Journal du sang et de la lymphe

Dengue is one of the most commonly encountered infectious diseases in tropical countries. The features overlap with other causes of Acute Febrile Illness, and a rapid diagnosis is required in most centers. The usual modalities of diagnosis are serological based, where NS1 antigen, IgM, or IgG antibodies are assayed. Fast card-based kits are available but are less reliable than their (enzyme-linked immunosorbent assay) ELISA-based counterparts. There has been a recent automation boom in all healthcare facilities sectors. Automated hematological analyzers are an integral part of it, providing much additional information other than blood counts. Among these research parameters are HFLC (High Fluorescence Lymphocyte Count) and CPD (Cell Population Data) provided by the Sysmex XN series. These have taken the interest of pathologists, and some research articles are available that analyze these parameters' utility in the expeditious diagnosis of dengue. Studies show that HFLC is increased in AFI and correlates with dengue. Some studies have drawn Receiver Operating Curves (ROC) for determining cut-off values to differentiate dengue from other AFI. Jayaram et al. calculated a cut-off of 1.35% with 82.8% sensitivity and 87% specificity. Chabbra et al. computed a cut-off of 1.75% with 52% sensitivity and 90% specificity, a positive predictive value (PPV) of 72%, and a negative predictive value (NPV) of 80%. They also did a regression analysis on CPD and found that LY-X, LY-Z, LY-WX, LY-WZ, and MO-X were independent predictors of dengue fever. Ningombam et al. had different cut-off values for NS-1 antigen-positive only, IgM antibody-positive and dual-positive dengue patients, of 5.2%, 3.2%, and 2.6%, respectively. These studies show promising results and can help manage dengue patients, especially in resource-constrained settings in endemic zones, leading to better managing of dengue patients.