2.4 | Data collection
After obtaining informed consent, the researcher interviewed the participants with a uniform questionnaire comprising of demographic and other data necessary for proper group qualification. Subsequently, basic anthropometric measurements were performed. Serum tryptase levels were determined using the ImmunoCAP method.
Blood samples for the measurement of plasma PAF-AH activity were collected on citrate and transported on ice to the laboratory. Afterwards, the samples were centrifuged at 4 °C for 10 minutes at an acceleration of 700 to 1000 g. The obtained plasma was stored frozen at -80 °C. Finally, the authorized laboratory analyst defrosted samples and loaded into the PAF Acetylhydrolase Assay Kit item No. 760901 produced by Cayman Chemical Company (USA). The test, based on the colorimetric method, was performed according to the manufacturer’s instructions. We used radiation with a wavelength of 412 nm. Measurements of the absorbance were made six times in a row, at 1-minute intervals in order to plot the appropriate linear function. The plasma PAF-AH activity was calculated in units of nmol/min/ml using a properly modified formula provided by the manufacturer of the kit.