In vitro and in vivo evaluation of inflammatory and humoral response in patients diagnosed with Acanthamoeba keratitis

• Grant number: 22/07131-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): December 01, 2022
• Effective date (End): July 31, 2026
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Denise de Freitas
• Grantee: Larissa Fagundes Pinto
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Acanthamoeba keratitis (AK) is a rare infection with high morbidity that develops in the cornea, with the protozoan Acanthamoeba spp. Amoebas of this genus are widely distributed in nature, and this suggests that humans are likely to come into contact with this parasite at some point in their lives, given that 50 to 100% of the population has specific serum antibodies to Acanthamoeba antigens. Given that the eye is an immune-privileged organ, the main factors involved in immune responses to the ocular surface are eyelids and eyelashes, tears, conjunctiva and cornea, sclera, complement system, and inflammatory cells. It was observed in studies in the literature that macrophages and neutrophils can eliminate trophozoites and cysts of some species of the genus Acanthamoeba, as well as, in other cases, some species are resistant to death induced by these phagocytes. For this reason, this work aims to evaluate in vivo the inflammatory responses activated and developed during eye infections caused by Acanthamoeba, as well as the production of IgA in healthy donors and patients diagnosed with AC, and also to investigate in vitro the responses and activation of inflammatory cells of innate immunity (neutrophils, macrophages, and dendritic cells), human origin, when challenged with different isolates of Acanthamoeba spp. from AK cases. Given that, in the literature, there is no clinical evidence that this investigation has been carried out in patients with AK and associated with the in vitro findings for isolates obtained from my patients evaluated in vivo.