Salivary IFN-γ/IL-4 Ratio as a Mirror of Patient Experience: Unraveling Self-Reported Health and Disease Etiology in Sjögren’s Disease – a Pilot Study

Background/Objectives: To determine whether self-reports on the onset, perceived causes and activity of Sjögren’s disease (SjD) can reflect the local immune status? Materials and methods: This prospective study enrolled a cohort of 80 patients with sicca symptoms (dry eyes and dry mouth) referred to the outpatient department of the State Research Institute Center for Innovative Medicine between September 2024 and January 2026. The study population comprised two distinct clinical groups: 37 patients diagnosed with SjD and 43 patients with non-autoimmune sicca syndrome (nonautoimmunSicca) due to gastroesophageal reflux disease (GERD). All patients indicated the perceived causes of their disease, the symptoms at the onset of the disease, and the activity of the disease using Visual analog scale (VAS). Cytokine levels in saliva were measured using enzyme-linked immunosorbent assay (ELISA). Results: The IFN-γ/IL-4 ratio was significantly increased in patients with SjD (median 158.7 (IQR 67.4–465.1) vs. 31.80 (IQR 20.9–45.5); p < 0.001). The IFN-γ/IL-4 ratio was significantly and negatively correlated with extraglandular symptoms at the onset of the disease, time from the 1st symptoms, salivary flow rates, and positively correlated with dryness score according to VAS in patients with SjD. The IFN-γ/IL-4 ratio was significantly and negatively associated with salivary flow rates and positively correlated with dryness score according to VAS in patients with nonautoimmunSicca. We also found a positive correlation between the perceived cause of the disease and the dryness score on the VAS, as well as a negative correlation between saliva flow rate and the concentration of IFN-γ in saliva among patients with SjD. The salivary IL-4 levels significantly and positively correlated with salivary flow rate, as well as negatively with pain and dryness score on the VAS in SjD group. Conclusions: Patient-reported information regarding disease onset, perceived causes, and symptoms severity of SjD significantly correlates with local Th1/Th2 mucosal immune status, suggesting that patient experiences may reflect underlying inflammatory trends and support patient-centered clinical evaluation.