Pentraxin-3 as a marker of disease severity and risk of death in patients with necrotizing soft tissue infections: a nationwide, prospective, observational study

BACKGROUND New biomarkers are needed to assess the severity of necrotizing soft tissue infection (NSTI) at an early stage and to individualize treatment strategies. We assessed pentraxin-3 (PTX3) as a marker of disease severity and risk of death in patients with NSTI. METHODS We conducted a prospective, observational study in the intensive care unit at Copenhagen University Hospital, where treatment of NSTI is centralized at a national level. We compared PTX3, procalcitonin and C-reactive protein in septic shock versus nonshock patients and in amputated versus nonamputated patients using the Mann-Whitney U test. The prognostic value of the markers for 180-day mortality was assessed using Cox regression analyses. RESULTS Patients with NSTI (n = 135) were included over 25 months with up to 2.5-year follow-up; 71% had septic shock, amputation was undertaken in 20% and the 180-day mortality was 27%. Baseline plasma PTX3 level was significantly higher in patients with septic shock (67.3 versus 24.6 ng/mL, p < 0.0001) and in patients who underwent amputation (118.6 versus 43.6 ng/mL, p = 0.019). No significant differences in baseline procalcitonin or C-reactive protein levels were found according to amputation (25.2 versus 7.0 μg/L, p = 0.060 and 202 versus 225 mg/L, p = 0.123), respectively. Baseline PTX3 level above the median was associated with death (p = 0.009, log-rank test) and the univariate Cox regression analysis revealed a significant association between PTX3 level upon admission and 180-day mortality (hazard ratio 2.60 (95% confidence interval 1.28-5.29), p = 0.008). When adjusted for age, sex, chronic disease and Simplified Acute Physiology Score II, no significant association was found. CONCLUSIONS High PTX3 level is associated with septic shock, amputation and risk of death in patients with NSTI, but it is not an independent predictor of 180-day mortality in this patient group. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02180906. Date of registration: June 29, 2014.