Pilot Proteomic Analysis of Immune Dysregulation in Dengue with Prior SARS-CoV-2 Infection

Elizabeth Cruz-Altamirano¹Miguel-Angel Mayoral¹Luis Román Ramírez-Palacios^2,3Luz Maria Quirino-Vela¹Diego Sait Cruz-Hernández¹Sergio Aguilar¹Juan Alpuche^1*

• ¹Universidad Autonoma Benito Juarez de Oaxaca Facultad de Medicina, Oaxaca, Mexico
• ²Laboratorio Estatal de Salud Pública de Oaxaca, Oaxaca, Mexico
• ³Universidad autonoma benito juarez de oaxaca Escuela de Ciencias, Oaxaca, Mexico

Background: In regions where dengue and COVID-19 co-circulate, cross-reactive antibodies elicited by SARS-CoV-2 may exacerbate dengue severity. This exploratory, cross-sectional, observational pilot study evaluated whether prior SARS-CoV-2 exposure modulated dengue pathogenesis through proteomic profiling and in vitro assays, identifying putative biomarkers and immune pathways for further validation. Methods: Eighteen participants from Oaxaca, Mexico, were prospectively stratified into four cohorts: healthy controls (CG), dengue with anti-SARS-CoV-2 IgG (NS1/SARS_IgG), dengue with both anti-SARS-CoV-2 and anti-dengue IgG (NS1/SARS-DENV_IgG), and dengue with anti-dengue IgG only (NS1/DENV_IgG). Serum levels of IL-6 and CRP were quantified and proteomic analysis was performed using label-free LC-MS/MS. In vitro ADE assays were performed using the DENV-1 and K562 cells. Results: The NS1/DENV_IgG group exhibited the most severe clinical presentation, including 39°C fever and 50% thrombocytopenia. In contrast, the NS1/SARS-DENV_IgG group presented milder symptoms. IL-6 and CRP concentrations peaked in the NS1/SARS_IgG group (18.3 ± 15.6 pg/mL and 51.6 ± 29.6 mg/L, respectively). Proteomic profiling identified 279 high-confidence proteins and 18 differentially expressed proteins (DEPs). The NS1/SARS-DENV_IgG group showed enrichment in complement/coagulation pathways (p = 0.016) and TGF-β signaling (p = 0.022). DEPs, including thrombospondin-1 and STXBP5, have been implicated in Th2 polarization and ADE-like immune dysregulation. ADE assays confirmed that anti-SARS-CoV-2 serum enhanced DENV replication in vitro. Conclusions: Prior SARS-CoV-2 exposure may potentiate dengue severity via cross-reactive antibody-mediated immune modulation, skewing toward Th2 responses, and enhancing viral replication. These findings suggest novel candidate biomarkers for stratifying the dengue risk in co-2 of 21 endemic regions. However, the study's exploratory nature, small cohort (n=18), pooled proteomic methodology, and limited clinical characterization necessitate validation in larger longitudinal studies.