In particular, F(ab)2-dependent action of immunoglobulin to inhibit activation of human dendritic cells, induction of autophagy, induction of COX-2-dependent PGE-2 in human dendritic cells leading to expansion of regulatory T cells, inhibition of pathogenic Th17 responses, and induction of human basophil activation and IL-4 induction via anti-IgE autoantibodies. Some believe that immunoglobulin therapy may work via a multi-step model where the injected immunoglobulin first forms a type of immune complex in the patient. Once these immune complexes are formed, they can interact with Fc receptors on dendritic cells, which then mediate anti-inflammatory effects helping to reduce the severity of the autoimmune disease or inflammatory state. Other proposed mechanisms include the possibility that donor antibodies may bind directly with the abnormal host antibodies, stimulating their removal; the possibility that IgG stimulates the hosts complement system, leading to enhanced removal of all antibodies, including the harmful ones; and the ability of immunoglobulin to block the antibody receptors on immune cells (macrophages), leading to decreased damage by these cells, or regulation of macrophage phagocytosis. Indeed, it is becoming more clear that immunoglobulin can bind to a number of membrane receptors on T cells, B cells, and monocytes that are pertinent to autoreactivity and induction of tolerance to self.A recent report stated that immunoglobulin application to activated T cells leads to their decreased ability to engage microglia. As a result of immunoglobulin treatment of T cells, the findings showed reduced levels of tumor necrosis factor-alpha and interleukin-10 in T cell-microglia co-culture.
Supply issues
The United States is one of a handful of countries that allow plasma donors to be paid, meaning that the US supplies much of the plasma-derived medicinal products (including immunoglobulin) used across the world, including more than 50% of the European Unions supply. The Council of Europe has officially endorsed the idea of not paying for plasma donations for both ethical reasons and reasons of safety, but studies have found that relying on entirely voluntary plasma donation leads to shortages of immunoglobulin and forces member countries to import immunoglobulin from countries that do compensate donors.In Australia, blood donation is voluntary and therefore to cope with increasing demand and to reduce the shortages of locally produced immunoglobulin, several programs have been undertaken including adopting plasma for first time blood donors, better processes for donation, plasma donor centres and encouraging current blood donors to consider plasma only donation. Research
Experimental results from a small clinical trial in humans suggested protection against the progression of Alzheimers disease, but no such benefit was found in a subsequent phase III clinical trial. In May 2020, the US approved a phase three clinical trial on the efficacy and safety of high-concentration intravenous immune globulin therapy in severe COVID-19. References
External links
"Immune globulin". Drug Information Portal. U.S. National Library of Medicine.