Pentraxins are a superfamily of conserved proteins that are characterized by a cyclic multimeric structure. The classical short pentraxins, C-reactive protein (CRP) and serum amyloid P component (SAP), are acute-phase proteins produced in the liver in response to inflammatory mediators. Short pentraxins regulate innate resistance to microbes and the scavenging of cellular debris and extracellular matrix components. In contrast, long pentraxins have an unrelated, long amino-terminal domain coupled to the carboxy-terminal pentraxin domain, and differ, with respect to short pentraxins, in their gene organization, chromosomal localization, cellular source, and in their stimuli-inducing and ligand-recognition ability. To investigate the in vivo function of the long pentraxin PTX3, we generated mice deficient in Ptx3 by homologous recombination. Ptx3-null mice were susceptible to invasive pulmonary aspergillosis. Ptx3 binds selected microbial agents, including conidia of Aspergillus fumigatus, and we found that susceptibility of Ptx3-null mice was associated with defective recognition of conidia by alveolar macrophages and dendritic cells, as well as inappropriate induction of an adaptive type 2 response. Thus, the long pentraxin Ptx3 is a secreted pattern-recognition receptor that has a non-redundant role in resistance to selected microbial agents, in particular to the opportunistic fungal pathogen Aspergillus fumigatus.

The long pentraxin (PTX) 3 is produced by macrophages and myeloid dendritic cells in response to Toll-like receptor agonists and represents a nonredundant component of humoral innate immunity against selected pathogens. We report that, unexpectedly, PTX3 is stored in specific granules and undergoes release in response to microbial recognition and inflammatory signals. Released PTX3 can partially localize in neutrophil extracellular traps formed by extruded DNA. Eosinophils and basophils do not contain preformed PTX3. PTX3-deficient neutrophils have defective microbial recognition and phagocytosis, and PTX3 is nonredundant for neutrophil-mediated resistance against Aspergillus fumigatus. Thus, neutrophils serve as a reservoir, ready for rapid release, of the long PTX3, a key component of humoral innate immunity with opsonic activity.

PTX3 is present in the intact myocardium, increases in the blood of patients with AMI, and disappears from damaged myocytes. We suggest that PTX3 is an early indicator of myocyte irreversible injury in ischemic cardiomyopathy.

Background-Inflammation has a pathogenetic role in acute myocardial infarction (MI). Pentraxin-3 (PTX3), a long pentraxin produced in response to inflammatory stimuli and highly expressed in the heart, was shown to peak in plasma Ϸ7 hours after MI. The aim of this study was to assess the prognostic value of PTX3 in MI compared with the best-known and clinically relevant biological markers. Methods and Results-In 724 patients with MI and ST elevation, PTX3, C-reactive protein (CRP), creatine kinase (CK), troponin T (TnT), and N-terminal pro-brain natriuretic peptide (NT-proBNP) were assayed at entry, a median of 3 hours, and the following morning, a median of 22 hours from symptom onset. With respect to outcome events occurring over 3 months after the index event, median PTX3 values were 7.08 ng/mL in event-free patients, 16.12 ng/mL in patients who died, 9.12 ng/mL in patients with nonfatal heart failure, and 6.88 ng/mL in patients with nonfatal residual ischemia (overall PϽ0.0001). Multivariate analysis including CRP, CK, TnT, and NT-proBNP showed that only age Ն70 years (OR, 2.11; 95% CI, 1.04 to 4.31), Killip class Ͼ1 at entry (OR, 2.20; 95% CI, 1.14 to 4.25), and PTX3 (Ͼ10.73 ng/mL) (OR, 3.55; 95% CI, 1.43 to 8.83) independently predicted 3-month mortality. Biomarkers predicting the combined end point of death and heart failure in survivors were the highest tertile of PTX3 and of NT-proBNP and a CK ratio Ͼ6. Conclusions-In a representative contemporary sample of patients with MI with ST elevation, the acute-phase protein PTX3 but not the liver-derived short pentraxin CRP or other cardiac biomarkers (NT-proBNP, TnT, CK) predicted 3-month mortality after adjustment for major risk factors and other acute-phase prognostic markers.