CD5L as a potential immunomodulator in dengue severity

CD5L (CD5 antigen-like) is a secreted glycoprotein involved in immune regulation, macrophage polarization, and lipid metabolism. While its role in inflammatory and bacterial diseases has been described, its function in viral infections such as dengue virus (DENV) infection remains unclear. This study aimed to evaluate serum CD5L levels in dengue-infected individuals and investigate its association with serological markers and disease severity. A cross-sectional study involving dengue-positive and dengue-negative individuals was conducted to compare serum CD5L concentrations and assess correlations with NS1, IgM, IgG status, and disease severity.

Serum samples were collected from confirmed dengue-positive patients and dengue-negative controls. CD5L concentrations were quantified using enzyme-linked immunosorbent assay (ELISA) and analyzed according to serological profiles (NS1, IgM, and IgG). Two-group comparisons were performed using the Mann-Whitney U test, and multiple groups were analyzed using the Kruskal-Wallis test with Dunn's post hoc test. A P-value < 0.05 was considered statistically significant.

CD5L levels were significantly elevated in dengue-positive individuals compared to dengue-negative controls (P < 0.05), with the highest levels observed in IgG-positive only individuals (P < 0.01). No significant differences were seen in NS1-positive only or IgM-positive only groups, suggesting that CD5L upregulation is associated with IgG seropositivity rather than acute-phase markers. Similarly, CD5L levels did not significantly differ among individuals with combined serological markers (NS1 & IgM-positive, NS1 & IgG-positive, IgM & IgG-positive). Among IgG-positive only individuals, CD5L levels were significantly higher in non-severe dengue cases compared to severe dengue cases (P < 0.05). No significant differences were observed in CD5L levels between severe and non-severe NS1-positive only or IgM-positive only individuals. These findings suggest a potential association between increased CD5L and later stages of dengue virus infection with less severe outcomes.

This study highlights CD5L's potential role in dengue pathogenesis, particularly its association with IgG seropositivity and non-severe disease. Further research is needed to clarify its mechanisms and evaluate its potential as a biomarker or therapeutic target in dengue virus infection.