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Biomedical subjects

B E García

Publications and source records attributed to B E García.

At least 19 recordsLinked to original sources
PubMed2000

Identification of allergens involved in occupational asthma due to carmine dye.

BACKGROUND: Carmine has been implicated as an etiologic agent of occupational asthma, but the allergens involved have not been yet identified. OBJECTIVE: To identify the allergens involved in occupational asthma due to carmine dye. METHODS: An in vitro study based in SDS-PAGE and IgE immunoblotting with carmine and cochineal extracts was performed. Sera from three carmine dye workers diagnosed with occupational asthma induced by carmine dye and from seven nonatopic subjects were used. RESULTS: Three proteins of around 30, 28, and 17 kD in raw cochineal extract and another protein of 50 kD in the boiled one were demonstrated by SDS-PAGE. Two proteins of around 50 and 28 kD were observed in the carmine extract by the same technique. Specific IgE binding bands at 17 kD in cochineal raw extract, at 50 kD in the boiled one, and at 28 kD in carmine extract were demonstrated by IgE immunoblotting. CONCLUSIONS: We have identified three allergens of around 17, 28, and 50 kD implicated in occupational asthma of three carmine workers.

Asthma↗
PubMed2000

Airway inflammation in asthma and perennial allergic rhinitis. Relationship with nonspecific bronchial responsiveness and maximal airway narrowing.

BACKGROUND: Eosinophilic airway inflammation is the hallmark of asthma, but it has also been reported in other conditions such as allergic rhinitis. We have tested whether the analysis of cells and chemicals in sputum can distinguish between patients with mild allergic asthma, those with allergic rhinitis, and healthy controls. The relationship between inflammation markers in sputum and nonspecific bronchial hyperresponsiveness to methacholine (BHR) (PD20 and maximal response plateau [MRP] values) was also evaluated. METHODS: We selected 31 mild asthmatics and 15 rhinitis patients sensitized to house-dust mite. As a control group, we studied 10 healthy subjects. Every subject underwent the methacholine bronchial provocation test (M-BPT) and sputum induction. Blood eosinophils and serum ECP levels were measured. Sputum cell differentials were assessed, and eosinophil cationic protein (ECP), tryptase, albumin, and interleukin (IL)-5 levels were measured in the entire sputum supernatant. RESULTS: Blood eosinophils and serum ECP levels were higher in asthma patients and rhinitis than in healthy controls, but no difference between asthma patients and rhinitis patients was found. Asthmatics had higher eosinophil counts and higher ECP and tryptase levels in sputum than rhinitis patients or control subjects. Sputum albumin levels were higher in asthmatics than in controls. Rhinitis patients exhibited higher sputum eosinophils than healthy controls. An association between sputum eosinophil numbers and MPR values (r= -0.57) was detected, and a trend toward correlation between sputum ECP levels and PD20 values (r= -0.47) was found in the rhinitis group, but not in asthmatics. No correlation between blood eosinophilic inflammation and lung functional indices was found. CONCLUSIONS: Induced sputum is an accurate method to study bronchial inflammation, allowing one to distinguish between rhinitis patients and mildly asthmatic patients. The fact that no relationship was detected between sputum inflammation and BHR suggests that other factors, such as airway remodeling, may be at least partly responsible for BHR in asthma.

Adolescent↗
PubMed2000

Effect of current exposure to Der p 1 on asthma symptoms, airway inflammation, and bronchial hyperresponsiveness in mite-allergic asthmatics.

The existence of a dose-response relationship between indoor allergen exposure and sensitization has been widely described, but the effect of allergen exposure on asthma activity (symptoms, bronchial hyperresponsiveness [BHR], and inflammation) is not clear. Our aim was to determine the existence of an association among current exposure to mite allergens and symptoms, BHR, and airway inflammation assessed in blood and sputum from asthmatic patients sensitized to Dermatophagoides pteronyssinus. We selected 31 mild and recently diagnosed (12-24 months) asthma patients sensitized to D. pteronyssinus. Allergenic exposure (Der p 1, Der 2) was assessed by a commercial assay based on monoclonal antibodies (mAb), carried out on the dust samples collected from patients' beds in a standardized way. Patients completed an asthma symptom questionnaire and underwent skin tests, methacholine bronchial challenge, and sputum induction. Sputum cell profile was analyzed and eosinophil cationic protein (ECP), tryptase, albumin, and interleukin(IL)-5 levels were quantified in sputum supernatant. Total eosinophil numbers and ECP levels were measured in blood samples. Most patients were exposed to Der p 1 levels under 2 microg/g of dust. Der p 1 exposure was higher among the subjects with positive sputum tryptase detection (P = 0.020). Der p 1 levels showed a trend toward correlation with asthma symptoms (P = 0.066, r = 0.36) and correlated with sputum tryptase levels (P = 0.032, r = 0.42). No relationship between BHR, eosinophilic inflammation, and allergenic exposure was found. Our results suggest that asthma symptoms and lung mast-cell activation are at least partially dependent on current allergen exposure. The lack of correlation between mite exposure, eosinophilic inflammation, and BHR supports the role of other factors that enhance the immunologic response initiated by allergen, increasing the activity of asthma.

Allergens↗
PubMed1998

Eosinophilic gastroenteritis and Anisakis.

BACKGROUND: The differential diagnosis of eosinophilic gastroenteritis (EG) includes, among other diseases, parasitic infections such as anisakiasis, which has acquired worldwide importance. METHODS: We reviewed all patients referred to our allergy service who had been diagnosed as having primary EG to determine the possible role of Anisakis simplex in the etiopathology of the disease. All patients (n = 10) were studied and diagnosed as having primary EG between 1989 and 1996, inclusive. Two different groups of subjects were used as controls: group A (149 subjects without digestive disorder) and group B (10 subjects with digestive disorder different from EG). Cutaneous prick tests were performed with the main foods, aeroallergens, and commercial extract of A. simplex. Total and specific serum IgE was measured in all patients. Gastric or gut histologic specimens were re-examined in five cases. RESULTS: Peripheral eosinophilia was detected in 40% of the patients with EG, and sensitization to A. simplex was detected in 80% of these. In both control groups, the rate of sensitization to A. simplex was 10%. Sensitization to A. simplex in EG patients with respect to control groups A and B showed odds ratios (OR) of 36 and 40, respectively. In one case, serialization of the histologic section allowed us to observe a whole Anisakis larva. CONCLUSIONS: Immunologic methods to detect specific antibodies against Anisakis should be used routinely before diagnosing EG as primary disorder. Preventive measures are of capital importance.

Animals↗
PubMed1996

Diversity of allergens causing occupational asthma among cereal workers as demonstrated by exposure procedures.

BACKGROUND: Occupational asthma among cereal workers is frequently due to cereals but other allergens can also be responsible. OBJECTIVE: We evaluated the allergens causing occupational asthma in the patients who had been diagnosed in our Department during the last 5 years. Specific bronchial reactivity to the implicated allergens was assessed and compared by standardized bronchial challenge. METHODS: Twenty-one patients (12 bakers, three millers and six farmers) were studied. We carried out in vivo tests (skin and challenge tests) and in vitro tests (specific IgE measurement) with cereals, enzymes, soyabean, storage mites and egg. A definitive diagnosis was established by means of specific bronchial provocation tests (BPT), except in three patients in whom it could not be carried out due to the severity of their asthma. In these cases the causative agent had to be determined by means of conjunctival challenge. RESULTS: Cereals were the main sensitizers among bakers (75%) and farmers (66%). Bakers were also sensitive to alpha-amylase (41%) and soyabean (25%), and farmers, to soyabean (33%) and storage mites (33%). Occupational asthma was due to cereals, soyabean and storage mites among millers. CONCLUSIONS: Besides cereals, other allergens such as enzymes, leguminous, egg and storage mites can be the causative agents of occupational asthma among cereal workers. Sensitization to different allergens in the different jobs is very likely due to differences in exposure.

Adult↗
PubMed1993

A prospective safety-monitoring study of immunotherapy with biologically standardized extracts.

We evaluated the safety of immunotherapy in 419 patients who attended our allergy department for treatment. They were suffering from rhinitis and asthma caused by sensitization to grass pollen or Dermatophagoides pteronyssinus. Immunotherapy was given by biologically standardized aluminum hydroxide adsorbed extracts according to a conventional schedule. Local reactions were recorded in 10.5% of the patients and systemic reactions in 4.8%. Only 0.37% of the doses administered were associated with systemic side-effects. We found that 84% of the patients who showed systemic reactions were asthmatic subjects (P < 0.01), and most of them were sensitized to D. pteronyssinus (71%). Side-effects occurred more frequently during the dose-increase period (P < 0.05). After 9482 doses had been administered, no anaphylactic shock or life-threatening reactions were registered. We believe the risk associated with immunotherapy to be drastically reduced when treatment is carefully monitored by skilled personnel. In such conditions, as shown by our study, immunotherapy is safe.

Adult↗
PubMed1991

Number of beta-receptors in patients allergic to Dermatophagoides pteronyssinus.

This study was carried out on 96 atopic patients with monosensitization against Dermatophagoides pteronyssinus and 30 control individuals. The patients were divided into 3 subgroups: 27 asymptomatic patients, 27 patients who only presented nasal symptomatology, and 27 patients with marked bronchial symptomatology. Total serum IgE, antigen-specific histamine release, and the number of beta 2-adrenergic receptors in peripheral blood lymphocytes in all patients were determined. The control group presented the highest number of beta-receptors in comparison with the bronchial symptomatic and nasal symptomatic patients. However, asymptomatic patients presented numbers of beta-receptors similar to controls, with no significant differences between both groups. No significant correlation was found between beta-adrenergic receptors and levels of total serum IgE. On the other hand, correlation between beta-receptors and specific histamine release was detected only in symptomatic nasal patients. It can be postulated that the decrease in beta-receptors is a consequence, and not the cause, of atopy.

Adult↗
PubMed1991

Number of beta-receptors in rhinitic pollinic patients.

The study was carried out on venous blood from 67 patients with seasonal rhinoconjunctivitis caused by sensitization to grass pollen and 30 control individuals. Total IgE determination, antigen-specific histamine release test against two concentrations of Phleum pratense, and quantification of beta 2-adrenergic receptor numbers in lymphocyte membrane of peripheral blood were done on all patients. Those pollinic patients who were asymptomatic at the time of the study had 500.07 +/- 237.27 receptors/cell; no significant differences were established with the control group, with 541.53 +/- 123.63 receptors/cell. However, both the control group and asymptomatic patients had receptor numbers which were significantly higher than those of symptomatic pollinic patients, with 376.81 +/- 158.65 receptors/cell (p < 0.01 and p < 0.05, respectively). The average decrease in number of receptors in symptomatic pollinic patients was 30.42% in relation to controls and 24.65% in relation to asymptomatic patients. Within the subgroup of pollinic patients, studied both in and out of season, the number of beta 2-adrenergic receptors had an average decrease of 13.22% during pollination, with 363.7 receptors/cell. Once the pollination season was over, this figure increased to 419.1 receptors/cell, establishing significant differences with p < 0.025. The number of beta 2-adrenergic receptors did not correlate with total seric IgE figures or with antigen-specific histamine release. These data indicate that the decrease of these receptors does not constitute the causal factor of atopic diseases; it seems more likely to be a consequence of the same.

Adolescent↗
PubMed1991

Study of IgE-dependent basophil releasability in allergic patients.

For this study, venous blood from 160 patients with a diagnosis of asthma and/or rhinitis was used. Histamine release test (H.R.T.) with anti-IgE at 1/5 and 1/25 dilutions and with causal antigen in the case of atopic patients (144) was carried out on all patients. Basophils from atopic patients released more histamine than those from nonatopic patients (p < 0.001). Basophils of atopic patients released more histamine with 1/5 anti-IgE dilution (p < 0.01), while non-atopic patients did so with the 1/25 dilution (p < 0.05). On grouping atopic patients according to positive or negative results in Ag-specific histamine release, 14% of patients presented negative Ag-specific H.R.T. and 85.7% of the cases did not respond to anti-IgE stimulus; this was 12% of the total number of atopics. On the other hand, 17% of the patients studied did not show positive histamine release against anti-IgE and 70.6% of them had negative Ag-specific release. As for the effect of age on IgE-dependent histamine release, the group of patients who presented greater releasability corresponded to those older than 6 years of age. The discrepancies observed between the clinical history, skin tests, serum IgE and antigen-dependent histamine release in some patients could be related to the individual basophil ability to release histamine. Therefore, this basophil releasability evaluation has an important practical application in discerning false negatives in antigen-specific H.R.T.

Adolescent↗
PubMed1989

Results of the in vitro follow-up of immunotherapy.

With the advances made in allergological diagnosis, thanks to the application of various in vitro immunological techniques, we have also learnt more about the immunological modifications produced during the course of the immunotherapy. Among the techniques which will detect immunological changes is the histamine release test, which will show a decrease in antigen-specific histamine release. On the other hand, both total IgE and IgG4 are modified in the course of this immunotherapeutic treatment.

Follow-Up Studies↗
PubMedDate not supplied

Long-term immunotherapy with an optimal maintenance dose of a standardized Dermatophagoides pteronyssinus extract in asthmatic patients.

In a previous dose-titration study of specific immunotherapy (SIT) with a Dermatophagoides pteronyssinus extract in asthmatic patients, we proposed a dose of 3.2 micrograms of Der p and 1/1.6 micrograms of Der p 2 as an optimal maintenance dose. Changes presented by a high-dose immunotherapy group, with a maximum tolerated dose between 4 and 16 micrograms Der p 1, were compared with those of a conventional immunotherapy group, with a maximum tolerated dose of 3.2 micrograms Der p 1 or lower. After 2 years of SIT, both groups achieved the same level of clinical benefit. We now present the results of long-term monitoring of 25 of these patients, covering the 5 years of SIT in which the maintenance dose was set at 3.2 micrograms Der p 1. The aims of the study were firstly to examine if this maintenance dose could sustain the changes induced by immunotherapy in the first 2 years; and secondly, to determine if this dose is clinically effective in patients known to tolerate higher maintenance doses. The clinical severity index (CSI), medication and symptom scores, cutaneous sensitivity and specific IgE and IgG4 to D. pteronyssinus, Der p 1 and Der p 2 were measured. Positive clinical and immunological changes presented in the first 2 years of SIT were sustained (CSI, medication score, specific IgE) or even increased (symptom score, cutaneous sensitivity) after 3 additional years of SIT. In conclusion, a maintenance dose of 3.2 micrograms of Der p 1/1.6 micrograms of Der p 2 induced intense clinical and immunological changes which were sustained during a 5-year course of treatment, even in patients able to tolerate higher doses.

Adolescent↗
PubMedDate not supplied

Cluster versus conventional immunotherapy in patients allergic to Dermatophagoides pteronyssinus: a controlled study of in vivo and in vitro parameters.

We designed a cluster schedule of immunotherapy for patients allergic to Dermatophagoides pteronyssinus which showed good safety and clinical efficacy. Here we compare the in vivo and in vitro changes with those of a conventional schedule in a controlled trial. Sixty-three patients were randomized as follows: 29 were treated with the cluster schedule, 15 with a conventional schedule and 19 received no immunotherapy. A standardized extract was used. Changes in in vivo parameters (skin prick test and conjunctival provocation test) and in in vitro parameters (IgE, IgG, IgG1 and IgG4 for the complete extract, Der p 1 and Der p 2) were measured before immunotherapy (T0), on reaching maintenance phase (T1), and after 6 (T2), 12 (T3) and 18 months of maintenance (T4). Cutaneous reactivity showed a significant decrease from T1 in both the cluster and conventional schedules, and conjunctival reactivity was also significantly lowered from T1 in these groups. Specific IgE decreased and specific IgG, IgG1 and IgG4 increased significantly from T1 in the cluster and conventional schedules. Neither of these parameters showed any changes in the group without immunotherapy. In conclusion, our cluster schedule induced changes in cutaneous and conjunctival reactivity and in immunological parameters that were similar to those achieved with the conventional schedule; these changes did not appear in patients who did not undergo immunotherapy.

Adolescent↗
PubMedDate not supplied

Dermatophagoides pteronyssinus cluster immunotherapy. A controlled trial of safety and clinical efficacy.

We designed a cluster schedule of immunotherapy for patients allergic to Dermatophagoides pteronyssinus to reach the maximal recommended dose in 7 weeks. We compared its safety and clinical efficacy with those of a conventional schedule in a controlled trial. Sixty-three patients were randomized as follows: 29 were treated with the cluster schedule, 15 with a conventional schedule and 19 without immunotherapy. A standardized extract was used. Clinical efficacy was measured by visual analog scale, clinical severity score, symptom/medication diary cards and control of peak expiratory flow (PEF) in asthmatic patients, before immunotherapy (T0), on reaching the maintenance phase (T1), and after 6 (T2), 12 (T3) and 18 months of maintenance (T4). The safety of immunotherapy was found to be good. Visual analog scale improved significantly at T4 in the cluster and conventional schedules, and clinical severity score also improved from T1 in these schedules. Diary cards improved from T1 in the cluster schedule and from T2 in the conventional schedule in asthmatic patients. Significant improvements in diary cards in rhinitis patients and PEF were found only in the cluster schedule. There were no changes in the group without immunotherapy. In conclusion, our cluster schedule showed as good tolerance and clinical efficacy as the conventional schedule in patients allergic to D. pteronyssinus. These clinical improvements did not appear in the group without immunotherapy.

Adolescent↗