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Food allergies are recognized as an increasing health concern. Proteins commonly identified as food allergens tend to have one of about 30 different biochemical activities. This leads to the assumption that food allergens must have specific structural features which causes their allergenicity. But these structural features are not completely understood. Uncovering the structural basis of allergenicity would allow improved diagnosis and therapy of allergies and would provide insights for safer food production. The availability of recombinant food allergens can accelerate their structural analysis and benefit specific studies in allergology. Plant chitinases are an example of food allergenic proteins for which structural analysis of allergenicity has only partially been reported. The recombinant maize chitinase, rChiA, was purified from Pichia pastoris extracellular medium by differential precipitation and cation exchange chromatography. Enzyme activity was evaluated by halo-assays and microcalorimetric procedures. rChiA modeling was performed by a two-step procedure, using the Swiss-Model server and Modeller software. Allergenicity of rChiA was verified by immunoblot assays with sera from allergic subjects. rChiA is active in the hydrolysis of glycol chitin and tetra-N-acetylchitotetraose and maintains its activity at high temperatures (70°C) and low pH ( pH 3). The molecule is also reactive with IgE from sera of maize-allergic subjects. rChiA is a valuable molecule for further studies on structure-allergenicity relationships and as a tool for diagnosing allergies. [ABSTRACT FROM AUTHOR]

Background Hypersensitivity to acetylsalicylic acid ( ASA) constitutes a serious problem for subjects with coronary artery disease. In such subjects, physicians have to choose the more appropriate procedure between challenge and desensitization. As the literature on this issue is sparse, this study aimed to establish in these subjects clinical criteria for eligibility for an ASA challenge and/or desensitization. Methods Collection and analysis of data on ASA challenges and desensitizations from 10 allergy centers, as well as consensus among the related physicians and an expert panel. Results Altogether, 310 subjects were assessed; 217 had histories of urticaria/angioedema, 50 of anaphylaxis, 26 of nonimmediate cutaneous eruptions, and 17 of bronchospasm related to ASA/nonsteroidal anti-inflammatory drugs ( NSAID) intake. Specifically, 119 subjects had index reactions to ASA doses lower than 300 mg. Of the 310 subjects, 138 had an acute coronary syndrome ( ACS), 101 of whom underwent desensitizations, whereas 172 suffered from a chronic ischemic heart disease ( CIHD), 126 of whom underwent challenges. Overall, 163 subjects underwent challenges and 147 subjects underwent desensitizations; 86 of the latter had index reactions to ASA doses of 300 mg or less. Ten subjects reacted to challenges, seven at doses up to 500 mg, three at a cumulative dose of 110 mg. The desensitization failure rate was 1.4%. Conclusions In patients with stable CIHD and histories of nonsevere hypersensitivity reactions to ASA/ NSAIDs, an ASA challenge is advisable. Patients with an ACS and histories of hypersensitivity reactions to ASA, especially following doses lower than 100 mg, should directly undergo desensitization. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disease associated with a partial deletion on chromosome 4q35. Few relevant investigations have been reported on its epidemiology and were essentially based on clinical diagnosis, having been performed before recognition of the molecular mutation. We report an epidemiological survey on FSHD patients, in which the diagnosis was obtained by combined clinical and molecular evaluation. The survey concerned the north-east Italian province of Padova, an area of 871,190 inhabitants (1 January 2004). We identified 40 patients affected by FSHD based on clinical diagnosis. In 33 of them, the EcoRI fragment size in the 4q35 region ranged from 14 to 35 kb. Four other patients belonging to the same family harbored a 38-kb fragment. In these four cases, the relationship between the borderline deletion with the mild FSHD phenotype was corroborated by additional haplotype reconstruction and segregation analysis. Interestingly, the same mild facial-sparing clinical pattern was apparent only in one other patient with an EcoRI fragment of 32 kb, suggesting that this unusual FSHD phenotype may be due to very small 4q35 deletions. On the whole, estimating a prevalence rate of 44 × 10−6, our survey confirmed FSHD as one of the most frequent neuromuscular disorders in Western populations. [ABSTRACT FROM AUTHOR]

Background and purpose: Patients affected by facioscapulohumeral muscular dystrophy (FSHD) with unusual large 4q35 deletions tend to present atypical features in early childhood. We explored the clinical presentation of patients with a very short 4q35 fragment (10–13 kb) focusing on hearing loss, a still debated FSHD extramuscular manifestation. Patients and methods: We evaluated six cases with EcoRI 4q35 fragment size ranging from 10 to 13 kb. Assessment of hearing function was carried out by otoscopy, audiometry and auditory-evoked brainstem responses (ABR). Patient data were compared with those of 28 similar subjects reported in the literature. Results: Sensorineural hearing loss was found in four patients, who presented infantile-onset dystrophic phenotype. Hearing loss was associated with mental retardation in three of them and with epilepsy in two. Auditory ability of the other two cases was mildly impaired. If findings related to 28 similar cases reported to date are also considered, auditory impairment appears evident in 68% of these subjects. Conclusions: Hearing loss represents a characteristic feature of FSHD patients with a large 4q35 deletion. Moreover, when considering only cases with 10–11 kb, it appears to be associated with early-onset dystrophic phenotype, with mental retardation (92%) and possibly with epilepsy (58%). [ABSTRACT FROM AUTHOR]

Background Maize allergy is not very common especially in Europe. The number of studies that address IgE mediated maize allergy is all too few. Objective Evaluate subjects with a history of maize allergy by double-blind, placebo-controlled food challenge; identify the spectrum of symptoms manifested during challenge; determine the lowest provocation dose (PD) during challenge; determine the performance characteristics of maize skin prick test and specific IgE. Methods Twenty-seven patients with a history of maize allergy were enrolled to be evaluated by skin test, specific IgE and double-blind placebo-controlled maize challenge. Results Forty-eight percent of the patients were challenge positive. PD range was 0.1–25 g. Fifty-four percent of the maize allergic subjects had a PD that was ⩽2.5 g; two subjects reacted to 100 mg of maize. Comparison of maize specific IgE levels and skin test results to the challenge results revealed the following (specific IgE level/skin testing): sensitivity 1.00/0.846, specificity 0.077/0.384, positive predictive value 0.520/0.579, and negative predictive value 1.00/0.714. Conclusion Maize is a cause of IgE-mediated allergic reactions to foods in adults and children. Nearly half of the subjects recruited were confirmed by challenge to be allergic to maize. Twenty-three percent of the positive challenge patients manifested symptoms that involved two organ systems, thus fulfilling the criteria for maize induced anaphylaxis. Maize is allergenic and can pose a risk for symptomatic food allergy at a dose of 100 mg. [ABSTRACT FROM AUTHOR]

Background: Food allergy to wheat and maize is an increasing factor of deterioration of life quality, especially childhood and can, in rare cases, even induce anaphylaxis. Although omega-5 gliadin from wheat and maize lipid transfer protein have been characterized as major cereal allergens on the molecular level, the list of food allergens is far to be complete. Methods: To identify the IgE-binding repertoires of wheat and maize we screened respective cDNA libraries displayed on phage surface with sera from patients with a confirmed food allergy. The study included six patients with a positive double-blind, placebo-controlled food challenge (DBPCFC) to wheat, nine patients with a positive DBPCFC to maize, and six patients with anaphylactic reactions after ingestion of wheat. Results: The enriched sequences encoding IgE-binding proteins showed heterogeneous repertoires for both, wheat and maize. The selected wheat repertoire yielded 12, the maize repertoire 11 open reading frames. Among these we identified allergens belonging to already characterized allergens families, such as gliadin, profilin and beta-expansin. Besides, we found novel proteins with high cross-reactive potential, such as thioredoxins, as well as sequences that had so far not been related to cereal allergy at all. The IgE-binding capacity of some selected proteins was evaluated in vitro and cross-reactivity was demonstrated by competition ELISA. Conclusion: With regard to the heterogeneity of the characterized sequences as well as to the biochemical nature of the new allergens detected we conclude that wheat and maize-related food allergy is more complex than so far anticipated. [ABSTRACT FROM AUTHOR]

Plant-origin foods, especially nuts and seeds, are the most important sources of food allergic reactions. An important characteristic is the quantitative and qualitative variability of their content in allergenic molecules, depending on plant growth, ripening, environmental stresses or industrial processing. In this review we will focus on newly identified allergens. Recent research have characterized and extensively studied their biochemistry, structure and immunological properties. [ABSTRACT FROM AUTHOR]

Allergic reactions to Hymenoptera stings are frequently observed all over Europe. Rarely they may induce long-standing morbidity or even be fatal. Several investigations have shown that the emergency treatment given to these patients is often inadequate. Cutaneous symptoms respond well to antihistamines and also to adrenaline. Adrenaline is the mainstay for outside hospital treatment of more severe reactions involving the respiratory tract (bronchial asthma, laryngeal oedema) and the cardiovascular system (anaphylactic shock). Inhaled adrenaline is especially useful in respiratory symptoms, while parenteral application of adrenaline is prefered for shock treatment. All patients with severe respiratory or cardiovascular reactions must be hospitalized, treated under intensive care conditions and observed for at least 24 hr. Emergency medications including adrenaline for inhalation or for self-injection must be given to all patients with a history of systemic allergic reactions to hymenoptera stings. These patients must also get instructions for safety measures to avoid further stings. They should be referred to an allergist in order to evaluate the indication for venom immunotherapy. [ABSTRACT FROM AUTHOR]

The article focuses on the diagnostic procedures problems of cross-reactions of allergens. It has been indicated that cross-reactivity can elicit positive in vitro or in vivo allergy tests. It is an in vitro phenomenon caused by immunoglobulin E antibodies directed against epitopes expressed in molecular structures.

The article provides information on the discovery of new allergens in fruits and vegetables. It has been noted that allergens in fruits and vegetables have been particularly studied in recent year. One of the reason is the clinical importance of cross-reactions between vegetable foods and pollens. However, the latest observations concerned allergens which are specific to fruits and closely related to the clinical expression of allergy.

This study evaluated the risk factors for developing allergic reactions to alternative drugs such as acetaminophen and nimesulide in 367 patients intolerant of nonsteroidal anti-inflammatory drugs (NSAID) compared to 243 healthy controls. All subjects were given test doses (TD) of acetaminophen and nimesulide, and age, sex, atopy, and history of reactions also to unrelated drugs were compared in those who reacted and those who were tolerant of the challenge. TD was positive in 49 of 367 (14%) NSAID-allergic patients and in one (0.4%) of the controls (P<0.001). No difference was found in age and sex between the TD-positive and TD-negative subjects, although a significantly larger number of females were NSAID allergic (P<0.01). Of the 367 patients, 208 had a history of reactions only to NSAID, and 148 to NSAID and antimicrobial drugs (AMD). TD with acetaminophen or nimesulide was positive in 6% of patients intolerant only of NSAID and in 24% of those intolerant of both NSAID and AMD, with an odds ratio of 4.82. Atopy was more frequent among patients (36%) than controls (23%) (P=0.004). among TD-positive (51%) than TD-negative patients (33.5%) (P<0.02), and among patients intolerant of NSAID and AMD (48%) than those intolerant only of NSAID (P=0.006). The odds ratios were, respectively, 1.87, 2.57, and 3.16. This study provides evidence that atopy and history of allergic reactions to AMD increase the likelihood of intolerance of usually well-tolerated alternative drugs such as acetaminophen and nimesulide in subjects allergic to NSAID. [ABSTRACT FROM AUTHOR]

The article discusses how hypoallergenic food can be developed. It also suggests ways to prevent severe food-induced anaphylaxis. According to the author, labels could be more comprehensive on the content of prepackaged foods. The severely allergic subject could choose foods from a list of "safe" foods in much the same way as the celiac patient does from a list of gluten-free foods and food technology could be employed to develop hypoallergenic foods. The author also suggests that genetic engineering methods can be used to prepare hypoallergenic foods.

This article presents information on skin tests for diagnosis of IgE-mediated allergy. The diagnostic value of a test is expressed by statistical indicators such as sensitivity, specificity, and positive and negative predictive value. These give the overall accuracy of the test considered. The significance of these indicators in allergic diseases depends on the likelihood of detecting subjects who are clinically, either true positive or true negative. Not all subjects with positive skin tests have clinical symptoms. The meaning of a positive skin reaction in an asymptomatic subject. These positive reactions, however, cannot be dismissed as "false positives" caused by an irritant effect, since some studies show that these positive can be passively transferred, while others show that asymptomatic subjects with positive skin tests have a higher risk of developing allergic symptoms than those with negative skin tests.

A double-blind, placebo-controlled study of immunotherapy was conducted in 19 patients with grass-pollen hay fever to evaluate the efficacy and safety of a formalinized depot grass allergoid. The patients were assessed before and during IT by clinical (symptom-medication scores during the grass- pollen season, specific nasal and skin reactivity) and immunological (specific IgE, IgG, IgG1 and IgG4 antibodies) parameters. High doses of grass allergoid, corresponding to a cumulative pre-seasonal dosage of 46,050 PNU, were administered, with only one systemic reaction. The actively treated patients had significantly lower symptom-medication scores than placebo (p < 0.01) during the month of May and showed a significant decrease in specific skin (p < 0.01) and nasal (p < 0.05) reactivity, and a significant early increase in specific IgE (p < 0.01), IgG (p < 0.0005), IgG1 (p < 0.001) and IgG4 (p < 0.05), with a subsequent decrease of IgE and IgG1. No differences were detected in any of these parameters in the placebo group. A correlation was found between high IgG4/IgG1 ratio and the specific skin reactivity decrease (r = 0.691, p < 0.05), whereas a high IgG4/IgG1 ratio was associated with higher symptom-medication scores (r = 0.654, p < 0.05). Possible explanations of these apparent discrepancies are proposed. [ABSTRACT FROM AUTHOR]

In a 2-year double-blind placebo controlled study an immunological evaluation was carried out on 33 patients (15 males, 18 females, mean age 29.2 years) with mite-induced perennial rhinitis who were submitted to specific immunotherapy (IT) with an alginate-conjugated extract of D. pteronyssinus. The behaviour of IgE, IgG, IgG1 and IgG4 antibodies specific to . pteronyssinus and its major allergen Der p1 was characterized by assessment of their changes in serum, and changes in IgG in nasal secretions during the treatment. The placebo-treated patents did not show any significant variation in the levels of specific antibodies, while in the actively treated patients we found: a statistically significant decrease (P < 0.005) of specific IgE, a statistically significant increase of specific IgG (P < 0.005), IgG1 (P < 0.005) and IgG4 (P < 0.005) in serum and a statistically significant increase (P < 0.001) of specific IgG in nasal secretions. The IgG response showed an early relative predominance of the IgG1 subclass and a late absolute predominance of IgG4 subclass, that confirmed the model of IgG4 restriction in prolonged allergen stimulation. No correlation was found between immunological and clinical data. [ABSTRACT FROM AUTHOR]

The article offers information on food allergy. Food allergy present two contrasting clinical perspectives in children and in adults. In children, the prevalence of food allergy is approximately 8%, the clinical presentation is atopic dermatitis and the most commonly involved foods are milk, eggs, fish and nuts. In contrast, stringent investigation of adults suspected of having food allergy revealed that less than 1% had clinically significant manifestations.

The article presents clinical aspects of Hymenoptera venom allergy. Hymenoptera venom allergy is demonstrably a self-limiting disease, as most patients after an initial reaction develop a spontaneous tolerance of subsequent stings. The likelihood of reacting to further stings depends on the kind of initial reaction and of the culprit insect, being higher in severe reactions and in honeybee stings.

The article evaluates new tests for the diagnosis of food allergy. A large numbers of patients are still labeled as food allergic merely on the basis positive skin prick tests (STP) and unspecific symptoms, such as chronic urticaria or gastrointestinal disorders, without any objective procedure. The diagnosis of food allergy by history and SPT is hampered by two main factors. First, clinical history of adverse reactions to foods offers a low level of reliability, because of the vast difference between patients' self-perception of being allergic to a food and the demonstration by objective procedures of whether that food actually causes a clinical reaction.

The clinical weight of Hymenoptera venom allergy can be assessed by evaluating both its mortality rate and prevalence in the general population. Epidemiologic studies on Hymenoptera venom allergy report prevalences of systemic reactions to stings of 0.3-3.3% . The prevalence observed in the present study was 2.7%, near the highest value. Considering the first factor, Hymenoptera venom allergy mainly affects those exposed to insect stings because they spend time outdoors, and consequently more males than females.

Sensitization to one or more non-specific lipid transfer proteins (nsLTPs), initially thought to exist mainly in southern Europe, is becoming accepted as a cause of allergic reactions to plant foods across Europe and beyond. The peach nsLTP allergen Pru p 3 is a dominant sensitizing allergen and peaches a common food trigger, although multiple foods can be involved. A frequent feature of reactions is the requirement for a cofactor (exercise, alcohol, non-steroidal anti-inflammatory drugs, Cannabis sativa) to be present for a food to elicit a reaction. The variability in the food and cofactor triggers makes it essential to include an allergy-focused diet and clinical history in the diagnostic workup. Testing on suspected food triggers should also establish whether sensitization to nsLTP is present, using purified or recombinant nsLTP allergens such as Pru p 3. The avoidance of known trigger foods and advice on cofactors is currently the main management for this condition. Studies on immunotherapy are promising, but it is unknown whether such treatments will be useful in populations where Pru p 3 is not the primary sensitizing allergen. Future research should focus on the mechanisms of cofactors, improving diagnostic accuracy and establishing the efficacy of immunotherapy., (© 2021 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Allergic rhinoconjunctivitis (AR) is an allergic disorder of the nose and eyes affecting about a fifth of the general population. Symptoms of AR can be controlled with allergen avoidance measures and pharmacotherapy. However, many patients continue to have ongoing symptoms and an impaired quality of life; pharmacotherapy may also induce some side-effects. Allergen immunotherapy (AIT) represents the only currently available treatment that targets the underlying pathophysiology, and it may have a disease-modifying effect. Either the subcutaneous (SCIT) or sublingual (SLIT) routes may be used. This Guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on AIT for AR and is part of the EAACI presidential project "EAACI Guidelines on Allergen Immunotherapy." It aims to provide evidence-based clinical recommendations and has been informed by a formal systematic review and meta-analysis. Its generation has followed the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included involvement of the full range of stakeholders. In general, broad evidence for the clinical efficacy of AIT for AR exists but a product-specific evaluation of evidence is recommended. In general, SCIT and SLIT are recommended for both seasonal and perennial AR for its short-term benefit. The strongest evidence for long-term benefit is documented for grass AIT (especially for the grass tablets) where long-term benefit is seen. To achieve long-term efficacy, it is recommended that a minimum of 3 years of therapy is used. Many gaps in the evidence base exist, particularly around long-term benefit and use in children., (© 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Background: The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis. To inform the development of clinical recommendations, we undertook a systematic review to assess the effectiveness, cost-effectiveness, and safety of AIT in the management of allergic rhinoconjunctivitis., Methods: We searched nine international biomedical databases for published, in-progress, and unpublished evidence. Studies were independently screened by two reviewers against predefined eligibility criteria and critically appraised using established instruments. Our primary outcomes of interest were symptom, medication, and combined symptom and medication scores. Secondary outcomes of interest included cost-effectiveness and safety. Data were descriptively summarized and then quantitatively synthesized using random-effects meta-analyses., Results: We identified 5960 studies of which 160 studies satisfied our eligibility criteria. There was a substantial body of evidence demonstrating significant reductions in standardized mean differences (SMD) of symptom (SMD -0.53, 95% CI -0.63, -0.42), medication (SMD -0.37, 95% CI -0.49, -0.26), and combined symptom and medication (SMD -0.49, 95% CI -0.69, -0.30) scores while on treatment that were robust to prespecified sensitivity analyses. There was in comparison a more modest body of evidence on effectiveness post-discontinuation of AIT, suggesting a benefit in relation to symptom scores., Conclusions: AIT is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy., (© 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

Adverse reactions to food may be toxic or non toxic, depending on the susceptibility to a certain food; non toxic reactions that involve immune mechanisms are termed allergy if they are IgE-mediated. If no immunological mechanism is responsible, it is termed intolerance. The following disorders are considered a consequence of food allergy: gastrointestinal reactions (oral allergy syndrome, vomiting, diarrhea, protein-induced enterocolitic syndrome, eosinophilic gastroenteritis); respiratory reactions (rhinitis, asthma, laryngeal edema); cutaneous reactions (urticaria-angioedema, atopic dermatitis); anaphylaxis. There is much recent evidence to consider celiac disease an immunological disorder. Food allergy diagnosis is based on history, SPT, specific IgE, food challenges. DBPCFC is fundamental for diagnosing true food allergy; patients who have had anaphylaxis to food must not undergo DBPCFC. Rapidly progressive respiratory reactions and anaphylactic shock are life-threatening reactions that can be caused by food allergy. The doses of food inducing anaphylaxis can be very low, therefore commercial cross-contamination with an unsuspected food during food processing can be risky for the food allergic patient. The prevention of severe anaphylactic food reactions may lie in interdisciplinary collaboration among allergologists, chemists, food technologists, and experts in food industry research.

Plant lipid transfer proteins, a widespread family of proteins, have been recently identified as important food allergens. Their common structural features, such as eight conserved cysteines forming disulfide bridges, basic isoelectric point and high similarity in amino acid sequence, are the basis of allergic clinical cross-reactivity. This has been demonstrated for the LTP allergens of the Prunoideae subfamily, whose similarity is about 95% as demonstrated for the purified allergens of peach, apricot, plum and apple. A relevant aspect is the existence of sequence homology of LTPs of botanically unrelated foods, as demonstrated for LTPs of maize and peach. A class of food allergens of well recognized clinical importance is that of seed storage 2S albumins. They have been identified in the most diffused edible seeds and nuts, such as mustard, sesame, Brazil nut, walnut and peanut. In particular, a strong correlation between IgE-binding to these proteins and food-induced anaphylaxis has been demonstrated for Brazil nut and sesame seeds.

Symptoms appear immediately at the site of contact with the food when a susceptible allergic patients eats the offending food. Allergy to fresh fruits and vegetables, associated with all kinds of pollinosis, is the more frequent cause of Oral Allergy Syndrome.

A double-blind, placebo-controlled study was conducted to evaluate the efficacy and safety of immunotherapy (IT) with a partially purified alginate-conjugated extract of Parietaria judaica (Conjuvac Parietaria, Dome/Hollister-Stier) in patients suffering from rhinoconjunctivitis caused by Parietaria pollen. Eighteen patients (10 women, 8 men, mean age 35 years) received active treatment and 17 (10 women, 7 men, mean age 42.5 years) received placebo. Actively treated patients had significantly lower nasal symptom/medication scores (running nose P = 0.0087 and sneezing P = 0.048) during the Parietaria pollen season. Significant decreases in specific skin (P < 0.01), nasal (P < 0.05), and conjunctival (P < 0.01) reactivity to the Parietaria extract and significant increases of specific IgG (P < 0.001), IgG1 (P < 0.001), and IgG4 (P < 0.001) in actively treated patients, but not in placebo, were found. IT was well tolerated, the active extract inducing five mild systemic reactions (four rhinitis and one urticaria) and placebo two (rhinitis). A significant correlation was found between low skin reactivity and high specific IgG (P = 0.0002) and IgG4 (P = 0.036). These findings indicate that IT with a partially purified P. judaica extract is an effective and safe treatment for Parietaria pollen allergy. The correlation between low immediate skin reactivity and high specific IgG and IgG4 suggests that, at least in the studied cutaneous model, these antibodies may exert a blocking effect.

We investigated the diagnostic value of a new in vitro test, Pharmacia CAP System (Pharmacia Diagnostics AB, Uppsala, Sweden), for the quantitative measurement of allergen-specific IgE antibodies by comparison with RAST in 2 groups of patients, 71 atopic and 48 non-atopic. In the last 20 years RAST has supplied a good diagnostic tool, but this test presents some problems, the main one being sensitivity. The new test has a solid phase able to bind even very small amounts of specific IgE and an anti-IgE tracer with very low cross-reactivity with other immunoglobulins, thus presenting more favourable conditions. From the analysis of our results, Pharmacia CAP System gave higher sensitivity (94% compared to 88% of RAST) with no loss of specificity (96% for both tests). The reliability of these results is ensured by the proper selection of patients who were all suffering from pollinosis and were clinically diagnosed as certainly hypersensitive to a single pollen. A positive trend was found between severity of asthma and levels of specific IgE for timothy. Pharmacia CAP System appears to identify a larger number of atopic patients than RAST.

In a 2-year double-blind placebo controlled study an immunological evaluation was carried out on 33 patients (15 males, 18 females, mean age 29.2 years) with mite-induced perennial rhinitis who were submitted to specific immunotherapy (IT) with an alginate-conjugated extract of D. pteronyssinus. The behaviour of IgE, IgG, IgG1 and IgG4 antibodies specific to D. pteronyssinus and its major allergen Der p1 was characterized by assessment of their changes in serum, and changes in IgG in nasal secretions during the treatment. The placebo-treated patients did not show any significant variation in the levels of specific antibodies, while in the actively treated patients we found: a statistically significant decrease (P less than 0.005) of specific IgE, a statistically significant increase of specific IgG (P less than 0.005), IgG1 (P less than 0.005) and IgG4 (P less than 0.005) in serum and a statistically significant increase (P less than 0.001) of specific IgG in nasal secretions. The IgG response showed an early relative predominance of the IgG1 subclass and a late absolute predominance of IgG4 subclass, that confirmed the model of IgG4 restriction in prolonged allergen stimulation. No correlation was found between immunological and clinical data.

The efficacy of hyposensitization with a standardised extract of Dermatophagoides pteronyssinus (D. pteronyssinus) conjugated to alginate and containing known amounts of antigen P1 (Conjuvac) was tested in a double blind, placebo controlled, multi-centre study in 66 adult patients with perennial rhinitis. Patients received 11 weekly injections of increasing concentrations of Conjuvac containing from 56 x 10(1) to 448 10(3) IU D. pteronyssinus or placebo injections of the alginate diluent to some of which 5 micrograms of histamine has been randomly added. This was followed by 15 monthly injections of Conjuvac or placebo. The severity of nasal blockage, sneezing and rhinorrhoea was recorded twice daily in a diary and visual analogue assessments (VAS) made at each clinic visit. Nasal provocation testing (NPT) was performed with increasing concentrations of the same extract of D. pteronyssinus as used in the hyposensitization injections, and changes in nasal airways resistance measured by passive anterior rhinomanometry. VAS was recorded and NPT was performed on entry to the study and after the fifth, ninth and final monthly injection. Conjuvac injections were well tolerated. Large local reactions (greater than 5 cm) occurred within 30 min in only 1% of patients but later in 23%. No systemic reactions or anaphylaxis occurred within 30 min of injections, but urticaria or worsening of asthma and rhinitis was reported later in 3% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)