Inflammation and Routine Laboratory Associations in Imported Falciparum Malaria Assessed by Partial Correlation
Damian Pikor1,2, Maciej Cymerys3, Małgorzata Paul3,4
1Department of Internal Medicine and Metabolic Disorders, Poznan University of Medical Sciences, Przybyszewskiego 49, 60-355, Poznań, Poland. damian.pikor@ump.edu.pl.
Purpose:
To examine whether associations among routine admission laboratory measurements in imported Plasmodium falciparum malaria persist after accounting for other measured variables, including C-reactive protein (CRP).
Methods:
This retrospective single-centre study included all adults recorded in a departmental malaria database as hospitalised with microscopically confirmed P. falciparum monoinfection between 2010 and 2025. A rank-based precision matrix yielded 28 partial correlations among seven laboratory measurements and age, each adjusted for the other six variables. Bonferroni correction was applied to the primary matrix. CRP-adjusted subset analyses and Firth logistic models were exploratory.
Results:
The primary cohort comprised 48 patients. Three partial correlations survived correction: alanine aminotransferase with aspartate aminotransferase (partial rho +0.88), haemoglobin with red blood cell count (partial rho +0.82) and CRP with platelet count (partial rho - 0.56). Platelet associations with procalcitonin and urea were attenuated after CRP adjustment (n = 39 and 35). In univariate Firth models, CRP was associated with concurrent severe thrombocytopenia (15 events; odds ratio 3.57 per standard deviation, 95% CI 1.70 to 9.15), whereas evidence for an association with parasitaemia was inconclusive.
Conclusion:
Routine laboratory abnormalities in falciparum malaria should be interpreted in their inflammatory and clinical context; their co-occurrence does not establish a direct link between organ injuries. Partial correlation analysis can explore this distinction but cannot determine whether an association is caused by inflammation or is organ-specific. These findings support contextual interpretation, not new diagnostic thresholds or treatment recommendations, and require prospective external validation.
