The atypical lymphocyte count: a novel predictive factor for severe thrombocytopenia related to dengue

Background Early identification of patients at risk of severe dengue disease (DD) is critical to guide its management. We evaluated whether the atypical lymphocyte count (ALC), generated from the Sysmex automated full blood count analyzer, is predictive of severe thrombocytopenia secondary to Dengue infection. Methods We prospectively collected data on patients admitted with DD between December 2017 and October 2018. ALC data were extracted from the Sysmex XS500i analyzer from day 1 to day 7 of admission. Clinical data were obtained from patients' medical records. Results We enrolled 256 patients with DD. A negative correlation between ALC on admission and platelet count on day 5 to day 7 (Spearmen's correlation; day 5:-0.485, day 6:-0.428 and day 7:-0.344) (p=0.001) was observed. Based on receiver operator characteristic curve analysis, we found that an ALC of >0.5x103/L had 90% sensitivity and 70% specificity for severe thrombocytopenia (platelet count <50x109/L) on day 5. The positive and negative predictive values were 74.4 and 91.2%, respectively (power 84.7). Conclusions We propose that ALC on admission may be a novel negative predictive factor for severe thrombocytopenia on day 5 to day 7 of DD. Further studies are required to validate our findings and evaluate whether ALC is predictive of other complications of DD.

HIGH FLUORESCENT LYMPHOCYTE COUNT EXAMINATION IN DENGUE HEMORRHAGIC PATIENTS WITH SYSMEX XN-1000 HEMATOLOGY ANALYZER

Sysmex XN-1000 hematology analyzer is an automated 5-part diff analyzer (eosinophils, basophils, neutrophils, lymphocytes, and monocytes). In the calculated area, the type of difference between the Sysmex hematology device and other hematology devices is Immature Granulocyte (IG), Nucleated Red Blood Cell (NRBC), and High Fluorescent Lymphocytes Count (HFLC). The cells calculated in the HFLC area are atypical lymphocytes. In patients with dengue hemorrhagic fever, it is often found atypical lymphocytes called blue plasma lymphocytes. The purpose of this study was to determine the description of HFLC in patients with dengue fever using the hematology analyzer Sysmex XN-1000. A descriptive retrospective study was conducted during April-May 2017. The subjects of the study were adult patients diagnosed with dengue hemorrhagic fever with WHO criteria. Of the 47 samples of Dengue Hemorrhagic Fever (DHF) patients, the average HFLC results were between 2.0-32.3%, which was 11.5%, while the average range of normal HFLC values was between 0.0-1.4% and was 0.3%. In cases of DHF, there is an increase in HFLC. This is likely to be attributed to atypical lymphocyte increase in dengue hemorrhagic fever. Further research with more varied samples still needs to be done.