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Biomedical subjects

D D Stevenson

Publications and source records attributed to D D Stevenson.

At least 37 records · Page 2Linked to original sources
PubMed1994

Recognition of T cell epitopes and lymphokine secretion by rye grass allergen Lolium perenne I-specific human T cell clones.

T cell lines (TCL) and CD4+ T cell clones (TCC) with specificity for the rye grass allergen Lolium perenne (Lol p) I were isolated from the blood of nine donors, six having active atopic disease, two being in remission, and one having IgE anti-Lol pI Abs but not atopic disease. The T cell epitopes of Lol pI were determined by TCLs and TCCs reactivity with 23 overlapping, 20 amino acid-long peptides spanning the entire length of the 230 amino acid-long allergen. In addition, the Th subsets (Th1, Th2, Th0, Thp) were determined by measuring IL-2, IFN-gamma, and IL-4 in the supernatants of TCC activated with Lol pI and irradiated APC. TCC from individuals from which a large panel of clones were obtained from 10(5) PBMC initial cultures recognized multiple peptides (5-9) and 23 overlapping peptides a total of 16 were recognized by at least one TCC from one of the patients. These 16 peptides were derived from all areas of the Lol pI molecule, indicating the ability of human Th cells to recognize many peptide epitopes on Lol pI. Although no clear cut immunodominant peptides were detected, T cell clones of 50% of the patients reacted with peptide 191-210. There was no correlation between peptide epitope reactivity and lymphokine secretion pattern of the TCC. Of 12 TCC obtained from six patients with active atopic disease, four (33%) were of Th1, five (42%) of Th2, one (8%) of Thp, and two (17%) of Th0 type. Of 14 TCCs isolated from three atopic donors in remission, five (36%) were of Th1, three (21%) of Th2, four (29%) of Thp, and two (14%) of Th0 type. The data demonstrate that T cells from rye grass pollen allergic patients can recognize multiple peptide epitopes on Lol pI scattered over the entire molecule. No correlation existed between epitope reactivity and lymphokine secretion pattern of the TCC.

Adolescent↗
PubMed1992

Arachidonic acid metabolism in monocytes of aspirin-sensitive asthmatic patients before and after oral aspirin challenge.

Aspirin and nonsteroidal antiinflammatory drugs induce bronchospastic reactions in patients with aspirin-sensitive respiratory disease. Although the mechanism of this reaction is unknown, all drugs that induce the respiratory reaction also inhibit the cyclooxygenase enzyme. The ensuing changes in arachidonate metabolism are presumed to play a role in the pathogenesis of the reaction. We measured generation of leukotrienes and thromboxane by calcium ionophore stimulated blood monocytes. Before aspirin challenge, monocytes released significantly more thromboxane B2 in patients with aspirin sensitivity than in patients without aspirin sensitivity or in healthy control subjects (p < 0.02). During aspirin-induced bronchospasm, release of leukotriene B4 increased significantly (45.5%, p = 0.018), whereas release of thromboxane B2 decreased (-46.9%, p = 0.028). Two hours after ingestion of 60 mg aspirin, normal monocyte release of thromboxane B2 did not drop, whereas leukotriene B4 release increased. Monocytes formed only minimal amounts of leukotriene C4. We conclude that the profile of released eicosanoids from aspirin-sensitive monocytes is distinct from non-aspirin-sensitive subjects, and that these differences could contribute to the development of bronchospasm after aspirin ingestion.

Administration, Oral↗
PubMed1992

Flurbiprofen (Ansaid) cross-sensitivity in an aspirin-sensitive asthmatic patient.

Flurbiprofen (Ansaid) is a newly released nonsteroidal antiinflammatory drug (NSAID) that is a potent inhibitor of prostaglandin synthesis. We report the first case (to our knowledge) of a flurbiprofen-induced asthmatic reaction confirmed by single-blind oral challenges. Cross-sensitivity and cross-desensitization between aspirin (ASA) and flurbiprofen were also demonstrated in this patient with rhinosinusitis and asthma, thus reinforcing the observation that NSAIDs capable of cyclooxygenase inhibition crossreact with ASA in producing characteristic respiratory reactions.

Aspirin↗
PubMed1991

Tryptase and histamine release during aspirin-induced respiratory reactions.

The involvement of mast cells in the pathogenesis of aspirin (ASA)-induced respiratory reactions was investigated by measuring serum levels of tryptase, a neutral protease that is a specific marker of mast cell activation. ASA challenges were performed in 17 ASA-sensitive patients with asthma and rhinosinusitis, and tryptase and histamine levels were measured in their venous blood samples. In three subjects who experienced moderate to severe respiratory reactions extending to the skin and/or gastrointestinal tract, marked elevations of tryptase levels in postreaction serum samples (peak levels, 51.9 and 40.0 ng/ml) were discovered in two of these three subjects, and a small elevation of tryptase occurred in the serum of the third subject (3.1 ng/ml peak). Plasma histamine levels in postreaction samples were significantly elevated over baseline values in all three subjects (delta mean plasma histamine, 238 pg/ml versus 56 pg/ml for the remaining 14 subjects; p less than 0.04). In the remaining 14 subjects, who experienced similar respiratory reactions without extrapulmonary symptoms during aspirin challenge, changes in tryptase and histamine levels were not observed.

Administration, Oral↗
PubMed1991

Aspirin sensitivity. A distressing reaction that is now often treatable.

Aspirin-induced hypersensitivity affects a substantial number of people, including 20% or more of asthmatic patients. A dramatic flare of symptoms occurs after indigestion of aspirin or a nonsteroidal anti-inflammatory drug, and symptoms can persist even after the agent is discontinued. Fortunately, aspirin desensitization, as described by the authors, now appears to be a treatment option.

Aspirin↗
PubMed1991

Safety and possible efficacy of fiberoptic bronchoscopy with lavage in the management of refractory asthma with mucous impaction.

Mucous impaction may be suspected in asthmatic exacerbation when, despite aggressive medical management, patients continue to produce sputum containing mucous plugs and exhibit prominent rhonchi and/or wheezes on chest auscultation. Spirometric measurements in this setting corroborate lack of improvement and reveal significant impairment in indices that may reflect small airways function (FEF25-75). We hypothesized that clearance of inspissated secretions by fiberoptic bronchoscopy with lavage (FOBwL) may promote or hasten the clinical improvement of such patients. Fifty-one therapeutic FOBwL were accomplished in 19 patients during 20 episodes of stabilized yet refractory asthma with mucous impaction. No significant complications were encountered. After FOBwL, spirometric measurements of FEV1, FEF25-75, and FVC increased significantly (P less than .01, paired t test), and correlated with relief of dyspnea and mobilization of secretions with cough. FOBwL can be safely performed in stabilized, refractory asthma, and with apparent efficacy. Further investigation is needed to document the therapeutic utility of FOBwL in refractory asthma.

Adult↗
PubMed1990

Long-term effects of aspirin desensitization--treatment for aspirin-sensitive rhinosinusitis-asthma.

One hundred seven known aspirin (ASA)-sensitive patients with rhinosinusitis-asthma were studied from 1975 to 1988. Forty-two of the patients avoided ASA and served as the control group. Thirty-five patients were desensitized to ASA and treated with daily ASA treatment (Rx) for as long as 8 years (mean, 3.75 years) to May 1988 and were designated the continuous group. Thirty patients, initially desensitized to ASA and treated with daily ASA, who stopped Rx permanently after a mean duration of 2 years, were designated the discontinued group. Retrospective analyses of baselines revealed that both continuous and discontinued groups during ASA Rx demonstrated statistically significant reduction in number of hospitalizations per year, emergency room visits per year, outpatient visits per year, upper respiratory infections-sinusitis-antibiotics per year, need for nasal polypectomies and additional sinus operations, and improvement in sense of smell compared to the control group. Simultaneously, the ASA-Rx groups were able to significantly reduce systemic corticosteroid dosage, corticosteroid bursts per year, and, in the continuous group only, significantly reduce inhaled corticosteroids. All three groups maintained control of respiratory symptoms. ASA desensitization followed by long-term daily ASA Rx appears to improve ASA-sensitive rhinosinusitis-asthma and concomitantly allows reduction of systemic corticosteroids.

Adrenal Cortex Hormones↗
PubMed1990

Salsalate cross-sensitivity in aspirin-sensitive patients with asthma.

Ten aspirin (ASA)-sensitive patients with asthma underwent double-blind, placebo-controlled oral challenges with salsalate followed by ASA-sensitive confirmatory challenges. All 10 patients sustained asthmatic reactions to ASA, but only two developed respiratory reactions to 2 gm of salsalate. In these two patients, repeat confirmatory challenges with 2 gm of salsalate reproduced the same asthmatic reactions. Both patients were desensitized to ASA, and cross-desensitization with 2 gm of salsalate was then achieved. We conclude that salsalate, a weak inhibitor of cyclooxygenase in vitro, is less likely than ASA to induce asthma in known ASA-sensitive patients with asthma but may occasionally cross-react in these patients. Such reactions were mild and easily treated with beta 2-agonists.

Acetaminophen↗
PubMed1989

Cross sensitivity with acetaminophen in aspirin-sensitive subjects with asthma.

Drugs inhibiting cyclooxygenase regularly cross-react with aspirin (ASA). Although some experiments suggest that acetaminophen (ACETM) is a weak inhibitor of cyclooxygenase in certain tissues, it has not been studied in human lung tissue, and controversy exists whether or not true cross-reactivity occurs between ASA and ACETM. Three ASA-sensitive subjects with asthma, who gave a history of reactions to ACETM, underwent double-blind, placebo-controlled challenges and reacted to 1000 mg of ACETM with a greater than 20% fall in FEV1. Two patients were desensitized to ASA and then were rechallenged with 1000 mg of ACETM without reaction. Two patients were desensitized to increasing doses of ACETM, achieving refractoriness to 1500 mg, but not 2000 mg. Thus, cross sensitivity between ASA and ACETM was documented when large challenge doses (1000 mg) of ACETM were used. Furthermore, cross desensitization suggests that in ASA-sensitive subjects with asthma, similar mechanisms are likely to be responsible for reactions to ASA, nonsteroidal anti-inflammatory drugs, and ACETM.

Acetaminophen↗
PubMed1988

Release of leukotrienes, prostaglandins, and histamine into nasal secretions of aspirin-sensitive asthmatics during reaction to aspirin.

The levels of leukotriene C4 (LTC4), leukotriene B4 (LTB4), prostaglandin E2 (PGE2), and histamine were measured in nasal lavage fluids obtained from aspirin-sensitive, desensitized aspirin-sensitive, and aspirin-insensitive asthmatics and normal volunteers before and after ingestion of aspirin. Increased levels of LTC4 and histamine were associated with significant decreases in the FEV1 for 3 of 4 aspirin-sensitive asthmatics who had both naso-ocular and bronchospastic reactions to aspirin. In contrast, no increase in LTC4 or histamine release was detected in aspirin-sensitive asthmatics who had only bronchospastic reactions to aspirin. No significant decreases in PGE2 levels or increases in LTB4 levels were detected during these reactions to relatively low doses of aspirin regardless of the clinical symptoms, nor was any increase in mediator release apparent in lavage fluids from normal donors, aspirin-insensitive asthmatics, and desensitized aspirin-sensitive subjects before or after various doses of aspirin. Levels of PGE2 decreased in nasal secretions from normal volunteers, aspirin-insensitive asthmatics, and desensitized aspirin-sensitive subjects after ingestion of 650 mg of aspirin. These decreases were not associated with increased LTC4 or LTB4 or with histamine release, decreased FEV1, or naso-ocular symptoms. In addition, reductions of PGE2 release were similar for normal and desensitized aspirin-sensitive volunteers (63 +/- 11 versus 61 +/- 10%, respectively). The data demonstrate that LTC4 and histamine are released into nasal secretions of aspirin-sensitive asthmatics with naso-ocular and bronchospastic reactions after ingestion of low doses of aspirin without a decrease in the levels of PGE2 and suggest that LTC4 and histamine contribute to the naso-ocular and bronchospastic symptoms characteristic of reactions to aspirin.

Adult↗
PubMed1985

Precipitating factors in asthma. Aspirin, sulfites, and other drugs and chemicals.

Several types of reactions to drugs and chemicals may precipitate or perpetuate asthmatic relapse. This review focuses on reactions to aspirin and sulfites. Approximately 40 percent of patients with rhinosinusitis, nasal polyps, and asthma and 5 to 10 percent of all asthmatic patients are sensitive to aspirin and aspirin-like nonsteroidal anti-inflammatory drugs at some time in their course. A prudent recommendation to all asthmatics is to substitute acetaminophen for aspirin. When aspirin/aspirin-like drug is essential for treatment of cardiovascular or musculoskeletal disorder, desensitization by cautious oral challenges with graded doses of aspirin can be accomplished. Treatment of the respiratory disorder per se by desensitization followed by daily therapeutic aspirin remains investigational. Sulfur dioxide and sulfites, commonly used as sanitizers and preservatives of foods and pharmaceuticals, may precipitate acute asthma in 5 percent or more of asthmatic patients. When the history suggests sulfite sensitivity, challenges can be used to confirm sensitivity and the patient counseled in avoidance of these chemicals.

Adult↗
PubMed1984

Diagnosis, prevention, and treatment of adverse reactions to aspirin and nonsteroidal anti-inflammatory drugs.

Aspirin (ASA) and nonsteroidal anti-inflammatory drugs (NSAIDs) share common pharmacologic effects in the prevention of inflammation, at least in part through inhibition of prostaglandin formation. ASA and NSAIDs have predictable side effects such as gastric pain, ecchymosis, and tinnitus. They also cause anaphylactoid shock, urticaria/angioedema, nephropathy, and hepatitis in individuals who appear to be normal and in whom prediction of such reactions cannot be made. Two selected populations of patients are likely to experience hypersensitivity reactions to both ASA and NSAIDs. Patients with asthma have an 8% to 20% chance of experiencing asthmatic attacks after ingesting ASA and NSAID. If such patients have associated rhinosinusitis (polyps), prevalence increases to 30% to 40%. Patients with chronic urticaria/angioedema have a 21% to 30% chance of experiencing an urticarial flare after ingesting ASA and NSAIDs.

Angioedema↗
PubMed1984

Aspirin-sensitive rhinosinusitis asthma: a double-blind crossover study of treatment with aspirin.

Twenty-five ASA-sensitive patients with rhinosinusitis asthma underwent oral ASA challenges followed by desensitization to the adverse respiratory effects of ASA. We then compared the efficacy of continuous ASA treatment for their respiratory tract disease to that of a placebo treatment during a double-blind crossover study. For this group of 25 patients, there was significant improvement in nasal symptoms and a reduction in use of nasal beclomethasone during the months when they received ASA treatment. Lower respiratory tract symptoms, values of FEV1, and the use of antiasthmatic medications including prednisone were not significantly changed during ASA treatment. Desensitization to ASA followed by ASA treatment appears to significantly alleviate symptoms of rhinosinusitis. However, only half the patients experienced improvement in their asthma symptoms during ASA treatment.

Aspirin↗