COVID-19—A Trigger Factor for Severe Immune-Mediated Thrombocytopenia in Active Rheumatoid Arthritis

Abstract

Thrombocytopenia is defined as a platelet count below 150,000/mm3 for adults. There is still controversy about whether individuals with platelet counts of 100,000/mm3 to 150,000/mm3 should be classified as having genuine thrombocytopenia or borderline thrombocytopenia. Thrombocytopenia is considered mild when the platelet count is between 70,000 and 150,000/mm3 and severe if the count is less than 20,000/mm3. Thrombocytopenia in rheumatoid arthritis is a rare complication, with an incidence estimated between 3 and 10%. The main etiological aspects include drug-induced thrombocytopenia and immune thrombocytopenic purpura. The most common hematological abnormalities in SARS-CoV-2 infection are lymphopenia and thrombocytopenia. It has been observed that the severity of thrombocytopenia correlates with the severity of the infection, being a poor prognosis indicator and a risk factor for mortality. COVID-19 can stimulate the immune system to destroy platelets by increasing the production of autoantibodies and immune complexes. Autoimmunity induced by viral infections can be related to molecular mimicry, cryptic antigen expression and also spreading of the epitope. During the COVID-19 pandemic, it is of great importance to include the SARS-CoV-2 infection in differential diagnoses, due to the increased variability in forms of presentation of this pathology. In this review, our aim is to present one of the most recently discovered causes of thrombocytopenia, which is the SARS-CoV-2 infection and the therapeutic challenges it poses in association with an autoimmune disease such as rheumatoid arthritis.

Severe Thrombocytopenic Purpura Associated with COVID-19 in a Pediatric Patient

“… 33 , 34 The most common hematological abnormalities in SARS-CoV-2 infection are lymphopenia, cited in literature in up to 83.2% of patients and thrombocytopenia in 5–21% of cases. 35 The potential mechanisms of thrombocytopenia in COVID-19 involve antiretroviral drugs, megakaryocyte suppression, hepatic or splenic sequestration, platelet clearance due to increased endothelial damage or due to platelet autoantibody formation. 36 …”

Immune Thrombocytopenia Following Booster Dose of the Moderna mRNA-1273 Vaccine

“…Up to one-third of COVID-infected patients have thrombocytopenia, of which 7% are asymptomatic and unaware of their COVID-19 infection [ 7 ]. Active COVID infection in patients with pre-existing autoimmune conditions has also been suggested as a triggering factor for the relapse of autoimmune conditions [ 8 ]. Therefore, the risk of thrombocytopenia in this case report should not be a deterrent to receiving the mRNA-based COVID-19 vaccine, as infection with the virus is more strongly associated with thrombocytopenia.…”

Dysregulated platelet function in COVID-19 patients

“…Считается, что SARS-CoV-2 напрямую заражает костный мозг через определенные рецепторы и ин-гибирует кроветворение, снижая образование первичных тромбоцитов, что приводит к тромбоцитопении [24]. Сходство нуклеотидов между SARS-CoV-2 и тяжёлым острым респираторным синдромом (SARS-CoV) составляет 82 %, а поскольку SARS-CoV и коронавирус человека 229E (HCoV-229E) проявляют эквивалентные антигенные свойства, многие авторы предполагают, что антигены SARS-CoV-2 и HCoV-229E родственны.…”