Biomedical subjects
Publications and source records attributed to S Quirce.
A 10-year-old child with asthmatic attacks related to Lathyrus sativus flour inhalation was studied in our department. Skin test and specific bronchial provocation challenge were positive. Specific IgE antibodies to Lathyrus sativus flour was demonstrated by indirect enzyme immunoassay. We suggest that our patient's allergic symptoms were due to the development of Type I allergic reactivity to L. sativus antigens.
Occupational or professional asthma is defined as adult asthma, i.e., an inflammatory respiratory disease characterized by the presence of variable airflow limitation or bronchial hyperreactivity secondary to conditions and causes associated with a given occupational or working environment - not with stimuli found outside the workplace. Depending on the physiopathological mechanism involved, a distinction is made between immune asthma (with or without IgE mediation) and non-immune asthma. It is difficult to establish the relationship among the symptoms of asthma, the patient's professional activity and the presence or absence of sensitization to certain agents in the working environment. Guided compilation of the case history and measurement of nonspecific bronchial hyperreactivity and bronchial inflammation are currently essential in the diagnostic approach to occupational asthma. Whenever possible, allergists should establish the cause-effect relationship in occupational asthma, as required by the medical-legal and social implications of the disease. Occupational asthma remains a minority diagnosis among occupational diseases in general. Adequate personnel training and the creation of diagnostic centers may help to ensure correct and rapid detection of this disease.
Since 1979 several reports of contact urticaria due to natural latex have been documented. In recent years cases of anaphylaxis, rhinitis, and asthma due to latex have appeared. Nine patients, studied in our clinic between 1986-1991, suffered immediate allergic reactions caused by rubber products. All showed an immediate skin reaction to latex extract. Rub testing with surgical gloves was positive in eight patients. Immunological techniques (RAST, ELISA, HRT) demonstrated specific IgE against latex. Specific bronchial provocation testing was performed in one patient who presented with asthma when she used latex surgical gloves. Patch testing to common rubber additives were negative in our patients. These results suggest that natural latex antigens present in rubber objects can cause hypersensitivity reactions probably due to IgE-mediated mechanisms.
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.
The immediate skin test due to interaction between allergen and mast cell bound IgE is one of the cornerstones in the clinical allergy workup. The release of histamine and other mediators from basophils and mast cells depends on the influx of Ca2+ into these cells when stimulated. The aim of this study was to evaluate the effect of common therapeutic doses of nifedipine (NFD), one of the calcium channel blockers, on the allergen skin tests. We prick tested 23 grass sensitive individuals with 7 different grass pollens at three times: at basal conditions (T0), 30 min. after having taken 20 mg of NFD s. l. (T1), and 17 of them after a week of receiving twice a day 20 mg of a NFD retard form (T2). The wheal surface obtained for each substance (allergen, histamine) at T0 was considered as basal value and compared with the one obtained at T1 and T2 for the same substance by the Wilcoxon's test. We found a significant increase in the wheal surfaces, both with allergen and histamine, at T1 and T2. In contrast to what could be expected, common therapeutic doses of NFD produce a discrete but statistically significant increase of the PT. Factors such as arteriolar vasodilation could be implicated. The increase of the allergen prick test and the increase of the histamine prick test both at T1 and T2 were not statistically different. Therefore, we do not think it necessary to stop NFD before allergen skin testing.
Clinical characteristics of allergic asthma due to inhalation of cockroach antigens have been reported sporadically in the literature. To assess the patterns of bronchial response in cockroach asthma we performed bronchial provocation tests (BPT) with cockroach extract in 25 asthmatic patients who had positive skin test with this extract. Of 25 patients, 23 had cockroach-specific-IgE-antibodies. Seventeen subjects presented only immediate asthmatic reaction, five patients had dual response (immediate + late), and one patient developed only late asthmatic response. BPT were negative in two patients who did not have cockroach-specific-IgE-antibodies. These results indicate that BPT with cockroach antigen is a very specific test for cockroach asthma. It shows immediate, dual and late responses, and correlates well with the presence of specific IgE antibodies against this allergen.
The oral and sublingual immunotherapy is still a controversial therapeutic procedure. One of the problems is knowing how much allergenic activity could the extracts loss due to the digestive process into the mouth and stomach. Using a grass-pollen oral and sublingual immunotherapy extract, we studied its degradation until reaching the small intestine. For this purpose we employed an in vitro model using the RAST-inhibition assay. We observed a 3.8 fold loss of allergenic activity after a 30 sec-incubation with saliva; a subsequent 5 min-incubation with gastric fluid got a final loss of allergenic activity of 10.3 fold. The incubation times were those expected occurring during the ingestion of the extract. It was surprising that after the enzymatic and acid actions of the gastric fluid, an important degree of allergenic activity still remained in the extract. This issue should be taken into account when considering the dose to be administered in oral and sublingual immunotherapy.
BACKGROUND: Indoor allergens are common causes of sensitization and asthma. Climatic and home conditions can modify their levels. OBJECTIVE: We studied the influence of climatic conditions and home characteristics on the exposure to indoor allergens of mite allergic asthmatic subjects in two Spanish cities with different climates (Las Palmas and Pamplona). METHODS: We included 65 subjects diagnosed with asthma caused by Dermatophagoides pteronyssinus. A questionnaire about their dwellings was completed. Home dust samples were collected. Mite (Der p1, Der f1, Der 2) and cat (Fel d1) allergens were measured by a monoclonal-antibodies based ELISA. RESULTS: Characteristics of dwellings were similar in both areas. Der p1 was the main allergen (0-44 micrograms/g). Der p1, Der f1 and Der 2 levels were higher in the homes in Las Palmas (p < 0.001, p < 0.01 and p < 0.001, respectively). Damp homes in Pamplona had higher Der p1 levels, similar to those detected in homes in Las Palmas. Fel d1 levels (0-78.90 micrograms/g) were only related to the presence of cats in the dwelling (p < 0.001). CONCLUSIONS: D. pteronyssinus allergen exposure was influenced by climatic conditions and dampness in homes in temperate regions. Humidity in homes can generate an ideal environment for mite growth despite unfavorable outdoor climatic conditions. Fel d1 levels were only related to the presence of a cat in the house.
Reactive airways dysfunction syndrome (RADS) is a type of asthma that develops in subjects without prior pulmonary disease, following single or multiple exposure to high levels of nonimmunogenic irritants. The main difference from classic occupational asthma is the absence of a latency period. Non-specific bronchial hyperresponsiveness is characteristic of the disease and usually persists after cessation of exposure. We report the cases of two subjects in whom RADS developed after occupational exposure to irritants.