D-dimer as a marker of severe disease in imported malaria: a retrospective observational study
Andrea Poloni1, Alberto Rizzo2, Andrea Giacomelli3
1Department of Infectious Diseases, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milano, Italy.
Background:
D-dimer has been evaluated to assess the severity of disease in sepsis and COVID-19 but its usefulness in the stratification of malaria severity is unknown. We aimed to assess the D-dimer level in imported malaria as a predicting marker of Plasmodium falciparum severe malaria.
Methods:
We performed a retrospective monocentric study including all adult patients with a diagnosis of P. falciparum malaria and with a D-dimer test performed within 24 h from diagnosis. Sensitivity, specificity and accuracy of D-dimer in the diagnosis of severe malaria were estimated. The association between D-dimer levels and malaria severity was assessed by means of a logistic regression analysis adjusted for age and sex.
Results:
85 patients with P. falciparum malaria were included, mostly male (63.5%) and with a median age of 39 years (IQR: 32-51) and 21 (24.7%) were classified as severe malaria. Median D-dimer level was higher in patients with severe malaria when compared to the non-severe ones [10,943 μg/L Fibrinogen Equivalent Units (FEU)] [IQR: 5201-20,000) vs 2245 μg/L FEU (IQR: 919-5890); p = 0.0005), respectively]. In the multivariable logistic regression analysis, the D-dimer level resulted associated with a higher odd of severe disease [aOR per 1000 μg/L FEU more 1.14 (95% CI: 1.06-1.23)]. The estimated sensitivity and specificity with an optimal cut-off of 4864 μg/L FEU were 0.76 (95% CI: 0.53-0.92) and 0.73 (95% CI: 0.61-0.84), respectively, accounting for an overall accuracy of 0.74 (95% CI: 0.63-0.83).
Conclusion:
We found that higher D-dimer levels were associated to malaria severity although the accuracy of D-dimer as a marker for the severity of disease was moderate.
Insights
Higher D-dimer levels indicate increased severity in Plasmodium falciparum malaria cases. While D-dimer shows moderate accuracy in predicting severe malaria, it can aid in disease stratification.
Area of Science:
- Infectious Diseases
- Hematology
- Biomarkers
Background:
- D-dimer is used to assess disease severity in sepsis and COVID-19.
- Its utility in stratifying malaria severity remains under investigation.
- This study focuses on Plasmodium falciparum malaria.
Purpose of the Study:
- To evaluate D-dimer levels as a predictive marker for severe Plasmodium falciparum malaria.
- To assess the association between D-dimer levels and malaria severity.
Main Methods:
- Retrospective monocentric study of adult patients with P. falciparum malaria.
- D-dimer testing performed within 24 hours of diagnosis.
- Logistic regression analysis adjusted for age and sex.
Main Results:
- Median D-dimer levels were significantly higher in severe malaria patients (10,943 μg/L FEU) compared to non-severe cases (2,245 μg/L FEU).
- D-dimer levels were associated with increased odds of severe disease (aOR per 1,000 μg/L FEU: 1.14).
- Optimal cut-off of 4,864 μg/L FEU yielded sensitivity of 0.76 and specificity of 0.73.
Conclusions:
- Elevated D-dimer levels correlate with increased severity in imported malaria.
- D-dimer demonstrates moderate accuracy as a severity marker for Plasmodium falciparum malaria.
- Further research may refine its role in malaria patient management.

