Table 1. Basal Serum tryptase (BST) from different laboratories. First 2 rows: routine diagnosis BST median values in 681 adults and 143 children in a single laboratory. Last 6 rows BST median values performed to determine local reference value in heathy donors, in adults, dosage performed either on serum or plasma, in two different type of instruments, and in different age in children from 3 days old newborns, in 1-9 years old children and 10-18 years old. Number of patients above the classical threshold (11.4µg/L) or the proposed threshold (8µg/L). Tryptase dosage was below the limit of detection of the technique (1µg/L) in few people. Data show mean (+1 SD) or median and [5-95 %] range. Female and male results show (%) of the population before median and range. BST values according to the age are compared to the adult, Unicap 250 values while female BST values