EVALUATION AND USEFULNESS OF OSTEOPROTEGERIN AND PRESEPSIN TITERS IN PATIENTS WITH SEPSIS: OUR PRELIMINARY EXPERIENCE

Blood culture is the gold standard for the diagnosis of severe sepsis and septic shock, but early diagnosis is the main objective to be pursued to improve patient survival. Osteoprotegerin (OPG), a glycoprotein belonging to the superfamily of tumor necrosis factor receptors (TNFr), is produced from stromal-osteoblastic line cells as well as activated T lymphocytes. OPG is able to inhibit bone resorption playing an important role in regulating bone degradation and it also prevents interaction with the RANK cellular receptor acting as a "fake" receptor activator of nuclear factor-ligand (RANKL). In fact, OPG binds to RANKL mimicking its receptor and decreasing availability for the RANK receptor, with offset of the biological effects of RANKL. During sepsis, OPG concentrations may increase. Presepsin is a protein whose blood concentrations specifically arise septic patients, and its dosage is useful in assessing severity of sepsis and in monitoring clinical response to therapeutic interventions. The purpose of this study was to assess whether a correlation exists between the concentrations of Presepsin and OPG in patients with positive blood culture. Materials and Methods: From April to May 2017, 15 patients having positive blood culture (11 males and 4 females) were selected (median age: M 58, F 78 ys). The presepsin (plasma lithium-heparine) assays were performed on the PathFast® analyzer (Mitsubishi Gepa) with chemiluminescence immunoenzymatic method. The OPG titer (serum) was determined on the DXSX System (TECHNO GENETICS) analyzer with ELISA method. Results: Linear Regression Line Parameters for Positive Specimens: log (y) = 0.79 + 0.000075 x; r = 0.74 (95% CI = 0.36 to 0.90) p <0.001. Conclusions: Our preliminary data show that, in patients with positive blood culture, the OPG concentration increase as well as of the Presepsin. During sepsis, there is on involvement of all tissues an increase of OPG concentration also suggest an involvement of bone tissue in particular inhibit bone resorption. Therefore, further studies with a larger groups of patients are needed to better understand the effective role of the OPG in sepsis.