FILE - A nurse checks on a patient in the acute care COVID-19 unit Momentum is building around a few key theories.One is that the infection or remnants of the virus persist past the initial illness, triggering inflammation that leads to long COVID.Another is that latent viruses in the body, such as the Epstein-Barr virus that causes mononucleosis, are reactivated.
A recent study in the journal Cell pointed to Epstein-Barr in the blood as one of four possible risk factors, which also include pre-existing Type 2 diabetes and the levels of coronavirus RNA and certain antibodies in the blood.
Those findings must be confirmed with more research.A third theory is that autoimmune responses develop after acute COVID-19.In a normal immune response, viral infections activate antibodies that fight invading virus proteins.
But sometimes in the aftermath, antibodies remain revved up and mistakenly attack normal cells. That phenomenon is thought to play a role in autoimmune diseases such as lupus and multiple sclerosis.Justyna Fert-Bober and Dr.