Search

A group of patients with serum precipitins against M. faeni culture filtrate antigens and with clinically proven farmer's lung disease was examined. A group of precipitin-negative farmers with comparable antigen exposure and with unrelated forms of pulmonary disease served as control. Immunoglobulins G and A were elevated at first consultation in the majority of the acute cases of farmer's lung. Immunological parameters normalized during corticosteroid medication and antigen avoidance. Autologous complement (C) consumption by M. Faeni antigens proved valuable for diagnostic purposes. Despite normalizing immunological factors and subsiding symptomatology, C-consuming antibody levels remained constant.

The frequency distribution of the blood group phenotypes ABO was examined in retrospect in a selected group of 241 Patients with grass pollen hayfever. A relative deficiency in blood group O was found, with a shift toward an over-represented B-phenotype as compared to the general population. This shift appeared to be largely due to the contribution from the female patients with pollinosis. Comparison with literature data confirmed a lower frequency of the O-phenotype in atopic patients in general, irrespective of the specific sensitivities.

Consideration of the physicochemical and biological properties of the common inhalant, food and nematode allergens has led the author to propose reintroduction of the term atopen. Atopens are nonspecific activators of physiological enzyme systems in man and are indicators of the atopic status. Allergens are considered to be those substances, not necessarily immunogenic by themselves, capable of deliberately directing the immune response into IgE production. Ongoing IgE synthesis may eventually produce IgE antibodies reacting with nonallergenic antigens.

The reactivity of complement (C) with housedust allergen has been investigated in separate groups of sera from atopic patients with seasonal hay fever, bronchial asthma, atopic dermatitis, animal dander allergy or asthmatic bronchitis as compared to controls. Complement consumption was more pronounced on average in the allergy groups, with the exception of atopic dermatitis. Total IgE levels were elevated in all groups, especially in atopic dermatitis. There was no correlation between C-sensitivity and IgE data (RAST and RIST). The mean levels of C1-inhibitor, 1-antitrypsin and 2-marcroglobulin in the atopic group were found normal. A significant correlation was found between the extent of C-consumption by house dust allergen and the level of C4 in sera. It is concluded that both C and IgE differ from normal in atopic patients, but that neither one is suited for the routine diagnosis of atopy in individual serum samples.

In an extended study of group of confectionery workers sensitized by exposure to egg spray, it was found that their blood serum contained antibodies to avian serum proteins. Comparison of the ratio of IgG antibodies determined by ELISA to egg yolk 'livetins' and pigeon serum in these patients and in pigeon breeders showed that the phenomenon is entirely due to immunological cross-reactivity among avian blood serum proteins. These avian serum proteins in hens' eggs, not ovalbumin, were identified as the major sensitizing antigens.

A crude aqueous extract of house dust and two house dust subfractions were tested for adjuvant activity in a sensitivity assay performed in mice. Evidence is presented that house dust contains at least two potent immunological adjuvants. One of these, present in both subfractions, was probably endotoxin and acted in a complement-independent way. The immunostimulatory effect of the other adjuvant was abrogated by prior complement depletion of the animals. This apparently complement-dependent adjuvant needs further identification.

Haemolytic complement (C) in human sera is readily consumed by most of the common inhalant allergens. The reactivity of C among individual sera differs considerably and is a characteristic parameter for the condition of atopy. The phenomenon is not mediated by specific IgE or IgG4 antibodies. Whereas in groups of patilues (by RAST) are negative in about 50 percent of the cases, this is not so with regard to C-reactivity. In somes cases, especially in allergy to guinea pigs, correlation with the clinical history is better with IgG4 than with IgE antibodies. In other allergies, there is a close correlation between Ige and IgG4 antibodoes.

The sera of patients with pigeon breeder's disease usually contain precipitating serum factors as well as human complement consuming factors as shown by incubation of the serum with pigeon dropping antigens. Although a single serum factor, possibly an IgG antibody, might account for both phenomena, affinity chromatography experiments revealed that the sera of patients with pigeon breeders' disease contain non-recipitating, human complement consuming, serum factors besides precipitating serum factors which are also capable of complement consumption. The non-precipitating serum factors most likely belong to the IgG3 immunoglobulin subclass, whereas the precipitating antibodies belong to the subclasses IgG1 and IgG2.

In patients with atopic dermatitis and in a control group prick and intracutaneous tests were performed with Pityrosporon extracts. Moreover, specific IgE against Pityrosporon was determined in these patients. Significant differences existed between the results obtained with these methods in both groups of patients. Therefore, both skin tests with Pityrosporon extract and IgE determinations may contribute to a diagnosis of AD; moreover, it is likely that Pityrosporon may be of significance in the pathogenesis of AD.

A house dust fraction was tested for complement activation in mouse serum using a microtitre complement fixation assay. It was observed that the preparation was a potent activator of the classical, but not of the alternative pathway suggesting an analogy with the complement activation in human serum. The activation showed similarity with that by classical complement activators such as aggregated IgG, DNA, lipopolysaccharide (LPS), but some discrepancy with mite allergen was observed. The contamination of the preparation with LPS was negligible and could not account for the anticomplementary effect. The role of DNA fragments in the activation of mouse complement by the house dust fraction is discussed. Our results suggest that the mouse is suited to study the role of complement activation by house dust constituents in the induction of the IgE response.

House dust extracts for clinical use must be purified in order to free them from indesirable irritants and pyrogens. A discussion is given of practical and simple methods for the standardized production of purified house dust allergens, which can be quantitated on the basis of relatively simple analytical and physicochemical parameters. Immunoelectrophoretic analysis may help in the controlled production of safe and potent preparations. In contrast, elaborate standardization by quantitative single radial immunodiffusion with anti house dust sera may lead to completely erroneous results.

Atopic allergens can readily be shown to inactivate hemolytic complement in human serum. This property has been explored as a means of in vitro allergen quantitation and standardization. The purification of house dust allergen, guided by skin tests and complement inactivation, demonstrates that the in vitro technique is clinically relevant. Since human sera differ in their sensitivity to complement inactivation by allergens, it is desirable to prepare a purified house dust allergen as a standard. By referring to this standard, other house dust extracts may then be standardized by using any given serum sample of human origin, provided that such extracts have undergone some degree of purification. Kinetic studies demonstrate that other allergens of the house dust group may be standardized in similar fashion; it was noted that the ratio of the complement inactivating powers of these respective allergens remains constant whatever the serum used. The method is not suited for the quantitation of pollen allergens.

Binding of specific IgE antibodies from the sera of patients allergic to animals was investigated by direct RAST, using the animal's dander, urine, saliva or blood serum as insolubilized allergens. In allergy to rat, mouse, guinea pig, dog, cat or horse, the RAST results with the excretions of a particular animal were mutually well correlated. RAST with the animal blood serum was positive less often, and only in cases of a positive dander RAST. It is concluded that a RAST with animal dander precludes the use of other animal products.

Skin sections of clinically involved and clinically normal-looking skin from patients with atopic dermatitis were incubated with anti-human IgE antibodies using the indirect immunoperoxidase technique. Apart from positive dermal anti-IgE staining, positive epidermal anti-IgE staining was also observed. The morphology of the epidermal staining cells suggested the involvement of dendritic cells. This was confirmed by positive immuno-double labelling with OKT6 and anti-IgE. This phenomenon seemed to be specific for atopic dermatitis since skin sections from normal non-atopic controls, patients with allergic asthma, contact dermatitis, and schistosomiasis showed no epidermal anti-IgE staining. To further elucidate the nature of the epidermal anti-IgE staining cells, epidermal cell suspensions were prepared from clinically involved skin from patients with atopic dermatitis. These cell suspensions also showed positive anti-IgE staining cells and positive immuno-double labelling with OKT6 and anti-IgE. Immunogold electron microscopy with anti-IgE on epidermal cell suspensions from patients with atopic dermatitis showed gold particles on the cell membranes of cells containing Birbeck granules, being Langerhans' cells. Epidermal cell suspensions from normal non-atopic controls were negative. The presence of IgE molecules on epidermal Langerhans' cells, which seems to be specific for patients with atopic dermatitis, provides an explanation for the high frequency of positive patch test reactions to inhalant allergens.

To evaluate the influence of haemoperfusion on haemodynamics, complement system, leucocyte and thrombocyte concentration, a controlled study was performed in three groups of five dogs each. During the first 30 min of haemoperfusion with columns containing cellulose-coated activated charcoal, a significant decrease of mean aortic pressure, cardiac output and stroke volume was observed, while heart rate and total systemic resistance decreased. A comparable phenomenon, although to a much lesser extent, was observed during perfusion using columns containing polystyrene resin. Perfusion with columns containing cellulose-coated activated charcoal caused a significant decrease in total haemolytic complement, indicating activation of the complement system. A significant decrease in the leucocyte and thrombocyte concentration due to sequestration of granulocytes and thrombocytes in the columns was observed during the first 30 min of perfusion in both groups. Pulmonary leucostasis, without decrease of arterial oxygen tension, occurred during perfusion with columns containing cellulose-coated activated charcoal. Both the simultaneous occurrence and the transient character of the haemodynamic changes, complement activation and sequestration of granulocytes and thrombocytes in the perfusion column suggest a relationship between these various changes. The results stress the importance of close monitoring of the haemodynamic parameters of the intoxicated patient, particularly during the early phase of haemoperfusion.

House dust subfractions obtained in the course of purification exhibit increasing skin reactivity in allergic patients, which runs parrallel to both complement-consuming and RAST-binding capacity. Working with highly purified house dust allergen in RAST, the correlation with clinical parameters for house dust allergy was found to remain poor. In a large group of sera a significant statistical correlation was found between total IgE and allergen-binding IgE. Ultracentrifugation experiments demonstrated that IgE binding to allergen in RAST occurs in complex with an unidentified serum protein. These results suggests that IgE binding in house dust RAST is indirect and is mediated by another serum factor.

A general survey is given of the chemistry and properties of the allergens causing bronchial asthma, eczema, and hay fever in "atopic" patients. The carrier molecules of, for example, the ubiquitous house-dust allergens are chemically unrelated structurally, though various allergens incorporate common structural sites of lysine--sugar conjugation. These sites probably activate a multi-enzyme system mediating allergic reactions and involving components of human complement. This process is non-immunological; the proposal is made that this mediator system is intrinsically more sensitive to nonspecific stimulation in allergic persons.

Two laboratory techniques have been applied for the diagnosis and follow-up of pigeon breeders' disease, viz. detection of precipitins against specific antigens from pigeon droppings and assays of human haemolytic complement (huC) consumption by pigeon dropping antigens. A simple laboratory test of huC consumption by pigeon antigens is described, revealing high huC sensitivity in almost all sera of pigeon breeders with manifest or former disease. False-positive results were seldom observed. Discontinuation of antigen exposure and/or corticosteroid therapy had no effect on the huC consumption level in the test system, despite precipitin titres falling below the level of detection. Titration studies revealed an initial decrease of the huC-consuming serum factors, but titres settled at a definite constant level, even after antigen avoidance for many years. Combined application of both the precipitin test and the huC consumption test appears to be a good procedure for the laboratory diagnosis of pigeon breeders' disease.

Hypersensitivity to ingested hen's egg yolk is described in a 65-year-old female patient. The patient's symptoms started in adult life and coincided with the acquisition of a parrot as a household pet. The bird's presence caused complaints of allergic rhinitis, while the ingestion of eggs caused urticaria and angioedema. Analysis of sequential blood serum samples revealed high levels of IgE antibodies to egg yolk and to various bird sera, but no precipitins. RAST-inhibition experiments indicated that the primary sensitization may have been to antigens from the parrot.

Complement factor's C3c, C4, factor B, C3d and the immunoglobulin IgA were determined in suction blister fluid of patients with erythropoietic protoporphyria and in normal controls. The levels increased when the skin of the patients had been previously irradiated with 'white light', but with Kromayer radiation, and were interpreted as being the result of increased vasopermeability.

A 33-year-old female patient with acquired cold urticaria, together with her 8-year-old healthy daughter, was subjected to a brief period of cold exposure. The effect of this treatment upon a number of key factors of the plasma coagulation, kallikrein and complement systems was investigated. Cold air provocation caused increased fibrinolysis, together with a measurable consumption of the protease inhibitors alpha1-antitrypsin (alpha1AT), alpha2-macroglobulin (alpha2M) and C1Inactivator (C1INA). Kaolin activation of the patient's plasma elaborated exceptionally high levels of esterolytic activity, both before and after cold exposure, indicating pre-enzyme lability. Both subjects had abnormally high serum ratios alpha2M/alpha AT. Impressive leucocytosis was observed in the symptomless child.

Three different aspects of delayed type hypersensitivity in atopic dermatitis (A.D.) were studied. (a) Intradermal testing demonstrated that positive reactions to bacterial vaccines were distinctly lower in patients with A.D. (b) Patch testing in patients with A.D. compared to tests in patients with anal eczema showed a striking difference in results concerning the substances to which positive reactions were found. (c) Patients with A.D. (n = 18), atopics without A.D. (n = 10), patients with contact dermatitis (n = 10), and normal controls (n = 10), were patch tested with various human dander (H.D.) fractions after stripping the stratum corneum with skin tape. Only patients with A.D. showed positive reactions, the maximum response being at 24-48 hours. There was no difference in reaction pattern between partially purified H.D. subfractions. Histopathological examination revealed an eczema-reaction. Patch testing within the same patient groups with purified house dust mite allergen P1 demonstrated similar results. Although this finding argues against a specific role of H.D. allergen in A.D. it may at least be concluded that H.D. preparations have the capacity to provoke immediate as well as delayed type skin reactions.

A 22-year-old female patient is described who was repeatedly hospitalised on account of severe asthmatic attacks presumably due to the ingestion of cow's milk or milk-containing products. There were no signs of gastrointestinal disturbance, but some urticaria and angioedema occurred. Strongly positive RASTs were observed in the blood serum against the proteins in cow's milk, bovine serum, egg white, cod fish, and house dust. The symptoms were successfully controlled by rigorous dietary measures.

Intradermal skin tests have been performed in atopic patients with allergenic extracts of different animal danders at uniform concentration. A high incidence of positive test was recorded which could not be related to the clinical histories, especially with the allergens of horse, cow and dog dander (NR). Better correlation was observed with guinea pig and cat allergens (R). The incidence of NR reactions was highest in the house dust allergy group of patients; with the exception of horse dander allergen, the frequency of R reactions was more pronounced in the grass pollen group. It is suggested that both allergen-specific and non-allergen-specific mechanisms may contribute to positive wheal and flare reactions.