Occupational asthma.

Occupational asthma accounts for a significant percentage of all asthma. Prevalence varies markedly, depending on host factors, the agent, and the manufacturing facility. The number of agents capable of inducing occupational asthma is large and will continue to increase as new agents are introduced into the workplace.

Basidiomycete mycelia and spore-allergen extracts: skin test reactivity in adults with symptoms of respiratory allergy.

One hundred fifty adults, with respiratory-allergic disease, and 14 control subjects, without symptoms of respiratory allergy, were skin prick tested with 16 common inhalant allergens, 12 extracts of mycelia from Basidiomycetes grown in vitro, and/or 10 to 15 basidiospore extracts. Eighty-three subjects (58%) had positive skin tests to two or more of the common inhalant allergens. Twenty-seven percent of the study subjects had positive skin reactions to one or more of the Basidiomycete mycelia extracts, and 32% demonstrated positive skin reactions to one or more basidiospore extracts.

Immunologic responses to inhaled cotton dust.

Byssinosis, a respiratory disease of workers on cotton, flax, and soft hemp, is classically characterized as shortness of breath, cough, and chest tightness on Mondays or the first day of return to work after a time off. Exposure to these vegetable dusts can also result in other respiratory diseases, and the term cotton dust-induced respiratory disease (CDIRD) is introduced. Although clinically characterized for more than a century, the underlying pathogenesis of CDIRD remains obscure.

Absence of hyperresponsiveness to methacholine in a worker with methylene diphenyl diisocyanate (MDI)-induced asthma.

A 29-year-old man had a persuasive history of respiratory illness following exposures to methylene diphenyl diisocyanate (MDI). He was evaluated by measuring bronchial reactivity to methacholine, both before and after controlled laboratory exposures to MDI. Despite evidence of progressive declines in FEV1 with increasing (but subirritant) doses of MDI on three consecutive days, there was no bronchial hyperresponsiveness to methacholine, before or after MDI challenge.

Biochemical and immunologic characterization of cotton bract extract and its effect on in vitro cyclic AMP production. II. Green bract.

Cotton bract has been proposed as a probable byssinogenic agent. Mill workers are exposed to bract which has weathered in the field, but it is not known whether biologic effects of bract are due to intrinsic plant compound(s) or to contamination occurring during field weathering. Exposure of mononuclear leukocytes (MNL) to green bract extract (GBE) lowered basal cyclic AMP levels.

Biochemical and immunologic characterization of cotton bract extract and its effect on in vitro cyclic AMP production. I. Field-dried bract.

Field-dried cotton bract, a contaminant of cotton dust, has been implicated in byssinosis pathogenesis. The results from this study demonstrated that a standard bract extract (FDBE) could be prepared. FDBE was antigenic in rabbits; however, precipitating antibodies were not detectable in the serum of cotton textile mill workers.

The effect of nonspecific binding by IgE on the radioallergosorbent test.

Human serum albumin (HSA), coupled to filter paper discs, was used in the radioallergosorbent test (RAST) to evaluate nonspecific binding which results from high levels of total serum IgE. Binding of 125I-labelled anti-IgE to HSA coated discs was significantly correlated with total IgE levels. A significantly better correlation was seen, however, using HSA chemically treated under alkaline conditions prior to coupling with the disc.

Basidiomycete allergy: what is the best source of antigen?

Skin prick test activity and antigenicity of extracts of in vitro growth of the Basidiomycete Pleurotus ostreatus (PO) were compared to extracts of spores from PO growing in the wild. Patients demonstrated significant differences in skin test reactivity to the PO extracts. Some reacted only to in vitro growth extracts, others only to the spore extracts and 1 patient to all extracts.

Immunologic studies of hollow-fiber dialyzer extracts.

Testing failed to detect free isocyanates in dialyzer rinses or significant levels of immunoglobulin E antibodies to isocyanate-protein conjugates in the serum of individuals reacting during hemodialysis with dialyzers containing Cuprophan membranes. Extended immunization of rabbits with Limulus lysate-reactive material from dialyzer rinses demonstrated antigenic activity of the rinse that appears to originate from cotton linters used in hollow-fiber membranes. The possibility that an immunologic response to these antigens may be a mechanism in adverse reactions to hemodialysis is discussed.

In vitro effects of aqueous cotton dust extract on leucocyte cyclic adenosine monophosphate levels.

Aqueous cotton dust extracts (ACDE) stimulated production of cyclic adenosine monophosphate (cAMP) in normal human peripheral blood mononuclear leucocytes (MNL). This response was not due to prostaglandin production by monocytes or platelets in the cell preparation nor to stimulation of the beta-adrenergic or H2 receptors; however, desensitization experiments indicated that the response may be receptor mediated. The possible involvement of such receptor desensitization in byssinosis pathogenesis is discussed.

Reactions during work shift among cotton mill workers.

Lung function and blood neutrophils were measured in 13 cotton mill workers on different days of the work week. Antigen was prepared from cotton dust and a radioallergosorbent (RAST) test made on serum and plasma. The exposure was determined as airborne dust and bacterial endotoxin using vertical elutriators and personal samplers.

Studies on the antigenic composition of aqueous cotton dust extracts.

An immune response to cotton dust components has been proposed as a possible mechanism of byssinosis. To evaluate this possibility, specific precipitating antibodies against aqueous cotton dust extracts (ACDE) were raised in rabbits, and a reference pattern for crossed immunoelectrophoresis (CIE) was established using this extract. A significant portion of the immune response was directed against Alternaria tenuis, Aspergillus niger, and Fusarium solani, all documented contaminants of cotton dust.

The respiratory effects of cotton dust.

It is apparent that occupational exposure to cotton dust, and in vivo exposure to its components, may result in a number of cellular and humoral events. These include specific antibody formation, mediator release, complement activation, endotoxin effects, and related phenomena. The role of these, either singly or in combination, in the pathogenesis of cotton dust-induced lung disease awaits elucidation.

Radioallergosorbent testing with p-tolyl monoisocyanate in toluene diisocyanate workers.

Sera from 149 occupationally exposed toluene diisocyanate (TDI) workers were tested by RAST with p-tolyl monoisocyanate human serum albumin (TMI-HSA). Of the seven positives, one had a history suggestive of TDI asthma and one had a rash which may have been TDI related. These results indicate that false positive RAST with TMI-HSA may occur in asymptomatic workers.

Development and loss of toluene diisocyanate reactivity: immunologic, pharmacologic, and provocative challenge studies.

Toluene diisocyanate (TDI) sensitivity accompanied by nonspecific bronchial hyperresponsiveness occurs in approximately 5% of occupationally exposed workers. We report the case of a 32-yr-old worker followed longitudinally after removal from isocyanate exposure. TDI reactivity was lost 11 mo after removal from exposure and nonspecific bronchial hyperresponsiveness resolved after 17 mo.

Five-year longitudinal study of workers employed in a new toluene diisocyanate manufacturing plant.

The respiratory health of 277 workers in a new toluene diisocyanate (TDI) manufacturing plant was studied prospectively during 5 yr of exposure. Personal TDI monitors were used to continuously measure peak and 8-h time-weighted average (TWA) concentrations in over 2,000 samples. Longitudinal change in pulmonary function was assessed in 223 men in whom 3 or more data points allowed construction of individual slopes of annual change.

Lung function consequences of exposure and hypersensitivity in workers who process green coffee beans.

Three hundred seventy-two workers were examined at two coffee processing plants in New Orleans. Workplace dust concentrations were relatively low, and respiratory symptom prevalences were not different in various areas of the plants. After controlling for other variables, men with lengthy employment and exposure to dust of green (unroasted) coffee had lower mean residual FEV1 values (regression coefficient, -0.