Pentraxin 3 is an inflammation-related biomarker that distinguishes early-stage from mid-advanced cardiovascular-kidney-metabolic syndrome.

The cardiovascular-kidney-metabolic (CKM) syndrome represents a continuum linking metabolic dysfunction, chronic kidney disease, and cardiovascular disease, in which chronic inflammation plays a central role. However, conventional inflammatory biomarkers may not fully capture local inflammatory processes involved in CKM stage transitions. Pentraxin 3 (PTX3), a long pentraxin produced locally at sites of inflammation, may provide complementary information, yet its association with CKM staging has not been systematically evaluated. In this cross-sectional study, circulating PTX3 levels were measured in 240 adults, including healthy controls (stage 0, S0; n = 60) and individuals with stage 2 (S2; n = 60), stage 3 (S3; n = 60), and stage 4 (S4; n = 60) CKM, classified according to the CKM staging framework. Associations between PTX3 and inflammatory, metabolic, cardiac, and renal biomarkers were assessed using Spearman correlation analysis. Multivariable logistic regression models were constructed within the CKM population (S2-S4) to distinguish early-stage CKM (S2) from mid-advanced-stage CKM (S3 + S4). Model discrimination and calibration were evaluated using receiver operating characteristic (ROC) analysis and the Hosmer-Lemeshow goodness-of-fit test. PTX3 levels were significantly elevated in early-stage CKM (S2) compared with healthy controls (p < 0.001) and showed further differentiation between S2 and S3 (p < 0.01). PTX3 showed moderate correlations with biomarkers reflecting inflammatory activation, metabolic dysregulation, myocardial injury, and renal dysfunction, including high-sensitivity C-reactive protein (hs-CRP; r