Predictive performance of platelet count, mean platelet volume, and mean platelet volume-to-platelet ratio in pediatric COVID-19: a cohort retrospective study in Indonesia

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus and was officially declared a pandemic by the World Health Organization (WHO) in 2020. Clinical manifestations in children are more heterogeneous than in adults, and several factors may influence the disease severity. Platelet count (PC), mean platelet volume (MPV), and mean platelet volume to platelet ratio (MPR) are simple and widely available inflammation markers used as predictors in pediatric patients with sepsis and other critical illnesses. This study aimed to determine the performance of PC, MPV, and MPR as biomarkers predicting severity in pediatric patients with COVID-19. A retrospective cohort study was conducted, involving COVID-19 pediatric patients admitted to Dr. Sardjito from January 2020 to December 2022. Samples were selected using a total sampling approach, applying defined inclusion and exclusion criteria. Data analysis included both bivariate and multivariate analyses, using logistic and linear regression. The associations between variables were expressed as odds ratios (OR) with 95% confidence intervals, with statistical significance determined at p < 0.05. A total of 297 pediatric COVID-19 patients were included in the study. ROC analysis revealed inadequate discriminative efficacy for all assessed biomarkers. The AUC values for platelet count (PC), MPV, and MPR approached 0.50, signifying a restricted capacity to differentiate between severe and non-severe COVID-19 cases. The bivariate analysis showed the cut-off value for PC was 246,500 cells/µL ( p = 0.089; OR = 1.57; 95% CI 0.93–2.64), MPV was 9.25 ( p = 0.069; OR = 1.72; 95% CI 0.96–3.09), and MPR was 8.95 ( p = 0.021; OR = 2.09; 95% CI 1.11–3.94) in association with severe COVID-19. And after testing together with clinical variables, a regression analysis revealed factors for predicting COVID-19 severity in children are MPV ≥ 9.25 ( p = 0.031; OR = 1.953; 95%CI 1.062–3.593), comorbidity ( p = 0.13; OR = 6.526; 95%CI 1.496–28.465), and moderate-to-severe malnutrition ( p = 0.18; OR = 2.210; 95%CI 1.147–4.257). This study found that platelet count, MPV, and MPR had minimal capacity to predict COVID-19 severity in pediatric patients.