Investigating the role of pentraxin 3 as a biomarker for bacterial infection in subjects with COPD

Abstract

BackgroundPentraxin 3 (PTX3) is an acute phase protein, involved in antibacterial resistance. Recent studies have shown PTX3 levels to be elevated in the presence of a bacterial infection and in a murine sepsis model.ObjectiveWe aim to investigate if sputum PTX3 can be used as a biomarker for bacterial infection in subjects with COPD.Materials and methodsSputum samples from 142 COPD patients (102 men) with a mean (range) age of 69 years (45–85) and mean (SD) post-bronchodilator percentage predicted forced expiratory volume in 1 second (FEV1) of 50% (19) were analyzed for PTX3, using a commercial assay at stable state and during an exacerbation. Association with bacteria, from culture, quantitative real-time polymerase chain reaction (qPCR) and colony-forming units (CFU) was investigated.ResultsThe geometric mean (95% CI) PTX3 level at stable state was 50.5 ng/mL (41.4–61.7). PTX3 levels correlated with absolute neutrophil count in sputum (r=0.37; P<0.01), but not FEV1 or health status. There was a weak correlation between PTX3 and bacterial load (CFU: r=0.29, P<0.01; 16S qPCR: r=0.18, P=0.05). PTX3 was a poor predictor of bacterial colonization (defined as >105 CFU/mL at stable state) with a receiver-operating characteristic (ROC) area under the curve (AUC) of 0.59 and 95% confidence interval (CI) 0.43–0.76 (P=0.21). During an exacerbation, there was a modest increase in PTX3 (fold difference 0.15, 95% of difference 0.02–0.29; P=0.02), and PTX3 fared better at identifying a bacteria-associated exacerbation (ROC AUC 0.65, 95% CI 0.52–0.78, P=0.03).ConclusionPTX3 is associated with bacterial infection in patients with COPD, but its utility as a biomarker for identifying a bacteria-associated exacerbation warrants further studies.

Biomarkers of sepsis: time for a reappraisal

“…To diagnose infection in patients with a particular pathology/condition After cardiac surgery Endocan [92], CD64 [93], pancreatic stone protein [94] After major surgery Peptidoglycan [95], elastase [96], leptin [84], calprotectin [75], a proliferation-inducing ligand [97], α-2 macroglobulin [89], lipopolysaccharide-binding protein [15] COPD Pentraxin 3 [98] Cirrhosis Interleukin (IL)-6 [72] Trauma IL-10 [99], NT-proCNP [100], P-selectin [101] Catheter-related infections Citrulline [102] Infants with necrotic enterocolitis IP-10 [103]…”

The Long Pentraxin PTX3 as a Humoral Innate Immunity Functional Player and Biomarker of Infections and Sepsis

“…Serum and urinary PTX3 levels are increased in pyelonephritis patients and correlated with parameters of disease severity (12). In patients with chronic obstructive pulmonary disease (COPD), levels of PTX3 in sputum samples are associated with bacterial infections and can potentially be a marker of exacerbation of the disease (58). On the opposite, in children with lower respiratory tract infections, mostly of viral origin, PTX3 levels were increased irrespective of the causative agent, but were indeed correlating with the febrile peak and reflected disease severity (60).…”

Host-response biomarkers for the diagnosis of bacterial respiratory tract infections

“…Studies suggest the potential diagnostic value of pentraxin-3 in RTIs. Sputum pentraxin-3 levels were higher in chronic inflammatory pulmonary disease (COPD) patients with bacterial exacerbations compared to those with viral and non-infectious exacerbations [7]. However, COPD is an inflammatory state that could potentially affect levels of the inflammatory marker pentraxin-3, the effect of COPD per se on pentraxin-3 levels requires further investigation.…”