Preliminary assessment of serum endocan as a biomarker of disease severity in Plasmodium falciparum and Plasmodium vivax malaria.

Background: Endocan, a component of endothelial glycocalyx, is a recognized biomarker of endothelial dysfunction in various inflammatory and infectious diseases. Malaria, characterized by marked endothelial activation and microvascular pathology, may involve endocan, but its role remains unclear. This study aimed to assess serum endocan levels in various clinical presentations of malaria and evaluate its correlation with laboratory parameters of disease severity.

Methods: Leftover serum samples from 99 participants were categorized into four groups: healthy controls (n = 20), Plasmodium vivax malaria (n = 36), uncomplicated Plasmodium falciparum malaria (n = 30), and severe P. falciparum malaria (n = 13). Serum endocan concentrations were measured via enzyme-linked immunosorbent assay on day 0 (pre-treatment) and day 7 (post-treatment). Correlation analyses examined associations between endocan levels and laboratory parameters, including parasite density, white blood cell count, haemoglobin, and platelet count.

Results: All malaria groups showed significantly higher serum endocan levels compared to healthy controls (p < 0.0001). Levels were highest in severe P. falciparum (median 4.67 [IQR 2.85-7.93] ng/ml), followed by uncomplicated P. falciparum (median 3.27 [IQR 2.24-4.33] ng/ml), and P. vivax malaria (median 1.85 [IQR 1.44-3.23] ng/ml). Endocan correlated positively with parasite density in P. vivax (r_s = 0.4632, p = 0.0066) and severe P. falciparum malaria (r_s = 0.6264, p = 0.0251) and negatively with platelet count in P. vivax infections (r_s = - 0.5523, p = 0.001).

Conclusion: Serum endocan is elevated in malaria in a severity-dependent manner-highest in severe P. falciparum malaria-and correlates with circulating parasite density and thrombocytopenia, highlighting its potential as a biomarker of endothelial injury in malaria.