A serious thrombotic event in a patient with immune thrombocytopenia requiring intravenous immunoglobulin: a case report

Treatment of Acute Ischaemic Stroke and Concomitant Multiple Arterial Splanchnic Thromboses in a Patient with Immune Thrombocytopenia on Thrombopoietin Agonist: A Case Report

Immune thrombocytopenia (ITP) is an autoimmune blood disorder characterised by isolated severe thrombocytopenia. Arterial thrombotic events, such as acute ischaemic stroke (AIS), are rare complications. A 56-year-old woman with chronic ITP on eltrombopag and dexamethasone therapy presented to the emergency department due to AIS in the vertebrobasilar territory, and lower abdominal pain. The computed tomography (CT) scan of the head was unremarkable, whereas CT angiography revealed left vertebral artery occlusion. As the platelet count was sufficient, intravenous thrombolysis (IVT) was initiated. However, after 15 min, an anaphylactic reaction occurred, which was appropriately solved. Although the IVT was prematurely stopped, the NIHSS score improved from 7 to 2, and the follow-up head CT scan remained unremarkable. CT angiography of the thoracoabdominal aorta revealed multiple thrombi in the infrarenal aorta, inferior mesenteric artery (IMA), and left renal artery. The abdominal pain subsided after IVT, but recurred within 24 h. Repeated CT angiography showed ischaemia of the descending colon, with persistent IMA occlusion. After the hemicolectomy condition stabilised. Discrete left-sided ataxia and impaired sensation were the only neurological sequelae. We found two articles reporting only three patients with ITP who suffered AIS and were treated with IVT. A favourable outcome was observed in two cases, while one patient suffered an intracranial haemorrhage (ICH) and died. A review of AIS cases with undefined thrombocytopenia treated with IVT reported ICH in up to 6.8% of patients. Our case suggests that IVT for AIS may be effective in patients with ITP. Further data are needed to better clarify this issue.

A Rare Case of COVID-19 Vaccine-Induced Thrombotic Thrombocytopenia in a Young Patient

The syndrome of pulmonary SARS-Cov-2 resulted in significant morbidity and mortality, with new variants spreading rapidly. Vaccines to prevent COVID-19 have been developed to minimize the impact and severity; however, adverse effects of the vaccine have been documented in several studies. In our case, we report a case of a young female who presented to the emergency department with fever, dizziness, headache, vomiting, blurring of vision, numbness, and weakness of left upper and lower limbs. This weakness progressed rapidly to all limbs within two hours associated with altered behaviors and visual hallucinations. The family reported a history of the patient receiving her first dose of COVID-19 AstraZeneca vaccine 18 days before admission. Based on her clinical picture and investigation, she was diagnosed with vaccine-induced immune thrombotic thrombocytopenia (VITT). She was treated successfully with intravenous immunoglobulin (IVIG) and direct oral anticoagulant apixaban.

In a time when there is a strategic goal to vaccinate the global population from COVID-19 to inhibit the spread of infection and reduce hospitalization, this particular clinical scenario emphasizes the need for all clinicians to remain vigilant for rare complications of the COVID-19 vaccination.

Early Utilization of Intravenous Immunoglobulin in Heparin-Induced Thrombocytopenia for Limb Salvaging Purposes

We present a case of a 28-year-old diabetic female who presented with high-burden lower extremity deep vein thrombosis (DVT) after previous exposure to unfractionated heparin (UFH). Heparin was discontinued, and non-heparin parenteral anticoagulant, argatroban, was started based on a high clinical suspicion of heparin-induced thrombocytopenia with thrombosis (HITT). The diagnosis of HIT was later proven by positive immune and functional assays. The severity of thrombocytopenia and the need for surgical intervention to salvage the limb prompted the use of intravenous immunoglobulin (IVIG) early on in the treatment course to recover platelet counts, halt the prothrombotic state, and prepare the patient for thrombectomy. The patient was put on direct oral anticoagulants (DOACs), apixaban, after thrombectomy, and platelet count recovery with no new thrombosis or bleeding episodes was reported after three months of follow-up.

Immune Thrombocytopenic Purpura as a Hemorrhagic Versus Thrombotic Disease: An Updated Insight into Pathophysiological Mechanisms

Immune thrombocytopenic purpura (ITP) is a blood disorder characterized by a low platelet count of (less than 100 × 109/L). ITP is an organ-specific autoimmune disease in which the platelets and their precursors become targets of a dysfunctional immune system. This interaction leads to a decrease in platelet number and, subsequently, to a bleeding disorder that can become clinically significant with hemorrhages in skin, on the mucous membrane, or even intracranial hemorrhagic events. If ITP was initially considered a hemorrhagic disease, more recent studies suggest that ITP has an increased risk of thrombosis. In this review, we provide current insights into the primary ITP physiopathology and their consequences, with special consideration on hemorrhagic and thrombotic events. The autoimmune response in ITP involves both the innate and adaptive immune systems, comprising both humoral and cell-mediated immune responses. Thrombosis in ITP is related to the pathophysiology of the disease (young hyperactive platelets, platelets microparticles, rebalanced hemostasis, complement activation, endothelial activation, antiphospholipid antibodies, and inhibition of natural anticoagulants), ITP treatment, and other comorbidities that altogether contribute to the occurrence of thrombosis. Physicians need to be vigilant in the early diagnosis of thrombotic events and then institute proper treatment (antiaggregant, anticoagulant) along with ITP-targeted therapy. In this review, we provide current insights into the primary ITP physiopathology and their consequences, with special consideration on hemorrhagic and thrombotic events. The accumulated evidence has identified multiple pathophysiological mechanisms with specific genetic predispositions, particularly associated with environmental conditions.

Increased levels of NETosis in myeloproliferative neoplasms are not linked to thrombotic events

Morbidity and mortality of Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) are mainly determined by thromboembolic complications. Thrombus formation is facilitated by a neutrophil-specific form of cell death linked to neutrophil extracellular trap (NET) formation (NETosis). Preclinical and clinical data suggested a potential link between NETosis and thrombosis in MPNs. In this study, we aimed to define the impact of NETosis on clinical end points in a large MPN cohort. NETosis was induced in vitro by ionomycin and quantified by enzyme-linked immunosorbent assay-based nucleosome release assays as well as fluorescent staining of free DNA in samples from 103 MPN patients and 28 healthy donors. NETosis rate was correlated with a broad set of clinical data, such as MPN subtype, mutational status, laboratory variables, history of thrombotic events, and treatment types. Triggered NETosis levels were clearly higher in MPN patients than in healthy donors. Positivity for JAK2 V617F or exon 12 as well as CALR mutations correlate with increased NET formation. However, neither JAK2 allelic burden nor history of thromboembolic complication nor the presence of other risk factors for thrombosis (eg, leukocytosis) were associated with the rate of NETosis. In addition, none of the analyzed laboratory parameters nor the type of treatment significantly impacted the rate of NETosis formation. The biology of MPNs has an impact on NET formation because genetic driver mutations favor induction of NETosis, but this does not seems to translate into important clinical end points such as thromboembolic complications. Therefore, NETosis may play a role in facilitating thrombosis, but it is not a sole causative determinant in MPN-associated thrombophilia.

Successful venous thromboprophylaxis in a patient with vaccine-induced immune thrombotic thrombocytopenia (VITT): a case report of the first reported case in Thailand

BACKGROUND

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but fatal complication of the Coronavirus Disease 2019 vaccine. The many reports of VITT have mostly been in the Caucasian population. Here, we present the first reported case in an Asian population.

CASE PRESENTATION

A 26-year-old female had severe headache and severe thrombocytopenia 8 days after administration of the ChAdOx1 nCoV-19 vaccine developed by AstraZeneca. Although no thrombosis was demonstrated by imaging studies, she had very highly elevated d-dimer levels during hospitalization. Serology for antibodies against platelet factor 4 was positive on several days with very high optical density readings. We found that the antibody could induce spontaneous platelet aggregation without the presence of heparin. We decided to treat her with intravenous immunoglobulin, high-dose dexamethasone, and a prophylactic dose of apixaban. She improved rapidly and was discharged from the hospital 6 days after admission. Neither thrombocytopenia nor thrombosis was subsequently detected at the three-week follow-up.

CONCLUSIONS

Despite the lower rate of thrombosis, VITT can occur in the Asian population. Early detection and prompt treatment of VITT can improve the patient's clinical outcome. Thromboprophylaxis with nonheparin anticoagulants also prevents clot formation.

A likely unavoidable clinical scenario during treatment for venous thromboembolism complicated with severe immune thrombocytopenia: A case report

Patients with immune thrombocytopenia have increased risks of bleeding and thrombosis. The acute-phase treatment for venous thromboembolism complicated with severe immune thrombocytopenia involves a "platelet dilemma" in therapeutic decision-making.