Automated leucocyte VCS parameter profiling for differentiating SARS-CoV-2 and dengue infections: A comparative...

The volume, conductivity and scatter(VCS) based technology developed in the automated hematology analysers provides cellular and functional changes that occur during various infections which elicit responses from different leucocytes to fight the pathogen. COVID-19 infection, a pandemic that affected the world was associated with significant mortality and morbidity. On the other hand, dengue infection is endemic in many parts of India and known for frequent outbreaks. We aimed at a comparative analysis of leucocyte-VCS parameters in SARS-CoV-2 and dengue infections as diagnostic tool.

A retrospective study of two hundred cases where CBC with VCS parameters of COVID-19 or dengue positive cases for a period of 6 months were studied. The CBC was performed on automated Beckman Coulter DxH 800/900 automated CBC analysers and the VCS properties of neutrophils, lymphocytes, eosinophils, and monocytes were compared between the two infections and changes were documented.

The study included a total of two hundred patients comprising of 100 COVID-19 and 100 dengue cases, respectively. COVID-19 infection was found to be associated with higher WBC count, absolute neutrophil count, and platelet count. In dengue, there was thrombocytopenia, higher absolute lymphocyte, and monocyte count with lower WBC count. COVID-19 showed a higher neutrophil volume and conductivity and dengue showed higher neutrophil scatter parameters. Higher monocyte conductivity was seen in dengue, but mean conductivity and scatter were raised in COVID-19. The ROC curves for relevant parameters showed a lower value implying that none of these parameters can be used individually to predict the severity of the diseases.

Significant changes in neutrophils, lymphocytes and monocytes were seen between two infections. When individually analysed, high WBC count and NLR, lymphopenia was noted in COVID-19 and leucopenia, lymphocytosis, thrombocytopenia was seen in dengue. Among VCS parameters, since no single parameter emerged as a predictive tool, individual parameter's predictive accuracy using modelling in adjunct with various parameters can be evaluated for predicting the severity of the disease in the future.