Recommendations for the Use of Tryptase in the Diagnosis of Anaphylaxis and Clonal Mastcell Disorders.

Summary: Tryptase is a serin-protease produced and released by mast cells after IgE-mediated or non-IgE mediated stimuli. We here review the various aspects related to the molecular characteristics of the enzyme and its biological effects, the genetic basis of its production and the release kinetics. Recommendations for the clinical use of tryptase measurement developed by a task force of Società Italiana di Patologia Clinica e Medicina di Laboratorio and Associazione Allergologi Immunologi Italiani Territoriali e Ospedalieri are given on the best procedure for a correct definition of the reference values in relation to the inter-individual variability and to the correct determination of tryptase in blood and other biological liquids, in the diagnosis of anaphylaxis (from drugs, food, insect sting, or idiophatic), death from anaphylaxis (post mortem assessment) and cutaneous or clonal mastcell disorders.

Effect of once daily and twice daily sustained release theophylline formulations on daytime variation of bronchial hyperresponsiveness in asthmatic patients.

BACKGROUND: Previous studies evaluating spirometric values and symptoms have shown that once daily theophylline administered in the evening produces greater stabilisation of the airway function in asthmatic patients than the prototype theophylline given twice a day. The aim of this study was to compare the effects on bronchial responsiveness to methacholine of an ultrasustained release theophylline formulation (Diffumal-24, Malesci, Florence, Italy) administered once a day, a sustained release theophylline formulation (Theo-Dur, Recordati, Milan, Italy) administered twice a day, and placebo. METHODS: The study was performed in 12 adult patients with asthma using a randomised, double blind, three phase, cross-over design. Each phase lasted seven days and was followed or preceded by at least three days of theophylline washout. Diffumal-24 was administered once a day at 20.00 hours whereas Theo-Dur was given twice a day at 08.00 hours and 20.00 hours. In each patient the total daily dose of theophylline was the same during both phases. The dose of the two active preparations was titrated to individual needs before the beginning of the study and then given in divided or once daily doses. At 08.00, 14.00, and 20.00 hours on day 7 of each phase serum theophylline concentrations were measured and spirometric tests (FEV1) and bronchial challenge with methacholine were also performed. RESULTS: When the administration of Diffumal-24 was compared with that of Theo-Dur, a higher serum theophylline concentration of the former was seen in the morning whereas at 20.00 hours the reverse was true. Compared with placebo, at 08.00 hours Diffumal-24 improved FEV1 whereas Theo-Dur did not (difference between treatments 0.29 1, 95% CI 0.12 to 0.45). At 08.00 hours Diffumal-24 decreased bronchial sensitivity to methacholine, expressed as a natural logarithm of PD20, to a greater extent than Theo-Dur (difference between treatments 0.54 log units, 95% CI 0.016 to 1.08). The morning advantage observed with Diffumal-24 administration was not associated with a deterioration in the state of the airway during the daytime, the protective activity against methacholine during the 12 hours of the monitoring period being constant. Furthermore there was no difference in the mean FEV1 between the two treatments at 14.00 and 20.00 hours. CONCLUSIONS: In adults with stable bronchial asthma treatment with a single dose of Diffumal-24 administered in the evening improved airflow obstruction and reduced bronchial hyperresponsiveness.