Evaluation of high-fluorescence lymphocyte count as an early diagnostic marker of dengue infection using the Sysmex XN-350 hematology analyzer

Shivangi Chaudhari; Gautam Chauhan

doi:10.18203/2320-6012.ijrms20264182

Authors

Shivangi Chaudhari Department of Pathology, GMERS Medical College and Hospital, Gandhinagar, Gujarat, India
Gautam Chauhan Department of Pathology, GMERS Medical College and Hospital, Gandhinagar, Gujarat, India

DOI:

https://doi.org/10.18203/2320-6012.ijrms20264182

Keywords:

Dengue, HFLC, Sysmex XN-350, Complete blood count, Diagnostic marker

Abstract

Background: Dengue is a major mosquito-borne viral infection prevalent in tropical and subtropical regions. Early diagnosis is essential for appropriate patient management. High-Fluorescence Lymphocyte Count (HFLC), generated by Sysmex XN-Series hematology analyzers, may provide additional information about lymphocyte activation during viral infections. The aim is to evaluate HFLC as an early diagnostic marker of dengue infection using the Sysmex XN-350 hematology analyzer.

Methods: This prospective observational case-control study was conducted in the Department of Pathology, GMERS Medical College and Hospital, Gandhinagar, from 1st August 2026 to 31st August 2026. The study included 100 participants, comprising 50 laboratory-confirmed dengue-positive patients and 50 dengue-negative controls. Complete blood count parameters, including hemoglobin, total leukocyte count, platelet count, lymphocyte percentage, and HFLC percentage, were analyzed. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis.

Results: Dengue-positive patients showed significantly lower mean WBC counts (5140±2033.70 vs. 6522±1843.28 cells/µl; p<0.001) and platelet counts (208,340±143,548 vs. 287,680±93,384 cells/µl; p=0.002) than controls. Lymphocyte percentage was significantly higher in dengue-positive patients (40.16±16.93% vs. 29.66±6.06%; p<0.001). Mean HFLC percentage was significantly lower in dengue-positive patients (9.16±7.73% vs. 24.50±14.58%; p<0.001). ROC analysis yielded an AUC of 0.807. At a cutoff of ≤20%, HFLC demonstrated 96.0% sensitivity, 58.0% specificity, 69.6% positive predictive value, and 93.5% negative predictive value.

Conclusions: HFLC may serve as a useful adjunctive screening parameter for suspected dengue infection. However, its moderate specificity necessitates interpretation alongside clinical findings, routine hematological parameters, and established dengue-specific diagnostic tests.

References

Gupta N, Srivastava S, Jain A, Chaturvedi UC. Dengue in India. Indian J Med Res. 2012;136(3):373-90.

Gupta E, Ballani N. Current perspectives on the spread of dengue in India. Infect Drug Resist. 2014;7:337-42.

Ganeshkumar P, Murhekar MV, Poornima V, Saravanakumar V, Sukumaran K, Anandaselvasankar A, et al. Dengue infection in India: a systematic review and meta-analysis. PLoS Negl Trop Dis. 2018;12(7):e0006618.

Singh MP, Majumdar M, Singh G, Goyal K, Preet K, Sarwal A, et al. NS1 antigen as an early diagnostic marker in dengue: report from India. Diagn Microbiol Infect Dis. 2010;68(1):50-4.

Datta S, Wattal C. Dengue NS1 antigen detection: a useful tool in early diagnosis of dengue virus infection. Indian J Med Microbiol. 2010;28(2):107-10.

Kulkarni R, Modak M, Gosavi M, Wani D, Mishra AC, Arankalle VA. Comparative assessment of commercial enzyme-linked immunosorbent assay and rapid diagnostic tests used for dengue diagnosis in India. Indian J Med Res. 2020;151(1):71-8.

Khatri S, Sabeena S, Arunkumar G, Mathew M. Utility of platelet parameters in serologically proven dengue cases with thrombocytopenia. Indian J Hematol Blood Transfus. 2018;34(4):703-6.

Jayashree K, Manasa GC, Pallavi P, Manjunath GV. Evaluation of platelets as predictive parameters in dengue fever. Indian J Hematol Blood Transfus. 2011;27(3):127-30.

Subiksha R, Ganesamoorthy VK, Edwin D, Banthavi PS. Study of high fluorescent lymphocyte count (HFLC) in the Sysmex XN-350 hematology analyzer in dengue infection. Zenodo. 2026.

Šimundić AM. Measures of diagnostic accuracy: basic definitions. EJIFCC. 2009;19(4):203-11.

Gupta S, Shakya A, Mishra N, Islahi S, Singh S, Nag S, et al. Investigating the clinico-demographic characteristics of dengue fever and its seroprevalence at a tertiary care hospital in Northern India. Cureus. 2024;16(4):e57640.

Ukey PM, Bondade SA, Paunipagar PV, Powar RM, Akulwar SL. Study of seroprevalence of dengue fever in central India. Indian J Community Med. 2010;35(4):517-9.

Raharjo B, Hadi S. High fluorescent lymphocyte count examination in dengue hemorrhagic patients with Sysmex XN-1000 hematology analyzer. Indones J Clin Pathol Med Lab. 2019;25(2):207-10.

Ningombam A, Acharya S, Sarkar A, Kumar K, Brijwal M, Routray S, et al. Evaluation of sensitivity and specificity of high fluorescence lymphocyte count percentage of Sysmex XN analyzer in diagnosis of dengue. J Appl Hematol. 2022;13(3):132-8.

Hong AV, Nguyen Trung K, Nguyen Thi Hien H, Ta Viet H. Evaluating high fluorescence lymphocyte count as a predictor of severe dengue infection. J Clin Lab Anal. 2025;39(17):e70083.

Chhabra G, Das B, Mishra S, Mishra B. Rapid screening of dengue fever using research parameters from new generation hematological analyzers. Int J Lab Hematol. 2022;44(3):477-82.