摘要Background:Inflammatory and nutritional indicators are established prognostic factors in patients with various types of solid tumors.However,it remains unclear whether differences in the baseline and early dynamic changes in these factors can predict the prognosis of immunotherapy in patients with advanced biliary tract carcinoma(aBTC).Methods:Data were retrospectively collected from 74 consecutive patients who were diagnosed with aBTC and received immunother-apy.Peripheral blood cell counts and other laboratory tests were performed at baseline and after two cycles of immunotherapy.The skeletal muscle index was measured using computed tomography/magnetic resonance imaging scans.Analyses of the relationship be-tween clinicopathological characteristics and survival outcomes were conducted using Kaplan-Meier curves and Cox regression models.Results:Seventy-four patients were enrolled in the study,with 42(56.8％)being male.The median age at diagnosis for all participants was 61 years(range,35-77 years).In the univariate analysis,six baseline indices were associated with survival,namely,lactate dehy-drogenase(LDH),carbohydrate antigen 199,neutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyte ratio,Prognostic Nutritional Index,and Controlling Nutritional Status score.In the multivariable analysis,an elevated baseline NLR(HR:3.363,95％CI:1.600-7.070,P=0.001)and elevated baseline LDH(HR:2.030,95％CI:1.122-3.670,P=0.019)were independent risk factors for a shorter overall survival.Sarcopenia was not correlated with the overall survival(P＞0.05).A persistently high NLR,platelet-to-lymphocyte ratio,and Controlling Nutritional Status score and low Prognostic Nutritional Index indicated a worse prognosis.Conclusions:Elevated baseline NLR and LDH values are independent negative prognostic factors in patients with aBTC receiving im-munotherapy.Patients with persistently high inflammation and poor nutritional status experience a poorer prognosis.