The
ability of the new
coronavirus SARS-CoV-2 to spread and contaminate is one of the determinants of the COVID-19 pandemic status.
SARS-CoV-2 has been detected in
saliva consistently, with
similar sensitivity to that observed innasopharyngeal swabs. We conducted ultrasound-guided postmortem
biopsies in COVID-19 fatal cases. Samples ofsalivary glands (SGs; parotid, submandibular, and
minor) were obtained. We analyzed samples using RT-qPCR, immu-nohistochemistry,
electron microscopy, and histopathological
analysis to identify
SARS-CoV-2 and elucidate qual-itative and quantitative viral proîles in
salivary glands. The study included 13
female and 11
male patients, with amean age of 53.12 years (range 883 years). RT-qPCR for
SARS-CoV-2 was positive in 30 SG samples from18
patients (60% of total SG samples and 75% of all cases). Ultrastructural analyses showed spherical 70100 nm
viral particles, consistent in size and shape with the
Coronaviridae family, in the ductal lining
cell cytoplasm,
acinar cells, and ductal lumen of SGs. There was also degeneration of
organelles in infected
cells and the presence of acluster of
nucleocapsids, which suggests
viral replication in SG
cells. Qualitative histopathological
analysis showedmorphologic alterations in the duct lining
epithelium characterized by cytoplasmic and nuclear vacuolization, as wellas nuclear pleomorphism.
Acinar cells showed degenerative changes of the
zymogen granules and enlarged nuclei.Ductal
epithelium and serous
acinar cells showed intense expression of ACE2 and TMPRSS receptors. An anti-
SARS-CoV-2 antibody was positive in 8 (53%) of the 15 tested cases in duct lining
epithelial cells and acinar cellsof major SGs. Only two
minor salivary glands were positive for
SARS-CoV-2 by
immunohistochemistry. Salivaryglands are a
reservoir for
SARS-CoV-2 and provide a pathophysiological background for studies that indicate theuse of
saliva as a diagnostic
method for COVID-19 and highlight this
biological îuid's
role in spreading the
disease.© 2021 The Pathological Society of
Great Britain and
Ireland. Published by John Wiley &
Sons, Ltd.