COVID-19 Vaccines and Autoimmune Hematologic Disorders

Abstract

Worldwide vaccination against SARS-CoV-2 has allowed the detection of hematologic autoimmune complications. Adverse events (AEs) of this nature had been previously observed in association with other vaccines. The underlying mechanisms are not totally understood, although mimicry between viral and self-antigens plays a relevant role. It is important to remark that, although the incidence of these AEs is extremely low, their evolution may lead to life-threatening scenarios if treatment is not readily initiated. Hematologic autoimmune AEs have been associated with both mRNA and adenoviral vector-based SARS-CoV-2 vaccines. The main reported entities are secondary immune thrombocytopenia, immune thrombotic thrombocytopenic purpura, autoimmune hemolytic anemia, Evans syndrome, and a newly described disorder, so-called vaccine-induced immune thrombotic thrombocytopenia (VITT). The hallmark of VITT is the presence of anti-platelet factor 4 autoantibodies able to trigger platelet activation. Patients with VITT present with thrombocytopenia and may develop thrombosis in unusual locations such as cerebral beds. The management of hematologic autoimmune AEs does not differ significantly from that of these disorders in a non-vaccine context, thus addressing autoantibody production and bleeding/thromboembolic risk. This means that clinicians must be aware of their distinctive signs in order to diagnose them and initiate treatment as soon as possible.

Pre-exposure to mRNA-LNP inhibits adaptive immune responses and alters innate immune fitness in an inheritable fashion

“…Altered hematopoiesis might have contributed to neutropenia. Severe aplastic anemia (affecting the hematopoietic stem cells and characterized by neutropenia and thrombocytopenia)-, cytopenia-and thrombocytopenia cases have all been reported with this platform in humans [43][44][45][46][47][48][49]. One small human study (56 volunteers) that monitored the immunological changes induced by this vaccine up to 21 days after the second shot reported a significant fluctuation in white blood cell numbers after the second injection of mRNA-LNP [11].…”

Serological responses triggered by different SARS-CoV-2 vaccines against SARS-CoV-2 variants in Taiwan

“…According to the statistical data from the TFDA website (https://www.cdc.gov.tw/En/File/Get/YTqTkmtAHH7fmK Y6JF3l_A), 93. phenomena, including vaccine-induced immune thrombotic thrombocytopenia, immune thrombocytopenic purpura, and rheumatoid arthritis, could be associated with COVID-19 vaccines (52)(53)(54)(55). Several studies have reported that SARS-CoV-2 infection could induce the production of autoantibodies (33,34,56).…”

Pre-exposure to mRNA-LNP inhibits adaptive immune responses and alters innate immune fitness in an inheritable fashion

“…Severe aplastic anemia (affecting the hematopoietic stem cells and characterized by neutropenia and thrombocytopenia)-, cytopenia-and thrombocytopenia cases have all been reported with this platform in humans [43][44][45][46][47][48][49]. One small human study (56 volunteers) that monitored the immunological changes induced by this vaccine up to 21 days of the second shot reported a significant fluctuation in white blood cell numbers after the second injection of mRNA-LNP [11].…”