. Though extremely uncommon, in cases where a patient is exclusively BGP allergen-sensitised, BGP-extract therapy is the appropriate therapeutic response.     

Evaluation of two grass pollen extracts for immunotherapy by serum determinations of specific IgE and IgG4 antibodies towards purified Timothy grass pollen allergens (Phl p 1, 2, 4, 5, 6, 7, 11, 12) in patients undergoing hyposensitization treatment

BackgroundThe diagnosis of allergic diseases with recombinant allergens allows us to detect antibodies specific for single allergens in extracts. The aim of the present study was to assess the early effect of grass pollen immunotherapy on IgE and IgG4 responses to eight purified grass pollen allergens in patients undergoing hyposensitization treatment.MethodsThe sera of 22 consecutive atopic individuals undergoing cluster regimen grass pollen immunotherapy were analyzed for IgE and IgG4 antibodies specific for grass pollen allergens (Phl p 1, 2, 4, 5, 6, 7, 11, 12). Two serum samples were taken, one before the start of therapy and one between 12 and 15 weeks after the first immunization. Immunotherapy was performed with two allergy vaccines comprising a standardized extract aluminum-adsorbed grass pollen mix and a standardized extract of grass pollen mix adsorbed onto calcium phosphate.ResultsOne treated patient showed a specific IgE conversion from negative (< 0.35 kUA/L) to positive in the capsulated hydrophilic carrier polymer (CAP) test for Phl p 2, 1 and 4 (1.89, 0.84 and 0.68 kUA/L, respectively). The sera of 10 of 11 patients treated with alluminum-adsorbed grass pollen extract showed a significant increase in specific IgG4 towards natural Timothy grass pollen extract and purified allergens, as well as significant IgG4 levels towards Phl p 1 (P = 0.000238) Phl p 2 (P = 0.000289), Phl p 4 (P = 0.000585), Phl p 5 (P = 0.000364), Phl p 6 (P = 0.000346) and Phl p 11 (P = 0.039623; Mann–Whitney U-test) 12 weeks after the onset of immunotherapy. The sera of seven of 11 subjects treated with calcium phospate-adsorbed grass pollen extract had significant IgG4 levels against Timothy pollen allergens, as well as significant IgG4 titers against Phl p 1 (P = 0.004703), Phl p 4 (P = 0.000282), Phl p 5 (P = 0.015480), Phl p 6 (P = 0.013012) and Phl p 11 (P = 0.005178). Patients treated with aluminum-adsorbed grass pollen extract had higher levels of IgG4 towards Phl p 2, 4 and 6 and natural Timothy grass extract compared with patients treated with calcium phosphate-adsorbed grass pollen extract. Both the alluminum-adsorbed and calcium phosphate-adsorbed grass pollen extract allergy vaccines induced significant titers of specific IgG4 towards Phleum pratense pollen extract (P = 0.008376 and 0.01148, respectively).ConclusionsThese results indicate that grass pollen immunotherapy elicits an array of antibody specificities that reflect the allergen content and the potency of allergen extracts; this could be of pivotal importance to define optimal allergen extract doses.     

Evaluation of Molecular Basis of Cross Reactivity between Rye and Bermuda Grass Pollen Allergens

BackgroundAllergenic cross reactivity between the members of the Pooids (Lolium perenne, Phleum pratense, and Poa pratensis) and Chloridoids (Cynodon dactylon and Paspalum notatum) is well established. Studies using crude extracts in the past have demonstrated limited cross reactivity between the Pooids and the Chloridoids suggesting separate diagnosis and therapy. However, little is known regarding the molecular basis for the limited cross reactivity observed between the 2 groups of grasses. The present study was undertaken to gain insights into the molecular basis of cross allergenicity between the major allergens from rye and Bermuda grass pollens.MethodsImmunoblot inhibition tests were carried out to determine the specificity of the proteins involved in cross reactivity. Crude pollen extract and bacterially expressed and purified recombinant Lol p 1and Lol p 5 from rye grass were subjected to cross inhibition experiments with crude and purified recombinant Cyn d 1 from Bermuda grass using sera from patients allergic to rye grass pollen.ResultsThe immunoblot inhibition studies revealed a high degree of cross inhibition between the group 1 allergens. In contrast, a complete lack of inhibition was observed between Bermuda grass group 1 allergen rCyn d 1, and rye grass group 5 allergen rLol p 5. Crude rye grass extract strongly inhibited IgE reactivity to Bermuda grass, whereas crude Bermuda grass pollen extract showed a weaker inhibition.ConclusionsOur data suggests that a possible explanation for the limited cross reactivity between the Pooids and Chloridoids may, in part, be due to the absence of group 5 allergen from Chloridoid grasses. This approach of using purified proteins may be applied to better characterize the cross allergenicity patterns between different grass pollen allergens.     

Change in the pattern of IgE reactivity to timothy grass and birch pollen allergens over a 20-year period.

BACKGROUND: Several studies have shown that the prevalence of allergy and allergen sensitization has increased in recent years. However, the changes in the pattern of IgE reactivity to individual allergens are mostly unknown. OBJECTIVE: The aim of this preliminary study was to assess the change in IgE reactivity profile to individual timothy grass and/or birch pollen allergens in sera from sensitized individuals randomly collected 20 years apart. METHODS: Serum samples from 51 sensitized individuals were obtained from 2 cross-sectional surveys performed in 1973 and 1994 using random samples from Vammala, Finland. The sera were analyzed for IgE reactivity to timothy grass and/or birch pollen extracts, recombinant (r)Phl p 1, 2, 5, 6, 7, 11, 12, native (n)Phl p 4, and rBet v 1, 2 and 4 by immunoassay (ImmunoCAP). RESULTS: The median (range) concentrations of IgE antibodies to timothy grass and birch pollen were higher in 1994 than in 1973 (6.47 [0.35 to >100] kU A/L vs 1.53 [0.40-25.3] kU A/L; P=.0035). The prevalence of IgE reactivity to some allergens was higher in 1994 than in 1973, particularly rPhl p 5 (52% vs 19%), rPhl p 6 (43% vs 12%), and rBet v 1 (100% vs 29%). There was a correlation between timothy grass pollen-specific serum IgE levels and the numbers of IgE reactivities to individual allergens (p=0.76, P<.001). CONCLUSIONS: The increase in specific IgE levels together with a possible increase in the prevalence of IgE reactivity to the major allergens Phl p 5 and Bet v 1 between 1973 and 1994 may have contributed to the increase in atopic conditions in Finland.     

Minimum prick test panel for adult patients with asthma and rhinitis in Ankara,Turkey

Objective: Determination of the number and type of allergens needed to be tested in epidemiological studies is important in order to identify most of the sensitized subjects with a cost-effective approach. This study aimed to investigate the minimum skin prick test panel for the identification of at least 95% of the sensitized subjects with symptoms of asthma and/or allergic rhinitis (AR) in Ankara, Turkey. Methods: Skin prick test results of 7492 patients who were referred to our outpatient clinic with clinical symptoms of asthma and/or AR between 1991 and 2005 were evaluated retrospectively. Seven allergens were tested in all and 13 allergens in 4202 patients. The allergen group needed for detection of 95% of the sensitized subjects was determined for both the 7 and 13 allergen panels. The study protocol was approved by the local ethics committee of Hacettepe University. Results: The atopy prevalences in the whole study population and in 4202 patients tested with the 13 allergen panel were calculated as 32.2% and 42.6%, respectively. Three allergens (Phleum pratense, Dermatophagoides pteronyssinus and Artemisia vulgaris) within the 7 allergen panel were adequate for the identification of at least 95% of the sensitized subjects. Olea europae was added to the previous three allergens when the 13 allergen panel was applied. Conclusion: Three to four allergens are sufficient for identification at least 95% of sensitized subjects with asthma and/or AR in Ankara, Turkey.     

变态反应性疾病变应原的体内外诊断及分析

目的 应用变应原皮肤点刺试验(SPT)分析西安地区不同变态反应性疾病的主要变应原,同时应用UniCAP 100检泓血清特异性免疫球蛋白E(IgE),并对结果进一步评价.方法 我院变态反应门诊就诊的变态反应性疾病患者679例,选用19种常见的变应原进行SPT,比较不同疾病患者主要变应原阳性率的异同;其中116例患者同时抽取静脉血检测血清粉尘螨特异性IgE,并与SPT结果比较.结果 ①在所有变态反应性疾病患者中,粉尘螨、屋尘螨均是最主要的变应原,总的阳性率分别是49.78%和43.00%,其次依次为蒿属花粉、霉菌、悬铃木属花粉和树Ⅰ花粉等,总阳性率均在10%以上,上述变应原是西安地区变态反应性疾病的主要变应原;②羽毛、鸡蛋、牛奶、蒿属、虾和花生6种变应原的阳性率在4种变态反应性疾病组间比较差异有统计学意义(P<0.05),其余变应原的阳性率在各组间差异无统计学意义,哮喘及过敏性鼻炎组患者的主要变应原以吸入性变应原为主,而荨麻疹组及过敏性紫癜组患者的主要变应原除以上吸入变应原外,还包括鸡蛋、牛奶、虾和花生等食人性变应原;③以血清特异性IgE为标准,以"+++及以上"为SPT阳性标准时的诊断价值高于以"++及以上"为SPT阳性标准,且IgE定量与SPT风团直径呈对数关系(r=0.629,P<0.05).结论 粉尘螨、屋尘螨、蒿属花粉、霉菌、悬铃木属花粉和树Ⅰ花粉等变应原是西安地区变态反应性疾病的主要变应原;不同疾病的主要变应原稍有不同;IgE定量与SPT风团直径呈对数关系,两者检测结果可以互补.     

Hidden allergic factors in the etiology of asthma

Increasing evidence from case control surveys, population studies and allergen avoidance studies suggest inhalant allergy plays an important role in the etiology of asthma. Recent studies in hospital emergency rooms have compared the prevalence of serum IgE antibodies to common allergens (mite, cat, cockroach, rye grass and ragweed pollen) in patients admitted with acute asthma attacks and in unselected age-matched control subjects. These studies, carried out in central Virginia and northern California, showed a highly increased prevalence of IgE antibodies to inhaled allergens among asthmatic patients, and suggest that the development of allergen specific IgE antibody responses is a major risk factor for emergency room admission with asthma. Presentation at the emergency room appeared to be related to patients' exposure to specific allergens: in central Virginia, in the fall, dust mite was the predominant allergy, whereas in northern California, in May-June, most asthmatic patients (greater than 90 percent) were allergic to rye grass. New immunoassay technology, based on the use of monoclonl antibodies, has been developed to measure the quantities of "indoor" allergens (mite, cat, cockroach) in asthmatic patients' houses. It is now possible to propose tentative levels of mite allergens which should be considered both as a risk for IgE antibody sensitization (2micrograms allergen/g dust) and as a risk for acute asthma attacks (10micrograms allergen/g dust). Future management of asthma will require analysis of indoor allergens and the development of efficient allergen avoidance procedures. Further research is necessary to investigate the relationship between airborne allergen levels, particle size and the precipitation of asthma attacks and also to investigate immunologic mechanisms which may cause bronchial hyperreactivity.     

Detection of specific IgE antibodies in sera of Japanese birch-allergic patients using recombinant allergens Bet v 1, Bet v 2 and Bet v 4.

BACKGROUND: Birch pollen is the major allergen in pollinosis in northern Japan. IgE reactivity to individual birch pollen allergens has been shown to differ between populations of birch pollen-allergic patients living in different countries. In this study, we examined the IgE profiles to recombinant birch pollen allergens in birch-sensitive patients living in Sapporo. METHODS: This study used the sera of 40 patients with specific IgE toward birch pollen extract. Their sera were analyzed for specific IgE reactivity to individual birch pollen allergens (recombinant Bet v 1, Bet v 2 and Bet v 4) and natural birch pollen extract using Pharmacia CAP SystemTM. RESULTS: Of 40 sera with positive CAP results for natural birch pollen extract, 39 (97.5%) had specific IgE towards Bet v 1; 6 (15%) contained specific IgE against Bet v 2. Bet v 4 reactivity was documented in only one subject (2.5%). CONCLUSIONS: The present data suggest that the specific IgE reactivity profiles to birch pollen allergen in birch-sensitive patients in Sapporo correspond to those in Scandinavia, possibly due to the heavy birch pollen exposure in this area. This observation provides useful information for future birch allergen-specific immunotherapy in Japan.     

Predictivity of clinical efficacy of sublingual immunotherapy (SLIT) based on sensitisation pattern to molecular allergens in children with allergic rhinoconjunctivitis

BackgroundThe diagnostic and therapeutic approach to grass pollen allergy is now possible by detecting specific IgE (sIgE) to its allergenic components.AimTo evaluate the correlation between the sensitisation to different molecular Phleum pratense (Phl p) allergens and clinical efficacy of SLIT.MethodsThe pilot study included 36 patients affected by allergic rhinoconjunctivitis, all treated with SLIT actively. We performed serum analysis of sIgE to Phl p 1, 2, 4, 5, 6, 7, 11 and 12. The Average Rhinoconjunctivitis Total Symptom Score (ARTSS) and the Average Combined Score (ACS) were evaluated before and after one year of immunotherapy.ResultsThree different groups of sensitisation were defined based on the range of IgE reactivity to Phleum pratense allergens at baseline: group I (sIgE reactive to 1–3 allergens); group II (sIgE reactive to 4–5 allergens); and group III (sIgE reactive to 6–8 allergens). At T0 ACS was 1.79 ± 0.18 in group I; 1.81 ± 0.23 in group II; and 1.95 ± 0.34 in group III. At T1 ACS was 0.85 ± 0.55 in group I; 1.01 ± 0.31 in group II; and 1.44 ± 0.39 in group III. At T1 there was a significant improvement of ARTSS and ACS for group I (p = 0.001).ConclusionsSublingual immunotherapy with a grass pollen is efficacious irrespective of the patients’ baseline sensitisation to either single or multiple grass pollen molecular allergens. We found that patients with few sensitisations have a greater improvement in combined symptom and medication score. SLIT improves the clinical course of allergic patients although new sensitisations may appear.     

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.     

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

ObjectiveTo assess the role of Dau c 1 in three patients with carrot induced asthma.Material and methodsPatient 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.ResultsIgE 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 howed 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.ConclusionsAirborne 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.     

Distribution of specific serum IgE to recombinant pollen allergens (rPhlp1, rPhlp2, rPhlp5, and rBetv2) and their relationship to each other and to their natural counterparts in patients allergic to grass pollen

Recombinant pollen allergens rPhlp1, rPhlp2, rPhlp5, and rBetv2 may function as effective markers of atopy and account for a substantial proportion of grass pollen-specific IgE. The purpose of the present study was to determine the frequency of IgE antibodies to rPhlp1, rPhlp2, rPhlp5 and rBetv2 in patients allergic to grass pollen. Blood was taken from 436 patients, aged 4-70 years, with allergy to grass. The sample was stratified by 10-year age groups. Specific serum IgE were measured by the immunoenzymatic CAP Fluoroenzyme Immunoassay System. Specific IgE binding to rPhlp1, rPhlp5, rPhlp2, was, respectively, detected in 388 (88.9%), 353 (80.9%) and 265 (60.7%) of 436 patients. Sera from 252 patients (57.7%) showed IgE binding to rPhlp1, rPhlp2 and rPhlp5; sera from 102 patients (23.3%) reacted to rPhlp1 and rPhlp5, but not rPhlp2; 30 sera (6.8%) reacted to rPhlp1 but not rPhlp2 and rPhlp5; 22 sera (5.1%) reacted only to rPhlp5; one serum reacted to rPhlp2 (0.2%); and nine sera (2%) did not react to recombinant allergens. It was found that patients in the age group 0-20 years had higher IgE levels to timothy grass and rPhlp1, rPhlp2 and rPhlp5, than patients in the older age group (41-60 years). We found, as expected, seasonal variation of IgE levels to recombinant allergens and natural allergen. Allergens rPhlp1, rPhlp2 and rPhlp5 were extremely positively correlated with timothy grass and rBetv2, but not rBetv1. These results encourage the use of recombinant pollen allergens for diagnosis and to improve specific immunotherapy in the near future.     

北京地区门诊患者常见吸入过敏原致敏谱

目的 了解北京地区过敏性疾病常见吸入过敏原致敏谱,探讨国产过敏原皮肤点刺试验(skin prick test,SPT)试剂的安全性.方法 选取2017年1月至2020年7月就诊于本科门诊可疑过敏性鼻炎、过敏性哮喘和过敏性鼻炎合并哮喘的患者,采用32种吸入过敏原试剂进行SPT,比较年龄和疾病变应原分布,观察评价国产SPT...     

Differential IgE reactivity to Der p 1 and Der p 2 allergens of Dermatophagoides pteronyssinus in mite-sensitized patients.

Several studies have shown that the presence of IgE antibodies to house dust mites (HDM), particularly Dermatophagoides pteronyssinus (Dpt), is an important risk factor for asthma. Allergen immunotherapy is indicated for patients with IgE antibodies to clinically relevant allergens. The aims of this study were to analyze the levels of specific serum IgE to Der p 1 and Der p 2 allergens in mite-sensitized atopic patients and to compare them with both in vivo (skin prick test) and in vitro (IgE-ELISA) sensitizations to Dpt crude extract. Forty-seven atopic patients with allergic rhinitis with or without intermittent or persistent mild asthma and positive skin prick test (SPT) to Dpt total extract were studied. Thirty age-matched healthy subjects with negative SPT to HDM were included as controls. Levels of total IgE and Dpt-, Der p 1- and Der p 2-specific IgE were measured by ELISAs in SPT-positive atopic patients and SPT-negative control subjects. Among 47 symptomatic atopic patients, 27 (57.4%) were double positive IgE to Der p 1 and Der p 2 allergens, 3 (6.4%) were single positive IgE to Der p 1, 4 (8.5%) were single positive IgE to Der p 2, and 13 (27.6%) were double negative IgE to both allergens. There was a significant correlation between Der p 1- and Der p 2-specific IgE levels, but not between Der p 1- or Der p 2-IgE levels and SPT results. The double negative IgE patients had the smallest skin test reactions although they showed high mean levels of total serum IgE. Therefore, the knowledge of specific IgE levels to Der p 1 and Der p 2 major allergens might support physicians for indication or follow-up in mite-sensitized patients under allergen-specific immunotherapy. These approaches might be important for obtaining improved safety and efficacy of the current clinical practice of allergen immunotherapy.     

Isolation and partial characterization of Fes p 4 allergen.

More than 75% of grass pollen-allergic patients produce specific IgE antibodies against group-4 allergens. Purification and characterization of different grass group-4 allergens should help to further understand their allergenicity. In this study, an attempt was made to isolate and characterize Fes p 4 allergen by several biochemical and immunochemical methods. Fes p 4 was purified by a combination of chromatographic techniques (gel permeation and ion exchange chromatography). Isolated protein revealed four main spots at a molecular weight of 60 kDa and a pI ranging from 8.7 to 9.1. Eight sera were selected from patients with positive result of skin prick test to the mixture of grass pollen extracts. ELISA inhibition technique was used to study Fes p 4-specific IgE in the patients' sera. ELISA to Festuca pratensis was inhibited up to 80% by F. pratensis pollen extract and up to 48% by Fes p 4. 2D-PAGE-immunoblot was used to identify allergenic and antigenic components of Fes p 4 with patients' IgE and monoclonal antibodies (MABs). Three components of purified protein expressed IgE binding ability. Two MABs which recognized unrelated regions on Phl p 4, bound three components of Fes p 4. The role of the carbohydrate moiety in allergenicity was examined with individual patient sera by using periodate-treated Fes p 4. Six out of eight patients reduced IgE binding to periodate-treated allergen. Isolated Fes R 4 glycoprotein consisted of four components, three of which were allergenic, and share common epitopes specific for grass group-4 homologs. The results of periodate oxidation of Fes p 4 suggest that the carbohydrate moiety is involved in IgE binding.     

Risk Factors for Asthma and Other Allergic Diseases in Seasonal Rhinitis

Background. Rhinitis and asthma are common comorbidities. The aim of this study was to determine the risk factors for asthma and other allergic diseases in seasonal rhinitis (SR) patients. Methods. Records of 922 patients diagnosed as SR between 1991 and 2005 were evaluated retrospectively. Patients were grouped according to the results of our standard skin prick tests as follows: I-No sensitization: no sensitization to any allergen; II-Mono-pollen sensitization: sensitization to only one pollen allergen; III-Poly-pollen sensitization: sensitization to more than one pollen allergen; IV-Mite sensitization: sensitization to mite with or without any other allergen sensitization. Results. The mean age of the patients was 29.5 ± 9.6 and 587 patients (63.2%) were females. Age at onset of SR was median 21 years (16–29 years). Of the 922 patients, 99 had no sensitization, 335 had poly-pollen sensitization, 346 had mono-pollen sensitization, and 142 had mite sensitization. The most prevalent allergens were P. pratense (85.3%) and O. europae (31.5%). No sensitization group as compared to poly-pollen sensitization group had significantly higher prevalence of asthma as a single accompanying disease (14.1%, p < 0.05). Mono-pollen sensitization was significantly associated with lower risk of any accompanying allergic disease (OR: 0.7, 95% CI 0,5–0,9) while no sensitization group (OR: 2.8, 95% CI 1.3–5.9) and mite sensitization were associated with asthma (OR: 2.3, 95% CI 1.2–4.4). Conclusion. SR is a condition that presents with different phenotypes. The group with no sensitization and mite sensitization has the highest prevalence of asthma while SR patients with mono-pollen sensitization are unlikely to have an accompanying allergic disease, including asthma.     

Les allergènes recombinants : leur apport à l’allergologie en 2006

Advances in molecular biology techniques have led to the production of recombinant allergens, about thirty of them now being available for measurements (DIAGNOSIS?) in vitro. These recombinant allergens correspond to a precise molecular variant of a natural allergen, and their biological activity has to be evaluated in comparison with the corresponding natural allergen. The advantages of recombinant allergens are essentially the creation of allergenic preparations having constant pharmaceutic properties, which allows determination of specific IgE directed against different molecular components of an allergenic source, for example, pollen, mites, etc. The main consequences of these biological advances are the following: evaluation of sensitivities to allergen molecules in different populations (molecular epidemiology), improvement of extracts used for diagnosis by selection of the most pertinent allergenic sources and in quantifying their major allergen content, definition of the spectrum of recognition of specific IgE vis-à-vis different molecular components (spectrotype), quantitative evaluation of IgE responses, establishing the molecular basis of cross-reactions between different inhaled allergens, between different food allergens, and between inhaled allergens and food allergens. As regards allergy practice, this new diagnostic tool can lead to better interpretation of polysensitivities, observed by skin tests and in vitro tests. Some examples of particular clinical cases associated with specific sensitivities vis-à-vis certain recombinant allergens will be presented.