Neutrophil-lymphocyte ratio as an indicator of recovery phase in children with dengue fever

Objective: Dengue is an infectious disease that burdens global public health, especially children. There are three phases of dengue infection; the last phase is the most expected, namely the recovery phase. One of the signs of this phase is platelet recovery. The platelet recovery time is still unclear because it is greatly influenced by several factors, such as immune response and lymphocyte and neutrophil activity. These factors play an important role in platelet repair and the recovery phase. Methods: This study was a cohort prospective study. Data were obtained between January and June 2024 in Dr. Moewardi Hospital. The inclusion criteria of this study were pediatric patients diagnosed with dengue and had complete laboratory data (neutrophils, lymphocytes, and platelets) until the fifth day of fever. Data was analyzed using the Mann-Whitney test, Fisher Exact tests, and receiver Operating Characteristic (ROC) method to obtain the Area Under Curve (AUC) value, cut point, sensitivity (Sn), and specificity (Sp). Results: This study shows absolute lymphocytes (30%; 9/30), predominance of lymphocytes (46.7%; 14/30), and Neutrophil-Lymphocyte Ratio (NLR) (63.3%; 19/30). Statistical analysis results in correlation with platelets improvement: absolute lymphocytes (AUC 77.8%, OR 5.00, Sn 66.7%, Sp 72.7%, p=0.102), predominance of lymphocytes (AUC 73.6%, OR 7.80, Sn 16.7%, Sp 66.7%, p=0.024), and NLR (AUC 78.7%, OR 10.00, Sn 91.7%, Sp 50.0%, p=0.009). Conclusion: Supporting examination of the neutrophil-lymphocyte ratio (NLR) has been proven to be a better indicator of the recovery phase, especially in monitoring the increase in platelets in children with dengue infection compared to lymphocyte examination.