A Morphological Approach to the Diagnosis of Protozoal Infections of the Central Nervous System

Abstract

Protozoal infections, though endemic to certain regions, can be seen all around the world, because of the increase in travel and migration. In addition, immunosuppression associated with various conditions, particularly with HIV infection, favors the occurrence of more severe manifestations and failure to respond to treatments. The CNS may be the only affected system; when not, it is often the most severely affected. Despite information obtained from clinical, laboratory, and imaging procedures that help to narrow the differential diagnosis of intracranial infections, there are cases that need confirmation with biopsy or autopsy. Predominant presentations are meningoencephalitis (trypanosomiasis), encephalopathy (cerebral malaria), or as single or multiple pseudotumoral enhancing lesions (toxoplasmosis, reactivated Chagas' disease). The immune reconstitution disease, resulting from enhancement of pathogen-specific immune responses after HAART, has altered the typical presentation of toxoplasmosis and microsporidiosis. In this paper, a morphological approach for the diagnosis of protozoal infections affecting the CNS (amoebiasis, cerebral malaria, toxoplasmosis, trypanosomiasis, and microsporidiosis) is presented.

Morphological changes, nitric oxide production, and phagocytosis are triggered in vitro in microglia by bloodstream forms of Trypanosoma brucei

“…At least, some evidence in line with the importance of T. brucei phagocytosis by microglia alluded in this study have been reported. In post-mortem samples of patients with African trypanosomiasis the presence of diffuse meningoencephalitis, diffuse microglial hyperplasia, proliferation of large astrocytes, and formation of microglial nodules was described by immunohistochemical observations 44 , 45 . Therefore, this study stresses the importance and opens up new avenues for understanding the cellular function of microglial cells in the meningoencephalitic stage of HAT.…”

Enfermedad de Chagas del sistema nervioso central en un paciente con SIDA demostrada por métodos cuantitativos moleculares

“…Estudios de series de casos estudiados con autopsias indican que la enfermedad de Chagas cerebral tiene compromiso de la materia gris y blanca, pero predominantemente en ésta última, se localizan en varios lóbulos cerebrales donde alcanzan su mayor tamaño y también se ubican en el cerebelo y tronco cerebral, pero sin compromiso de los ganglios basales. En contraste, los pacientes con toxoplasmosis cerebral, tiene compromiso de corteza cerebral o sustancia blanca pero a nivel subcortical y casi todos presentan compromiso de los ganglios basales 19,20 . Sin embargo, en ocasiones los pacientes con toxoplasmosis cerebral pueden presentar lesiones infratentoriales 20 .…”

“…En contraste, los pacientes con toxoplasmosis cerebral, tiene compromiso de corteza cerebral o sustancia blanca pero a nivel subcortical y casi todos presentan compromiso de los ganglios basales 19,20 . Sin embargo, en ocasiones los pacientes con toxoplasmosis cerebral pueden presentar lesiones infratentoriales 20 . La evolución de las imágenes en nuestro paciente fue confirmando este patrón con compromiso supra e infratentorial, cerebeloso y de tronco sin afectar los ganglios basales.…”

Antimalarial Agents as Therapeutic Tools Against Toxoplasmosis—A Short Bridge between Two Distant Illnesses

“…Infectious diseases continue to represent leading causes of the global burden at social, economic, and public health levels [1][2][3][4]. Several parasite-borne infectious diseases are especially threatening because of their global impact, including malaria, leishmaniases, and toxoplasmosis.…”