Distinct inflammatory markers in primary and secondary dengue infection: can cytokines CXCL5, CXCL9, and CCL17 act as surrogate markers?

Dengue fever poses a significant global health threat, with symptoms including dengue hemorrhagic fever and dengue shock syndrome. Each year, India experiences fatal dengue outbreaks with severe manifestations. The primary cause of severe inflammatory responses in dengue is a cytokine storm. Individuals with a secondary dengue infection of a different serotype face an increased risk of complications due to antibody-dependent enhancement. Therefore, it is crucial to identify potential risk factors and biomarkers for effective disease management. In the current study, we assessed the prevalence of dengue infection in and around Aligarh, India, and explored the role of cytokines, including CXCL5, CXCL9, and CCL17, in primary and secondary dengue infections, correlating them with various clinical indices. Among 1,500 suspected cases, 367 tested positive for dengue using Real-Time PCR and ELISA. In secondary dengue infections, the serum levels of CXCL5, CXCL9, and CCL17 were significantly higher than in primary infections (P < 0.05). Dengue virus (DENV)-2 showed the highest concentrations of CXCL5 and CCL17, whereas DENV-1 showed the highest concentrations of CXCL9. Early detection of these cytokines could serve as potential biomarkers for diagnosing severe dengue, and downregulation of these cytokines may prove beneficial for the treatment of severe dengue infections.