Diagnostic value and challenges in the immune regulation of pentraxin 3 in infectious diseases

Infectious diseases pose a severe threat to human health, and their early and precise diagnosis and intervention remain a major challenge in clinical practice. This review systematically examines the diagnostic value and immunomodulatory role of PTX3 across a spectrum of infectious diseases, including those affecting the respiratory, cardiovascular, digestive, urinary, and nervous systems, as well as orthopedic and skin infections. The aim is to provide novel perspectives for overcoming the bottleneck in precise diagnosis and treatment of infectious diseases. Currently, diagnosis and assessment primarily rely on clinical manifestations, conventional inflammatory markers such as C-reactive protein (CRP) and procalcitonin, and pathogen detection. However, these methods often have limitations in sensitivity, specificity, and early warning capability, underscoring the need for novel, high-value biomarkers to enhance diagnostic and therapeutic precision. Long pentraxin 3 (PTX3), a key acute-phase reactant protein and soluble pattern recognition receptor (PRR), has recently garnered considerable attention for its role in infectious diseases. PTX3 is rapidly synthesized by innate immune and endothelial cells in response to stimulation by pathogens or inflammatory mediators. Functionally, PTX3 contributes to host defense through opsonophagocytosis, complement activation, and modulation of inflammatory responses. Quantification of circulating PTX3 levels demonstrates potential as an adjunctive biomarker for the diagnosis of infectious diseases and holds considerable value in early risk stratification, precise disease assessment, and personalized therapeutic strategies. Nevertheless, the clinical application of PTX3 faces two major challenges in immune regulation. Its broad-spectrum responsiveness to inflammation limits its specificity in pathogen differentiation, and the mechanisms underlying its immunomodulatory activity remain complex. This review systematically summarizes recent advances in the diagnostic significance and immunoregulatory mechanisms of PTX3, providing new insights into overcoming current challenges in the precision diagnosis and treatment of infectious diseases.