Discrimination of the infectious or non-infectious origin of a pulmonary infiltrate remains an everyday clinical problem. CPIS was introduced for that purpose helping considerable in cases of ventilator-associated pneumonia (VAP) [23] . TREM-1 is a surface receptor on cells of the myeloid lineage. Activation of TREM-1 leads to the production of pro-inflammatory cytokines [9, 31, 32] . Binding of its ligand is possibly linked to the activation of several transcription complexes that synergize with NF-B in order to elicit transcription of genes of pro-inflammatory cytokines [8] . sTREM-1 is the soluble counterpart of TREM-1 and it is probably shed in the systemic circulation from cell membranes of neutrophils and monocytes [7, 33, 34] . The physiologic role of sTREM-1 remains under question despite data support a probable anti-inflammatory role [31, 35] .