Magnetic Resonance Imaging Findings in a Patient With Isolated Histoplasma Brain Abscess

Parihar, Anit; Tomar, Vaishali; Ojha, Bal Krishna; Husain, Nuzhat; Gupta, Rakesh K.

doi:10.1001/archneurol.2011.59

Cited by 8 publications

(6 citation statements)

References 3 publications

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“…In humans, central nervous system (CNS) involvement occurs in 2–20% of disseminated cases [ 51 ]. It has been reported that Histoplasma yeasts in the human brain appear to be extracellular [ 52 ], which was also the case for 50% of the Histoplasma in the TLR7/9 -/- mice. One intriguing idea is that Histoplasma is better able to survive within TLR7/9 -/- DCs compared to wild-type DCs, and that these host cells provide a vehicle or Trojan horse for the fungus to disseminate to the CNS.…”

Section: Discussionmentioning

confidence: 75%

CD103+ Conventional Dendritic Cells Are Critical for TLR7/9-Dependent Host Defense against Histoplasma capsulatum, an Endemic Fungal Pathogen of Humans

et al. 2016

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Innate immune cells shape the host response to microbial pathogens. Here we elucidate critical differences in the molecular response of macrophages vs. dendritic cells (DCs) to Histoplasma capsulatum, an intracellular fungal pathogen of humans. It has long been known that macrophages are permissive for Histoplasma growth and succumb to infection, whereas DCs restrict fungal growth and survive infection. We used murine macrophages and DCs to identify host pathways that influence fungal proliferation and host-cell viability. Transcriptional profiling experiments revealed that DCs produced a strong Type I interferon (IFN-I) response to infection with Histoplasma yeasts. Toll-like receptors 7 and 9 (TLR7/9), which recognize nucleic acids, were required for IFN-I production and restriction of fungal growth in DCs, but mutation of TLR7/9 had no effect on the outcome of macrophage infection. Moreover, TLR7/9 were essential for the ability of infected DCs to elicit production of the critical cytokine IFNγ from primed CD4+ T cells in vitro, indicating the role of this pathway in T cell activation. In a mouse model of infection, TLR7/9 were required for optimal production of IFN-I and IFNγ, host survival, and restriction of cerebral fungal burden. These data demonstrate the critical role of this pathway in eliciting an appropriate adaptive immune response in the host. Finally, although other fungal pathogens have been shown to elicit IFN-I in mouse models, the specific host cell responsible for producing IFN-I has not been elucidated. We found that CD103+ conventional DCs were the major producer of IFN-I in the lungs of wild-type mice infected with Histoplasma. Mice deficient in this DC subtype displayed reduced IFN-I production in vivo. These data reveal a previously unknown role for CD103+ conventional DCs and uncover the pivotal function of these cells in modulating the host immune response to endemic fungi.

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Section: Discussionmentioning

confidence: 75%

CD103+ Conventional Dendritic Cells Are Critical for TLR7/9-Dependent Host Defense against Histoplasma capsulatum, an Endemic Fungal Pathogen of Humans

et al. 2016

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“…MRIs often show single or multiple ring-enhancing lesions in CNS histoplasmosis cases 13 16 20 23 24 25 26 27 28 29 as presented here. However, ring-enhancing lesions can also be indicative of an abscess, a necrotic tumor, 30 subdural and epidural empyema, 31 or toxoplasmosis.…”

Section: Discussionmentioning

confidence: 55%

Histoplasmosis with Deep CNS Involvement: Case Presentation with Discussion and Literature Review

et al. 2015

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Central nervous system (CNS) histoplasmosis is rare and difficult to diagnose because it is often overlooked or mistaken for other pathologies due to its nonspecific symptoms. A 32-year-old Hispanic man with advanced acquired immunodeficiency virus presented with altered mental status and reported confusion for the past 3 months. He had a Glasgow Coma Scale of 12, repetitive nonfluent speech, and a disconjugate gaze with a right gaze preference. Lung computed tomography (CT) findings indicated a pulmonary histoplasmosis infection. Magnetic resonance imaging of the brain revealed a ring-enhancing lesion in the left caudate nucleus. A CT-guided left retroperitoneal node biopsy was performed and indicated a benign inflammatory process with organisms compatible with fungal yeast. Treatment with amphotericin B followed by itraconazole was initiated in spite of negative cerebrospinal fluid (CSF) cultures and proved effective in mitigating associated CNS lesions and resolving neurologic deficits. The patient was discharged 3 weeks later in stable condition. Six weeks later, his left basal ganglia mass decreased. Early recognition of symptoms and proper steps is key in improving outcomes of CNS histoplasmosis. Aggressive medical management is possible in the treatment of intracranial deep mass lesions, and disseminated histoplasmosis with CNS involvement can be appropriately diagnosed and treated, despite negative CSF and serology studies.

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“…Se ha descrito que esta prueba tiene baja sensibilidad, por lo que debe estar acompañada por otros métodos diagnósticos. El tratamiento se realizó con anfotericina B e itraconazol (4)(5)(6).…”

Section: Discussionunclassified

Presentaciones atípicas de histoplasmosis

et al. 2015

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La histoplasmosis es una enfermedad granulomatosa, producida por Histoplasma capsulatum. Causa un amplio espectro de manifestaciones clínicas, la más frecuente es la pulmonar. En algunos casos se presentan formas diseminadas, con afectación de uno o múltiples órganos, de características atípicas, difíciles de reconocer. La patogenia de esta enfermedad es igual a la de tuberculosis y se ha descrito coinfección. Se reportan tres casos de histoplasmosis de presentación infrecuente: ancianos, coinfección con micobacterias y localizaciones atípicas y revisión de la literatura. El primero fue un paciente de 19 años de edad con absceso cerebral. El segundo y tercero, personas mayores de 60 años, con infección mixta por Histoplasma y micobacterias, uno de presentación articular y otra con enfermedad ginecológica. En Venezuela, zona endémica para esta micosis, el médico está obligado a tener un alto índice de sospecha acerca de la misma, teniendo en cuenta factores como la edad y la epidemiologia.

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Magnetic Resonance Imaging Findings in a Patient With Isolated Histoplasma Brain Abscess

Cited by 8 publications

References 3 publications

CD103+ Conventional Dendritic Cells Are Critical for TLR7/9-Dependent Host Defense against Histoplasma capsulatum, an Endemic Fungal Pathogen of Humans

CD103+ Conventional Dendritic Cells Are Critical for TLR7/9-Dependent Host Defense against Histoplasma capsulatum, an Endemic Fungal Pathogen of Humans

Histoplasmosis with Deep CNS Involvement: Case Presentation with Discussion and Literature Review

Presentaciones atípicas de histoplasmosis

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