Platelet parameters as potential biomarkers for sepsis: a systematic review and meta-analysis

Sepsis remains a major global health issue, especially in low- and middle-income countries (LMICs) with limited diagnostic resources. This meta-analysis evaluates platelet index ratios (mean platelet volume-to-platelet count, MPV/PLT; platelet distribution width-to-platelet count, PDW/PLT; and platelet distribution width-to-plateletcrit, PDW/PCT) as cost-effective biomarkers for sepsis diagnosis and prognosis in resource-constrained settings.

A systematic search was conducted for studies evaluating platelet parameter ratios in sepsis. Inclusion criteria comprised the following: (1) cohort/case-control designs; (2) non-duplicated datasets; (3) available quantitative data for meta-analysis. Exclusion criteria included reviews, abstracts, letters to the editor, and studies with incomplete data. Synthesis methods employed random-effects models to calculate standardized mean differences (SMD) and diagnostic metrics (sensitivity, specificity, etc.), with heterogeneity assessed via I-squared statistics. Publication bias was evaluated through funnel plots and Egger's test.

Fourteen studies were included. The results revealed that MPV/PLT ratios were significantly higher in neonatal (SMD = 1.48, P = 0.004) and adult sepsis patients (SMD = 0.35, P < 0.001) than in controls. Survivors had significantly lower MPV/PLT ratios than non-survivors in both children/neonate (SMD = 0.67, P < 0.01) and adult group (SMD = 0.41, P < 0.01), with similar trends observed in longitudinal assessments. PDW/PLT was also lower in pediatric survivors (P = 0.009), while no significant differences were found for MPV/PCT in neonates or PDW/PLT in adults. For diagnosing sepsis, MPV/PLT had a sensitivity of 0.55 and specificity of 0.71 in adults, and 0.58 and 0.87 in neonates. For predicting mortality, neonatal sepsis showed higher sensitivity (89%) and specificity (73%) than adult sepsis (63%, 58%). In LMICs, MPV/PLT was elevated at admission in both age groups but was linked to survival only in neonates.

The MPV/PLT ratio shows promise as a cost-effective biomarker for sepsis diagnosis and prognosis, particularly in neonatal patients, with important potential applications in LMICs.

This study has been registered on the international platform of registered systematic review and meta-analysis protocols (INPLASY) (Registration Number: INPLASY202540096). https://doi.org/10.37766/inplasy2025.4.0096 .