Immunopathogenicity of Acanthamoeba spp. in the Brain and Lungs

Abstract

Free-living amoebas, including Acanthamoeba spp., are widely distributed in soil, water, and air. They are capable of causing granulomatous amebic encephalitis, Acanthamoeba pneumonia, Acanthamoeba keratitis, and disseminated acanthamoebiasis. Despite low occurrence worldwide, the mortality rate of Acanthamoeba spp. infections is very high, especially in immunosuppressed hosts. Acanthamoeba infections are a medical problem, owing to limited improvement in diagnostics and treatment, which is associated with incomplete knowledge of pathophysiology, pathogenesis, and the host immune response against Acanthamoeba spp. infection. The aim of this review is to present the biochemical and molecular mechanisms of Acanthamoeba spp.–host interactions, including the expression of Toll-like receptors, mechanisms of an immune response, the activity of metalloproteinases, the secretion of antioxidant enzymes, and the expression and activity of cyclooxygenases. We show the relationship between Acanthamoeba spp. and the host at the cellular level and host defense reactions that lead to changes in the selected host’s organs.

Pathomechanisms in the Kidneys in Selected Protozoan Parasitic Infections

“…also cause granulomatous amoebic encephalitis (GAE). It is an opportunistic, rare disease with a mortality rate of 97-98% [135,136]. Infection occurs by inhalation of air or water aspiration containing invasive forms of Acanthamoeba spp.…”

“…Infection occurs by inhalation of air or water aspiration containing invasive forms of Acanthamoeba spp. Severe headaches, neck pains, confusion, irritability, hallucinations, fever, nausea, and vomiting have been observed in GAE patients [135,136]. Due to the difficult, often long-term diagnosis of granulomatous encephalitis, treatment of this disease is problematic [129,137].…”

Molecular identification and genotyping of Acanthamoeba spp., in bronchoalveolar lavage fluid from immunocompetent patients with chronic respiratory disorders (CRD)

“…Acanthamoeba spp., infection of the lungs occurs mostly in immunosuppressed patients (Kaul et al 2008 ). According to previous studies, 19 cases of AP or disseminated acanthamoebiasis with lung infection were reported (Kot et al 2021 ). These patients had a history of acute and chronic marrow leukemia, acute myeloblastic leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, atypical pneumonia, and organ transplant recipients (Kot et al 2021 ).…”

“…According to previous studies, 19 cases of AP or disseminated acanthamoebiasis with lung infection were reported (Kot et al 2021 ). These patients had a history of acute and chronic marrow leukemia, acute myeloblastic leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, atypical pneumonia, and organ transplant recipients (Kot et al 2021 ). However, according to the literature review, Vernon et al reported a case of Acanthamoeba infection in a lung transplant patient, who presented with rhinosinusitis (Vernon et al 2005 ).…”

Successful management of post-COVID-19 acanthamoebic encephalitis

“…Optimal approach to the treatment of this disease is uncertain. Only a few reports of successful treatment with combination drug therapy are available in the literature; the following drugs were used in various combinations for variable durations ranging from two weeks to several months: miltefosine, fluconazole, ketoconazole, trimethoprimsulfamethoxazole, sulfadiazine, metronidazole, rifampicin, vancomycin, ceftriaxone, dexamethasone, albendazole, carbamazepine, pentamidine, liposomal amphotericin B, flucytosine, and voriconazole ([9] Kot et al, 2021).…”