{
  "abstract": "Patient: Female, 55-year-old\n\nFinal Diagnosis: HHV-6 encephalitis\n\nSymptoms: Impaired consciousness • nausea\n\nClinical Procedure: Bronchoscopy • lumbar puncture\n\nSpecialty: Hematology • Infectious Diseases • Neurology\n\nObjective: Rare coexistence of disease or pathology\n\nBackground: Human herpesvirus 6 (HHV-6) encephalitis is best recognized after allogeneic hematopoietic stem cell transplantation but can also occur in non-transplant immunocompromised patients. Hyponatremia and syndrome of inappropriate antidiuretic hormone secretion (SIADH) may precede or accompany HHV-6 encephalitis. Severe SIADH as an early dominant clue in non-transplant patients with smoldering adult T-cell leukemia/lymphoma (ATLL) is not fully described.\n\nCase Report: A 55-year-old woman with smoldering ATLL received systemic corticosteroid therapy for clinically diagnosed human T-cell leukemia virus type 1 (HTLV-1)-associated uveitis and was admitted for progressive pulmonary infection. Bronchoscopic specimens revealed polymicrobial infection, including Nocardia and Actinomyces; invasive pulmonary aspergillosis was also clinically suspected. Although pulmonary findings improved with antimicrobial and antifungal therapy, she developed nausea, acute impairment of consciousness, and severe SIADH-associated hyponatremia. Serum sodium decreased to 113 mmol/L, and consciousness did not adequately improve after sodium correction. Cerebrospinal fluid obtained by lumbar puncture on hospital day 13 showed HHV-6 DNA positivity (1.0 × 103 copies/mL). Brain magnetic resonance imaging demonstrated bilateral cortical and limbic abnormalities, supporting a clinical diagnosis of HHV-6 encephalitis. Ganciclovir was initiated on hospital day 15 along with sodium correction, tolvaptan, and supportive care. The patient subsequently developed hypercapnic respiratory failure and CO2 narcosis requiring mechanical ventilation. Her neurologic and respiratory status gradually improved, and she was discharged on hospital day 53.\n\nConclusions: In non-transplant patients with ATLL, corticosteroid exposure, and opportunistic infection, severe SIADH accompanied by new neurologic symptoms can be an early clue to HHV-6 encephalitis. Early recognition and prompt initiation of antiviral therapy may help to improve neurologic outcomes.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Respiratory Medicine, Fukuoka University Hospital, Fukuoka, Japan",
    "Department of Neurology, Fukuoka University Hospital, Fukuoka, Japan",
    "Department of Pathology, Fukuoka University Hospital, Fukuoka, Japan"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Kana Tateishi"
    },
    {
      "affs": [
        0
      ],
      "name": "Toyoshi Yanagihara",
      "orcid": "0000-0002-2212-0631"
    },
    {
      "affs": [
        0
      ],
      "name": "Ryoma Kawabata"
    },
    {
      "affs": [
        0
      ],
      "name": "Eriko Kinoshita"
    },
    {
      "affs": [
        1
      ],
      "name": "Takeshi Miyazaki"
    },
    {
      "affs": [
        1
      ],
      "name": "Yuji Tateishi"
    },
    {
      "affs": [
        2
      ],
      "name": "Kaori Koga"
    },
    {
      "affs": [
        2
      ],
      "name": "Makoto Hamasaki"
    },
    {
      "affs": [
        0
      ],
      "name": "Masaki Fujita",
      "orcid": "0000-0003-1209-1272"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/47v97nxbjepza.bib",
  "cited_by": 0,
  "doi": "10.12659/ajcr.954380",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13726342/",
  "id": "47v97nxbjepza",
  "issns": [
    "1941-5923"
  ],
  "landing_url": "https://doi.org/10.12659/ajcr.954380",
  "language": "en",
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Articles"
    ],
    [
      "openalex",
      "2730|Viral-associated cancers and disorders"
    ]
  ],
  "openalex": "W7211970726",
  "pdf_url": "https://amjcaserep.com/download/inPress/idArt/954380",
  "pmcid": "PMC13726342",
  "pmid": "42947366",
  "published": "2026-10-28",
  "publisher": "International Scientific Information, Inc.",
  "ris": "https://research.draconitic.com/paper/47v97nxbjepza.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T12:22:43Z",
      "native_id": "PMC13726342",
      "source": "pmc",
      "url": "https://doi.org/10.12659/ajcr.954380"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2730|Viral-associated cancers and disorders",
      "subfield": "oncology"
    }
  ],
  "title": "HHV-6 Encephalitis Presenting With Severe SIADH and CO2 Narcosis in Non-Transplant Smoldering Adult T-Cell Leukemia/Lymphoma",
  "title_text": "HHV-6 Encephalitis Presenting With Severe SIADH and CO2 Narcosis in Non-Transplant Smoldering Adult T-Cell Leukemia/Lymphoma",
  "type": "peer-reviewed",
  "updated_at": "2026-11-06T12:22:20Z",
  "url": "https://research.draconitic.com/paper/47v97nxbjepza",
  "venue": "The American Journal of Case Reports",
  "versions": []
}