Performance of different in vitro techniques in the molecular diagnosis of peanut allergy

INTRODUCTION

Peanut allergy is an increasingly serious disorder with a heterogeneous pattern of sensitization across different countries. In vitro diagnostic techniques may help in establishing these patterns.

OBJECTIVES

To analyze the usefulness of determining specific immunoglobulin E (sIgE) with the ImmunoCAP fluorescence enzyme immunoassay (FEIA), the ImmunoCAP ISAC CRD103 microarray (ISAC), and the basophil activation test (BAT) in the molecular diagnosis of peanut allergy.

METHODS

In 26 peanut-allergic patients, sIgE antibodies against allergic components were measured with FEIA, ISAC, and BAT.

RESULTS

The major peanut component in our population wasAra h 9.The detection of sIgE toAra h 9 using FEIA and BAT with this allergen yielded a sensitivity of 92% and 88% and a specificity of 95% and 100%, respectively. Overall diagnosis of peanut allergy by ISAC showed a sensitivity of 11% but a specificity of 95% since Ara h 9 was not present in the microarray version used. There was diagnostic agreement between the 3 techniques for the peanut allergens studied.

CONCLUSIONS

The determination of sIgE to Ara h 9 using FEIA and BAT offers high sensitivity and specificity in the diagnosis of peanut allergy in the Spanish population. The CRD103 version of ISAC is not of value in our region as it does not include the most common allergen, Ara h 9.

Functional analysis of Plasmodium vivax VIR proteins reveals different subcellular localizations and cytoadherence to the ICAM-1 endothelial receptor

The subcellular localization and function of variant subtelomeric multigene families in Plasmodium vivax remain vastly unknown. Among them, the vir superfamily is putatively involved in antigenic variation and in mediating adherence to endothelial receptors. In the absence of a continuous in vitro culture system for P. vivax, we have generated P. falciparum transgenic lines expressing VIR proteins to infer location and function. We chose three proteins pertaining to subfamilies A (VIR17), C (VIR14) and D (VIR10), with domains and secondary structures that predictably traffic these proteins to different subcellular compartments. Here, we showed that VIR17 remained inside the parasite and around merozoites, whereas VIR14 and VIR10 were exported to the membrane of infected red blood cells (iRBCs) in an apparent independent pathway of Maurer's clefts. Remarkably, VIR14 was exposed at the surface of iRBCs and mediated adherence to different endothelial receptors expressed in CHO cells under static conditions. Under physiological flow conditions, however, cytoadherence was only observed to ICAM-1, which was the only receptor whose adherence was specifically and significantly inhibited by antibodies against conserved motifs of VIR proteins. Immunofluorescence studies using these antibodies also showed different subcellular localizations of VIR proteins in P. vivax-infected reticulocytes from natural infections. These data suggest that VIR proteins are trafficked to different cellular compartments and functionally demonstrates that VIR proteins can specifically mediate cytoadherence to the ICAM-1 endothelial receptor.

Is it necessary to treat all asthmatic children with raised levels of exhaled nitric oxide?: treating the patient or the data

BACKGROUND

The aim of the present study is to assess whether a single determination of the fraction of exhaled nitric oxide (FENO), added to the measurements usually taken during a routine checkup, helps in the prediction of the recurrence of asthma attacks in controlled patients who are not receiving any baseline treatment; and whether or not treatment of the said latent inflammation is appropriate.

METHODS

Observational study of prospective cohorts. Over a period of three months, data was collected from 28 patients (6 to 14 years) who met the conditions of the inclusion criteria, with a follow up appointment after six months.

RESULTS

Patients were divided into two groups: 13 with FENO values of 49 and over, and 15 with values of under 49. Five patients in the subgroup with low FENO values suffered recurrence, in contrast to only one in the group with high values. The positive predictive value of the high values of the FENO was 7.69, with no significant differences between the two groups.

CONCLUSIONS

Certain doubts were raised about the usefulness of the FENO, as opposed to the traditional methods of asthma control with regard to the therapeutic management of clinically controlled patients who are not receiving treatment and who have high FENO values. It would appear unwise to recommend the systematic treatment of patients with high FENO values, when measured during a routine check-up, in cases of asthma with an allergic component and are asymptomatic or in a phase of asthma under good control.

The effect of spontaneous breathing on systemic interleukin-6 during ventilator weaning

During the weaning process, spontaneous breathing trials (SBTs) involve cardiopulmonary stress for ventilated patients. As interleukin (IL)-6 is a major modulator of the stress response, we hypothesised that systemic IL-6 increases during a SBT and that this increase is more evident in SBT failure. 49 SBTs of 30-min duration were performed on different mechanically ventilated patients, and classified as SBT failure or success. Blood samples were drawn before and at the end of the SBT. An additional sample was drawn 24 h later in a subset of patients (n = 39). Serum IL-6 levels and other inflammatory mediators commonly associated with stress were determined. IL-6 levels increased from mechanical ventilation to spontaneous breathing in all patients (p = 0.02) and in the chronic obstructive pulmonary disease (COPD) population (p = 0.05) with SBT failure compared with success, but not in non-COPD patients (p = 0.12). After 24 h of SBT stress, IL-6 levels decreased in patients with SBT failure (under mechanical ventilation at that point) (p = 0.02) and those with weaning success (p = 0.04). No changes were observed in the remaining inflammatory mediators. Systemic IL-6 increases during a 30-min, failed SBT, especially in COPD patients. Future studies may corroborate the different IL-6 responses among different populations who initiate weaning, together with the potential clinical implications.

Properties of the COPD assessment test in a cross-sectional European study

A short, easy-to-use health status questionnaire is needed in the multidimensional assessment of chronic obstructive pulmonary disease (COPD) in routine practice. The performance of the eight-item COPD assessment test (CAT) was analysed in 1,817 patients from primary care in seven European countries. The CAT has a scoring range of 0-40 (high score representing poor health status). Mean CAT scores indicated significant health status impairment that was related to severity of airway obstruction, but within each Global Initiative for Obstructive Lung Disease stage (I to IV) there was a wide range of scores (I: 16.2 ± 8.8; II: 16.3 ± 7.9; III: 19.3 ± 8.2; and IV: 22.3 ± 8.7; I versus II, p = 0.88; II versus III, p<0.0001; III versus IV, p = 0.0001). CAT scores showed relatively little variability across countries (within ± 12% of the mean across all countries). Scores were significantly better in patients who were stable (17.2 ± 8.3) versus those suffering an exacerbation (21.3 ± 8.4) (p<0.0001); and in patients with no (17.3 ± 8.1) or one or two (16.6 ± 8.2) versus three or more (19.7 ± 8.5) comorbidities (p<0.0001 for both). The CAT distinguished between classes of other impairment measures and was strongly correlated with the St George's Respiratory Questionnaire (r = 0.8, p<0.0001). The CAT is a simple and easy-to-use questionnaire that distinguishes between patients of different degrees of COPD severity and appears to behave the same way across countries.

Effect of antihistamine up-dosing in chronic urticaria

Chronic urticaria has an important impact upon patient quality of life, and no treatment has yet been developed capable of effectively controlling the disease. The most recent guidelines recommend the use of non-sedating antihistamines at high doses as second-step therapy before resorting to other treatments. The present review examines the studies published to date on the use of H1 antihistamines at doses higher than those indicated as therapeutic doses in chronic urticaria. Most of the studies report no significant differences among the studied doses-only a tendency towards increased response on elevating the dose. There are no clinically well designed, randomized double-blind trials comparing efficacy between therapeutic doses and doses higher than those indicated in the corresponding Summary of Product Characteristics. Likewise, there are insufficient data to conduct a meta-analysis and thus classify the degree of evidence of the few available studies, which moreover present contradictory results. At present, the prescription of high-dose H1 antihistamines is based only on experts opinion. However, considering the high safety profile of these drugs, it would be a good option to evaluate their efficacy at high doses, before moving on to other therapeutic steps.

Effect of bilastine upon the ocular symptoms of allergic rhinoconjunctivitis

Ocular symptoms often accompany allergic rhinitis and can be as or even more bothersome for the patient than the actual nasal symptoms. Ocular manifestations of allergic rhinoconjunctivitis may result from both direct allergen-mediated mast cell stimulation on the surface of the eye and naso-ocular reflexes--histamine being one of the mediators of symptoms onset. An H1 antihistamine would be the first line treatment for allergic conjunctivitis. Since allergic conjunctivitis is always (or almost always) accompanied by nasal symptoms, a second-generation H1 antihistamine administered via oral route is the drug of choice for jointly managing both the nasal and the ocular symptoms--minimizing the impact of the effects inherent to first-generation H, antihistamine, including particularly drowsiness. Bilastine is a new H1 antihistamine with an excellent safety profile, developed for the treatment of allergic rhinoconjunctivitis and urticaria, with potency similar to that of cetirizine and desloratadine, and superior to that of fexofenadine. This new drug has been shown to be effective in controlling the ocular symptoms of allergic rhinoconjunctivitis.

Bilastine and the central nervous system

Antihistamines have been classifed as first or second generation drugs, according to their pharmacokinetic properties, chemical structure and adverse effects. The adverse effects of antihistamines upon the central nervous system (CNS) depend upon their capacity to cross the blood-brain barrier (BBB) and bind to the central H1 receptors (RH1). This in turn depends on the lipophilicity of the drug molecule, its molecular weight (MW), and affinity for P-glycoprotein (P-gp) (CNS xenobiotic substances extractor protein). First generation antihistamines show scant affinity for P-gp, unlike the second generation molecules which are regarded as P-gp substrates. Histamine in the brain is implicated in many functions (waking-sleep cycle, attention, memory and learning, and the regulation of appetite), with numerous and complex interactions with different types of receptors in different brain areas. Bilastine is a new H1 antihistamine that proves to be effective in treating allergic rhinoconjunctivitis (seasonal and perennial) and urticaria. The imaging studies made, as well as the objective psychomotor tests and subjective assessment of drowsiness, indicate the absence of bilastine action upon the CNS. This fact, and the lack of interaction with benzodiazepines and alcohol, define bilastine as a clinically promising drug with a good safety profile as regards adverse effects upon the CNS.

A new rapid desensitization protocol for chemotherapy agents

BACKGROUND

Desensitization has been used for some decades to treat patients with the allergenic drug when an alternative drug with similar efficacy and safety is not available. We present the results from a series of oncology patients desensitized at our hospital during the last 2 years.

OBJECTIVE

To assess the efficacy of a new desensitization protocol in patients allergic to chemotherapy drugs.

METHODS

We performed an observational retrospective study of 11 women (6 breast cancer and 5 ovarian cancer) who underwent our desensitization protocol. Four patients had immediate reactions to carboplatin, 3 to docetaxel, 3 to paclitaxel, and 1 to both docetaxel and paclitaxel. Premedication was administered in all cases. A 5-step protocol based on 5 different dilutions of the drugs was used.

RESULTS

We performed 39 desensitization procedures: 14 to carboplatin, 3 to oxaliplatin, 16 to docetaxel, and 6 to paclitaxel. Eight patients tolerated the full dose in 36 procedures. One patient suffered an anaphylactic reaction to carboplatin that reverted with treatment. One patient had dyspnea after a paclitaxel cycle. One patient experienced dyspnea due to chronic pulmonary thromboembolism related to her disease.

CONCLUSION

Desensitization is a useful procedure in patients who are allergic to their chemotherapy agents.

Effect of bilastine upon nasal obstruction

H1 antihistamines constitute one of the main references for the treatment of allergic rhinitis. Classically, these drugs have been considered effective in controlling sneezing, rhinorrhea and itching, though they have not been regarded as particularly effective in application to nasal obstruction. The most recent studies, involving second-generation H1 antihistamines (desloratadine, fexofenadine, levocetirizine, rupatadine), have shown these drugs to offer effects upon nasal obstruction significantly superior to those of placebo. The present review examines the effect of bilastine, a new, potent and highly specific H1 antihistamine without sedative effects or cardiac toxicity, upon nasal obstruction. The analysis of the data from the different clinical trials indicates that in patients with allergic rhinitis, the effect of bilastine upon nasal obstruction is superior to that of placebo and similar to that of other second-generation H1 antihistamines, manifesting within 24 hours after the start of treatment.

Placebo effect in clinical trials involving patients with allergic rhinitis

Interest in understanding the underlying mechanisms of the placebo effect has considerably grown during the last few decades. Studies made in this sense have led to a change in the conception of this peculiar phenomenon, and nowadays the placebo effect is viewed as a psychobiological event resulting from the interaction between individual patient factors and factors relating to the physician and the therapeutic environment. Investigation of the placebo effect in disease conditions such as pain or Parkinson's disease has improved our understanding of its underlying psychological and neurobiological mechanisms. Clinical studies directly designed to investigate the placebo effect have shown placebo to have a more beneficial effect upon diseases evaluated by means of physical or subjective parameters than by means of biochemical parameters. A strong placebo effect has been observed in allergic diseases, where the evaluating parameters tend to be physical or subjective. Biomedical research and the development of new drugs implies an important investment of human and economical resources for conducting clinical trials designed to evaluate the efficacy and safety of new medications. Knowledge of the mechanisms of the placebo effect and how the latter can influence the results of the different efficacy variables in these research studies appears essential in order to optimize the available resources in application to the development of new drugs.

Bilastine and quality of life

The evaluation of quality of life (QoL) and its modification through therapeutic interventions has become a prioritary concern in recent years and a requirement on the part of regulatory agencies for the authorization of new drugs. In clinical studies of allergic disorders, particularly allergic rhinitis and urticaria, different types of generic questionnaires have been used - especially disease specific instruments such as the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) or skin disease specific tools such as the Dermatology Life Quality Index (DLQI). Throughout its clinical development, bilastine has been shown to be more effective than placebo and at least as effective as cetirizine, levocetirizine, fexofenadine or desloratadine in controlling the symptoms of seasonal allergic rhinitis and chronic urticaria. QoL has been studied as a secondary objective in three allergic rhinitis clinical trials, using the RQLQ, in a total of 2335 patients. Likewise, in chronic urticaria, QoL has been evaluated using the DLQI in a total of 525 patients, versus levocetirizine and placebo. The improvement in the QoL parameters in these studies (RQLQ or DLQI domains) at all times proved proportional to the symptoms improvement. In general, the data obtained relating to changes in QoL are concordant with the mean global visual analog scale (VAS in mm) values and their changes, from the beginning until the end of the treatment period, for all of the trials, for bilastine and all its comparators.

Discrimination between moderate and severe disease may be used in patients with either treated or untreated allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a common disease with major socioeconomic burden and a significant impact on quality of life.

OBJECTIVE

  The aim of this study was to discriminate between moderate and severe AR patients whether receiving treatment or not, using a modified criterion of allergic rhinitis and its impact on asthma (ARIA) classification.

METHODS

The modified ARIA severity classification (J Allergy Clin Immunol, 120, 2007, 359) categorizes AR as mild (no items affected), moderate (1-3 items affected), and severe (all four items affected). We applied these criteria to 1666 treated and 1058 untreated AR patients and compared their symptoms total four-symptom score (T4SS) and quality of life (ESPRINT-15), according to their clinical severity.

RESULTS

Allergic rhinitis clinical status was significantly worse (P < 0.001) in treated than in untreated patients. For both treated and untreated patients, T4SS and ESPRINT-15 Quality of life scores were significantly worse (P < 0.001) in severe than in moderate patients.

CONCLUSIONS

The modified ARIA severity classification is a useful clinical tool to discriminate moderate from severe AR among both treated and untreated patients.

Health-related quality of life in patients by COPD severity within primary care in Europe

Pan-European data on health-related quality of life (HRQL) in chronic obstructive pulmonary disease (COPD) are lacking. This cross-sectional epidemiological study evaluated health status in 1817 COPD patients from an 'all-comers' primary care population in seven European countries (87% stable disease; 13% with current exacerbation) using: St George's Respiratory Questionnaire-COPD specific (SGRQ-C), the short form health survey (SF-12) and the Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue scale. Mean total score for SGRQ was 44.7 ± 19.4 showing marked impairment of HRQL. Scores differed little between countries (range 39.2-50.1). Impairment was associated with the severity of airway obstruction, but within each GOLD stage the variation (SD) was wide [Stage I: 38.5 ± 19.3 (n = 223); Stage II: 40.4 ± 18.1 (n = 868); Stage III: 50.2 ± 18.6 (n = 551); Stage IV: 58.6 ± 17.7 (n = 144)]. Patients suffering an exacerbation had a worse SGRQ score (54.9 ± 19.3) than those with stable disease (43.3 ± 19.0). The presence of ≥3 co-morbidities (CM) was also associated with a significantly worse score (49.9 ± 19.1) vs. 1-2 CM (42.1 ± 19.1) or no CM (42.3 ± 18.6). Findings with the SF-12 and FACIT-F results were consistent with those from the SGRQ-C. This large observational primary care study shows that health status is significantly impaired in COPD patients of all severities, even in those with mild airway obstruction. Within each GOLD stage of severity there is considerable heterogeneity in HRQL impairment among patients. (Study number: 111749).