Galectin-9 plasma levels reflect adverse hematological and immunological features in acute dengue virus infection

Background: Dengue virus (DENV) infection remains a major public health burden worldwide. Soluble mediators may play a critical role in the pathogenesis of acute DENV infection. Galectin-9 (Gal-9) is a soluble p-galactoside-binding lectin, with multiple immunoregulatory and inflammatory properties. Objective: To investigate plasma Gal-9 levels as a biomarker for DENV infection. Study design: We enrolled 65 DENV infected patients during the 2010 epidemic in the Philippines and measured their plasma Gal-9 and cytokine/chemokine levels, DENV genotypes, and copy number during the critical and recovery phases of illness. Results: During the critical phase, Gal-9 levels were significantly higher in DENV infected patients compared to healthy or those with non-dengue febrile illness. The highest Gal-9 levels were observed in dengue hemorrhagic fever (DHF) patients (DHF: 2464 pg/ml; dengue fever patients (DF): 1407 pg/ml; non-dengue febrile illness: 616 pg/ml; healthy: 196 pg/ml). In the recovery phase, Gal-9 levels significantly declined from peak levels in DF and DHF patients. Gal-9 levels tracked viral load, and were associated with multiple cytokines and chemokines (IL-1 alpha, IL-8, IP-10, and VEGF), including monocyte frequencies and hematologic variables of coagulation. Further discriminant analyses showed that eotaxin, Gal-9, IFN-alpha 2, and MCP-1 could detect 92% of DHF and 79.3% of DF, specifically (P<0.01). Conclusion: Gal-9 appears to track DENV inflammatory responses, and therefore, it could serve as an important novel biomarker of acute DENV infection and disease severity. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.