The relationship between platelet count and the onset of leaking phase in dengue patients

Abstract

Introduction: The complications of dengue are related to reduced intravascular volume following plasma leakage. Thrombocytopenia or platelet dysfunctions are detected in all stages of the illness and are related to the clinical outcome. The main objective of the study was to correlate absolute platelet count to the onset of leaking phase in dengue patients who had entered into leaking phase after the hospital admission.

Methods: One hundred and sixteen patients (age range 14-74 years, median age 33 years) who entered the leaking phase after admission were recruited to the study. Dengue infection in patients was confirmed with either the presence of positive NS1 or positive IgM antibodies. Serial ultrasonography was done from admission until the leaking phase is detected. Platelet counts were assessed twice per day just prior to the ultrasonography.

Results: There were 47 (40.5%) females and 69 (59.5%) males among the recruited patients. The mean number of days at which leaking was detected following onset of fever was 4.9 ± 0.9 days. The mean platelet count at the onset of leaking phase was 30,051 ± 17,023 /μL. Age and the platelet count at the time of onset of leaking phase was significantly negatively correlated (whole group r = -0.323 p < 0.001; in females r = -0.369, p = 0.011; males r = -0.280 p = 0.020). Platelet count at the time of onset of leaking phase was significantly lower in the patients older than 30 years of age (27,577.5 ± 17,361.4) compared to those of the patients younger than 30 years (33,955.6 ± 15,888.8) (p=0.032). Upper limit of the range of platelet count at the onset of leaking phase was 77, 000/ μL which was slightly lower in females.

Conclusions: According to this study, the value of platelet count as a predictor of the progression of dengue infection depends on the age of the patients. Young patients are more prone to develop leaking phase with higher platelet counts than the older patients.