{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:11:53Z","timestamp":1753891913001,"version":"3.41.2"},"reference-count":52,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,11,17]],"date-time":"2023-11-17T00:00:00Z","timestamp":1700179200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Parasitol."],"abstract":"<jats:sec><jats:title>Background and methods<\/jats:title><jats:p>Circulating <jats:italic>Loa loa<\/jats:italic> antigens are often detected in individuals with heavy <jats:italic>L. loa<\/jats:italic> infections by diagnostic tests for lymphatic filariasis (LF) caused by <jats:italic>Wuchereria bancrofti<\/jats:italic>. This is a major challenge to LF mapping and elimination efforts in loiasis co-endemic areas. However, it also provides an opportunity to identify antigen biomarkers for loiasis. To determine which <jats:italic>L. loa<\/jats:italic> antigens might be promising biomarkers for distinguishing true LF from loiasis, we screened for <jats:italic>L. loa<\/jats:italic> antigens in a group of individuals with heavy <jats:italic>L. loa<\/jats:italic> infections living in the Okola Health District of Cameroon. In this longitudinal study, participants were tested for cross-reactive antigenemia by filariasis test strip (FTS), ELISA, and western blot, and were monitored for FTS status at 6, 9, 12, and 15 months post-enrollment. We then identified specific circulating <jats:italic>L. loa<\/jats:italic> antigens by liquid chromatography-tandem mass spectrometry (LC-MS\/MS) from baseline and 15-month plasma samples.<\/jats:p><\/jats:sec><jats:sec><jats:title>Principal findings and conclusions<\/jats:title><jats:p>Among 73 FTS-positive (FTS+) and 13 FTS-negative (FTS-) participants with high <jats:italic>L. loa<\/jats:italic> microfilarial loads, 83% maintained their FTS status over the course of the study, while 17% experienced at least one FTS conversion event (from FTS+ to FTS- or vice versa). Cross-reactive antigens were detected in both FTS+ and FTS- sera by western blot, and there was poor agreement in antigen detection by FTS, western blot, and ELISA methods. One protein family, a group of Nas-14 metalloproteases, was detected by LC MS\/MS in &amp;gt;80% of tested samples, including FTS- samples. These data identify Nas-14 as a promising loiasis biomarker potentially capable of distinguishing loiasis from lymphatic filariasis.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fpara.2023.1292837","type":"journal-article","created":{"date-parts":[[2023,11,18]],"date-time":"2023-11-18T10:09:35Z","timestamp":1700302175000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Longitudinal study of cross-reactive antigenemia in individuals with high Loa loa microfilarial density reveals promising biomarkers for distinguishing lymphatic filariasis from loiasis"],"prefix":"10.3389","volume":"2","author":[{"given":"Linda","family":"Djune-Yemeli","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marla","family":"Hertz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hugues C.","family":"Nana-Djeunga","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amy","family":"Rush","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Petra","family":"Erdmann-Gilmore","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robert","family":"Sprung","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jean Gabin","family":"Bopda","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Reid","family":"Townsend","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Palmer Masumbe","family":"Netongo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joseph","family":"Kamgno","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Philip J.","family":"Budge","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2023,11,17]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"420","DOI":"10.1038\/s41587-019-0036-z","article-title":"SignalP 5.0 improves signal peptide predictions using deep neural networks","volume":"37","author":"Almagro Armenteros","year":"2019","journal-title":"Nat. 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