Diagnostic biomarkers for Sepsis and septic shock: A NMR based serum metabolomics study

Despite the availability of advanced treatment, sepsis and septic shock have the highest mortality in the intensive care unit. Theories suggested that targeting hyper inflammation can aid treatment, but oxidative stress plays a major role in disease pathogenesis. The present study aimed to explore the nuclear magnetic resonance (NMR) - based serum biomarkers of sepsis and septic shock resultant of oxidative stress. The serum metabolic profile of n = 41 septic shock, n = 21 sepsis, and n = 16 disease control patients were collected and analyzed using a 1D ¹H Carr Purcell Meiboom Gill (CPMG) pulse program. NMR spectroscopy-based quantitative assessment of metabolites was performed to compare the activity of lactate dehydrogenase and phenylalanine hydroxylase between sepsis, septic shock, and disease control in sepsis and septic shock by comparing pyruvate/lactate (Pyr/Lac) and phenylalanine/tyrosine (Phe/Tyr) ratios. These ratios were evaluated for their discriminatory potential, statistical and clinical significance. We found out that Pyr/Lac ratio was lowest in septic shock followed by sepsis and disease control, Phe/Tyr ratio was highest in septic shock, followed by sepsis and disease control. Pyr/Lac ratio and Phe/Tyr were negatively and positively correlated with APACHE II. Both the ratios illustrated high discriminatory potential in AUROC evaluation. The results presented in the study demonstrate that lactate dehydrogenase activity is elevated and phenylalanine hydroxylase declines in septic shock. This could be used as an effective tool for diagnosis, prognosis, evaluation of disease activity, and treatment response.