Clinical Importance of the Inflammatory Prognostic Index in Patients with Sepsis

Background and Objectives: Sepsis is a life-threating organ dysfunction condition caused by the body's uncontrolled response to an infection. Many traditional and novel inflammatory markers have been used to determine poor prognosis in patients' sepsis. The inflammatory prognostic index (IPI) is also a novel marker of inflammation. As there are no studies examining the association of the IPI with in-hospital mortality in patients with sepsis nor its performance compared with other inflammatory markers, we aimed to investigate the clinical importance of the IPI for predicting in-hospital mortality in sepsis patients. Materials and Methods: A total of 157 consecutive patients diagnosed with sepsis were retrospectively included in this study. The systemic immune-inflammation index (SII; platelet × neutrophil/lymphocyte), the systemic inflammatory response index (SIRI; neutrophil × monocyte/lymphocyte), the aggregate index of systemic inflammation (AISI; neutrophil × platelet × monocyte/lymphocyte) and the IPI (C-reactive protein × neutrophil-to-lymphocyte ratio [NLR]/albumin) were calculated for all patients. Patients were divided into two groups: survivors (n = 81) and non-survivors (n = 76). Results: Non-survivor patients had significantly higher SII (p = 0.002), SIRI (p < 0.001), AISI (p = 0.002) and IPI (p < 0.001) than survivors. The AUC of the IPI was significantly higher than those of the SII (0.751 vs. 0.645; p = 0.010) and the AISI (0.751 vs. 0.648; p = 0.021) and tended to be higher than that of the SIRI (0.751 vs. 0.687; p = 0.091). Based on logistic regression analysis, the IPI was found to be an independent predictor of mortality (OR: 1.007, 95%CI: 1.002-1.012, p = 0.006). Conclusions: The IPI is a novel combined inflammatory marker that can be easily obtained from laboratory parameters. We determined that the IPI had moderately higher discriminatory ability than the SII and the AISI in patients with sepsis, which indicates that it may be used for risk stratification in this population.