Serum Mitochondrial Quality Control Related Biomarker Levels are Associated with Organ Dysfunction in Septic Patients.

Background: To investigate the feasibility and the value of using mitochondrial quality control (MQC)-related proteins as biomarkers in septic patients.

Methods: The enrolled subjects were divided into four groups: healthy control group (n = 30), intensive care unit (ICU) control group (n = 62), septic nonshock group (n = 40), and septic shock group (n = 94). Serum levels of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), fission protein 1 (Fis1), mitofusin2 (Mfn2), and Parkin were measured by enzyme-linked immunosorbent assay at the time of enrollment for all groups. Clinical parameters and laboratory test results were also collected.

Results: The levels of MQC-related biomarkers between any two of the four groups were significantly different (P < 0.001 for all). The serum levels of PGC-1α, Mfn2, and Parkin were lowest in healthy individuals; the levels were dramatically higher in the ICU control group compared with the others, and they decreased progressively from the septic nonshock group to the septic shock group. However, the pattern for Fis1 was inverse; the more severe the condition was, the higher the level of Fis1. Moreover, there was moderate correlation between MQC-related biomarkers and the SOFA score (PGC-1α, r = -0.662; Fis1, r = 0.609; Mfn2, r = -0.677; Parkin, r = 0.-0.674, P < 0.001 for all).

Conclusions: The serum levels of PGC-1α, Fis1, Mfn2, and Parkin were significantly correlated with organ dysfunction and reflected the disease progression and severity. The dynamic surveillance of these four biomarkers could be beneficial to predict outcome and guide treatment.