Salivary kallikrein in Sjögren's syndrome

Using a chromogenic substrate (H-D-Val-Leu-Arg-pNA) salivary kallikrein levels were measured in whole saliva samples from patients suffering from Sjögren's syndrome (SS). Compared to healthy control individuals, SS patients, especially those without corticosteroid medication, exhibited significantly elevated kallikrein levels. A diurnal variation was found with the highest kallikrein activities in morning saliva. No correlation between kallikrein levels and extension of the inflammation in labial salivary glands (focus score), salivary flow rates or diagnosis (primary versus secondary SS) could be observed. A pathogenic mechanism for kallikrein in autoimmune sialadenitis is discussed.