Diagnostic value of pentraxin 3 in plasma and bronchoalveolar lavage fluid for invasive pulmonary aspergillosis in non-neutropenic patients: a prospective multicenter clinical study

Objectives: To evaluate the diagnostic performance of pentraxin 3 (PTX3) in plasma and bronchoalveolar lavage fluid (BALF) for invasive pulmonary aspergillosis (IPA) in non-neutropenic patients. Methods: This prospective, multicenter cohort study enrolled 605 patients with clinically suspected IPA, including 195 IPA cases and 410 non-IPA controls. BALF and/or plasma samples were collected from all participants. PTX3 levels were measured by enzyme-linked immunosorbent assay. Diagnostic value was assessed using receiver operating characteristic curve analysis. Results: PTX3 levels in both BALF and plasma were significantly higher in IPA patients than in non-IPA controls (BALF: 8.98 [3.47–22.53] ng/ml vs. 1.12 [0.46–3.35] ng/ml, P < 0.0001; plasma: 8.29 [4.68–21.41] ng/ml vs. 2.60 [1.35–5.02] ng/ml, P < 0.0001). The optimal cutoff value of BALF PTX3 for diagnosing IPA was 2.67 ng/ml, with an area under the curve (AUC) of 0.84 (95% CI, 0.80-0.89), sensitivity of 85.57% (95% CI, 77.22-91.20), and specificity of 71.72% (95% CI, 66.28-76.60). For plasma PTX3, the optimal cutoff value was 4.17 ng/ml, with an AUC of 0.80 (95% CI, 0.75-0.85), sensitivity of 79.51% (95% CI, 71.50-85.72), and specificity of 69.79% (95% CI, 64.26-74.81). In paired analysis, BALF PTX3 showed significantly higher sensitivity than BALF galactomannan (GM) (86.96% vs. 72.83%, P = 0.037). Parallel combination of BALF PTX3 and GM increased diagnostic sensitivity to 97.83%. Conclusions: Both BALF and plasma PTX3 serve as valuable adjunctive biomarkers for IPA in non-neutropenic patients. PTX3 markedly improves diagnostic sensitivity, especially when combined with GM, supporting its role in the early and rapid rule-out of IPA.