Profile of plasma amino acids values as a predictor of sepsis in patients following living donor liver transplantation: Special reference to sarcopenia and postoperative early nutrition

Aim: Sarcopenia is an independent predictor of mortality and sepsis after living donor liver transplantation (LDLT). However, the exact mechanisms by which sarcopenia affects poor prognosis or worse immunity against postoperative sepsis are unclear, particularly regarding muscular amino acid metabolism, and the authors aimed to identify the role of plasma amino acids in sarcopenia by retrospective study. Methods: The area of the psoas muscle in 228 recipients of LDLT was retrospectively measured by dynamic computed tomography. Additionally, plasma amino acid levels were measured both pre- and postoperatively. The impact of plasma amino acids for postoperative sepsis and the relationship between sarcopenia and early nutrition after LDLT were analyzed. Results: Among the plasma amino acids, only leucine, isoleucine and glutamine in patients with sarcopenia were significantly lower than those without sarcopenia (each, P < 0.05). Multivariate analysis identified the lower plasma glutamine levels as a risk factor of postoperative sepsis after LDLT (odds ratio 5.371, P = 0.002). In sarcopenia patients, plasma glutamine levels after LDLT were significantly decreased compared with before LDLT in patients both with and without postoperative early nutrition. However, in non-sarcopenia patients with early nutrition, plasma glutamine levels after LDLT were comparable with those before LDLT. Conclusion: This is the first report to study the profile of plasma amino acid change before and after LDLT. Low preoperative glutamine values were an independent risk factor for predicting postoperative sepsis. The efficacy of postoperative early nutrition may prevent postoperative sepsis by improving glutamine levels.