Utility of Platelet and Lymphocyte Indices among Dengue Seropositive Patients

Introduction: Dengue Fever is a common mosquito-borne viral infection that causes epidemics in countries like India 1. Dengue Hemorrhagic Fever and Dengue Shock Syndrome are life-threatening complications where a sudden drop in platelet count leads to plasma leakage and bleeding manifestations 2, 3.Platelet Count, Platelet indices, Total Leucocyte Count and Lymphocyte Count are useful for the early diagnosis and prognosis of Dengue Fever 3, 4. Aim: The aim of the study is to assess the utility of Platelet and Lymphocyte parameters among the Dengue-Seropositive patients. Methodology: This is a longitudinal observational study done in the Department of Pathology in Sri Muthukumaran Medical College, Hospital& Research Institute, Chennai during the period March 2022 to February 2023. The study participants who fulfilled the inclusion criteria were included in this study. Demographic details like name, age and sex were taken. Laboratory testing was done for NS1 antigen. Complete Blood Count was done. Results: The mean age of the study participants was found to be 28.70 ±14.26. Among the 33 study participants, 8 were children (24%). Male predominance was observed in our study (n=20, 60.6%).The Platelet-crit (PCT) was found to increase with increase in platelet count, whereas the Mean Platelet Volume (MPV) and Platelet Distribution Width (PDW) showed mild variation. Absolute Lymphocyte Count increased as the Platelet Count improved. The amount of cytoplasm in the lymphocytes also was studied on Leishman-stained peripheral blood smears and appeared to decrease as the platelet count improved. Thus they act as a surrogate markers to find out the severity of Dengue fever. Conclusion: It is concluded from our study that, Platelet count and Absolute Lymphocyte Count are useful parameters in the Dengue infection. Platelet Indices and Lymphocyte Morphology are also useful in diagnosing Dengue at its earliest and predicting its severity.