"Viral reservoirs" in human tissue may preserve the SARS-CoV-2 virus, provoking an immune response that could drive long COVID-associated symptoms.
The first-ever tissue bank dedicated to long COVID has been established at the University of California San Francisco (UCSF), according to a UCSF announcement.
Genesis for the undertaking is largely rooted in recent research that shows the SARS-CoV-2 virus may not fully clear from the body after the initial infection appears resolved. Rather, the virus lingers in what has been termed “viral reservoirs” observed in individual’s tissue months or even years after the virus abates. A school of thought has developed that posits the reservoirs are a primary driver of long COVID, continuing to provoke the immune system to respond, causing conditions like blood clotting disorders, systemic inflammation, and cognitive dysfunction.
“Based on our work so far, we believe that long COVID is a tissue-based disease,” said Michael Peluso, MD, principal investigator of the UCSF Long COVID Tissue Program and an infectious disease physician-scientist in the UCSF School of Medicine.
“This program will allow us to comprehensively study the biological processes occurring across tissue compartments – in the blood, gut, lymph nodes, spinal fluid and bone marrow – in people living with long COVID. This will help us better understand the underlying mechanisms of long COVID,” said Peluso, who co-led recent research with Timothy Henrich, MD, a UCSF physician-scientist, that showed the virus was present in colon tissue up to 676 days following infection.
In October 2023 the US Centers for Disease Control and Prevention (CDC) estimated that approximately 14% of Americans had currently or had had long COVID, the statement said. The condition may present as a continuation of the virus’ acute symptoms or as new symptoms that may affect any part of the body. In more severe cases, moreover, multiple organ systems may be involved, including brain, heart, lung, kidneys, and the skin.
Investigators will obtain tissue specimens from current and future participants in UCSF’s “Long-term impact of infection with novel coronavirus” (LIINC) study and share with other scientists conducting similar and complementary research, said UCSF. The study itself was launched in April of 2020, some time before long COVID was recognized, and any adult who has ever tested positive for COVID-19 is eligible to enroll.
“The persistence of SARS-CoV-2 in tissue is a major target for our rapid research and clinical trials,” said Steven Deeks, MD, co-principal investigator of LIINC, professor of medicine in residence at UCSF and an internationally recognized HIV expert. Deeks describes current clinical trials of a monoclonal antibody and an antiviral therapy that blocks viral replication.
The UCSF Long COVID Tissue Program is supported by a $3 million grant from the Long Covid Research Consortium of the PolyBio Research Foundation, a nonprofit dedicated to complex chronic conditions, which also funded the LIINC study.
“The UCSF team includes people who helped make HIV and AIDS a treatable disease,” said Amy Proal, PhD, president of PolyBio. “These researchers rapidly pivoted into long COVID research at the outset of the pandemic, leveraging years of experience performing similar research with patients with HIV and AIDS.”