Simultaneous Occurrence of Immune-Mediated Thrombocytopenia and Myocarditis After mRNA-1273 COVID-19 Vaccination: A Case Report.

With the global spread of severe acute respiratory syndrome coronavirus 2, several vaccines were developed; messenger RNA (mRNA) vaccines have recently been widely used worldwide. However, the incidence of myocarditis following mRNA vaccination is increasing; although the cause of myocarditis has not yet been clearly identified, it is presumed to be caused by a problem in the innate immune system. Immune-mediated thrombocytopenia (ITP) after vaccination is rare but has been reported and is also assumed to occur by the same mechanism. We report the first case of simultaneous myocarditis and ITP after mRNA vaccination. A 38-year-old woman presented with chest pain, mild dyspnea, and sweating after vaccination with mRNA-1273 vaccine (Moderna) 4 days prior to admission. Upon admission to the emergency department, cardiac enzymes were elevated; blood test performed 5 months ago showed normal platelet count, but severe thrombocytopenia was observed upon admission. After administration of intravenous immunoglobulin, the platelet count improved; subsequently, myocarditis was observed on endomyocardial biopsy. Thus, myocarditis and ITP were judged to have occurred simultaneously due to the expression of the innate immune system markers after mRNA vaccination. The patient was discharged on day 6 of admission.

Eltrombopag-Induced Thrombocytosis and Thrombosis in Patients With Antiphospholipid Syndrome and Immune Thrombocytopenic Purpura.

Antiphospholipid syndrome (APS) may be either as a primary or in association with an underlying systemic autoimmune etiology (36.2%), particularly systemic lupus erythematosus (SLE). Thrombocytopenia is infrequently observed in APS patients, with an occurrence of 22% to 42% with the frequency of thrombocytopenia, higher in APS and SLE combination than in primary APS. There have been some controversial reports regarding the treatment of APS syndrome with thrombocytopenia with TPO agonists. We like to report a case with APS syndrome with severe thrombocytopenia treated with TPO-RA and developed severe thrombocytosis and thrombosis. Our case represented the first case of TPO-RA in treating APS syndrome developed severe thrombocytosis and our case also concurred that use of TPO-RA agents should be strongly discouraged in APS until larger studies clarify the safety of TPO-RA agents in APS.

COVID-19 vaccination in patients with immune thrombocytopenia.

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder that is characterized by low platelet count and increased bleeding risk. COVID-19 vaccination has been described as a risk factor for de novo ITP, but the effects of COVID-19 vaccination in patients with ITP are unknown. We aimed to investigate the effects of COVID-19 vaccination in patients with ITP on platelet count, bleeding complications, and ITP exacerbation (≥50% decline in platelet count, or nadir platelet count < 30 × 109/L with a >20% decrease from baseline, or use of rescue therapy). Platelet counts in patients with ITP and healthy controls were collected immediately before and 1 and 4 weeks after the first and second vaccinations. Linear mixed-effects modeling was applied to analyze platelet counts over time. We included 218 patients with ITP (50.9% female; mean age, 55 years; and median platelet count, 106 × 109/L) and 200 healthy controls (60.0% female; mean age, 58 years; median platelet count, 256 × 109/L). Platelet counts decreased by 6.3% after vaccination. We did not observe any difference in decrease between the groups. Thirty patients with ITP (13.8%; 95% confidence interval [CI], 9.5-19.1) had an exacerbation and 5 (2.2%; 95% CI, 0.7-5.3) suffered from a bleeding event. Risk factors for ITP exacerbation were platelet count < 50 × 109/L (odds ratio [OR], 5.3; 95% CI, 2.1-13.7), ITP treatment at time of vaccination (OR, 3.4; 95% CI, 1.5-8.0), and age (OR, 0.96 per year; 95% CI, 0.94-0.99). Our study highlights the safety of COVID-19 vaccination in patients with ITP and the importance of the close monitoring of platelet counts in a subgroup of patients with ITP. Patients with ITP with exacerbation responded well on therapy.

Hematopoietic responses to SARS-CoV-2 infection.

Under physiological conditions, hematopoietic stem and progenitor cells (HSPCs) in the bone marrow niches are responsible for the highly regulated and interconnected hematopoiesis process. At the same time, they must recognize potential threats and respond promptly to protect the host. A wide spectrum of microbial agents/products and the consequences of infection-induced mediators (e.g. cytokines, chemokines, and growth factors) can have prominent impact on HSPCs. While COVID-19 starts as a respiratory tract infection, it is considered a systemic disease which profoundly alters the hematopoietic system. Lymphopenia, neutrophilia, thrombocytopenia, and stress erythropoiesis are the hallmark of SARS-CoV-2 infection. Moreover, thrombocytopenia and blood hypercoagulability are common among COVID-19 patients with severe disease. Notably, the invasion of erythroid precursors and progenitors by SARS-CoV-2 is a cardinal feature of COVID-19 disease which may in part explain the mechanism underlying hypoxia. These pieces of evidence support the notion of skewed steady-state hematopoiesis to stress hematopoiesis following SARS-CoV-2 infection. The functional consequences of these alterations depend on the magnitude of the effect, which launches a unique hematopoietic response that is associated with increased myeloid at the expense of decreased lymphoid cells. This article reviews some of the key pathways including the infectious and inflammatory processes that control hematopoiesis, followed by a comprehensive review that summarizes the latest evidence and discusses how SARS-CoV-2 infection impacts hematopoiesis.

Natural history of PF4 antibodies in vaccine-induced immune thrombocytopenia and thrombosis.

The COVID-19 pandemic has resulted in the rapid development of a range of vaccines against SARS-CoV-2. Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare but life-threatening complication of primarily adenoviral-based vaccines associated with the presence of antibodies to a PF4/polyanion neoepitope and measured by using enzyme-linked immunosorbent assays. Presented are serial anti-PF4/polyanion antibody, platelet, and D-dimer measurements in a large cohort of patients and their relation to relapse. Overall, 51% of patients using the Stago assay had persistently positive anti-PF4/polyanion levels 100 days' postdiagnosis, whereas 94% of patients monitored by using the Immucor assay remain positive. The median duration of positivity of the PF4 assay is 87 days, with 72% of patients remaining positive after a median follow-up of 105 days. The use of plasma exchange seemed to reduce anti-PF4/polyanion levels and increase platelet counts in the acute setting more rapidly than other therapies. The rate of relapse in this study was 12.6%, with all relapsed cases exhibiting persistently positive PF4 antibodies and falling platelet counts. Only one patient had extension of their thrombosis. Overall, despite the persistence of PF4 antibodies in 72% of patients, the rate of relapse was low and did not seem to result in recrudescence of the aggressive clinical picture seen at index presentation. Monitoring of these patients in the UK cohort is ongoing and will aid in definition of the natural history of this novel condition.

Cerebral Venous Thrombosis in Patients With Heparin-Induced Thrombocytopenia a Systematic Review.

BACKGROUND: Cerebral venous thrombosis (CVT) has recently been reported as a common thrombotic manifestation in association with vaccine-induced thrombotic thrombocytopenia, a syndrome that mimics heparin-induced thrombocytopenia (HIT) and occurs after vaccination with adenovirus-based SARS-CoV-2 vaccines. We aimed to systematically review the incidence, clinical features, and prognosis of CVT occurring in patients with HIT. METHODS: The study protocol was registered with PROSPERO (CRD42021249652). MEDLINE, EMBASE and Cochrane CENTRAL were searched up to June 1, 2021 for HIT case series including >20 patients, or any report of HIT-related CVT. Demographic, neuroradiological, clinical, and mortality data were retrieved. Meta-analysis of proportions with random-effect modeling was used to derive rate of CVT in HIT and in-hospital mortality. Pooled estimates were compared with those for CVT without HIT and HIT without CVT, to determine differences in mortality. RESULTS: From 19073 results, we selected 23 case series of HIT (n=1220) and 27 cases of HIT-related CVT (n=27, 71% female). CVT developed in 1.6% of 1220 patients with HIT (95% CI,1.0%-2.5%, I2=0%). Hemorrhagic brain lesions occurred in 81.8% of cases of HIT-related CVT and other concomitant thrombosis affecting other vascular territory was reported in 47.8% of cases. In-hospital mortality was 33.3%. HIT-related CVT carried a 29% absolute increase in mortality rate compared with historical CVT controls (33.3% versus 4.3%, P<0.001) and a 17.4% excess mortality compared with HIT without CVT (33.3% versus 15.9%, P=0.046). CONCLUSIONS: CVT is a rare thrombotic manifestation in patients with HIT. HIT-related CVT has higher rates of intracerebral hemorrhage and a higher mortality risk, when compared with CVT in historical controls. The recently reported high frequency of CVT in patients with vaccine-induced thrombotic thrombocytopenia was not observed in HIT, suggesting that additional pathophysiological mechanisms besides anti-platelet factor-4 antibodies might be involved in vaccine-induced thrombotic thrombocytopenia-related CVT.

COVID-19-associated Evans syndrome: A case report and review of the literature.

Evans syndrome is a rare condition characterized by simultaneous or sequential development of autoimmune hemolytic anemia and immune thrombocytopenia (and/or immune neutropenia). Coronavirus disease 2019 (COVID-19) may cause various hematologic conditions, such as coagulation abnormalities (e.g., bleeding or thrombosis) or cell count alterations (e.g., lymphopenia and neutrophilia). COVID-19 may also induce Evans syndrome via immune mechanisms. Here, we describe the case of a patient developing Evans syndrome shortly after COVID-19 infection. Immune thrombocytopenia and warm-type autoimmune hemolytic anemia developed simultaneously, and intravenous immunoglobulin and methylprednisolone were initially administered. Additionally, we intend to review all COVID-19-induced Evans syndrome cases currently present in the literature and emphasize the differences as well as the similarities regarding patient characteristics, relationship to COVID-19 infection, and treatment approach. Since autoimmune cytopenias are frequent in COVID-19 patients, clinicians should pay particular attention to profound and abrupt-onset cytopenias. In these circumstances, hemolysis markers such as lactate dehydrogenase, haptoglobulin, Coombs tests, etc. should be investigated, and the possibility of Evans syndrome should always be considered to ensure prompt and appropriate treatment. These factors are essential to ensure hematologic recovery and prevent complications such as thrombosis.

Models for SARS-CoV-2 associated thrombocytopenia associated with hemophagocytic histiocytes.

A subset of COVID-19 patients is experiencing secondary immune thrombocytopenia, also called immune thrombocytopenic purpura (ITP) or secondary hemophagocytic lymphohistiocytosis (HLH). The pathogenesis of SARS-CoV-2 associated thrombocytopenia is unknown. Very rare cases of vaccine induced prothrombotic immune thrombocytopenia (VIPIT) are occurring associated with COVID-19 vaccines. COVID-19 VIPIT is associated with autoantibodies targeting platelet factor 4 (PF4) for COVID-19 adenovirus vaccines. Herein, four models for hemophagocytic histocytes contributions to the etiology of thrombocytopenia associated with SARS-CoV-2 are proposed. One of the models proposes potential involvement of hemophagocytic histocytes targeting platelets bound by autoantibodies consistent with observed PF4 autoantibodies in COVID-19 VIPIT.

COVID 19 vaccine in patients of hypercoagulable disorders: a clinical perspective.

COVID 19 is an infectious disease caused by severe acute respiratory syndrome corona virus 2. Thromboembolism has been a characteristic manifestation in most of the severely ill COVID-19 patients. Thromboembolism in COVID 19 infection is attributed to injury to the vascular endothelial cell, hypercoagulability and blood stasis. The hypercoagulable state of blood and thrombophilic diseases leads to hypercoagulability. COVID 19 infected patients with pre-existing hypercoagulable disorders have higher risk of developing thrombosis and thromboembolism and such thrombotic episodes may prove to be severely morbid in these patients. As immune-prophylaxis COVID 19 vaccines are being administered to the public. The known side effects of the COVID 19 vaccine are mild to moderate and include fever, chills, nausea, vomiting, headache, fatigue, myalgia, malaise, pain and swelling at injection site and diarrhea. Thrombosis with thrombocytopenia has been noted as a rare side effect of COVID 19 vaccine. Such side effect of COVID 19 vaccine in patients of hypercoagulable disorder may prove to be fatal. The health care workers should be cautious and judicious in managing such patients. A detailed lab profile for coagulable state of blood should be carried out in all patients COVID 19 infected patients with pre-existing hypercoagulability diseases. The patients should also be health educated regarding side effects of vaccine especially with those indicating thrombosis and they should be warranted to receive immediate medical care in case of any side effects or complications. Paucity of literature gave us an impetus to review management profile in patients of hypercoagulable disorders.

Thromboembolism after COVID-19 vaccine in patients with preexisting thrombocytopenia.

While vaccination is the single most effective intervention to drastically reduce severe disease and death following SARS-CoV-2 infection, as shown in UK and Israel, some serious concerns have been raised for an unusual adverse drug reaction (ADR), including vaccine-induced immune thrombotic thrombocytopenia (VITT) with concurrent low platelets as well as capillary leak syndrome. In fact, the overall safety of the vaccine is highlighted by the low frequency of ADR considering that in UK, by the early June, 40 million first doses and 29 million second doses have been injected; nonetheless, 390 thrombotic events, including 71 fatal events have been reported. Interestingly, the cases reported low platelet counts with the presence of anti-platelet factor-4 (PF4) antibodies, indicating an abnormal clotting reaction. Here, out of three referred cases, we report a post-vaccine clinical case of fatal thrombosis with postmortem examination and whole exome sequencing (WES) analysis, whose pathogenesis appeared associated to a preexisting condition of thrombocytopenia due to myelodysplasia.

Resolution of One-Year Persisting COVID-19 Pneumonia and Development of Immune Thrombocytopenia in a Follicular Lymphoma Patient With Preceding Rituximab Maintenance Therapy: A follow-up Report and Literature Review of Cases With Prolonged Infections.

BACKGROUND: We previously reported elsewhere of a follicular lymphoma patient suffering from persistent COVID-19 pneumonia that was still ongoing at 2 months after onset. MATERIALS AND METHODS: We provide a follow-up report of the case along with a literature review of immunocompromised lymphoma patients experiencing prolonged COVID-19 infections. RESULTS: Although requiring a full 1 year, the presented case eventually achieved spontaneous resolution of COVID-19 pneumonia. Anti-SARS-CoV-2 antibodies could not be detected throughout the disease course, but COVID-19-directed T-cell response was found to be intact. The patient also developed secondary immune thrombocytopenia subsequent to COVID-19 pneumonia. We found 19 case reports of immunocompromised lymphoma patients with prolonged COVID-19 infections in the literature. All 5 patients who died did not receive convalescent plasma therapy, whereas resolution of COVID-19 infection was achieved in 8 out of 9 patients who received convalescent plasma therapy. CONCLUSIONS: We demonstrate through the presented case that while time-consuming, resolution of COVID-19 infections may be achieved without aid from humoral immunity if cellular immunity is intact. Immunocompromised lymphoma patients are at risk of a prolonged disease course of COVID-19, and convalescent plasma therapy may be a promising approach in such patients.

The complicated relationships of heparin-induced thrombocytopenia and platelet factor 4 antibodies with COVID-19.

COVID-19 (coronavirus disease 2019) represents a prothrombotic disorder, and there have been several reports of platelet factor 4/heparin antibodies being present in COVID-19-infected patients. This has thus been identified in some publications as representing a high incidence of heparin-induced thrombocytopenia (HIT), whereas in others, findings have been tempered by general lack of functional reactivity using confirmation assays of serotonin release assay (SRA) or heparin-induced platelet aggregation (HIPA). Moreover, in at least two publications, data are provided suggesting that antibodies can arise in heparin naïve patients or that platelet activation may not be heparin-dependent. From this literature, we would conclude that platelet factor 4/heparin antibodies can be observed in COVID-19-infected patients, and they may occur at higher incidence than in historical non-COVID-19-infected cohorts. However, the situation is complex, since not all platelet factor 4/heparin antibodies may lead to platelet activation, and not all identified antibodies are heparin-dependent, such that they do not necessarily reflect "true" HIT. Most recently, a "HIT-like" syndrome has reported in patients who have been vaccinated against COVID-19. Accordingly, much more is yet to be learnt about the insidious disease that COVID-19 represents, including autoimmune outcomes in affected patients.

Clinical Implications of Hematologic and Hemostatic Abnormalities in Children With COVID-19.

Leukopenia, thrombocytopenia, elevated D-dimer, and prolonged prothrombin time are considered poor prognostic factors in adults with acute Coronavirus Disease 2019. The prognostic significance of these abnormalities among pediatric patients remains underreported in the literature. This retrospective cohort study evaluates the prognostic implications of hematologic and hemostatic derangements in patients younger than 22-years-of-age who were admitted to a tertiary-care referral institution for management of acute Coronavirus Disease 2019 infection. Leukopenia and thrombocytopenia were identified as independent prognostic factors of disease severity. Although the majority of children, with available results, had elevated D-dimer or prolonged prothrombin time upon initial presentation, these markers were not found to be associated with the development of severe clinical complications.