Utility of DxH 800 VCS Parameters and Lymph Index in Predicting Dengue

Abstract

Introduction: Dengue is an acute febrile illness where high fever is accompanied by headache, arthralgia and myalgia. Volume, Conductivity and Scatter (VCS) positional parameters have been reported to be useful in indicating dengue infection. The derived indices like lymph index are being introduced to predict dengue. Aim: To evaluate diagnostic utility of lymph index and VCS positional parameters in dengue fever. Materials and Methods: Peripheral blood samples of 100 serology proven cases of dengue, 25 proven cases of malaria and 50 healthy controls were evaluated in Coulter DxH 800 automated analyser, VCS positional parameters were analysed, and lymph index was derived. Results: Lymphocytes, neutrophils and monocytes positional parameters were significantly different in dengue group when compared to the cases of malaria and healthy individuals, indicating morphological changes in leucocytes. The mean volume of lymphocytes, neutrophils and monocytes were significantly increased, whereas the mean conductivity of neutrophils and monocytes were significantly decreased in dengue. Lymph index was significantly increased (mean: 16.64±5.63) in cases of dengue as compared to control (mean: 11.56±1.68), and had a sensitivity of 73% and specificity of 88%. Conclusion: Lymph index, along with the positional parameters, the scatterplot, and the histogram, is a fairly accurate parameter in prediction of dengue in suspected cases and could be used to select cases for testing dengue.

Keywords

• coulter
• positional parameters
• volume conductivity and scatter