Value of serum tryptophan in stratified management of 90-day mortality risk in patients with hepatitis B virus-related acute-on-chronic liver failure: a multicenter retrospective study.

Objectives: To explore the correlation of serum tryptophan level with 90-day mortality risk in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF).

Methods: This retrospective study was conducted among 108 patients with HBV-ACLF, whose survival outcomes within 90 days after diagnosis were recorded. The correlation of baseline serum tryptophan levels measured by high-performance liquid chromatography with 90-day mortality of the patients was analyzed, and the predictive value of serum tryptophan for 90-day mortality was explored.

Results: Within 90 days after diagnosis, 53 (29.4%) of the patients died and 127 (70.6%) survived. The deceased patients had significantly lower baseline serum tryptophan levels than the survivors (7.31±3.73 pg/mL 13.32±7.15 pg/mL, <0.001). Multivariate analysis suggested that serum tryptophan level was an independent factor correlated with mortality of HBV-ACLF after adjustment for confounding variables. The patients with serum tryptophan levels below the median level (10.14 pg/mL) at admission had significantly higher 90-day mortality risks than those with higher tryptophan levels (43.3% 15.6%, : 3.157, 95% : 1.713-5.817), and the complication by kidney dysfunction further increased the risk to 73.3% as compared with patients with higher serum tryptophan levels with normal kidney function (15.0%; HR: 7.558, 95% : 3.369-16.960). Serum tryptophan levels had an area under the receiver operating characteristic curve of 0.771 (95% : 0.699-0.844) for predicting 90-day mortality.

Conclusions: Serum tryptophan level is closely correlated with the survival outcomes of patients with HBV-ACLF, and a decreased tryptophan level indicates a high 90-day mortality risk, which can be further increased by the complication by kidney dysfunction.