Detection of inflammatory cytokines in Sjögren's syndrome patients using a novel salivary collection devic

Sjogren's syndrome (SS) is an autoimmune disease with an unknown cause that primarily affects women. SS is estimated to have a prevalence of 0.6% worldwide. Clinically, SS is characterized by xerostomia and xerophthalmia. Up to 4 millions Americans are affected by this disease. SS is challenging to diagnose and manage, as many individuals struggle with symptoms of disease for many years before a definitive diagnosis is rendered. The current diagnosis of SS is complicated and involves the confluence of several specialty areas. Saliva is emerging as a diagnostic fluid, as it is easy to collect and contains valuable diagnostic material. Our objective was to determine whether saliva from patients with SS has higher levels of inflammatory mediators as compared to healthy controls. Moreover, we sought to establish whether a novel collection device was superior to a conventional saliva collection method for detection of inflammatory cytokines. We recruited SS (n = 9) and healthy controls (n = 8), and collected saliva from them using a conventional method and a novel collection device termed the RNAPro SAL. We analyzed saliva using a cytokine multiplex array. Our results showed that the conventional method is superior to the RNAPro SAL for the detection IL-1alpha and IL-1beta. In contrast, the RNAPro SAL was superior to the conventional method in detecting IL-2, IL-5, TNFbeta, and IL-23. Saliva collected with the RNAPro SAL device revealed that SS patients showed higher levels of TNFbeta and lower levels of IL-5 compared to healthy controls. Therefore, cytokines in saliva may be useful in distinguishing SS patients, and the RNAPro SAL may be a valuable novel collection device for salivary diagnostics.