An ongoing study by American researchers have alarmingly found the persistence of SARS CoV-2 spike 1 protein in CD16+ monocytes in Post-Acute Sequelae of COVID-19 (PASC) up to 15 Months post infection.
The study team from IncellDx Inc-USA, Lawrence General Hospital-Massachusetts, 3Bio-Rad-USA, Langone Medical Center-New York University-USA, Universidad de Costa Rica-Costa Rica, Avrok Laboratories Inc-USA and Oregon Health and Science University-USA published their preliminary findings as an abstract in the peer reviewed journal: Frontiers in Immunology.
The recent COVID-19 pandemic is a treatment challenge in the acute infection stage but the recognition of chronic COVID-19 symptoms termed post-acute sequelae SARS-CoV-2 infection (PASC) may affect up to 30% of all infected individuals.
The underlying mechanism and source of this distinct immunologic condition three months or more after initial infection remains elusive. Here, we investigated the presence of SARS-CoV-2 S1 protein in 46 individuals. We analyzed T-cell, B-cell, and monocytic subsets in both severe COVID-19 patients and in patients with post-acute sequelae of COVID-19 (PASC).
The levels of both intermediate (CD14+, CD16+) and non-classical monocyte (CD14Lo, CD16+) were significantly elevated in PASC patients up to 15 months post-acute infection compared to healthy controls (P=0.002 and P=0.01, respectively).
A statistically significant number of non-classical monocytes contained SARS-CoV-2 S1 protein in both severe (P=0.004) and PASC patients (P=0.02) out to 15 months post-infection.
Non-classical monocytes were sorted from PASC patients using flow cytometric sorting and the SARS-CoV-2 S1 protein was confirmed by mass spectrometry.
No full length sequences were identified, and no sequences that could account for the observed S1 protein were identified in any patient.
Non-classical monocytes are capable of causing inflammation throughout the body in response to fractalkine/CX3CL1 and RANTES/CCR5.