Upregulation of SCUBE1 in Dengue Virus Infection

BACKGROUND: Dengue is a major communicable disease in tropical areas, with an increasing prevalence every year. Thrombocytopenia is one of the commonly used laboratory parameters for predicting the severity of the disease. It is detected on day 6 or day 7 after the febrile stage, and its presence indicates that the disease has become potentially fatal. Therefore, it is necessary to identify a marker for the early recognition of dengue virus infection during the febrile stage before the detection of thrombocytopenia on day 6 to prevent severe disease outcomes. Signal peptide-CUB- (complement C1r/C1s)-EGF (epidermal growth factor)-like domain-containing protein 1 (SCUBE1) is secreted in activated platelets under inflammatory conditions and enhances platelet-platelet adhesion and agglutination. This gene was first identified in human vascular endothelium, but its biological role in platelets remains unknown. AIM: This study aims to identify SCUBE1 expression during the febrile stage of dengue virus infection and examine the correlation of its expression with thrombocytopenia occurrence on day 6. MATERIAL AND METHODS: Blood samples were collected from 17 patients infected with dengue virus on day-3 fever and from 16 healthy controls who met the inclusion and exclusion criteria for dengue virus infection according to the World Health Organization (WHO) classification for dengue virus infection. All samples were subjected to SCUBE1 gene analysis using real-time reverse transcription quantitative PCR (RT-PCR). RESULTS: The results showed that upregulation of SCUBE1 gene in infected patients (8.9 ± 3.1-fold) compared to that in healthy controls, indicating SCUBE1 involvement in dengue virus infection. Furthermore, we analysed the laboratory parameters of infected patients on day 3 and day 6, when thrombocytopenia is usually detected. Platelet count was found to be significantly decreased from day 3 until day 6 in the infected patients. Unfortunately, our results showed no correlation between SCUBE1 expression in the febrile stage and the occurrence of thrombocytopenia on day 6. CONCLUSION: The conclusion of this study is SCUBE1 might play a role in dengue virus infection but does not correlate with thrombocytopenia on day-6 fever.