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Notes: Atopic subjects treated with pollen-tyrosine showed increased IgG and IgE antibody levels; in the second year of treatment the IgE response was suppressed.

Notes: Background Although most of the common allergen extracts that are used for diagnosis of type 1 hypersensitivity are now well standardized, this gives no assurance that they are within the concentration range that gives the best chance of a true diagnosis.Objective The objective of this study was to identify the most appropriate concentration range of timothy grass pollen Phleum pratense extract to diagnose sensitivity to this pollen correctly through skin-testing.Methods Dilutions of a well-standardized extract were made and used to skin test ‘true’ positive and ‘true’ negative populations of subjects as identified by case history, challenge tests and radioallergosorbent test (RAST). Weal diameters were measured and the data were submitted to receiver operating characteristics (ROC) analysis. For any particular weal size cut–off, the optimal diagnostic concentration (ODC) range was thus calculated.Results A 3 mm weal diameter cut-off was chosen as an appropriate size for routine diagnosis. Therefore the ODC range at this diameter was used to establish a product target concentration and specification for formulation of the diagnostic reagent. This method of allergen extract standardization can lead to a true-biological unitage that can be used for labelling purposes.Conclusion The optimun concentration range at which to formulate an allergen extract, in terms of an in vitro immunologically based assay, can be determined by carrying out ROC analysis of the results of clinical studies as described in this communication. Diagnostic units (DU), are now used by us for labelling of such final formulations which conveys the information that the product is at the most appropriate concentration for diagnosis.

Notes: Hyposensitization therapy gave a subjective improvement in 84% of grass pollen-sensitive patients receiving an eighteen dose course of aqueous pollen extract (SDV) and in 69 % of patients receiving a three dose course of glutaraldehyde-treated pollen-tyrosine adsorbate (Pollinex). Systemic reactions to treatment were considerably more frequent with the aqueous course, but virtually absent with the short adsorbate course, which seems therefore more convenient for the patient. The SDV treatment induced a more pronounced IgG antibody response both in patients and in guinea-pigs receiving the clinical dosage schedule. The Pollinex treatment showed a tendency to enhance the IgE antibody response in new patients.

Notes: Total IgG, IgG subclass and IgE antibodies specific for grass pollen allergens were measured by the red cell linked antigen-antiglobulin reaction (RCLAAR) in serum samples from nineteen patients who had undergone a course of hyposensitization. Increases in both specific IgG and IgE antibodies were seen after treatment in most patients. In the IgG subclasses the predominant response was for IgG1 and IgG4 antibodies. Attempts were made to correlate the antibody responses with the clinical response and the results are discussed with reference to the possible mechanisms of hyposensitization.

Notes: Background: We present data showing that a Th1-inducing adjuvant can reduce the number of injections required for allergy vaccination. Allergy vaccination is the only treatment for type 1 hypersensitivity that can alter the underlying disease process. A switch of specific T-cell activity from Th2〉Th1 to Th1〉Th2 is believed to be an important change seen after long-term vaccination therapy. An immunologic adjuvant that enhances such a switch could be used to reduce the number of injections required. This would improve compliance with the treatment and provide pharmacoeconomic advantages. Such an adjuvant is 3-deacylated monophosphoryl lipid A (MPL® adjuvant, Corixa). Methods: A multicentre, placebo-controlled, randomized, double-blind clinical study was performed with a new standardized allergy vaccine comprising a tyrosine-adsorbed glutaraldehyde-modified grass pollen extract containing MPL® adjuvant. Four subcutaneous injections of the active product were given preseasonally to 81 grass pollen-sensitive subjects, and 60 received placebo injections (tyrosine alone). Diary cards were used to record symptoms and medication taken during approximately 30 days of the grass pollen season. Results: There was a statistical advantage in favour of the active treatment for nasal (P=0.016) and ocular (P=0.003) symptoms and combined symptom and medication scores (P=0.013). Titrated skin prick testing revealed a significant reduction of skin sensitivity in the active group compared to placebo (P=0.04). Grass-pollen-specific IgG antibody was raised by active treatment (P〈0.01). A rise in IgE antibody was seen in the placebo group during the season (P〈0.01). The first year's treatment rise of IgE was not seen in the active group, and no rise occurred during the pollen season. More local adverse events were seen in the active group. There was no difference in generalized adverse events. Conclusions: A new, well-tolerated allergy vaccine, incorporating a Th1-inducing adjuvant, MPL®, was efficacious and after only four preseasonal injections produced antibody changes normally associated with long injection schedules. This may encourage wider application of allergy vaccination. The vaccine is now available in a number of countries as Pollinex Quattro®.

Notes: Summary Hypocotyls of detached stems standing in culture solution produced adventitious roots sooner than did petioles of detached primary leaves. An auxin, probably indol-3-ylacetic acid, appeared in the solutions before the hypocotyls or petioles produced roots. After attaining a maximum, the amounts of auxin in the solutions decreased as fewer roots were formed. Two cytokinins were found in the culture solutions; one had a similar Rf to zeatin, the other ran more slowly on chromatograms. The amounts of cytokinin in the solutions were associated with root formation. Stems soon died unless their hypocotyls formed roots, but the primary leaves survived without roots forming provided a callus formed on the petiole. Hence adventitious roots, or callus tissues, may have produced cytokinins that replaced those produced by the original roots, found in sap exuded from the stem stumps, and were essential for survival of the stems and leaves.