Clinical value of soluble fms-like tyrosine kinase 1 (sFlt-1) in adult secondary hemophagocytic lymphohistiocytosis

Abstract

Background: Secondary hemophagocytic lymphohistiocytosis (sHLH) is a syndrome characterized by an excessive systemic inflammatory response, manifested by multiple organ dysfunction, lacking reliable immune biomarkers for predicting their inflammatory status and prognosis. Soluble fms-like tyrosine kinase 1 (sFlt-1) is associated with various inflammation-related diseases, including sepsis and severe organ failure. Methods: This study retrospectively included 32 adult sHLH patients diagnosed from January 2020 to December 2021. The expression of Flt-1 in peripheral blood CD14+ monocytes was detected by flow cytometry, and the level of plasma sFlt-1 was detected by ELISA. Results: In our study, the results of flow cytometry reveal that the Flt-1 expression on CD14+ monocytes of peripheral blood from sHLH patients was higher than that in normal control. In plasma samples of sHLH patients, sFlt-1 levels were 677.8 (463.2–929.7) pg/mL, significantly higher than in normal controls 377.18 (350.4–424.6) pg/mL and sepsis group 378.3 (257.0–499.1) pg/mL. Besides, a positive correlation was found between sFlt-1 and IL-6 in sHLH patients. The analysis of univariate Cox regression indicated that sFlt-1 >681.5 pg/mL demonstrated unfavorable overall survival (p = 0.022). Multivariate analysis demonstrated that sFlt-1 >681.5 pg/mL was an independent factor associated with OS (p = 0.041) after adjustment for confounders. Restricted cubic spline confirmed a linear and positive association between sFlt-1 and mortality risk. Conclusion: Retrospective analysis showed that sFlt-1 was a promising prognostic factor.