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Biomedical subjects

S Quirce

Publications and source records attributed to S Quirce.

At least 55 records · Page 3Linked to original sources
PubMed1998

T-lymphocyte responses to plicatic acid-human serum albumin conjugate in occupational asthma caused by western red cedar.

BACKGROUND: T cells are known to play a major role in the pathogenesis of atopic allergic asthma, but it is less clear whether they are involved in occupational asthma caused by low molecular weight chemicals such as plicatic acid. OBJECTIVES: We sought to determine whether peripheral blood T cells from patients with western red cedar asthma (WRCA) recognize plicatic acid (PA) conjugated to human serum albumin (HSA) as judged by proliferation or cytokine production and to analyze the response to PA inhalation with flow cytometry. RESULTS: Significant proliferative responses to PA-HSA were observed in eight of 33 patients with WRCA, none of 10 exposed nonasthmatic cedar workers, and one of 18 nonasthmatic control subjects. Two of 25 patients with WRCA also showed proliferative responses to unconjugated PA. All the WRCA responders were either currently exposed to cedar or had ceased exposure within the preceding 2 years. None of the four patients receiving oral steroids responded, but inhaled steroids did not seem to influence responsiveness. No correlations were found between the maximum stimulation response and any of the current FEV1 values, the current PC20 methacholine values, or the magnitude of the late asthmatic response to PA. Peripheral blood T-cell subset proportions and their degree of activation were similar in patients with WRCA and exposed control subjects. There was no change in T-cell phenotypes or their activation markers after PA inhalation challenge. In vitro, PA-HSA stimulation did not affect subset ratios but led to release of small amounts of IL-5 and IFN-gamma, with no detectable increase in IL-4. CONCLUSIONS: PA-HSA-specific T lymphocytes seem to be present in small numbers in the peripheral blood of patients with WRCA and may respond to antigenic exposure by producing IFN-gamma and IL-5. However, the proportion of responding cells would appear to be lower than in comparable studies of atopic asthma.

Adult↗
PubMed1998

Asthma caused by Ficus benjamina latex: evidence of cross-reactivity with fig fruit and papain.

BACKGROUND: Ficus benjamina or weeping fig is a plant used increasingly for indoor decoration that can cause allergic rhinitis and asthma. OBJECTIVE: We report a clinical and immunologic study in a patient with perennial asthma caused by F. benjamina latex in whom several episodes of angioedema of the oropharyngeal tract and tongue followed ingestion of figs and kiwi. METHODS: Hypersensitivity to latex from F. benjamina and from Hevea brasiliensis, fig fruit, kiwi, papain, and bromelain was investigated by means of skin prick test, specific IgE determination by CAP, histamine release test, and bronchial provocation test to F. benjamina latex. CAP-inhibition assays were carried out to study possible cross-reactivity among these antigens. RESULTS: Hypersensitivity to F. benjamina latex, fig, kiwi, and proteases was demonstrated by means of skin prick test, determination of specific IgE and histamine release test. Bronchial provocation test with F. benjamina latex resulted in a dual asthmatic reaction, confirming the etiologic role of this plant. A rise of eosinophil cationic protein in patient's serum was observed 21 hours after bronchial challenge, suggesting activation of eosinophils. Inhibition assays showed that F. benjamina latex as liquid-phase inhibited up to 95% the CAP to fig and up to 57% the CAP to papain. Neither sensitization nor cross-allergenicity with H. brasiliensis latex was found. CONCLUSIONS: Hypersensitivity to F. benjamina latex may cause IgE-mediated respiratory allergy. The association with allergy to fig and papain is likely due to the existence of cross-reactive allergen structures.

Adult↗
PubMed1998

Inhalant allergy to egg yolk and egg white proteins.

BACKGROUND: Several egg white and egg yolk and avian proteins have been described as a cause of inhalant allergy. Sometimes inhalational type I hypersensitivity to these proteins is associated with food allergy to egg. OBJECTIVE: We studied two patients who experienced respiratory and food allergic symptoms upon exposure to egg or avian antigens through the inhalative or digestive routes. Clinical and immunological studies were carried out in order to identify individual allergens from these sources that could be responsible for crossreactivity reactions. RESULTS: Patient 1 showed IgE sensitization to egg yolk livetins, feathers, and chicken serum. Specific bronchial challenge with chicken albumin and livetin extracts elicited a positive early asthmatic response and an increase in serum eosinophil cationic protein. Immunoblot and CAP-inhibition studies in this patient supported that chicken albumin (alpha-livetin) was the crossreactive antigen present in egg yolk and chicken serum and feathers. Patient 2 showed sensitization to egg white, ovomucoid and lysozyme. However, SDS-PAGE and immunoblot studies demonstrated contaminating lysozyme in the ovomucoid extract and identified lysozyme as the main allergen causing egg sensitization in this patient. Conjunctival challenge test confirmed allergy to lysozyme. CONCLUSION: Egg yolk and egg white proteins may act not only as ingested allergens but also as aeroallergens. Immunological studies using highly purified preparations of egg proteins are useful for the accurate diagnosis of allergic reactions to egg proteins and to identify individual allergens that may be responsible for crossreactivity reactions.

Adult↗
PubMed1998

Hypersensitivity pneumonitis due to an ultrasonic humidifier.

We describe a woman with hypersensitivity pneumonitis that was related to using a home ultrasonic humidifier. A micronodular infiltrate was seen in her chest radiograph. The inhalation challenge test was performed with the humidifier, and she exhibited a positive response. The cultures of the humidifier water grew Candida albicans, Rhodotorula spp., and Aspergillus spp. The test for precipitating antibodies against the humidifier water gave a positive response, and specific IgG, IgM, and IgA antibodies against extracts of A. fumigatus, C. albicans, and Rhodotorula spp. were demonstrated in the patient's serum by ELISA. A strong, dose-dependent inhibition of Rhodotorula IgG-ELISA by humidifier water was observed, suggesting that Rhodotorula might be the cause of hypersensitivity pneumonitis in this patient.

Adult↗
PubMed1998

Eosinophilic lung disease associated with Candida albicans allergy.

A significant number of cases of chronic eosinophilic pneumonia remain idiopathic in spite of a comprehensive search of associated causes. This study reports a patient with a classical clinical presentation of chronic eosinophilic pneumonia and peripheral blood eosinophilia in whom selective sensitization to Candida albicans was demonstrated. This yeast was present in the bronchoalveolar lavage culture and specific serum immunoglobulin (Ig)E and IgG against C. albicans were found in the patient's serum. Levels of these specific immunoglobulins diminished with corticosteroid treatment and increased coinciding with a new outbreak of symptoms after lowering the dosage of corticosteroids. To the author's knowledge, this is the first case described of chronic eosinophilic pneumonia associated with sensitization to C. albicans. Evaluation of allergy to C. albicans should be performed in chronic eosinophilic pneumonia before labelling cases as idiopathic.

Adult↗
PubMed1997

Laboratory and clinical evaluation of a portable computerized peak flow meter.

A mini-Wright based peak flow meter (VMX Mini-Log), which stores the readings together with the time and date of each measurement, has recently been marketed but has not yet been evaluated. The accuracy, reproducibility, and interdevice variability of this instrument were investigated using a pneumotachograph connected in series as a standard. Flows from 100 to 700 L/min were generated by an explosive decompression chamber. The performance of this instrument was also tested in 20 normal subjects and in 20 patients with airflow obstruction. The accuracy of the instrument was expressed as the percentage of error, and reproducibility and interdevice variability were assessed using the coefficient of variation. In the laboratory evaluation, all devices recorded flow rates that were within +/-10% of the pneumotachograph readings at flows between 200 and 600 L/min. At the extreme flow rates of 100 and 700 L/min, the mean error was higher than 10%. The reproducibility of the VMX was within +/-5% at all the flows tested. The interdevice variability was less than 5% at flow rates between 200 and 700 L/min. When tested on normal subjects with PEF between 400 and 700 L/min, the VMX performed well. In patients with airflow obstruction, four devices had greater than 10% error. The largest error was observed in those patients with PEF below 200 L/min. The VMX Mini-Log peak flow meter is accurate and precise in the flow range between 200 and 600 L/min. Its performance, however, may be affected in subjects with airflow obstruction and PEF below 200 L/min.

Adolescent↗
PubMed1996

In vitro T-lymphocyte response and house dust mite-induced bronchoconstriction.

BACKGROUND: There is considerable evidence that T cells may play an important role in asthma. The purpose of this study was to determine whether the responsiveness of T lymphocytes to mite allergen stimulation in vitro is a determinant of bronchial response to house dust mite (HDM) allergen challenge in subjects who are allergic to HDM. METHODS: Peripheral blood was taken from seven healthy nonatopic subjects and 23 subjects with positive skin test reactions to HDM. Of the subjects in the latter group, 16 had an asthmatic reaction on inhalation challenge with HDM extract (HDM-responders), whereas the remaining seven had a negative reaction (HDM allergic). The proportion of subsets of T lymphocytes and their activation and the amount of IL-2, IL-4, IL-5, and interferon-gamma released in the supernatants with and without stimulation with the HDM extract were determined. RESULTS: Without stimulation, the proportions of subsets of T lymphocytes and their activation were similar between groups. When stimulated with the HDM allergen, the proportion of CD4+CD25+ cells from HDM responders was significantly higher than those in the control group. Comparison within groups of cell cultures with and without stimulation with the mite allergen showed that the proportion of CD4+, CD4+CD25+, CD4+/CD8+, and CD3+HLADR+ cells were significantly increased in HDM responders with stimulation; there was a trend for CD4+CD25+ cells to be increased in the HDM-allergic subjects; no increase in any T-lymphocyte subsets was found in the control subjects. The release of IL-5 was significantly greater in HDM responsers than in the other two groups. The severity of the immediate asthmatic reaction was significantly associated with the degree of nonallergic bronchial hyperresponsiveness and the amount of IL-5 released but not with the level of specific IgE to the mite allergen or subsets of T lymphocytes with and without stimulation. CONCLUSION: The findings suggest that responsiveness of T lymphocytes to allergen challenge in vitro may play a role in determining the bronchial response to the allergen in vivo.

Animals↗