Angioedema Due to Acquired Deficiency of C1-Inhibitor: A Cohort Study in Spain and a Comparison With Other Series

BACKGROUND

Data on acquired angioedema due to C1-inhibitor deficiency (C1-INH-AAE) from 4 European countries (France, Italy, Germany, and Hungary) were recently published.

OBJECTIVE

To report data from a group of 50 patients with acquired C1-INH deficiency from Spain, of whom 46 had angioedema, and compare them with other European series.

METHODS

We performed a retrospective observational study of 46 patients with C1-INH-AAE and 4 asymptomatic patients. Clinical and biological characteristics and associated diseases were assessed and compared with other European series.

RESULTS

Women accounted for 73.9% of cases. The prevalence of C1-INH-AAE related to hereditary forms was 1/10.1. Overall, 8.7% patients were aged <40 years. Diagnostic delay was 1.1 years. Angioedema mainly affected the face (91.3%), followed by the oropharynx (63%), extremities (50%), and abdomen (37%). Only 1 patient underwent orotracheal intubation. Erythema marginatum was present in 1 patient. A hematologic disorder was recorded in 50% of patients. Angioedema preceded all benign conditions, mostly monoclonal gammopathy of undetermined significance, but appeared very close to or after malignant hematologic diseases (median, 2.2 and 0.29 years). Autoimmune diseases were associated in 50% (autoimmune thyroiditis, 21.5%; systemic lupus erythematosus, 10.9%). Half of them coexisted with hematologic disorders. Anti-C1-INH antibodies were found in 67% of tested patients and were not related to the associated disease. Long-term prophylaxis was necessary in 52.2%, most of whom responded to tranexamic acid.

CONCLUSIONS

This study emphasizes the possibility of C1-INH-AAE in patients younger than 40 and in autoimmune diseases other than systemic lupus erythematosus such as autoimmune thyroiditis.

Hypersensitivity to Gadolinium-Based Contrast Media

Gadolinium-based contrast agents (GBCAs) are frequently used in magnetic resonance imaging (MRI) examinations to increase sensitivity in diagnoses. Recently, an increase in the description of hypersensitivity reactions to GBCAs has been detected. We performed research in PubMed, PubMed, SCOPUS, and EMBASE until September 2021, searching for studies regarding immediate and delayed hypersensitivity reactions to gadolinium-based contrast agents in which an allergy study was performed. The initial research identified 149 articles written in English. After excluding articles duplicated and articles that had irrelevant designs, 26 articles were included. Finally, 17 studies concerning immediate reactions, six studies concerning non-immediate reactions, and three concerning both that performed allergy evaluations were selected. In the review, we analyzed the characteristics of immediate and delayed reactions and the results of the allergy study and cross-reactivity. Skin tests seem to have acceptable accuracy, but drug provocation tests are still needed when skin tests are negative o to find alternative agents. Although cross-reactivity patterns are not well established, cross-reactivity seems to exist among macrocyclic agents. Notwithstanding, the number of patients analyzed is low and further studies are required. A management algorithm is suggested.

A prospective study of costs associated with the evaluation of allergic reactions to radiological contrast media

BACKGROUND AND OBJECTIVE

The prevalence of hypersensitivity reactions to radiological contrast media (RCM) is increasing due to the greater performance of diagnostic and therapeutic tests that require RCMs. Objective: We carried out a year-long real-life observational study to prospectively evaluate the patients referred to the Allergy Service from Primary Care, Emergency Room, and other Services with suspected moderate to severe RCM hypersensitivity.

METHODS

To study the costs of RCM hypersensitivity evaluation, we systematically recorded direct and indirect costs.

RESULTS

Sixty-nine patients with previous reactions to RCM were evaluated in the Allergy Service from June 1st, 2017, to May 31st, 2018. Total direct health care costs were € 10715.84, with a mean cost per patient of € 155.30 ± 77.08. Specifically, direct non-health costs reached € 1605.42 (mean € 23.27 ± 41.14), and indirect costs were € 6490.85 (mean € 94.07 ± 110.61). In summary, the total cost was € 18812.11, which means a mean cost of € 272.64 ± 164.77.

CONCLUSION

Our study reflects that the costs of an elective evaluation of hypersensitivity to RCM are low. This fact reaffirms that correct and safe management of these patients could be cost-effective, so our efforts should be directed to implement the necessary logistics.

Analysis of the Costs Associated With the Elective Evaluation of Patients Labelled as Allergic to Beta-Lactams or Nonsteroidal Antiinflamatory Agents

Introduction: Being labelled as allergic to different drugs results in patients receiving other treatments, which are more toxic, less effective and more expensive. We aimed to analyze different studies of the costs of drug hypersensitivity assessment.

Methods: A bibliographic search on studies regarding this issue was performed, including the available scientific evidence up to June 2020. We searched three databases with terms related to costs and allergy testing in drug hypersensitivity reactions.

Results: Our search revealed 1,430 publications, of which 20 met the inclusion criteria. In the manuscript, prospective studies evaluating the costs of the evaluation of patients with suspected allergy to beta-lactams or non-steroidal anti-inflammatory drugs are analyzed. Also, comment is made on the costs associated with incorrect labeling as non-steroidal anti-inflammatory drug or penicillin hypersensitivity.

Conclusions: Taking all costs into account, the study of drug hypersensitivity is not expensive, particularly considering the economic and clinical consequences of labeling a patient with hypersensitivity to drugs.

Usefulness of an Artificial Neural Network in the Prediction of β-Lactam Allergy

BACKGROUND

An accurate diagnosis of β-lactam (BL) allergy improves the use of antibiotics, increases patients' safety, and reduces costs to health systems. Nevertheless, it requires skin and drug provocation tests, which are time-consuming and put the patient at risk. Furthermore, allergy testing is not available in circumstances such as the urgent need for antibiotic therapy.

OBJECTIVE

To evaluate the usefulness of an artificial neural network (ANN) in the prediction of hypersensitivity to BLs, and compare it with logistic regression (LR) analysis.

METHODS

In a single-center study, 656 patients evaluated for BL allergy between 1994 and 2000 were retrospectively analyzed, and the data were used to construct an ANN. The ANN predictive capabilities were compared with LR and then prospectively evaluated in 615 patients who underwent BL evaluation between 2011 and 2017.

RESULTS

A total of 1271 patients were evaluated. All patients had a definite diagnosis as allergic or nonallergic to BL. The prospective sample showed a lower percentage of patients with allergy than the retrospective sample (20.7% vs 25.8%; P = .018). In the retrospective and prospective series, the ANN reached a sensitivity of 89.5% and 81.1%, a specificity of 86.1% and 97.9%, a positive predictive value of 82.1% and 91.1%, and a negative predictive value of 92.1% and 95.2%, respectively. The ANN's performance was far superior to that of the LR, whose best performance reached a sensitivity of 31.9% and a specificity of 98.8%.

CONCLUSIONS

This ANN demonstrated a superior performance than the LR in predicting BL hypersensitivity without misdiagnosing severe allergic reactions. The ANN could be a helpful tool to classify the reaction risk, particularly in the identification of low-risk patients, in which an open challenge could be done to delabel patients.

A Comprehensive Prospective Study of the Costs Associated With Evaluation of ß-Lactam Allergy

BACKGROUND AND OBJECTIVE

Being labeled as allergic to penicillin (unverified ß-lactam allergy) can result in patients receiving broader-spectrum antibiotics than necessary that may be more toxic, less effective, and/or more expensive than alternative options. Objective: We aimed to evaluate the real costs of evaluating ß-lactam allergy.

METHODS

We performed a prospective real-life observational study designed to evaluate all adult patients who consulted for suspected ß-lactam allergy over a 1-year period. Direct and indirect costs were systematically recorded. Direct health costs were calculated based on the number of visits and all additional and diagnostic tests performed, direct nonhealth costs based on the number of visits and the distance from their homes to the Allergy Department, and indirect costs based on absenteeism.

RESULTS

A total of 296 patients with suspected allergy to ß-lactams were evaluated in our outpatient clinic from June 1, 2017 to May 31, 2018. Total direct health care costs were €28 176.70, with a mean (SD) cost of €95.19 (37.20). Direct nonhealth costs reached €6551.73, that is, €22.13 (40.44) per patient. Indirect health costs reached €20 769.20, with a mean of €70.17 (127.40). In summary, the total cost was €55 497.63, that is, a cost per patient of €187.49 (148.14).

CONCLUSIONS

When all possible costs are taken into account, the evaluation of ß-lactam allergy is not expensive and can reduce future expense arising from unnecessary use of more expensive and less effective antibiotics.

Using β-lactam antibiotics in patients with a history of β-lactam allergy: current concepts

β-lactams are the most widely used antibiotic family, but they are also the most common cause of drug-induced hypersensitivity reactions. The estimated prevalence of reported penicillin allergy ranges between 9% and 12%, although a high percentage of patients with a history of penicillin allergy have no subsequent reactions on reexposure to β-lactams. A self-reported penicillin allergy has been associated with antimicrobial resistance, increased cost, intensive care admission, and death, making it essential to establish an accurate diagnosis. In addition to a thorough clinical history, diagnostic methods include skin tests, in vitro tests, and drug-challenge tests. In this review, the diagnosis and management of patients with self-reported penicillin allergy is discussed, including the recently introduced antimicrobial stewardship strategy.

Performance in real life of the European Network on Drug Allergy algorithm in immediate reactions to beta-lactam antibiotics

European Network on Drug Allergy (ENDA) has proposed an algorithm for diagnosing immediate beta-lactam (BL) allergy. We evaluated its performance in real life. During 1994-2014, 1779 patients with suspected immediate reactions to BL were evaluated following ENDA's short diagnostic algorithm. Five hundred and nine patients (28.6%) were diagnosed of BL hypersensitivity. Of them, 457 (25.7%) were at first evaluation [403 by skin tests (ST), 12 by positive IgE and 42 by controlled provocation tests (CPT)]. At second evaluation (SE), 52 additional patients (10.2% of allergic patients) were diagnosed, [50 (2.8%) by ST and 2 (0.1%) by CPT]. Time between reaction and study was significantly longer in patients diagnosed at SE (median 5 vs 42 months; IQR 34 vs 170; P < 0.0001). Anaphylaxis was significantly associated with a diagnosis at SE. European Network on Drug Allergy/EAACI protocol was appropriate and safe when evaluating BL immediate reactions. Re-evaluation should be performed, particularly when anaphylaxis and long interval to diagnosis are present.

Adverse reactions to immunotherapy are associated with different patterns of sensitization to grass allergens

The aim of the study was to investigate whether adverse drug reactions (ADRs) during immunotherapy with a grass extract (AVANZ® Phleum, ALK-Abelló) are related to the different patterns of sensitization of patients to grass allergens. A total of 192 patients with rhinitis and/or asthma sensitized to grass pollen received a 4-week updosing with five injections. ADRs were evaluated following EAACI guidelines. A total of 432 ADRs in 133 (69%) patients were recorded, 64% local and 31% systemic. There was a significant association between the number of grass allergens that sensitized the patients and the total number of ADRs (P = 0.004) occurred locally (P = 0.003) and systemically (P = 0.01). Sensitization to Phl p1 + Phl p5 or Phl p1 + Phl p5 + Phl p12 was significantly associated with a higher frequency of local or systemic reactions (P = 0.001, both). Different patterns of sensitization to grass allergens may potentially be considered a risk marker to the development of ADRs to immunotherapy.

(CCTTT)n polymorphism of NOS2A in nasal polyposis and asthma: a case-control study

BACKGROUND

Nitric Oxide (NO) has been proposed as an important signaling molecule. NO produced by the inducible NO synthase enzyme NOS2A is generated at high levels in certain types of inflammation. A pentanucleotide polypyrimidine microsatellite CCTTT has been identified in the promoter region of the NOS2A gene.

OBJECTIVE

The aim of this study was to analyze the (CCTTT)n polymorphism in patients with asthma and nasal polyposis.

MATERIAL AND METHODS

The study included 292 white individuals (194 patients and 98 controls). Asthma was diagnosed according to American Thoracic Society criteria and classified in accordance with the guidelines of the Global Initiative for Asthma. Skin prick tests were performed in all individuals. The polymorphism was analyzed by an electrophoretic method and by direct sequencing.

RESULTS

A significant association was detected for a 15-repeat cutoff in nasal polyposis (Fisher P value = .0001, Monte Carlo P value [after 10(4) simulations] = .002). Multivariate analysis adjusted for age and sex confirmed this association with an increased risk of nasal polyposis (odds ratio, 14.39; 95% confidence interval, 3.02-68.60; P = .001).

CONCLUSION

The number of CCTTT repeats in the promoter region of NOS2A could be associated with the inflammatory process of nasal polyposis in our population. Modifications of NOS2A transcription levels could be involved in this association.

Usefulness of intradermal test and patch test in the diagnosis of nonimmediate reactions to metamizol

BACKGROUND

Metamizole is a pyrazolone derivative, and its most common reactions are IgE-mediated reaction and idiosyncratic reactions. Non-immediate reactions are poorly described and there are very few reports on non-immediate reactions to pyrazolones.

MATERIALS AND METHODS

We evaluated 12 patients (nine men) who consulted for a non-immediate reaction after metamizol administration. We performed cutaneous tests (skin prick tests and immediate and delayed intradermal tests) and epicutaneous tests, and, if necessary, an oral challenge test.

RESULTS

All skin prick and intradermal tests, if necessary, were negative in immediate reading. Delayed intradermal tests were positive in six of 10 patients (60%) and epicutaneous tests were positive in four of 11 patients (36%). Three cases (25%), were diagnosed by a positive oral challenge test.

DISCUSSION

Delayed-reading intradermal tests and patch tests are useful tools in the diagnosis of nonimmediate reactions to pyrazolones and should be considered the first step when evaluating these type of reactions. Intradermal test appears to be more sensitive than patch test. The positivity of skin tests suggests an immunological reaction, probably mediated by T lymphocytes, but further studies are required.

Prevention of allergic diseases

The prevalence of asthma and allergic diseases has increased in recent years, particularly in the industrialized world. Allergic disease begins to manifest in the first years of life. The disorder usually manifests initially in the form of food allergy and atopic dermatitis, followed in later stages by respiratory allergy with rhinitis and/or asthma. This has led to the adoption of preventive measures in those children with a high risk of atopy, based on the following considerations: 1) A family history of allergic diseases (asthma, eczema, and/or allergic rhinitis); 2) A personal history of atopy such as atopic dermatitis, particularly when associated to food allergy; and 3) The existence of allergic sensitization, particularly to pneumoallergens, of early or late onset, but persistent during childhood. Prevention is established at three different levels: primary prevention, avoiding sensitization; secondary prevention, avoiding appearance of the disease; and tertiary prevention, avoiding the symptoms. The present study discusses current knowledge of prevention and its efficacy, with mention of the importance of breastfeeding and the use of pre- and probiotics for securing adequate prevention.

Selective immediate hypersensitivity to cefepime

Cefepime is a fourth-generation cephalosporin with a broad antimicrobial spectrum and good activity against both gram-positive and gram-negative organisms. We present the case of a 61-year-old man who developed an immediate urticarial reaction after receiving a single dose of cefepime. Skin tests were positive to cefepime and negative to the other beta-lactam antibiotics. Controlled administration of amoxicillin-clavulanic acid and ceftazidime was well tolerated by the patient. To the best of our knowledge, this is the first report of selective hypersensitivity to cefepime demonstrated by skin and challenge tests. Complete allergological studies, including challenge tests with other beta-lactam antibiotics that produce a negative result in skin tests, should be considered in these patients.

927T>C polymorphism of the cysteinyl-leukotriene type-1 receptor (CYSLTR1) gene in children with asthma and atopic dermatitis

Asthma and atopic dermatitis share several common features and Cysteinyl-leukotrienes are mediators that participate in the pathogenesis of both diseases. Recently, a new polymorphism (927T>C) has been identified in cysteinyl-leukotriene type-1 receptor (CYSLTR1) gene. This gene is found on the X chromosome. The aim of this study was to analyze this SNP in a population of children with asthma and atopic dermatitis. In this study, 166 individuals, 79 adult controls (CTR) and 87 children with asthma (AA) were included. Forty-one patients with asthma presented atopic dermatitis (AA-AD). Adults were chosen as controls to confirm lack of development of asthma and allergy during childhood. Standardized history, physical examination, skin prick tests, and lung function measurements were performed in all patients. The 927T>C CYSLTR1 SNP was analyzed by direct sequencing after PCR amplification. In males (53 individuals), the C allele was significantly more common among AA-AD patients (47%) than in CTR (8%) (Fisher's p < 0.005; Monte Carlo p < 0.008; OR:9.78; 95%CI: 1.73-55.30). When comparing AA-AD vs. AA-NAD (patients with asthma but not atopic dermatitis), significant differences were observed, (47% vs. 15%, Fisher's p = 0.014; Monte Carlo p = 0.022; OR: 4.97; 95%CI: 1.29-19.13). No differences in allele distribution were observed between these disease sub-groups in females. The 927T>C is a silent SNP; however, it could affect transcription or translation or may be linked to an unidentified, functional polymorphism and thus may pre-dispose male children to asthma and atopic dermatitis in our population. Further studies are needed to confirm these findings.

Promoter genetic variants of prostanoid DP receptor (PTGDR) gene in patients with asthma

BACKGROUND

PTGDR gene has been identified as an asthma-susceptibility gene. Recently, functional genetic variants have been associated with asthma. The objective of this work was to study -549T>C, -441C>T and -197T>C PTGDR promoter polymorphisms in a Spanish population.

METHODS

In this study, 197 Caucasian individuals were included. Asthma was specialist-physician diagnosed according to the American Thoracic Society (ATS) criteria and classified following the Global Initiative for Asthma (GINA) guidelines. Skin prick tests were performed in all patients. The polymorphisms were analyzed by direct sequencing.

RESULTS

-197T>C polymorphism was significantly associated with asthma [Fisher's P-value = 0.007, Monte Carlo P-value (10(4) simulations) = 0.004]. Multivariate analysis adjusted for age and sex confirmed this association with an increased risk of asthma (OR, 3.06; 95% CI, 1.28-7.32; P-value = 0.012). CCT CCC diplotype was associated with asthma (P-value < 0.0001; OR, 1.15; 95% CI, 1.07-1.23), specifically with allergic asthma (P-value < 0.0001). CCT CCC diplotype is unambiguous. All individuals carrying this diplotype had asthma.

CONCLUSION

We identified a specific promoter variant of PTGDR that could be associated with asthma. This diplotype is a combination of the two highest transcriptional efficiency haplotypes, recently described. Our in vivo results would support for the first time what was demonstrated in vitro about high-transcriptional efficiency PTGDR haplotypes in asthma.

Analysis of 927T> C CYSLTRI and -444A > C LTC4S polymorphisms in patients with asthma

BACKGROUND

The cysteinyl leukotrienes (cys-LTs) are proinflammatory mediators synthesized through the 5-lipoxygenase pathway of arachidonic acid metabolism. Cys-LTs exert their biological action by binding two types of G-protein-coupled seven transmembrane receptors, CYSLTR1 and CYSLTR2. The contribution of the cys-LT receptors to bronchial asthma has been established by the therapeutic efficacy of biosynthetic inhibitors and selective CYSLTR1 blockers.

OBJECTIVE

The present study was designed to analyse two different polymorphisms 927T>C CYSLTR1 and -444A>C LTC4S, and to determine whether there is an association between these polymorphisms and the asthma phenotype in a Spanish population.

METHODS

Both single nucleotide polymorphisms (SNPs) were analysed in 208 individuals (130 asthmatic subjects and 78 controls). A standardized history, physical examination, skin prick tests and lung function measurement were taken from all patients. Genotypes were determined by direct sequencing after polymerase chain reaction (PCR) amplification.

RESULTS

In the group of male patients, the C allele of 927T> C CYSLTRI was more common among patients with asthma than controls. No association was detected between the -444A> C LTC4S polymorphism and the asthma phenotype. The combination of 927T CYSLTR1 and -444A LTC4S was less common in male patients with asthma than in controls (Fisher's P-value =.039; Monte Carlo P-value (after 104 simulations)= .045 and the combination of 927C CYSLTR1 and -444A LTC4S was slightly more frequent in patients with asthma. No differences were observed in the female group.

CONCLUSIONS

The results suggest a certain trend of associations that could help to explain some controversial results in association studies of these genes from the leukotriene pathway, when considered individually. Further studies are needed to confirm such an association.

Interleukin-4 (IL4) and Interleukin-4 receptor (IL4RA) polymorphisms in asthma: a case control study

Background

IL4/IL4RA pathway plays an important role in atopy and asthma. Different polymorphisms in IL4 and IL4RA genes have been described. Particularly, -33C>TIL4 and 576Q>RIL4RA SNPs have been independently associated to atopy and asthma. The purpose of this study was to analyse these polymorphisms in a population of patients with a well-characterized asthma phenotype.

Methods

A total of 212 unrelated Caucasian individuals, 133 patients with asthma and 79 healthy subjects without symptoms or history of asthma or atopy and with negative skin prick tests were recruited. Lung function was measured by spirometry and asthma was specialist physician-diagnosed according to the ATS (American Thoracic Society) criteria and classified following the GINA (Global Initiative for Asthma) guidelines. Skin prick tests were performed according to EAACI recommendations. -33C>TIL4 was studied with TaqMan assay and 576Q>RIL4RA by PCR-RFLP technique. Hardy-Weinberg equilibrium was analysed in all groups. Dichotomous variables were analysed using χ², Fisher exact test, Monte Carlo simulation test and odds ratio test. To model the effects of multiple covariates logistic regression was used.

Results

No statistically significant differences between the group of patients with asthma and the controls were found when the allele and genotype distribution of -33C>TIL4 and 576Q>RIL4RA polymorphisms were compared. However, the T allele of the -33C>TIL4 SNP was more frequent in patients with persistent asthma. Multivariate analysis adjusted for age and sex confirmed that carriers of allele T had an increased risk of persistent asthma (OR:2.77, 95%CI:1.18–6.49; p = 0.019). Analysis of combination of polymorphisms showed that patients carrying both the T allele of -33C>TIL4 and the A allele of 576Q>RIL4RA had an increased risk of asthma. This association was particularly observed in persistent asthma [Fisher's p value = 0.0021, Monte Carlo p value (after 10⁴ simulations) = 0.0016, OR:3.39; 95% CI:1.50–7.66].

Conclusion

Our results show a trend of association between the genetic combination of the T allele of -33C>TIL4 and the A allele of 576Q>RIL4RA with asthma. This genetic variant was more frequently observed in patients with persistent asthma. As long as this study was performed in a small population, further studies in other populations are needed to confirm these results.

El polimorfismo Q576R del gen IL4RA se asocia con valores elevados de IgE total en pacientes con antecedentes familiares de atopia

BACKGROUND AND OBJECTIVE

Atopy is a common immunological disorder underlying allergic rhinitis, atopic dermatitis and allergic asthma. There is an association between atopy and the polymorphism Q576R in the IL4RA gene. The aim of this study is to analyze the allelic distribution of the Q576R polymorphism in an atopic and non atopic population and the relationship with total IgE levels and the family history of atopy.

PATIENTS AND METHOD

Q576R polymorphism of IL4RA gene was analyzed by PCR-restriction fragment length polymorphism (RFLP) using MspI restriction enzyme in 154 patients from the Allergy Department of the University Hospital of Salamanca.

RESULTS

We have not found an association between the R576 allele and higher serum IgE levels nor atopy in this population. Nevertheless, there is an association between this allele and IgE levels in patients with positive skin prick test and family history of atopy.

CONCLUSIONS

Our results suggest that the R576 allele could characterize a specific group of patients with a familial history of atopy in whom the presence of this allele may be related to higher levels of serum IgE.

[Viral infection and asthma: immunologic mechanisms]

The role of viral respiratory infections in lactating infants and other children continues to generate controversy. The debate concerns the difference, or the apparent differences, in the natural history of wheezing. Viral infections frequently provoke wheezing episodes in non-asthmatic small children but in the majority of these the wheezing disappears without the child subsequently developing asthma. In some cases, however, the wheezing persists and in others the child has asthma. Both the role of viral infection and the mechanisms by which wheezing can be produced in a previously healthy child or exacerbated in asthmatic children are unknown. Several hypotheses have been put forward to explain the relationship between viral infections and persistent wheezing and asthma: 1. Altered immune response to various allergens, whether producing sensitization to these allergens or inhibiting tolerance response to airborne allergens. The number of such patients is increasing, among them those with bronchiolitis, asthma, positive skin tests and specific IgE antibodies. Although there is no unanimity on the matter, these patients also present elevated IL-4 levels and reduced IFN-gamma levels. 2. Induction of inflammation typical of allergic asthma. This occurs when the virus interacts with T lymphocytes; (the natural response to viral infection is Th0 and Th1 lymphocyte differentiation and release of IFN-gamma, which has antiviral properties. In children infected with respiratory syncytial virus Th2 lymphocyte differentiation is produced, which is characteristic of allergic reactions, to the detriment of Th1); epithelial cells (in these cells active viral infection activates nuclear transcription kappa-beta and nuclear IL-6 factor, producing the release of numerous pro-inflammatory cytokines and chemokines as well as expression of adhesion molecules); eosinophils (inducing variable eosinophilia which, to a certain degree, has predictive value for the persistence of wheezing) and other inflammatory cells such as neutrophils and macrophages. In the same context, during viral respiratory infection, the presence of mediators (leukotrienes, especially LTC4, histamine, prostaglandins and tryptase) are observed in respiratory secretions and a correlation between levels of specific IgE mediators can be observed. 3. Increased allergic inflammation--producing bronchial hyperreactivity, mediator release by the various inflammatory cells and neuropeptides from C-sensitive fibers, and even interfering with nitric oxide bronchodilators. In spite of all of the above, it seems that recurrent wheezing after childhood bronchiolitis is not exclusively the result of viral infection and that other factors also play a role in this disease.

Tick-bite-induced anaphylaxis in Spain

Although there are very few reports of human anaphylaxis induced by tick bites, two such cases have recently been seen in Salamanca, Spain. To identify the tick species responsible, salivary-gland extracts from six species of hard tick and two of soft tick were prepared and used as allergens/antigens in skin-prick tests and serological analyses. For each case, the results of the skin tests were positive for several species of hard tick but negative for the soft ticks. ELISA and western blots revealed high titres of IgG against hard ticks (but not soft ticks) in the sera from both cases. However, serum from only one of the cases was found to be ELISA- and western-blot-positive for tick-specific IgE. Accordingly, the anaphylaxis seen in one case was IgE-mediated whereas that in the other case appeared to be IgE-independent. In both cases, most of the tick-specific antibodies only recognized carbohydrate epitopes. High levels of cross-reactivity between the salivary-gland extracts from several species of hard tick made it impossible to identify which species was responsible for each anaphylactic reaction, although the immunological results seem to point to Ixodes ricinus.

[Preventive measures for allergic diseases]

Allergic diseases, particularly asthma and asthma equivalents, are among the most frequent disorders seen in the pediatric clinic. Approximately 25% of children from developed countries have presented wheezing in recent years, and half of these children later experience major asthma attacks. Likewise, 25% of children between 8 and 11 years have at some time used beta agonists and at least 10% of them use preventive asthma medication. Prevention measures for allergic asthma include: 1) avoiding allergic sensitization; 2) avoiding the presentation of disease in sensitized patients; and 3) preventing symptoms after the disease has appeared. Allergic diseases have a multifactorial origin that includes genetic, perinatal, and specific and non-specific environmental factors. From a genetic point of view, asthma is a multifactorial and heterogeneous pathology with a variable degree of penetration and phenocopy. Allergy is more frequent among the offspring of atopic parents. Genetic variations in different chromosomes affect molecules and receptors involved in atopy: IgE elevation, Fce1 receptor and chromosome 11; IL-4 and chromosome 3; gamma interferon and chromosome 12; TcR a/d receptor and chromosome 14; TcR-beta and chromosome 7; and the main histocompatibility complex HLA I and II and chromosome 6. Likewise, it has been confirmed that genetic variants affect structures in the impact organs, such as the beta 2 receptors of IL-4 soluble receptors, which favor bronchial hyperreactivity. Recently, somatometric measures have been related (low weight and large head circumference at birth) with a later increase in IgE and the occurrence of asthma. The environmental factors most closely involved in the occurrence of asthma are: diet (early exposure to sensitizing foods); domestic, outside, and occupational seroallergens; pollution (particularly smoking and urban and industrial pollution); and infections, particularly viral infections. In the present study, the methods used for the early identification of children at risk are evaluated, as well as the role of the primary care pediatrician in the early detection of allergic children and the interventions that they carry out. Finally, an analysis is made of the preventive measures that should be taken in children at risk of allergic disease, particularly: 1) increasing awareness of health, 2) reduction of exposure to smoking. 3) reduction of urban and industrial pollution, 4) delayed introduction of certain foods, reduction in the level of domestic allergens, 6) control of infections, and 7) pharmacological measures designed to prevent the occurrence of asthma in children.

Hypersensitivity to latex, chestnut, and banana

The incidence of latex-allergic patients is probably higher than suspected. A spectrum of IgE-dependent allergic reactions to latex products including urticaria, rhinitis, asthma, angioedema, and life-threatening anaphylaxis has been increasingly reported in recent years. We describe three patients with rubber hypersensitivity and allergy to fruit (banana and chestnut). Immediate positive responses were obtained in prick tests with latex, banana, and chestnut extracts. Histamine release was positive and specific IgE antibodies to all three extracts were detected by fluorescence radioimmunoassay. In the RAST-inhibition studies, the extract of latex inhibited the binding of chestnut and banana, but chestnut and banana extracts did not inhibit the binding of latex. These results suggest a sensitivity to crossreacting antigens in latex allergy associated with allergy to certain fruits.