Intelectin-1 and systemic inflammation indices as potential biomarkers in alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative condition marked by amyloid-beta deposits, tau pathology, chronic systemic inflammation, and metabolic disturbances. Recent evidence highlights the relevance of inflammatory markers and adipokines as practical blood-based biomarkers in AD diagnosis. In this cross-sectional study, 70 patients with probable AD and 50 healthy controls matched for age and sex were evaluated. Cognitive performance was measured using the Standardized Mini Mental Test (SMMT). Serum intelectin-1 (ITLN1) and tumor necrosis factor-alpha (TNF-α) levels were analyzed, and hematologic indices were used to calculate the Systemic Immune-Inflammation Index (SII), Systemic Inflammation Response Index (SIRI), and CALLY index. Compared to controls, individuals with AD exhibited significantly lower ITLN1, albumin, lymphocyte counts, and CALLY index, while CRP, neutrophil and monocyte counts, SII, and SIRI were notably higher. TNF-α concentrations showed no significant difference between groups. ITLN1 and CALLY levels correlated positively with SMMT scores, whereas SII and SIRI correlated negatively. ROC analysis indicated that ITLN1 (AUC = 0.764), CALLY (AUC = 0.754), SII (AUC = 0.734), and SIRI (AUC = 0.787) had moderate discriminatory ability. This study suggests that reduced ITLN1 and increased systemic inflammation indices are associated with AD and may reflect underlying metabolic and inflammatory pathways involved in disease progression. Although TNF-α levels were variable, ITLN1, SII, SIRI, and CALLY indices demonstrated potential as peripheral biomarkers to help distinguish patients with AD. Future large-scale prospective research is needed to further clarify their clinical utility.