Prognostic importance of systemic immune inflammation index in chronic obstructive pulmonary disease

Objective: Chronic obstructive pulmonary disease (COPD) is associated with various immunopathophysiological pathways. Therefore, several inflammatory, hematological and immunological biomarkers are essential for diagnosis, prognosis, and survival of COPD. Among these inflammatory markers, such as C-reactive protein (CRP), neutrophil, lymphocyte and platelet counts were shown to have strong correlations with prognosis, survival and mortality. Recently, a novel inflammatory marker stated as systemic immune-inflammation index (SII) were presented as the most accurate in predicting inflammatory status and prognosis in various clinical settings. We aimed to investigate whether SII can be a useful tool for predicting prognosis and survival in COPD patients. Material and Methods: We aimed to evaluate retrospectively the effect of SII (the ratio of platelet and lymphocyte multiplication to neutrophil count) on the course of the COPD in 270 patients. The effect of hemogram values, spirometric measurements, such as FEV1, and CRP on the number of attacks in COPD patients seen in the outpatient clinic and the effect of SII on clinical or intensive care hospitalization in COPD patients were evaluated. Whether the SII correlates with symptoms and one-month survival in COPD patients were evaluated. FEV1 and CRP values, duration of hospitalization, smoking and modified Medical Research Council (mMRC) scales were correlated among each other. Results: mMRC was significantly correlated with FEV1(%) and FEV1(lt) levels, and CRP. The effects of mMRC, FEV1/FVC and smoking on survival in COPD patients were also significantly shown. CRP values were significantly correlated with WBC, neutrophil and lymphocyte counts, and SII values. Unfortunately, SII values were non-significantly correlated with FEV1 values, duration of hospitalization, smoking and mMRC, due to earlier stage and small number of cases. Conclusion: We investigated the clinical significance of SII on prognosis of COPD patients. SII might assist the identification of high-risk patients with low FEV1 and high CRP values. This study sheds light on future research on SII as a prognostic marker.