Analysis of green coffee bean and castor bean allergens using RAST inhibition.

Coffee workers with occupational allergic symptoms and positive skin tests to green coffee bean and factor dust antigens have elevated serum IgE antibodies (by radioallergosorbent test--RAST) to green coffee and castor bean allergens. These antibodies were used in a RAST inhibition assay to analyse coffee and castor allergens. Bean allergens were extracted by homogenization in PBS, centrifugation and concentration of supernates by ultrafiltration. Green coffee bean allergens, fractionated by gel filtration and Pevikon block electrophoresis, were shown to be very heterogeneous with a molecular weight range of 50 000 to 500 000 daltons. Castor allergens were more homogeneous with a molecular weight of 14 000 daltons and were partially purified by Pevikon block electrophoresis, gel filtration and isoelectrofocusing. Chemical analysis showed that protein was the major component in both allergen extracts. However, proteolytic enzymes could only partially destroy allergenic activity. Such isolation and characterization of these allergens should result in better methods of diagnosis and treatment of coffee workers with occupational allergic disease.

An approach to fungal antigen relationships by radioallergosorbent test inhibition.

Antigenic relationships among three species of Aspergillus (A. fumigatus, A. glaucus, and A. flavus) were examined by paired cross-radioallergosorbent test (RAST) inhibition analysis, an in vitro technique based on human IgE antibody specificity. Alternaria tenuis was found to be antigenically unrelated to each of the three species of Aspergillus and was used as a negative control. A single test serum yielded uninhibited RAST indices of 6, 7.4, 8.1, and 7.8 for A. fumigatus, A. glaucus, A. flavus, and Alternaria tenuis, respectively. At a concentration of 10 mg/ml, A. fumigatus inhibited A. glaucus RAST by 63% and A. flavus RAST by 62%. A. glaucus inhibited A. fumigatus RAST by 36% and A. flavus RAST by 63%. A. flavus inhibited A. fumigatus RAST by 44% and A. glaucus RAST by 81%. Each species of Aspergillus produced significant but only partial inhibition of RAST to each of the other two species analyzed. Results indicate the existence of both shared and unique antigens among these three species of Aspergillus. Paired cross-RAST inhibition may be used as an approach to study species relationships among genera of several classes of clinically relevant fungi. Unless many strains are employed, data obtained do not represent a definitive analysis of species, because of possible different degrees of inhibition by various strains of a particular species. They do, however, allow for the antigenic comparison of two or more crude, poorly characterized preparations thought to be important in human allergic disease.

Detection of castor allergens in castor wax.

The presence of castor bean allergens in castor wax products was determined by in vivo and in vitro analysis of castor wax extracts. Allergens were detected in one extract of castor wax by the PCA reaction in mice, the RAST inhibition reaction, and skin prick test in castor bean sensitive individuals. However, these allergens in the wax were of much lower potency than those in the bean, and were not detectable in a deodorant product utilizing castor wax.

IgE antibody response of smokers, nonsmokers, and "smoke-sensitive" persons to tobacco leaf and smoke antigens.

Serum samples from cigarette smokers, nonsmokers, and persons reporting "smoke sensitivity" were tested for IgE antibodies to tobacco leaf and smoke extracts by the radioallergosorbent test. Results indicated that none of the serum samples tested contained detectable IgE antibodies to smoke extracts. Occasionally, serum specimens from smokers or nonsmokers demonstrated reactivity to leaf antigen. The most significant reaction to leaf antigens was detected in serum from one of the 7 smoke-sensitive subjects tested. These results demonstrate that smoking, nonsmoking, and clinical "smoke sensitivity" are not correlated with the presence of IgE antibodies to tobacco leaf or smoke antigen.

Inhalation challenge and pharmacologic studies of toluene diisocyanate (TDI)-sensitive workers.

Workers with "sensitivity" to toluene diisocyanate (TDI) studied in depth in an attempt to determine mechanisms of bronchial hyperreactivity. Tests included provocative inhalation challenge (PIC) with TDI and methacholine challenge. Blood samples obtained prior to and at various times after PIC were used to measure complement and split products of complement and plasma histamine levels and to determine dose-response slopes of lymphocyte cyclic adenosine monophosphate (cAMP) following stimulation with agonists. TDI-reactive individuals were all reactive to methacholine and responded to PIC with TDI by immediate, delayed, or dual bronchospastic reactions. No change in plasma histamine, total complement levels, or split products of complement were measurable. TDI reactors gave decreased lymphocyte cAMP dose response slopes to stimulation with isoproterenol, prostaglandin E1, and TDI, which suggests that impairment of adrenergic receptors may play an important role in TDI reactivity.

Hypersensitivity pneumonitis and extrinsic asthma. An unusual association.

A farmer who had no prior history of pulmonary disease developed tightness in the chest of rapid onset, shortness of breath, fever, and pulmonary infiltration while farming. The symptoms of his disease worsened with repeated exposure to the dusty farm field but remitted after each of five hospitalizations. Provocative challenge with inhalation of a water-soluble extract of dust from the field reproduced both asthmatic and pneumonitic features of the disease, while administration of corticosteroids clinically controlled the entire process. The data suggest a common cause for asthma and pneumonitis in this patient.

Extraction and analysis of coffee bean allergens.

Workers in the coffee industry can develop occupational allergic disease upon exposure to dust associated with coffee manufacturing. Since controversy exists as to the source or chemical nature of these allergens, the mouse model of reaginic antibody production was used to assess the potential sources of allergens in samples obtained from a local coffee manufacturing plant. Mice were immunized with extracts of coffee dust and beans and the resulting reaginic antibody response determined by the passive cutaneous anaphylaxis reaction. Cross-reacting allergens were detected in samples of coffee dust, cleaner can debris and green coffee beans, but not in chaff or roasted coffee beans. None of the allergens detected in coffee samples cross-reacted with extract of castor beans, although these extracts contained the potent castor bean allergen. Green coffee bean allergens partially purified by gel filtration were heterogeneous with respect to molecular size, although quite similar in their reactivity with reaginic antiserum. These results suggest that the green coffee bean is the major source of allergen in coffee manufacturing plants. This allergen is heterogeneous with respect to size and heat lability, and is immunochemically different from the castor bean allergen.