Pathophysiology
IL-6, induced by B. mandrillaris in human brain microvascular endothelial cells, activates phosphatidylinositol 3-kinase and Akt pathways to increase BBB permeability [PMID:41112237].
Histopathological examination revealed chronic granulomatous encephalitis with presence of cysts and trophozoites in the brain, alongside Acanthamoeba pneumonitis characterized by massive consolidation in the lungs [PMID:8918032].
Epidemiology
The study analyzed US cases of BAE from 1980-2010, finding that BAE affected patients of all ages with no significant age-related differences [PMID:21954652].
Consistent predisposing factors identified included male gender, exposure in southern tier US states, and Hispanic ethnicity [PMID:21954652].
This study reports the first case of congenital infection with Acanthamoeba culbertsoni, suggesting a novel epidemiological pathway for granulomatous amebic encephalitis [PMID:8918032].
Clinical Presentation
In China, patients frequently exhibit skin lesions initially, with encephalitis developing several years later [PMID:41112237].
Clinicians are advised to consider BAE in patients with refractory meningoencephalitis, particularly those with predisposing factors [PMID:21954652].
The study indicates that congenital infection could manifest with significant neuropathological features and associated respiratory compromise, highlighting the multisystem involvement [PMID:8918032].
Management
While anti-inflammatory steroids are used to reduce CNS inflammation, they may paradoxically enhance the hematogenous spread of the amebae [PMID:41112237].
References
1 Zhang J, Jia X, Yang B, Ge Y, Jiang W, Cong Y et al.. Bulk and single-cell transcriptome profiling reveals the dynamic immune response in granulomatous amebic encephalitis caused by Balamuthia mandrillaris: a cohort study. Frontiers in immunology 2025. link 2 Diaz JH. The public health threat from Balamuthia mandrillaris in the southern United States. The Journal of the Louisiana State Medical Society : official organ of the Louisiana State Medical Society 2011. link 3 Awadalla HN, Sadaka HA. The possibility of congenital infection with Acanthamoeba culbertsoni. Journal of the Egyptian Society of Parasitology 1996. link