When we considered only the 70 patients who fulfilled clinical criteria for the diagnosis of pneumonia at the time of BAL fluid sampling, PTX3 diagnostic accuracy was confirmed both by both the AUCROC curve (AUCROC =0.838, 95% CI =0.737 to 0.941, P <0.0001) and univariate analysis (PTX3 levels ≥1 ng/ml in BAL fluid: β =3.065, SE =0.809, P <0.001), whereas all other mediators could not predict pneumonia. This evidence concerns the gene PTX3 and susceptibility to pneumonia measurement.