PROGNOSTIC SIGNIFICANCE OF LYMPHOCYTE-TO-PLATELET RATIO IN PREDICTING SEVERITY AND CLINICAL OUTCOME IN DENGUE INFECTION

Abstract

Dengue continues to be a pressing public-health concern in tropical areas, where early identification of patients at risk for dengue severity is critical for appropriate patient triage and resource management. A prospective observational cohort study was carried out at a Tertiary Care Hospital, Karachi among 180 laboratory-confirmed dengue patients admitted within the first five day of fever. Information was gathered on structured proformas including demographic particulars, clinical features haematological profile and the outcomes like ICU admission, requirement of blood transfusion, length of stay and in-hospital mortality. Quantitative analysis demonstrated the differences in platelet count, lymphocyte count and LPR between non-severe and severe dengue groups. Patients with severe dengue had significantly lower platelet counts (67.4 vs 112.9 ×10^9/L) and higher median LPR (0.021 vs 0.013). The optimal LPR cutoff 0.018 obtained by ROC analysis had good discriminative performance (AUC = 0.82) with 78% sensitivity and 80% specificity for predicting severe outcomes. LPR was superior to PLR (AUC = 0.69) and NLR (AUC = 0.66). The predictive value of LPR remained in patients presented with early (day 1–3) and late (day 4–5) fever syndromes by subgroup analysis. This observation suggests that admission LPR is a feasible inexpensive and clinically relevant tool for rapidly identifying patients at increased risk for death under resource constrained dengue endemic conditions.