A NEW BIOMARKER IN SJOGREN’S SYNDROME? PAN-IMMUNE-INFLAMMATION VALUE AND ITS CLINICAL APPLICABILITY

Objective: Primary Sjogren’s syndrome (pSS) is a systemic autoimmune disease that primarily affects exocrine glands. The conventional inflammatory markers commonly used to assess disease activity, such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), have limited sensitivity. This study aimed to investigate the relationship between the Pan-Immune-Inflammation Value (PIV), disease activity (ESSDAI), and inflammatory markers (CRP, ESR) in patients with pSS. Material and Methods: This retrospective study included 63 patients diagnosed with pSS according to the 2016 ACR/EULAR criteria and 52 healthy controls.PIV was calculated using neutrophil, monocyte, platelet, and lymphocyte counts at diagnosis. Disease activity was assessed using the EULAR Sjogren's Syndrome Disease Activity Index (ESSDAI), and CRP and ESR levels were recorded. Statistical analysis included the Mann-Whitney U test for group comparisons, Spearman correlation for associations,ROC analysis to evaluate discriminative performance, and univariate logistic regression for effect assessment. Results: The mean PIV was 329.52±264.32 in the patient group and 291.67±201.54 in the control group (p=0.552). ESR levels were significantly higher in patients compared to controls(p=0.000), while CRP levels did not differ significantly (p=0.093). A weak, non-significant positive correlation was observed between PIV and ESSDAI (rho=0.107, p=0.414), whereas a significant moderate correlation was found between PIV and ESR (rho=0.311, p=0.018). Although the mean PIV was higher in the moderate-high disease activity group, the difference did not reach statistical significance (p=0.071). ROC analysis yielded an AUC of 0.675 for PIV in predicting higher disease activity. Conclusion: PIV may serve as an indirect indicator of inflammatory activity in pSS. While not sufficient as a standalone marker, it has potential as a complementary biomarker to identify patients with higher systemic disease activity. Further prospective studies with larger sample sizes are warranted.