With input from Dr Monica Vasudev

People hospitalized with severe COVID-19 were found to have a lot of antibodies against the SARS-CoV-2 virus, but they also had a distinct set of antibodies against their own tissues and molecules.

Some autoantibodies attack the organs or tissues in a way that mimics autoimmune diseases, such as lupus. Others tend to attack the immune system, thus suppressing the bodys ability to fight the infection. In some cases, people may have autoantibodies even before they have been infected with SARS-CoV-2. In others, they may arise as the body fights the virus.

Autoantibodies could play a role in the persistent symptoms experienced by long-haulers. 

Antibodies are the Y-shaped molecules that are produced by B cells. The two top tips of the Y have regions that tend to differ in every antibody, thus conferring the ability to recognize different molecules. When they stick to their targets, they eliminate those molecules or the cells that contain them.

Each type of B cell makes its own type of antibody. If one of the B cells identifies its target, it starts copying itself, and more B cells are created, besides effector cells that eject the antibodies into the bloodstream as well as memory B cells that store the antibody for future use.

However, it takes a few weeks for B cells to reach the active state.

This is due to the careful weeding out of B cells that would target the bodys own tissues and molecules. The immune system has several ways to kill B cells with the harmful autoantibodies.

Yale University Researchers, in New Haven, Connecticut, assessed the blood samples of 194 people with COVID-19 for 2,770 different autoantibodies.

They found more than the usual amount. And individuals with severe COVID-19 had the most. When similar autoantibodies were administered into mice before infecting them with COVID-19, these mice got sicker compared to others that received only the virus.

The antibodies in individuals with severe COVID-19 included the ones against several parts of the immune system, such as signaling molecules termed cytokines and proteins on the surface of immune cells. Antibodies against interferons were found in over 5% of the hospitalized COVID-19 patients.

These antibodies appear to be more common in older adults. The autoantibodies were also more prevalent among men: 95 of the 101 individuals with anti-interferon were male. (Medscape)

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA