Monitoring treatment response using serial PTX3 levels in chronic and invasive pulmonary aspergillosis.

Background: Pentraxin 3 (PTX3) is an innate immune biomarker involved in host defense against Aspergillus species. While elevated PTX3 levels have been observed in various infection states, its utility in monitoring treatment response in pulmonary aspergillosis remains underexplored.

Methods: We assessed serial PTX3 levels in total 216 patients with chronic pulmonary aspergillosis (CPA, n = 48) and invasive pulmonary aspergillosis (IPA, n = 48) before and after antifungal therapy. Comparative groups included controls (n = 69), COVID-19 patients (n = 36), and allergic bronchopulmonary aspergillosis (ABPA, n = 15). Serum PTX3 concentrations were measured by ELISA and analyzed in relation to treatment response. Neutrophil extracellular trap (NET) formation under various stimuli was evaluated and correlated with PTX3 levels to explore immune activation patterns.

Results: PTX3 levels were significantly elevated in CPA and IPA compared to controls. Among patients with serial samples, PTX3 levels declined significantly in favorable responders (from 299.0 [119.5-477.0] to 138.3 [80.9-386.1] pg/mL; p < 0.05), but increased in unfavorable responders (from 177.1 [117.8-318.8] to 243.0 [169.5-488.4] pg/mL; p < 0.05). PTX3 changes correlated with disease course and NET responses in a phenotype-specific manner.

Conclusion: Serial measurement of PTX3 may serve as a useful biomarker for monitoring treatment response in pulmonary aspergillosis. PTX3 dynamics reflect underlying immune activity and may aid in identifying disease progression or relapse.