Pathomorphological aspects of heparin-induced thrombocytopenia II (HIT-II syndrome)

Histopathologically TMA-like distribution of multiple organ thromboses following the initial dose of the BNT162b2 mRNA vaccine (Comirnaty, Pfizer/BioNTech): an autopsy case report

Background

Coronavirus disease 2019 (COVID-19) has spread worldwide. Vaccination is now recommended as one of the effective countermeasures to control the pandemic or prevent the worsening of symptoms. However, its adverse effects have been attracting attention. Here, we report an autopsy case of multiple thromboses after receiving the first dose of the BNT162b2 mRNA vaccine (Comirnaty, Pfizer/BioNTech) in an elderly woman.

Case presentation

A 72-year-old woman with a history of diffuse large B-cell lymphoma in the stomach and hyperthyroidism received the first dose of the BNT162b2 mRNA vaccine and died 2 days later. The autopsy revealed multiple microthrombi in the heart, brain, liver, kidneys, and adrenal glands. The thrombi were CD61 and CD42b positive and were located in the blood vessels primarily in the pericardial aspect of the myocardium and subcapsular region of the adrenal glands; their diameters were approximately 5–40 μm. Macroscopically, a characteristic myocardial haemorrhage was observed, and the histopathology of the characteristic thrombus distribution, which differed from that of haemolytic uraemic syndrome and disseminated intravascular coagulation, suggested that the underlying pathophysiology may have been similar to that of thrombotic microangiopathy (TMA).

Conclusion

This is the first report on a post-mortem case of multiple thromboses after the BNT162b2 mRNA vaccine. The component thrombus and characteristic distribution of the thrombi were similar to those of TMA, which differs completely from haemolytic uraemic syndrome or disseminated intravascular coagulation, after vaccination. Although rare, it is important to consider that fatal adverse reactions may occur after vaccination and that it is vital to conduct careful follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00418-7.

Near fatal stent thrombosis in an aneurysmatic RCX as first manifestation of heparin induced thrombocytopenia (HIT) without thrombocytopenia

Background

Thrombosis resulting from heparin-induced thrombocytopenia (HIT) occurs in about 2% of patients without a significant decrease in platelet counts. We report on such a near fatal thrombotic event caused by coronary intervention.

Case presentation

A supposedly “completely healthy” 53-year-old patient was admitted to hospital with covered rupture of an aneurysm of the Aorta descendens. He was successfully operated on and underwent coronary angiography due to NSTEMI six days later. Immediately after intervention of a 90% RCX stenosis he developed ventricular flutter, was defibrillated, and re-angiography showed partial occlusion of the RCX stent. Lots of white thrombi could be retrieved by aspiration catheter and gave reason for a HIT without thrombocytopenia. The detection of platelet factor 4/heparin complex antibodies by immunoassay supported and the subsequent Heparin Induced Platelet Activation Assay proved this diagnosis.

Conclusions

The clinical event of an acute stent thrombosis should alarm the interventional team to the diagnosis of HIT even with a normal platelet count.

Intra-Arterial Eptifibatide in the Management of Thromboembolism during Endovascular Treatment of Intracranial Aneurysms: Case Series and a Review of the Literature

OBJECTIVES

Thromboembolic complications are well recognized during the endovascular management of intracranial aneurysms. In this study, we present a case series of 40 patients with intraprocedural thrombotic complications who were treated with intra-arterial eptifibatide (IAE), and a review of the literature.

METHODS

Twenty-five patients with ruptured intracranial aneurysms (RIA), 10 with unruptured intracranial aneurysms (UIA) and 5 with aneurysmal subarachnoid hemorrhage-induced vasospasm (VSP) received IAE for intraprocedural thrombi during endovascular treatment. Rates of recanalization, strokes, and hemorrhagic complications were assessed.

RESULTS

Recanalization was achieved in 96% (24/25) of the RIA patients [72% (18/25) complete; 24% (6/25) partial], in 100% (10/10) of the UIA patients [90% (9/10) complete; 10% (1/10) partial], and in 100% (5/5) of the VSP patients [80% (4/5) complete; 20% (1/5) partial]. Strokes following intraprocedural thrombosis were coil-related (20%, 5/25) or stent-related (12%, 3/25) in RIA patients, stent-related (10%, 1/10) in UIA patients, and heparin-induced thrombocytopenia type II-related (60%, 3/5) or vasospasm-related (20%, 1/5) in VSP patients. There were no intracerebral hemorrhagic complications in UIA. Intracerebral hemorrhage was observed in 20% of the RIA patients (5/25), all of whom had received intra-arterial thrombolytics and/or high-dose heparin infusion in addition to IAE; in 12%, this was external ventricular drain-related (3/25), 4% had parenchymal hematoma type 1 (1/25), and 4% parenchymal hematoma type 2 (1/25). One of the 5 VSP patients, who had received argatroban in addition to IAE, had parenchymal hematoma type 1. No clinically significant systemic hemorrhage was observed in this study.

CONCLUSION

Treatment of thromboembolic complications with IAE during endovascular management of aneurysms was effective in achieving recanalization and overall well tolerated in this series.

Fatal paraneoplastic embolisms in both circulations in a patient with poorly differentiated neuroendocrine tumour

Arterial embolism with lower limb ischemia is a rare manifestation of paraneoplastic hypercoagulability in cancer patients. We report a unique case of fatal thromboembolism involving both circulations associated with a poorly differentiated neuroendocrine tumor of the lung with rapid progress despite high doses of unfractioned heparin and review the current literature on anticoagulative regimen in tumour patients.

Heparin-induced thrombocytopenia with multiple organized thrombi accompanied by unusual cholesterin deposition: autopsy case after long-term follow up

Heparin-induced thrombocytopenia (HIT) is characterized by a reduction in the platelet count and systemic thromboembolism during heparin therapy. Herein is reported a case of HIT with characteristic thrombus formation. A 68-year-old man who had been treated for hypertension for 27 years suffered a brain infarction and was treated with heparin. After this treatment, other new infarctions occurred in multiple organs. Because serum antibodies against heparin/PF4 complex were detected, he was diagnosed as having HIT, and warfarin and argatroban were administered instead of heparin. He died, however, 119 days after the first onset. At autopsy infarction due to organized thrombi with cholesterin deposition in multiple organs were found, similar to usual atherosclerotic emboli, but different to them with regard to clinical course and distribution of thrombi. This case in which organization and frequent cholesterin deposition were found in thromboembolized lesions of multiple organs after relatively long-term follow up, is unusual. The findings suggest that HIT accompanied by marked hypercholesterolemia of long duration contributes to a characteristic form of thromboembolism that needs careful management.

Glycoprotein IIb/IIIa inhibitor-induced thrombocytopenia

Thrombocyte glycoprotein IIb/IIIa inhibitors prevent fibrinogen binding and thereby thrombocyte aggregation. The inhibition of thrombocyte activation at the damaged coronary plaque is the target of the new therapeutic strategies in treating acute coronary syndrome. This reduces the ischemic complications associated with the non-STelevation myocardial infarction (NSTEMI) and percutaneous coronary intervention (PCI). Thrombocytopenia is a known complication of glycoprotein (GP) IIb/IIIa inhibitors. Although, in general, GP IIb/IIIa inhibitor-induced thrombocytopenia is a harmless side effect which responds readily to thrombocyte transfusion, it can occasionally be a very serious complication associated with serious bleeding. In addition patients developing thrombocytopenia have unfavorable outcome (e.g., death, myocardial infarction, bypass surgery or additional PCI) in comparison to patients without thrombocytopenia. Advanced age (> 65 years), low BMI and a low initial thrombocyte count (<180,000/microl) are independent risk factors of thrombocytopenia. The risk of bleeding is higher with this form of thrombocytopenia not only due to the low thrombocyte count but also to the impaired function of the remaining thrombocytes. It is important to closely monitor platelet count during GP IIb/IIIa antagonist treatment. Platelet count monitoring two, six, twelve and 24 hour after starting the treatment reveals most cases of acute thrombocytopenia. Side effects can be avoided by the early discontinuation of the GP IIb/IIIa antagonist treatment. This article reviews the diagnosis and treatment of glycoprotein IIb/IIIa inhibitor-induced thrombocytopenia and summarizes the differential diagnosis from heparin-induced thrombocytopenia and laboratory-related pseudothrombocytopenia.

A case of heparin-induced thrombocytopenia with sepsis and congestive heart failure--first autopsy report on Japan--

An 84-year-old man was referred to the emergency department with severe dyspnea. Based on his physical findings, electrocardiogram, X-ray and echocardiographic findings, congestive heart failure was suspected and drip infusion of prophylactic heparin against intracardiac thrombosis was commenced together with dopamine, nitroglycerin and furosemide. Diuresis occurred and the pulmonary congestion ameliorated remarkably. Starting on the 20th hospital day, the platelet count was gradually reduced (from 256,000 to 55,000 /microl) and the fibrin degradation product concentration rose (27.6 microg/ml). However, prothrombin time was not prolonged (89%), the concentration of antithrombin III was low -normal (69%) and the fibrinogen concentration was high (650 mg/dl). Thus, heparin-induced thrombocytopenia (HIT), rather than disseminated intravascular coagulation (DIC), was suspected. Heparin was withdrawn on the 24th hospital day and replaced by nafamostat mesilate after which the platelet count was restored to 100,000 /microl. Enzyme-linked immunosorbent assay for HIT antibodies was positive. Unfortunately, the patient died from uncontrolled sepsis on the 29th hospital day. At autopsy, platelet-rich thrombi were found in the small pulmonary arteries and intestinal arteries. No evidence of DIC, such as fibrin-rich thrombosis, was observed. This is the first autopsy report of HIT in Japan.

[Sinus vein thrombosis. A rare complication of heparin-induced thrombocytopenia type II]

In the past 10 years numerous reports of cases referring to complications and their outcome with heparin-induced thrombocytopenia type II (HIT II) have been published. Clinically these symptoms are manifested as a combination of arterial and venous thromboembolisms. Mostly affected are the vessels of the limbs, the abdomen, kidneys and coronary arteries. We present the most rare initial manifestations of cerebral symptoms with headache, nausea, change of character and generalised convulsion, which have found their origin in sinus vein thrombosis and the treatment with the heparinoid danaparoid.