{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T09:07:06Z","timestamp":1788944826422,"version":"build-2803163510"},"reference-count":28,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T00:00:00Z","timestamp":1788912000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background\/Objectives: Host factors angiotensin-converting enzyme 2 (ACE2), transmembrane protease-serine 2 (TMPRSS2), furin paired basic amino acid cleaving enzyme (FURIN), and neuropilin-1 (NRP1) facilitate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry, but it is unclear whether their upper-airway expression after recovery is associated with the severity of the preceding acute illness. We examined the association between post-acute expression of these genes and previous coronavirus disease 2019 (COVID-19) severity. Methods: This multicenter cross-sectional study included 104 adults with polymerase chain reaction (PCR)-confirmed COVID-19 during the first two pandemic waves in Murcia, Spain. Nasal and\/or oropharyngeal swabs were collected in the post-acute phase, at a median of 75 days after symptom onset, and transcript levels were quantified by quantitative real-time PCR. Severity was categorized using the World Health Organization (WHO) Clinical Progression Scale, and associations were evaluated using logistic regression adjusted for age, sex, and race\/ethnicity. Results: In the primary analyses using continuous expression measures, none of the four genes was significantly associated with severity. In exploratory tertile-based analyses, the intermediate ACE2 tertile (odds ratio [OR] = 0.17, 95% confidence interval [CI] 0.05\u20130.61; p = 0.007) and intermediate NRP1 tertile (OR = 0.29, 95% CI 0.10\u20130.88; p = 0.030) were associated with lower odds of severe disease; no significant associations were observed for the high tertiles or for FURIN or TMPRSS2. Conclusions: Primary adjusted analyses did not reveal statistically significant associations between post-acute nasal expression of ACE2, TMPRSS2, FURIN, or NRP1 and COVID-19 severity. Because expression was measured after clinical recovery, these associations cannot be interpreted as predictors of acute severity and may instead reflect persistent molecular remodeling after more severe disease; reverse causation cannot be excluded. Longitudinal studies with acute-phase and serial post-acute sampling and healthy controls are needed.<\/jats:p>","DOI":"10.3390\/diagnostics16182896","type":"journal-article","created":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T08:05:43Z","timestamp":1788941143000},"page":"2896","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Post-Acute Nasal Expression of ACE2, TMPRSS2, FURIN, and NRP1 in Relation to COVID-19 Severity: A Multicenter Cross-Sectional Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3241-0050","authenticated-orcid":false,"given":"Ana Mar\u00eda","family":"Piqueras-S\u00e1nchez","sequence":"first","affiliation":[{"name":"Department of Otolaryngology, Virgen de la Arrixaca University Clinical Hospital (HCUVA), 30120 Murcia, Spain"},{"name":"Department of Ophthalmology, Optometry, Otorhinolaryngology, and Pathological Anatomy, University of Murcia (UMU), 30100 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7412-7624","authenticated-orcid":false,"given":"Jos\u00e9 Francisco","family":"L\u00f3pez-Gil","sequence":"additional","affiliation":[{"name":"School of Medicine, Universidad Esp\u00edritu Santo, Samborond\u00f3n 092301, Ecuador"},{"name":"Faculty of Health Sciences, Universidad Aut\u00f3noma de Chile, Temuco 4810101, Chile"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"given":"Diego","family":"Hell\u00edn-Meseguer","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Virgen de la Arrixaca University Clinical Hospital (HCUVA), 30120 Murcia, Spain"},{"name":"Department of Ophthalmology, Optometry, Otorhinolaryngology, and Pathological Anatomy, University of Murcia (UMU), 30100 Murcia, Spain"},{"name":"Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9053-5380","authenticated-orcid":false,"given":"Juan","family":"Cabezas-Herrera","sequence":"additional","affiliation":[{"name":"Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain"},{"name":"Molecular Therapy and Biomarkers Research Group, Virgen de la Arrixaca University Clinical Hospital (HCUVA), 30120 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-0392-7569","authenticated-orcid":false,"given":"Gin\u00e9s Francisco","family":"Blesa-Llaona","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Virgen de la Arrixaca University Clinical Hospital (HCUVA), 30120 Murcia, Spain"},{"name":"Department of Ophthalmology, Optometry, Otorhinolaryngology, and Pathological Anatomy, University of Murcia (UMU), 30100 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Jos\u00e9","family":"Meseguer-Cabezas","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Virgen de la Arrixaca University Clinical Hospital (HCUVA), 30120 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Enrique","family":"Bernal-Morell","sequence":"additional","affiliation":[{"name":"Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain"},{"name":"Department of Internal Medicine, Section of Infectious Diseases, Reina Sof\u00eda Universitary Hospital (HRSU),  30003 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2472-5893","authenticated-orcid":false,"given":"Alfredo","family":"Minguela-Puras","sequence":"additional","affiliation":[{"name":"Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain"},{"name":"Immunology Service, Virgen de la Arrixaca University Clinical Hospital (HCUVA), 30120 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Francisco Mateo","family":"Piqueras-P\u00e9rez","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Morales Meseguer Hospital,  30008 Murcia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4565-6105","authenticated-orcid":false,"given":"Jos\u00e9 Antonio","family":"D\u00edaz-Manzano","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Virgen de la Arrixaca University Clinical Hospital (HCUVA), 30120 Murcia, Spain"},{"name":"Department of Ophthalmology, Optometry, Otorhinolaryngology, and Pathological Anatomy, University of Murcia (UMU), 30100 Murcia, Spain"},{"name":"Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, 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