Search

The levels of immune complex-like material in serum from 18 patients in connection with skin eruptions appearing during penicillin therapy were determined with a modified ELISA. Immune complex-like material could only be shown in the serum of 3 out of the 17 patients. However, according to ELISA results, the complexes appeared without the simultaneous presence of penicilloyl-specific antibodies. Neither could penicilloyl-specific antibodies be recorded in 9 patient treated with parenteral penicillin without adverse reactions. 3 of these patients had immune complex-like material in their serum. It was concluded that immune complex-like material with penicilloyl specificity is not likely to contribute to the development of skin eruptions often seen in connection with penicillin treatment.

RAST analyses were performed with house dust, animal dander and eleven pollen allergens in 410 adult patients with asthma and/or rhinitis and the findings were compared with skin test and provocation test results. The overall correlation between 1,316 provocation tests and RAST was 78% and the correlation between 1,778 skin tests and RAST was 66%. The relationships between RAST and in vivo tests differed considerably from allergen to allergen. No significant differences were found between various age groups. According to the in vivo tests the RAST showed more often positive results in patients with pronounced allergy than in patients with low-grade allergy. Higher RAST classes were most often combined with positive in vivo tests. It is concluded that in cases with RAST classes 2-4, a reasonably well-established allergy diagnosis can be reached without the inclusion of additional in vivo tests. In other cases, however, application of further diagnostic methods is required.

A procedure for the preparation of RAST disks used to assay isocyanate-specific IgE antibodies was developed. The outcome of the RAST was found to be strongly dependent on how the isocyanate test antigen was synthesized. Specific IgE from selected workers with isocyanate asthma reacted optimally to conjugates with less than or equal to 10 isocyanate molecules bound per molecule of human serum albumin. Further haptenization resulted in decreased specific binding and increased nonspecific binding because of high levels of total IgE. The hapten and carrier specificity of isocyanate-induced IgE antibodies were studied by direct RAST and RAST inhibition. The existence of new antigenic determinants related to both the isocyanate hapten and the carrier could be demonstrated. It was important to use a test antigen prepared from the same isocyanate as that to which the worker had been exposed, since the cross-reactivity between different isocyanate haptens was partial and varied from one patient to another. It was confirmed that isocyanate-specific IgE antibodies can be demonstrated only in a subgroup of workers with isocyanate-related bronchial asthma.

The relation between the health of workers and the environment in swine confinement buildings was investigated in a study of 57 workers on 30 swine farms in southern Sweden and 55 matched controls. Swine workers reported significantly higher frequencies of respiratory symptoms, more frequent colds and absence due to chest illness, and a history of pneumonia. The increased frequency of symptoms of respiratory disease was related to the number of years and percent of the day spent working with swine. Symptoms were also associated with respirable dust, total dust, endotoxin in total dust, and number of microbes in the air of the work environment. In a multiple regression analysis of the relation between 16 different environmental parameters to work period shifts of five pulmonary function parameters, endotoxin was found to be significantly related to the FEV1 in a dose dependent way.

The aim of biological standardization (BS) is to equilibrate the activity (potency) of allergen extracts from different source materials. This was done by performing skin prick tests (SPT) on patients who were sensitive to one of the following 10 allergens: Birch, alder, hazel, timothy, rye grass, velvet grass, cultivated rye, mugwort, D. farinae and Cladosporium herbarum. Patient sensitivity varied within a range of three to four powers of ten for each allergen investigated. The weal size in each patient corresponding to that elicited by histamine 1 mg/ml was calculated using the model log (mean weal diameter) = a + b log (concentration). The correlation coefficients of the regression lines of the allergen dose response relationship were found to be greater than 0.85 in most cases. The median slope for all extracts was 0.24. The slope for Cladosporium was significantly steeper than that for pollens. The amount of material in microgram dry weight (d.w./ml) equal to 1000 biological units/ml (BU/ml) varied within a factor of three between species for all tested purified allergen preparations but Cladosporium. For Cladosporium, about 30 times more material was needed than for D. farinae. When using crude rather than purified material, it was necessary to use five to ten times more to elicit a reaction corresponding to 1000 BU/ml, but the difference was significant only for Cladosporium. The narrow range of allergen concentrations used by us as well as other investigators does not assure positive skin prick test results in all patients with clinical symptoms due to the allergen in question. Skin prick testing should therefore be done over a wide range of concentrations to improve the methods for BS.

Fifty-one patients with clinical history of dog allergy were skin prick tested with eight individual standardized dog breed-allergen preparations, one mixed breed-allergen preparation (Poodle/Alsatian), dog-serum albumin, and histamine hydrochloride, 1 mg/ml. All extracts were characterized by crossed immunoelectrophoresis and crossed radioimmunoelectrophoresis with a pool of sera from patients clinically sensitive to dog. The dog-breed extracts contained common antigens/allergens, as well as components represented only in one or two dog-breed extracts. The concentration corresponding 1000 BU/ml varied from 16 to 100 micrograms of protein per milliliter. The sensitivity of skin prick test was 67% to 88% for the various dog breed-allergen preparations, but only 18% for dog-serum albumin. Significant difference between the skin test response to different dog breed-allergen preparations indicating dog breed-specific allergens was obtained in 15% of the patients. There was no significant correlation between skin prick test results and symptoms related to a specific dog breed.

Pulmonary function was studied in 66 wood trimmers exposed to organic dust (moulds) after a month of no exposure (summer vacation) and then three and 27 months later, and also during a working week. The results of forced expirometry and single breath nitrogen washout were compared with those obtained in local controls and in larger reference materials. The forced vital capacity (FVC) and forced expired volume in one second (FEV1) were reduced by an average of 0.4 and 0.31, respectively, after one month of no exposure, however, the nitrogen washout variables showed no clear changes. Repeated measurements three months later on a Monday morning after two days of no exposure showed a further reduction in FVC and FEV1 by an average of 0.21 in a sawmill with high exposure to moulds (10 colony-forming units/m3), but not in another sawmill with ten times lower exposure. Further recordings 27 months later (Monday morning before work) displayed no further worsening in any spirometric variable. No change in lung function was noted after one day of work (Monday morning to Monday evening), but a further reduction in FVC of an average of 0.31 was seen in non-smokers at the end of the week, with apparent resolution over the weekend. The impairment was more obvious at the sawmill with higher air concentrations of organic dust than at the other sawmill. It is concluded that wood trimmers may develop restrictive pulmonary dysfunction, which might be explained by an immunopathological reaction to heavy mould exposure.