Adipose tissue in COVID-19: detection of SARS-CoV-2 in adipocytes and activation of the interferon-alpha response

• DOI: 10.1007/s40618-022-01742-5
• Publication Date: 2022-02-15T18:05:11Z
• Authors: A. Basolo; A. M. Poma; D. Bonuccelli; A. Proietti; E. Macerola; C. Ugolini; L. Torregrossa; R. Giannini; P. Vignali; F. Basolo; F. Santini; A. Toniolo
• Keywords: Parenchyma

Obesity is a recognized risk factor for the progression to severe forms of COVID-19, yet mechanisms association are unclear.Subcutaneous abdominal adipose tissue specimens subjects deceased from COVID-19 (n = 23) were compared those controls dying abruptly causes other than infectious (accidental trauma, sudden cardiac death). Alterations lung parenchyma consistent with moderate disease detected in all cases, not controls. Investigations included: histopathologic features, detection virus antigens and genome, characterization infiltrating leukocytes, transcription levels immune-related genes.By RT-PCR, SARS-CoV-2 genome was 13/23 (56%) cases cohort. The nucleocapsid antigen cytoplasm 1-5% adipocytes 12/12 that virus-positive by PCR (one case could be assessed due insufficient tissue). showed leukocyte infiltrates upregulation interferon-alpha pathway. After adjusting age sex, activation score IFN-alpha directly related ACE2 gene, key entry SARS-CoV-2.In lethal has been sizeable proportion adipocytes, showing may infect parenchymal cells subcutaneous fat. Infection appears activate IFN alpha pathway attract leukocytes. Due huge numbers adults, represents significant reservoir an important source inflammatory mediators.