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Biomedical subjects

A I Tabar

Publications and source records attributed to A I Tabar.

At least 55 records · Page 3Linked to original sources
PubMed1993

Occupational asthma and contact urticaria from dried flowers of Limonium tataricum.

Dried flowers of Limonium tataricum (LT) are widely used for semipermanent floral arrangements. We report a case of a floral industry worker in whom exposure to LT precipitated rhinoconjunctivitis, asthma, and contact urticaria. Studies revealed the presence of immediate skin test reactivity and positive leukocyte histamine release in response to LT extract. Specific anti-LT antibodies were detected in the patient's serum by direct RAST. Bronchial challenge with LT extract also resulted in an isolated immediate asthmatic response. Both the positive methacholine inhalation test and the significant changes observed in PEFR measurements when the patient handled LT supported the diagnosis of occupational asthma. These findings strongly suggest that an IgE-mediated immunologic mechanism is responsible for the patient's respiratory and cutaneous symptoms.

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↗
PubMedDate not supplied

[Treatment perspectives: immunotherapy with latex].

Latex allergy currently constitutes a serious problem because of the severity of its symptoms and the at-risk groups it affects. Since complete avoidance of this substance is practically impossible, in the last few years intense efforts have been made to standardize a latex extract with the aim not only of improving clinical diagnosis but also of being able to offer other therapeutic alternatives, such as specific immunotherapy.Since 1998, reports of immunotherapy with oral (three patients) subcutaneous (one patient) and sublingual latex desensitization (one patient) have been published. In all cases, clinical improvement was evident. In 2000, Laynadier published the first pilot study, a phase IIB multicenter, randomized, double-blind, placebo-controlled trial that evaluated the efficacy and safety of specific immunotherapy with latex in patients with occupational allergy. Twenty health care workers without obvious latex exposure and with latex allergy-induced symptoms of rhinitis and/or asthma were included. Treatment started with a 2-day course of rush immunotherapy in hospital and maintenance therapy was continued for 1 year. Efficacy was assessed by symptom and medication scores and by variation in the conjunctival reactivity threshold. The safety of the extract was also evaluated. In the overall analysis of symptom score, the treated group showed a marked improvement and the medication score was significantly lower in patients in the active treatment group than in the placebo group. Concerning safety, almost half the patients receiving active treatment showed local reactions starting with the first injection and four of the nine patients in this group suffered moderate-to-severe systemic reactions. In view of this first clinical trial, it can be concluded that this treatment is effective but that its tolerance is low.A second clinical trial with the same characteristics and extract is currently underway. Its aim is to validate the previous protocol, confirm the efficacy of specific immunotherapy with latex, improve its safety and, if possible, determine the optimal dose.J. Sastre et al. have recently (Formigal 2002) presented the results of the first double-blind study with latex immunotherapy using an extract standardized by the ALK-Abelló-España group. The authors included 24 patients with latex sensitization and symptoms of occupational allergy. To diagnose respiratory allergy, an inhalation challenge was performed in a closed 7-m2 chamber and, in case of contact urticaria, glove-wearing and rubbing tests were performed, using a vinyl glove as negative control. Treatment consisted of a first phase of incremental doses for 14 weeks, with 18 injections, followed by maintenance doses for 6 months. Sixteen patients received active treatment and 8 received placebo. Of the 578 doses administered, adverse effects were observed in 41 (7.1 %). There were 21 immediate systemic reactions (5.7 % of the doses) and 10 delayed systemic reactions (2.6 % of the doses). Adverse effects were more frequent in patients with underlying respiratory disease (p < 0.05). After 6 months' treatment, a clear improvement in the cutaneous response index was found in the active treatment group and in the rubbing and glove-wearing tests. The authors conclude that the immunotherapy tested was a high-risk treatment and that the greatest clinical improvement was found in cutaneous symptoms.In conclusion, although effective, latex immunotherapy is currently a high-risk treatment.

Desensitization, Immunologic↗
PubMedDate not supplied

[Sublingual immunotherapy in children. Immunotherapy Committee of the Spanish Society for Clinical Immunology and Pediatric Allergology].

Sublingual immunotherapy is currently attracting growing interest because of its ease of administration and, according to previous studies, its infrequent and mild adverse effects. However, at least in children, the efficacy of this therapy has not been completely demonstrated. In addition, the mechanisms of action remain to be elucidated since few studies have been published and the results have been contradictory and sometimes inconclusive. For this reason, we performed a literature review through the MEDLINE database, selecting double-blind studies carried out in children. Only 10 studies meeting these requirements were retrieved. All the studies were performed by European researchers and nine were published in European journals. Efficacy was evaluated by clinical parameters and by reduction in medication use. The results on efficacy are not homogeneous, although most support the utility of this route of administration. Moreover, reports of allergens other than those used in these studies dust mites and grass pollens are lacking. In conclusion, further studies evaluating the efficacy of this therapy in children are required. Among the general population, if the efficacy of sublingual immunotherapy in the treatment of sensitization to hymenoptera venoms were demonstrated, as has been the case with subcutaneous immunotherapy, the utility of this route of administration would be definitively confirmed. Finally, sublingual immunotherapy could be used in children who have shown systemic reactions to subcutaneous immunotherapy or who refuse to undergo injections.

Administration, Sublingual↗
PubMedDate not supplied

Evaluation of paediatric tolerance to an extract of Alternaria alternata under two treatment regimes. A multicentre study.

In order to evaluate the efficacy and safety of an extract of Alternaria alternata in a paediatric population, a two phase study plan has been elaborated that in the first place consists of a retrospective analysis of tolerance under the standard treatment regimes used by the clinical groups involved. This was achieved by analysing the records of 94 patients that have been treated with this extract, these being consecutive patients included at 7 clinics over a period of 6 months. Two regimes were used: a conventional short regime of 7 doses and a cluster regime. Under neither of these two regimes were any serious reactions registered. The percentage of local reactions was significantly greater using the short conventional regime than with the cluster regime (1.9% and 0.4% respectively, p = .035). In contrast, no significant differences were observed with respect to the systemic reactions (0.5% and 1.2%), these percentages also being similar to those registered with other extracts in which identical regimes have been used. In conclusion, we can confirm that a very satisfactory tolerance profile was observed, with the advantage that through using shorter regimes than the conventional regime of 13 doses, a considerable saving is made both in the number of visits and the doses necessary to reach the maintenance dose.

Adolescent↗
PubMedDate not supplied

[The study of the inflammation of the airway in bronchial asthma by cytological and chemical analysis in the fluid phase of samples taken by sputum induction].

In recent years the study of samples of bronchial biopsies and bronchoalveolar lavage fluid has made it possible to show the existence of significant airway mucosal inflammation, even in cases of mild bronchial asthma. This has led to a renewed interest in the use of sputum to assess airway inflammation non-invasively. Sputum induction has recently been proposed as a non-invasive alternative to bronchoscopy for the collection of airway secretions from asthmatic subjects. Sputum induction yields satisfactory samples of sputum in the great majority of asthmatic subjects, and both differential cell counts and the measurement of molecular markers of inflammation in the sputum fluid phase are feasible. In this paper we review studies where these measurements have been taken from subjects who were asthmatic, affected by other respiratory pathologies or healthy, and we assess their validity. Finally, we consider possible future clinical applications of sputum measurement of airway inflammation in asthma.

English Abstract↗
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↗
PubMedDate not supplied

Tolerance of immunotherapy with a standardized extract of Alternaria tenuis in patients with rhinitis and bronchial asthma.

We studied the safety of immunotherapy with an Alternaria extract in patients with rhinitis and bronchial asthma. The few studies that have investigated immunotherapy with mold allergens suggest that they cause adverse reactions more frequently than do other extracts. All treatments prescribed by our allergology service with Alternaria immunotherapy between 1988 and 1996 were recorded and analyzed. In all cases a biologically standardized depot extract of Alternaria tenuis containing 5 BU/ml was used according to a conventional immunotherapy schedule. During the study period 129 patients received immunotherapy with Alternaria extract. Of the 3,892 doses given, 1.95% led to adverse reactions, which occurred in 39.5% of the patients. Most of the adverse reactions were systemic and mild, and reproduced the underlying disease. The risk of adverse reactions was significantly higher in children, patients with asthma, and during the initial phase of treatment. Patients who suffered from adverse reactions had a significantly higher level of total and specific IgE. It was concluded that tolerance of Alternaria mold extract was worse than for other allergenic extracts, although most reactions recorded were mild. The risk of adverse reactions was greater in children and patients with asthma, and during the initial phase of immunotherapy.

Adolescent↗
PubMedDate not supplied

Urticaria pigmentosa. Histaminuria and treatment.

We present the case of an adult patient with urticaria pigmentosa. The sudden presence of severe symptomatology (symptoms to mast cell mediators release), made us think of evaluating extracutaneous affection. Our results are consistent with recent reports in the medical literature. We have confirmed an increase of conjugated histamine levels (methyl-histamine) during the attack and its return to normal values after the treatment. For these reasons we comment on the importance of histamine levels in diagnosis and treatment control. The gastrointestinal biopsy suggestive of mastocytosis; the severe clinical manifestations, and the histamine metabolite levels during the clinical course, led us to include this case in the group of "indolent SMCD" according to the TRAVIS classification.

Adult↗
PubMedDate not supplied

IgE receptors (FcR epsilon) modifications. II. Effect of regulator soluble factors of human IgE synthesis, isolated in polyacrylamide gels.

In a series of works done on humans patterned after animal experimental models, we created an "in vitro" model which allowed us to produce soluble IgE regulator factors. We observed its biological activity in IgE synthesis and constructed changes that protein fractions from affinity chromatography (fractions enriched in soluble regulator IgE factors) exercised on IgE receptor expression. We then decided to determine the molecular weight of each one of the active protein fractions. We performed electrophoresis on the gel of polyacrylamide (Weber-Osborn technique). Protein bands were processed, with the aim of isolating the gel and quantifying the biological activity. The protein fractions obtained from the chromatographies with affinity to CON-A sepharose were subjected to electrophoresis in polyacrylamide gel, with the aim of obtaining molecular weights of proteins comprising it. Using rosette technique, there were no changes seen in Fc epsilon expression just as what happened in the experiment with material fractionated by chromatography. However, these changes are produced and are statistically significant using the immunofluorescence technique. The highest inhibition of rosettes or immunofluorescence is that of the protein band of 10,000 daltons extracted in NaCl and that of 20,000 daltons extracted in PBS. Both effects are similar. The inhibition reached by the 20,000 dalton band in NaCl is less although there are no significant differences. The material extracted in PBS of the band between 6.9 and 7.2 mm of gel (G4) did not have any changes. None of the proteins added to the culture medium had any effects of receptor gamma expression. The average values of the receptor expression was similar to basal levels.

Antigens, Differentiation↗