A nylon ball solid-phase radioimmunoassay for specific antibodies in human sera. Application to measurement of IgG antibodies to pollen allergens.

The principle of the radioallergosorbent test (RAST) has been used to measure IgG antibodies to timothy grass pollen allergens in sera from desensitized allergic subjects. 125I-labeled goat anti-human IgG was used as detector protein. Non-specific binding was eliminated by use of a non-porous nylon ball an antigen carrier and by use of a special buffer with high ionic strength and pH, containing 1% bovine gamma globulin and 5% normal rabbit serum as 'balance proteins'. At dilution 1:80 non-specific binding was only 0.28% and the binding ratio for a high-liter serum was about 10. By inhibition experiments the assay was demonstrated to be specific for IgG antibodies to timothy grass pollen. The results obtained with this assay correlated statistically significantly with those found th a double -antibody method (rs equal 0.68, n equal 20, t equal 3.93, P less than 0.001). Serum dilution curves were parallel, indicating that the assay is in allergen excess. The within-assay coefficient of variation ranged from 3.9 to 7.6%; the between-assay coefficient of variation from 8.4 to 19.5%. The assay is very simple to perform, requiring no centrifugation. The allergen-coated balls are stable for at least 3 months. The assay should be applicable to measurement of IgG antibodies and IgG subclass antibodies to any protein antigen of interest.

A sensitive and reproducible method for the determination of subnanogram quantities of immunoglobulin E (IgE).

An immunoradiometric assay for immunoglobulin E (IgE) using high adsorption polystyrene test tubes as the solid phase (the 'Maxisorp' assay) is described. The sensitivity of the method was found to be 50 pg IgE/ml and the within-assay reproducibility was 3-7%. The accuracy was estimated by means of a comparison between the Maxisorp assay and paper radioimmunosorbent test (PRIST) and a correlation coefficient of 0.98 (P less than 0.001) was obtained. We conclude that the Maxisorp assay is a fast and reliable assay for IgE determination in cord blood, cell culture supernatants and other highly diluted IgE preparations.

Reproducibility of challenge tests at different times.

Bronchial challenge for determination of bronchial reactivity is widely used in the diagnosis of asthma, the grading of severity, and evaluation of effect of treatment with new antiasthmatic drugs. Allergen challenge is also used for diagnosis of specific IgE-mediated asthma and evaluation of the effect of immunotherapy. A number of factors influence the result of the challenge test including the selection of patients, criteria for carrying out the challenge test, a number of technical factors concerning the challenge, the dosing schedule, pulmonary function tests carried out and analysis of the data. All these factors have to be taken into consideration before reproducible challenge tests can be performed. Detailed description of the equipment and procedures used and inclusion criteria for the patients should be included in all publications concerning challenge tests in order to be able to compare results from different laboratories. Each clinic or laboratory needs to perform reproducibility studies on bronchial challenge testing procedures and equipment used in their clinic.

Comparison between different techniques for measuring nasal patency in a group of unselected patients.

Many techniques for measuring nasal patency have been developed in search for a reliable, easily performed and reproducible method. Rhinomanometry is easily performed in the clinic but daily records of nasal blocking cannot be obtained. In this study we examined the correlation between posterior rhinomanometry (PR), nasal peak flow (nPF), the ratio nasal patency index (NPI), and the opening interrupter method (Rtn) for measuring nasal patency. Twenty-eight subjects with no symptoms of rhinitis and 20 patients with diagnosed rhinitis were investigated. A significant (p less than 0.05) correlation was found between PR and nPF after stratification according to the diagnosis of rhinitis and between nPF, PR, and height. All other correlations tested proved non-significant. We conclude that PR is the method which ought to be used in the hospital, but nPF is an easy way to measure nasal patency and might even be used by the patient at home.

[High dose inhaled steroids in the treatment of bronchial asthma. A comparison of the effects of budesonide and beclomethasone dipropionate on pulmonary function, symptoms, bronchial reactivity and adrenocortical function]. / Højdosis inhalerede steroider i behandlingen af asthma bronchiale. En sammenligning af effekten af budesonid og beklometason-dipropionat på lungefunktion, symptomer, bronkial reaktivitet og binyrebarkfunktion.

The effects of high-dose inhaled budesonide (800 micrograms twice daily) and those of inhaled beclomethasone dipropionate (750 micrograms twice daily) were compared with respect to lung function, symptoms, bronchial reactivity and adrenocortical function in a doubleblind, double-dummy cross-over study. The subjects were 40 adult patients suffering from either allergic or non-allergic asthma. The asthma was categorized as moderate to severe, and the asthma was insufficiently controlled on inhalational steroids given in doses of 300 to 500 micrograms daily. After a two week "run-in" period the patients were randomized to six weeks treatment with either budesonide or beclomethasone dipropionate, followed by six weeks treatment with the opposite drug. Both inhaled budesonide and inhaled beclomethasone dipropionate were able to improve objective measures of lung function and bronchial sensitivity to histamine. Neither drug affected adrenocortical function, and no serious side-effects were noted during the trial. It is concluded that budesonide and beclomethasone dipropionate are safe and effective drugs for the treatment of asthma in adults. The substances are equally effective taken microgram for microgram.

Immunotherapy of extrinsic asthma.

It is an elegant treatment of IgE allergic inflammation in the airways. It must be started very early in the allergic disease together with allergen avoidance, prevention, optimal symptomatic and antiinflammatory treatment and general health care.