Brain-derived neurotrophic factor and oncostatin M as diagnostic and prognostic biomarkers for sepsis: Association between myokines and muscle mass

Background: Biomarkers for the diagnosis and prognosis of sepsis are urgently needed. Myokines secreted from muscles play a key role in the immune system. In the present study, we evaluated two myokines, brain-derived neurotrophic factor (BDNF) and oncostatin M, for their potential use as diagnostic and prognostic biomarkers for patients with sepsis. We also evaluated the association between myokines and muscle mass. Methods: . BDNF and oncostatin M levels were measured upon the initial diagnosis of sepsis, and again at the end of treatment, in patients who visited the emergency room between January 2016 and January 2020. On abdomen/pelvis computed tomography (CT) performed during the hospital stay, muscle mass was measured as an index of the total abdominal muscle area index (TAMAI). We evaluated the relationship between mortality due to sepsis, myokine levels, and muscle mass. Results: . A total of 210 participants (168 patients and 42 healthy controls) were enrolled in the present study. Median BDNF levels in patients diagnosed with sepsis and septic shock were significantly lower than in healthy controls. In contrast, median oncostatin M levels in patients with sepsis and septic shock were significantly higher than in healthy controls. BDNF and oncostatin M levels showed a statistically significant negative correlation. TAMAI in patients with sepsis and septic shock were 34.6 cm 2 /m 2 and 34.2 cm 2 /m 2 , respectively; however, the TAMAI had no correlation with either BDNF or oncostatin M levels. BDNF level was significantly higher in the 28-day survivors than in those that died. Increased oncostatin M levels were associated with higher 14- and 28-day mortalities. At the end of treatment, BDNF levels and muscle mass were significantly higher in survivors than in deceased patients. Conclusions: . BDNF levels were significantly lower, and oncostatin M levels were significantly higher in patients with sepsis and septic shock than in healthy controls. Muscle mass was significantly lower in patients who died as the result of sepsis; however, the levels of myokines were not associated with muscle mass. These results highlight the potential of BDNF and oncostatin M as diagnostic and prognostic biomarkers of sepsis.