{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T12:27:13Z","timestamp":1785414433259,"version":"3.56.0"},"reference-count":18,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T00:00:00Z","timestamp":1774396800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union-NextGenerationEU","award":["BG-RRP-2.004-0004-C01"],"award-info":[{"award-number":["BG-RRP-2.004-0004-C01"]}]},{"award":["BG-RRP-2.004-0004-C01"],"award-info":[{"award-number":["BG-RRP-2.004-0004-C01"]}],"id":[{"id":"https:\/\/ror.org\/019w4f821","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Background: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder frequently associated with ovarian teratomas in young women. Although infectious triggers have been proposed to contribute to immune activation, direct evidence linking viral presence within tumor tissue to disease pathogenesis remains limited. Case Presentation: An 18-year-old woman presented with acute neuropsychiatric symptoms, fever, gastrointestinal prodrome, and rapidly progressive behavioral disturbance progressing to encephalopathy. Cerebrospinal fluid and blood test results, together with clinical features, supported the diagnosis of anti-NMDAR encephalitis. Imaging identified an ovarian mass, and surgical resection was performed. Histopathology confirmed a mature teratoma containing neuroglial elements. Molecular analysis detected parvovirus B19 DNA within the resected teratomatous tissue. No systemic viremia or active central nervous system viral infection was identified. The patient received immunotherapy combined with tumor removal, with subsequent clinical improvement. Discussion: Ovarian teratomas remain a critical etiologic factor in anti-NMDAR encephalitis and mandate prompt surgical management. Detection of B19 viral DNA within teratomatous neuroglial tissue raises the hypothesis that viral persistence could enhance local immune activation and autoantibody generation. However, in this case polymerase chain reaction positivity does not indicate active infection, and the biological significance of this finding remains uncertain. Conclusions: This case documents rare detection of B19V DNA within an ovarian teratomatous tissue in anti-NMDAR encephalitis. The observation is hypothesis-generating rather than causal; established management priorities remain immunotherapy and tumor resection, and viral nucleic acid detection should be interpreted within the broader clinical context.<\/jats:p>","DOI":"10.3390\/v18040405","type":"journal-article","created":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T10:07:13Z","timestamp":1774433233000},"page":"405","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Parvovirus B19 DNA Detected in Ovarian Teratomatous Tissue in Anti-NMDAR Encephalitis: A Case Report"],"prefix":"10.3390","volume":"18","author":[{"given":"Trifon","family":"Valkov","sequence":"first","affiliation":[{"name":"Department of Infectious Diseases, Medical University of Sofia, Prof. Ivan Kirov Hospital, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dobroslav","family":"Kyurkchiev","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Medical University of Sofia, University Hospital \u201cIvan Rilski\u201d, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ekaterina","family":"Kurteva","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Medical University of Sofia, University Hospital \u201cIvan Rilski\u201d, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kalina","family":"Tumangelova-Yuzeir","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Medical University of Sofia, University Hospital \u201cIvan Rilski\u201d, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2440-2760","authenticated-orcid":false,"given":"Jeliazko","family":"Arabadjiev","sequence":"additional","affiliation":[{"name":"Acibadem City Clinic, University Hospital \u201cTokuda\u201d, 1407 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6335-0831","authenticated-orcid":false,"given":"Vesela","family":"Ivanova","sequence":"additional","affiliation":[{"name":"Department of General and Clinical Pathology, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3489-3570","authenticated-orcid":false,"given":"Dimitrinka","family":"Kisova","sequence":"additional","affiliation":[{"name":"Department of General and Clinical Pathology, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Radka","family":"Argirova","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Acibadem City Clinic Tokuda Hospital, 1407 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9925-9025","authenticated-orcid":false,"given":"George","family":"Dimitrov","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology, Medical University of Sofia, University Hospital \u201cTsaritsa Yoanna\u201d, 1527 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yordanka","family":"Yamakova","sequence":"additional","affiliation":[{"name":"Department Anaesthesiology and Intensive Care, Medical University of Sofia, University Hospital \u201cAleksandrovska\u201d, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1038\/s41572-025-00650-1","article-title":"Autoimmune encephalitis","volume":"11","author":"Leypoldt","year":"2025","journal-title":"Nat. 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