Transcriptome Based Analysis of Brazilian Dengue Patients Provides Insights Into Disease Severity Progression

This study aimed to enhance the understanding of early mechanisms associated with the progression to severe dengue by analyzing total and small RNA transcriptomes from whole blood samples of Brazilian patients. The cohort, comprising 70 individuals, was stratified into three groups based on clinical classification and availability of clinical material: (I) classical DENV infection, (II) WS DENV infection, and (III) severe DENV infection. Group I consisted of 26 subjects, Group II comprised 24 subjects, and Group III included 20 subjects. Whole blood samples (3 mL) were collected from all patients in Tempus tubes following standard procedures. Total RNA was extracted from these samples using the MagMax for Stabilized Blood Tubes RNA Isolation Kit (ThermoFisher, San Jose, CA, USA) as per the instructions of the manufacturer. Total RNA libraries were prepared using the TruSeq Stranded Total RNA Library Prep kit with RiboZero Gold (Illumina, San Diego, California, USA) following the protocol of the manufacturer, and sequencing was performed with the Illumina NextSeq 500/550 High Output kit v2.5 (150 Cycles). The small RNA library was prepared using the TruSeq Small RNA Library Preparation kit (Illumina, San Diego, California, USA) according to the protocol of the manufacturer, and sequenced using the Illumina NextSeq 500/550 High Output kit v2.5 (75 Cycles). Signatures associated with immune response evasion, inflammation modulation, viral entry, spread, and vascular permeability were linked to poor prognosis. Collectively, these findings elucidate features of severe dengue progression, shedding light on factors contributing to worsened prognosis in the studied cohort.