{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T23:31:55Z","timestamp":1790033515854,"version":"4.0.1"},"reference-count":48,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2024,2,6]],"date-time":"2024-02-06T00:00:00Z","timestamp":1707177600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002322","name":"CAPES","doi-asserted-by":"crossref","award":["88887.475118\/2020-00"],"award-info":[{"award-number":["88887.475118\/2020-00"]}],"id":[{"id":"10.13039\/501100002322","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100004586","name":"FAPERJ","doi-asserted-by":"crossref","award":["E-26\/201.682\/2021 (266508)"],"award-info":[{"award-number":["E-26\/201.682\/2021 (266508)"]}],"id":[{"id":"10.13039\/501100004586","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Ocular toxoplasmosis (OT) is caused by protozoan <jats:italic>T<\/jats:italic>. <jats:italic>gondii<\/jats:italic>. Ophthalmological examination is considered the gold standard for OT diagnosis, and laboratory tests are used for diagnostic confirmation. However, these tests can present different results, which change depending on their basis, on sample type and on patients\u2019 clinical alteration. Thus, the aim of the present study is to assess immunodiagnostic and molecular techniques applied in blood, serum and tear fluid to diagnose <jats:italic>T<\/jats:italic>. <jats:italic>gondii<\/jats:italic> infection in patients seen at an Ophthalmology Clinic. In total, 160 patients were included in the study, 40 of them had OT with active lesions (G1); 40 had OT with healed lesions (G2), 40 had non-toxoplasmic uveitis (G3) and 40 had no ocular alterations (G4). Serum samples were subjected to Immunoenzymatic Assay (ELISA) and to Indirect Immunofluorescence Reaction (IFAT) to search for anti-<jats:italic>T<\/jats:italic>. <jats:italic>gondii<\/jats:italic> IgM and IgG. Tear fluid samples were analyzed through ELISA for IgA research. All blood and tear fluid samples were subjected to conventional polymerase chain reaction (cPCR) and in a Nested PCR model for <jats:italic>T<\/jats:italic>. <jats:italic>gondii<\/jats:italic> DNA amplification with targets B1, GRA7 and REP 529. IgG and IgM anti-<jats:italic>T<\/jats:italic>. <jats:italic>gondii<\/jats:italic> was detected in serum samples from 106 and 15 patients, respectively, when combining ELISA and IFAT results. Anti-<jats:italic>T<\/jats:italic>.<jats:italic>gondii<\/jats:italic> IgA antibodies were detected in 9.2% of the tear material. Nested PCR with GRA7 target showed higher positivity in blood samples (24.4%); Nested PCR with B1 target showed a higher frequency of positivity in tears (15%). Biological samples of patients with active lesions showed the highest positivity frequencies in all immunodiagnostic assays, as well as in most PCR models. The present results highlighted the need of associating techniques with different fundamentals to confirm OT diagnosis. Furthermore, further tear fluid analyses should be performed to validate this biological material as lesser invasive alternative for the more accurate OT diagnosis.<\/jats:p>","DOI":"10.1371\/journal.pone.0298393","type":"journal-article","created":{"date-parts":[[2024,2,6]],"date-time":"2024-02-06T18:30:22Z","timestamp":1707244222000},"page":"e0298393","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":6,"title":["Comparison of immunological and molecular methods for laboratory diagnosis of ocular toxoplasmosis in blood, serum and tears in Brazil"],"prefix":"10.1371","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5848-7435","authenticated-orcid":true,"given":"Raissa Cristina Ferreira","family":"Ramos","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5007-1339","authenticated-orcid":true,"given":"Alynne da Silva","family":"Barbosa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana Luisa Quintella do Couto","family":"Aleixo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Igor Falco","family":"Arruda","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0867-1445","authenticated-orcid":true,"given":"Maria Regina Reis","family":"Amendoeira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2024,2,6]]},"reference":[{"key":"pone.0298393.ref001","doi-asserted-by":"crossref","first-page":"1965","DOI":"10.1016\/S0140-6736(04)16412-X","article-title":"Toxoplasmosis","volume":"36","author":"JG Montoya","year":"2004","journal-title":"The Lancet"},{"issue":"1","key":"pone.0298393.ref002","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1007\/s10792-021-01994-9","article-title":"Ocular toxoplasmosis: a review of the current diagnosticand therapeutic approaches","volume":"42","author":"D Kalogeropoulos","year":"2022","journal-title":"Int Ophthalmol"},{"issue":"1","key":"pone.0298393.ref003","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1186\/s13071-023-06080-w","article-title":"Genetic diversity of Toxoplasma gondii in South America: occurrence, immunity, and fate of infection","volume":"16","author":"RMM Brito","year":"2023","journal-title":"Parasit Vectors"},{"key":"pone.0298393.ref004","doi-asserted-by":"crossref","first-page":"1385","DOI":"10.1016\/j.ijpara.2009.04.003","article-title":"Toxoplasmosis snapshots: global status of Toxoplasma gondii seroprevalence and implications for pregnancy and congenital toxoplasmosis","volume":"39","author":"G Pappas","year":"2009","journal-title":"Int J Parasitol"},{"key":"pone.0298393.ref005","doi-asserted-by":"crossref","first-page":"1375","DOI":"10.1017\/S0031182012000765","article-title":"Toxoplasmosis in humans and animals in Brazil: high prevalence, high burden of disease, and epidemiology","volume":"139","author":"JP Dubey","year":"2012","journal-title":"Parasitol"},{"issue":"1","key":"pone.0298393.ref006","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1186\/s12879-018-3613-8","article-title":"Coinfections and differential diagnosis in immunocompetent patients with uveitis of infectious origin","volume":"19","author":"A De-La-Torre","year":"2019","journal-title":"BMC Infect Dis"},{"key":"pone.0298393.ref007","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1590\/S0037-86822005000100020","article-title":"Pesquisa de anticorpos anti-Toxoplasma gondii em fluidos intra-oculares (humor v\u00edtreo e humor aquoso) de pacientes com toxoplasmose ocular, na Cidade de Bel\u00e9m, PA","volume":"38","author":"EL Carmo","year":"2005","journal-title":"Rev Soc Bras Med Trop"},{"key":"pone.0298393.ref008","doi-asserted-by":"crossref","first-page":"472","DOI":"10.3389\/fcimb.2019.00472","article-title":"Evaluation of Serological and Molecular Tests Used for the Identification of Toxoplasma gondii Infection in Patients Treated in an Ophthalmology Clinic of a Public Health Service in S\u00e3o Paulo State, Brazil","volume":"9","author":"FHA Murata","year":"2020","journal-title":"Front Cell Infect Microbiol"},{"issue":"5","key":"pone.0298393.ref009","first-page":"197","article-title":"Peculiaridades da toxoplasmose ocular no Rio Grande do Sul","volume":"51","author":"J. 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