FELIPE LOURENCO LEDESMA
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/03 - Laboratório de Medicina Laboratorial, Hospital das Clínicas, Faculdade de Medicina
LIM/03 - Laboratório de Medicina Laboratorial, Hospital das Clínicas, Faculdade de Medicina
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- Understanding Sabia virus infections (Brazilian mammarenavirus)(2022) NASTRI, Ana Catharina; DUARTE-NETO, Amaro Nunes; CASADIO, Luciana Vilas Boas; SOUZA, William Marciel de; CLARO, Ingra M.; MANULI, Erika R.; SELEGATTO, Gloria; SALOMA, Matias C.; FIALKOVITZ, Gabriel; TABORDA, Mariane; ALMEIDA, Bianca Leal de; MAGRI, Marcello C.; GUEDES, Ana Rubia; NETO, Laura Vieira Perdigao; SATAKI, Fatima Mitie; GUIMARAES, Thais; MENDES-CORREA, Maria Cassia; TOZETTO-MENDOZA, Tania R.; FUMAGALLI, Marcilio Jorge; HO, Yeh-Li; SILVA, Camila ALves Maia da; COLETTI, Thais M.; JESUS, Jacqueline Goes de; ROMANO, Camila M.; HILL, Sarah C.; PYBUS, Oliver; PINHO, Joao Renato Rebello; LEDESMA, Felipe Lourenco; CASAL, Yuri R.; KANAMURA, Cristina; ARAUJO, Leonardo Jose Tadeu de; FERREIRA, Camila Santos da Silva; GUERRA, Juliana Mariotti; FIGUEIREDO, Luiz Tadeu Moraes; DOLHNIKOFF, Marisa; FARIA, Nuno R.; SABINO, Ester C.; AVANCINI, Venacio; ALVES, Ferreira; LEVIN, Anna S.Background: Only two naturally occurring human Sabi ' a virus (SABV) infections have been reported, and those occurred over 20 years ago. Methods: We diagnosed two new cases of SABV infection using metagenomics in patients thought to have severe yellow fever and described new features of histopathological findings. Results: We characterized clinical manifestations, histopathology and analyzed possible nosocomial transmission. Patients presented with hepatitis, bleeding, neurological alterations and died. We traced twenty-nine hospital contacts and evaluated them clinically and by RT-PCR and neutralizing antibodies. Autopsies uncovered unique features on electron microscopy, such as hepatocyte ""pinewood knot"" lesions. Although previous reports with similar New-World arenavirus had nosocomial transmission, our data did not find any case in contact tracing. Conclusions: Although an apparent by rare, Brazilian mammarenavirus infection is an etiology for acute hemorrhagic fever syndrome. The two fatal cases had peculiar histopathological findings not previously described. The virological diagnosis was possible only by contemporary techniques such as metagenomic assays. We found no subsequent infections when we used serological and molecular tests to evaluate close contacts.
- Chronic exposure to cigarette smoke transiently worsens the disease course in a mouse model of pulmonary paracoccidioidomycosis(2022) BUCCHERI, Renata; DUARTE-NETO, Amaro Nunes; SILVA, Flaviano Luiz Batista; HADDAD, Gabrielle Carvalho; SILVA, Leandro Buffoni Roque da; AZEVEDO NETTO, Raymundo; LEDESMA, Felipe Lourenço; TABORDA, Carlos Pelleschi; BENARD, GilABSTRACT Paracoccidioidomycosis (PCM) may present as an acute/subacute clinical form, characterized by a progressive disease arising from the airborne initial infection, or, most often, as an asymptomatic or subclinical infection that may manifest later during an individual’s life, the chronic form. Epidemiological studies show the existence of a strong association between smoking and the development of the chronic form. Current evidence demonstrates that cigarette smoke (CS) has immunosuppressive properties that could be implicated in the increasing susceptibility to the chronic form of PCM. To address this issue, we developed a murine model of a non-progressive pulmonary form of PCM that was exposed to CS at a magnitude that mimicked a moderate smoker. The chronic CS exposure started after 2 weeks and lasted up until 20 weeks post-infection, with the aim of mimicking human natural history, since it is estimated that individuals from endemic areas are infected early in life. The control group consisted of infected but not CS-exposed mice. We assessed the lung fungal burden (colony forming units [CFU]) and the area affected by the granulomatous inflammatory response, fungal dissemination to spleen and liver, and, by immunohistochemistry, the presence of CD4 and CD8 lymphocytes, CD68 and MAC-2 macrophages, and IFN-γ, IL-10 and TNF expressing cells within the granulomatous response. We detected a CS effect as early as 2 weeks after exposure (four weeks post-infection) when the lung CFU of exposed animals was significantly higher than in their non-exposed counterparts. At 12 weeks, the CS-exposed animals presented a more severe disease, as witnessed by the persistent higher lung fungal load (although it did not reach statistical significance [ p = 0.054]), greater dissemination to other organs, greater affected area of the lung, decreased IFN-γ/IL-10 ratio, and higher TNF expression within the granulomas, compared with CS-non-exposed mice. The number of CD4 and CD8 lymphocytes infiltrating the granulomas was similar between both mice groups, but there was a decrease in the number of MAC-2+ macrophages. No difference was noted in the CD68+ macrophage number. However, the follow-up in week 20 showed that the immunological effects of exposure to CS ceased, with both CS and NCS mice showing the same infectious features, i.e., a trend for resolution of the infection. In conclusion, we show that chronic CS-exposure alters the course of the disease in an experimental model of subclinical pulmonary PCM, confirming the epidemiological link between CS-exposure and the chronic form of PCM. However, we also show that this effect is transitory, being detected between 4- and 12-weeks post-infection but not thereafter. The possible immune mechanisms that mediate this effect and the reasons for its transitory effect are discussed.
- Understanding yellow fever-associated myocardial injury: an autopsy study(2023) GIUGNI, Fernando Rabioglio; DEMARCHIAIELLO, Vera; FARIA, Caroline Silverio; POUR, Shahab Zaki; CUNHA, Marielton dos Passos; GIUGNI, Melina Valdo; PINESI, Henrique Trombini; LEDESMA, Felipe Lourenco; MORAIS, Carolina Esteves; HO, Yeh-Li; SZTAJNBOK, Jaques; FERNEZLIAN, Sandra de Morais; SILVA, Luiz Fernando Ferraz da; MAUAD, Thais; ALVES, Venancio Avancini Ferreira; SALDIVA, Paulo Hilario do Nascimento; ANTONANGELO, Leila; DOLHNIKOFF, Marisa; DUARTE-NETO, Amaro NunesBackground Yellow fever (YF) is a viral hemorrhagic fever, endemic in parts of South America and Africa. There is scarce evidence about the pathogenesis of the myocardial injury. The objective of this study is to evaluate the cardiac pathology in fatal cases of YF.Methods This retrospective autopsy study included cases from the Sao Paulo (Brazil) epidemic of 2017-2019. We reviewed medical records and performed cardiac tissue histopathological evaluation, electron microscopy, immunohistochemical assays, RT-qPCR for YF virus (YFV)-RNA, and proteomics analysis on inflammatory and endothelial biomarkers.Findings Seventy-three confirmed YF cases with a median age of 48 (34-60) years were included. We observed myocardial fibrosis in 68 (93.2%) patients; cardiomyocyte hypertrophy in 68 (93.2%); endothelial alterations in 67 (91.8%); fiber necrosis in 50 (68.5%); viral myocarditis in 9 (12.3%); and secondary myocarditis in 5 (6.8%). Four out of five patients with 17DD vaccine-associated viscerotropic disease presented with myocarditis. The cardiac conduction system showed edema, hemorrhages and endothelial fibrinoid necrosis. Immunohistochemistry detected CD68-positive inflammatory interstitial cells and YFV antigens in endothelial and inflammatory cells. YFV-RNA was detected positive in 95.7% of the cardiac samples. The proteomics analysis demonstrated that YF patients had higher levels of multiple inflammatory and endothelial biomarkers in comparison to cardiovascular controls, and higher levels of interferon gamma-induced protein 10 (IP-10) in comparison to sepsis (p = 0.01) and cardiovascular controls (p < 0.001) in Dunn test.Interpretation Myocardial injury is frequent in severe YF, due to multifactorial mechanisms, including direct YFV-mediated damage, endothelial cell injury, and inflammatory response, with a possible prominent role for IP-10.