Prognostic Nutritional Index Negatively Correlates with Lung Allocation Score and Predicts Survival after Both Cadaveric and Living-Donor Lobar Lung Transplantation

Abstract

The preoperative nutritional status affects the clinical outcome of surgery. To predict the clinical outcome, a prognostic nutritional index (PNI) calculated using serum albumin levels (ALB) and total lymphocyte count (TLC) has been shown to be valuable in various fields of surgery. In this study, we investigated the relationship between PNI and lung allocation score (LAS) as well as the impact of PNI on outcomes of lung transplantation (LT), including cadaveric lung transplantation (CLT) and living-donor lobar lung transplantation (LDLLT). Between June 2003 and August 2016, a total of 127 patients underwent LT at Okayama University Hospital, including 71 recipients of CLT and 56 recipients of LDLLT. The PNI was calculated by the following equation: PNI = (10 × ALB(g/dl)+(0.005 × TLC(/mm3)). The overall survival was evaluated by univariate analysis (the log rank test) and multivariate analysis (the Cox proportional hazard regression model) using preoperative factors, including sex, age, BMI, diagnosis, oxygen concentration, mechanical ventilation, tracheostomy, ECMO support, use of glucocorticoids, serum creatinine level, diabetes mellitus, LAS, and PNI. PNI was significantly negatively correlated with LAS (r=-0.3, P=0.00062) (Fig. 1A). The univariate analysis revealed that the overall survival was significantly worse in the patients with age>28 (P=0.047), BMI<24.2 (P=0.0098), LAS>58.04 (P=0.000072), PNI<46.35 (P=0.018) (Fig. 1B). The multivariate analysis demonstrated that age (P=0.00093), BMI (P=0.0024), and PNI (P=0.0047) were independent prognostic factors of worse outcome. In the subgroup analysis, low PNI is a significant prognostic factor of worse survival after CLT (P=0.015) (Fig. 1C) and LDLLT (P=0.041) (Fig. 1D). Preoperative nutritional evaluation using PNI could contribute to the assessment of LT recipient's severity and predict survival after both CLT and LDLLT.