Circulating Pentraxin-3 and its association with C-reactive protein levels and disease activity in patients with chronic spontaneous urticaria

Introduction: Pentraxin-3 (PTX3) is a soluble long pentraxin molecule that regulates inflammatory responses. This study aimed to determine the plasma levels of plasma PTX-3 as an inflammation marker in chronic spontaneous urticaria (CSU) and whether the PTX3 levels correlate with disease activity and other clinical parameters, including acute phase reactants and biomarkers. Methods: The study included 70 CSU patients and 30 healthy controls. Plasma PTX3 levels were measured by ELISA. CSU disease activity was evaluated with the urticaria activity score summed over 7 days. Complete blood count, C-reactive protein (CRP), transaminases, total IgE, antinuclear antibody, anti-thyroid peroxidase, anti-thyroglobulin, and D-dimer levels were recorded. Results: Of the 70 patients, 52 (74.3%) were female, with a mean age of 37.51 ± 11.80 years. Disease activity was severe in 43, moderate in 15, and mild in 12 patients. Mean PTX3 levels were elevated in CSU patients compared to healthy controls (0.81 vs. 0.55 ng/mL, p = 0.031). The mean CRP levels were higher in patients than in the controls (4.26 vs. 1.57 mg/L, p = 0.023). Patients also had higher D-dimer levels than the controls (5.96 vs. 0.59 mg/L, p < 0.001). A significant positive correlation was found between PTX3 and CRP levels (r = 0.508, p < 0.001) and between D-dimer levels and UAS7 (r = 0.338, p = 0.004) and CRP (r = 0.213, p = 0.034) levels. A multivariable stepwise regression analysis showed that the one-unit increase in the CRP level increased to 38.19 units in the PTX3 level (95% confidence interval [17.40–58.98], p < 0.001). Conclusion: Circulating levels of CRP and PTX3, two members of the pentraxin family, are significantly correlated and elevated in CSU patients with increasing disease activity, indicating their utility as inflammatory markers in CSU.