|
The severity of COVID-19 varies by individual spanning from asymptomatic, mild, moderate, severe, critical, and chronic disease. Prior to the availability of vaccines, high antibody titers correlated with disease severity. This was also observed for SARS disease. These high antibody titers on initial infections result from memory B cell responses with cross-reactive antibody responses from previous infection of likely other betacoronavirus family members. In general, family members of the betacoronavirus family leverage Fc receptor antibody uptake of viruses by phagocytic cells to infect these innate immune cells. This extended cellular tropism of phagocytic immune cells is dependent upon Fc receptors and antibodies. It is hypothesized that SARS-CoV-2 with higher antibody titers can infect phagocytic immune cells; SARS-CoV-2 infection of these cells has been observed in some patients with severe COVID-19. This proposed antibody-dependent enhancement (ADE) of disease has been proposed to a key transition of infection from respiratory infection to multi-organ disease in some severe COVID-19 patients. While the main medical community believes that there is no ADE associated with SARS-CoV-2 infections, multiple clinical studies are consistent with SARS-CoV-2 infection of monocytes and macrophages in some severe COVID-19 patients. The podcast discusses data available in the summer of 2022.
Covid-19 Part 1: Antibody-dependent Enhancement of Disease
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019 (COVID-19), Multisystem Inflammatory Syndrome in Children (MIS-C), Adults (MIS-A), Neonates (MIS-N), and some Vaccinees (MIS-V). These are all considered clinically distinct diseases; however, the MIS-X diseases have overlapping symptoms and treatments with Kawasaki Disease (KD). MIS-C, MIS-A, MIS-N, and KD occur with increased frequencies several weeks following increased numbers of COVID-19 and for KD other pathogens. The incidence rate for MIS-C, MIS-A, MIS-N, and KD are typically a factor of roughly 5,000 lower than COVID-19 and for KD other pathogens. In this podcast, Dr. Darrell Ricke advances the hypothesis that MIS-C, MIS-A, MIS-N, MIS-V, and KD all represent a novel type of antibody-dependent enhanced (ADE) diseases associated with hyperactivation of granulocytes or mast cells. Symptoms for these diseases overlap those of histamine intolerance (HIT) coupled with pathogen associated symptoms. This ADE model proposes that antibody titer levels higher than primary immune response levels can hyperactivate granulocytes or mast cells to release inflammatory molecules including histamine; MIS-X and KD disease symptoms onset when histamine levels exceed the individual’s tolerance level. The proposed ADE model purports that patient treatment with intravenous immunoglobulin (IVIG) is successful in treating the MIS-X disease because IVIG compete with pathogen antibodies for binding to Fc receptors on immune cells, thereby reducing the immune responses to the pathogen or vaccine protein. This model is further supported with the vaccine spike protein activating immune cells via envisioned Fc receptor binding. This ADE model proposes additional antihistamine and diamine oxidase (DAO) adjunctive treatments combined with current standard of care treatments for investigation.
Covid-19 Part 2: New Type of Antibody-Dependent Enhancement Associated with SARS-CoV-2 Virus: MIS-C, MIS-A, and MIS-N
Select ToxChats© podcast episodes are available on iTunes and Google (search ToxChats), in addition, all episodes are on the ACT website. The podcasts report on cutting-edge news in toxicological research from around the globe, and feature interviews with experts and a review of current advances. We encourage you to listen to and follow ToxChats. We welcome any feedback or suggestions for future topics.
|