{
  "abstract": "Background: Long COVID (LC) is characterized by persistent systemic symptoms, but its oral inflammatory profile remains unclear. This study evaluated oral inflammatory biomarkers, particularly matrix metalloproteinase (MMP) -8, -9 and their regulators in oral rinse samples from LC patients. Methods: This cross-sectional study analyzed oral rinse samples from 115 LC patients and 103 comparable controls. Periodontal inflammation was screened using a chair-side active MMP-8 (aMMP-8) point-of-care test (POCT). Biomarkers (aMMP-8, total MMP-8, MMP-9, TIMP-1, and MPO) were quantified and validated by Western blotting and gelatin zymography. Associations with LC and clinical variables were assessed using bivariate analysis and multivariable regression. Results: LC patients had significantly higher total MMP-8, MMP-9, TIMP-1, and MMP-9/TIMP-1 ratio (all P < 0.05 in both analyses). IFMA-measured active MMP-8 became independently associated with LC after multivariable adjustment. Chair-side aMMP-8 POCT showed a nonsignificant trend toward higher positivity in LC (16.5% vs 8.7%). BMI was positively associated with aMMP-8, tMMP-8 and tMMP-8/TIMP-1 molar ratio. Antidepressant use was associated with tMMP-8/TIMP-1 molar ratio. Western blotting confirmed active MMP-8 species and gingipain. Conclusion: These findings suggest an altered oral inflammatory biomarker profile in LC. The potential role of chair-side aMMP-8 POCT for screening oral inflammation in this population merits further investigation.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Oral and Maxillofacial Diseases, Faculty of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Periodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India",
    "Department of Oral and Maxillofacial Diseases, Faculty of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland",
    "Outpatient Clinic for Long-Term Effects of COVID-19, Helsinki University Central Hospital, Helsinki, Finland",
    "Outpatient Clinic for Long-Term Effects of COVID-19, Helsinki University Central Hospital, Helsinki, Finland; Department of Hospital Hygiene and Infection Control, TYKS Turku University Hospital, Turku, Finland",
    "Department of Oral and Maxillofacial Diseases, Faculty of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden",
    "Department of Oral and Maxillofacial Diseases, Faculty of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Virology, University of Helsinki, Helsinki, Finland; Department of Infectious Diseases, Meilahti Vaccine Research Center MeVac, University of Helsinki and Helsinki University Hospital, Helsinki, Finland"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "name": "Nur Rahman Ahmad Seno Aji"
    },
    {
      "affs": [
        0
      ],
      "name": "Julie Toby Thomas"
    },
    {
      "affs": [
        1
      ],
      "name": "Taina Tervahartiala"
    },
    {
      "affs": [
        1
      ],
      "name": "Ismo T. Räisänen"
    },
    {
      "affs": [
        2
      ],
      "name": "Mikko Varonen"
    },
    {
      "affs": [
        2
      ],
      "name": "Helena Liira"
    },
    {
      "affs": [
        3
      ],
      "name": "Mari Kanerva"
    },
    {
      "affs": [
        2
      ],
      "name": "Velina Vangelova-Korpinen"
    },
    {
      "affs": [
        4
      ],
      "name": "Timo Sorsa"
    },
    {
      "affs": [
        5
      ],
      "name": "Hanna Välimaa"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fzy675eq3pe3y.bib",
  "cited_by": 0,
  "doi": "10.1016/j.ijid.2026.109183",
  "fulltext_url": "http://www.sciencedirect.com/science/article/pii/S1201971226008180",
  "id": "fzy675eq3pe3y",
  "issns": [
    "1201-9712",
    "1878-3511"
  ],
  "landing_url": "https://doi.org/10.1016/j.ijid.2026.109183",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "lcc",
      "RC109-216"
    ],
    [
      "openalex",
      "2728|Long-Term Effects of COVID-19"
    ]
  ],
  "openalex": "W7221755880",
  "pdf_url": "https://www.ijidonline.com/article/S1201-9712(26)00818-0/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/fzy675eq3pe3y.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T14:20:46Z",
      "native_id": "103cfbd7e72c40c495e8175a9f85d74f",
      "source": "doaj",
      "url": "https://doi.org/10.1016/j.ijid.2026.109183"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2728|Long-Term Effects of COVID-19",
      "subfield": "neurology"
    }
  ],
  "title": "Oral fluid inflammatory biomarker profile in long COVID: evaluation of oral active and total MMP-8, MMP-9, and TIMP-1 in relation to BMI and disease status",
  "title_text": "Oral fluid inflammatory biomarker profile in long COVID: evaluation of oral active and total MMP-8, MMP-9, and TIMP-1 in relation to BMI and disease status",
  "type": "peer-reviewed",
  "updated_at": "2026-11-06T14:20:10Z",
  "url": "https://research.draconitic.com/paper/fzy675eq3pe3y",
  "venue": "International Journal of Infectious Diseases",
  "versions": []
}