Study: Start IVIG, Non-Heparin Anticoagulation Treatment Before Positive Anti-PF4 Tests

Management with intravenous immunoglobulin (IVIG) and non-heparin anticoagulation can improve patient outcomes of vaccine-induced immune thrombotic thrombocytopenia (VITT) after a COVID-19 vaccination, according to a case study of a patient with VITT.

Investigators reported on the case of a young woman who developed cerebral vein thrombosis but showed recovery when treated with a non-heparin direct oral anticoagulant and IVIG.

VITT is a rare prothrombotic disordered combined with thrombocytopenia that was reported as a severe adverse event (AE) of COVID-19 vaccines Ad.26.COV2.S (Janssen) and ChAdOx1 nCoV-19 (AstraZeneca; Oxford)

The disorder is associated with high titers of immunoglobulin G class antibodies that act against the cationic platelet chemokine, platelet factor 4. Females under aged 55 years are considered at higher risk for VITT.

The woman in the case study was 23 years old and went to the emergency department with symptoms including blurred vision, dizziness, fever, headache, numbness, vomiting, and weakness in the left arm and leg. Within 2 hours, the weakness spread to all her limbs and was associated with altered behavior and visual hallucinations.

It was reported that the individual had received the first dose of the COVID-19 vaccine, ChAdOx1 nCoV-19, 18 days before hospital admission.

She was conscious and orientated during examination but irritable. Her heart rate was 88/min, with blood pressure of 190/70 mmHg, oxygen saturation of 96%, a normal Glasgow coma scale score, normal pupils, a respiratory rate of 20/minute, and a temperature of 100.4ºF.

Hypertonia was found in all her limbs. . Her cranial nerve and meningeal signs were intact, and an initial brain computed tomography (CT) scan showed no major abnormalities.

A diagnosis of post-vaccination meningoencephalitis was made, and she was given a small dose of dexamethasone 6 mg injection per day and a prophylactic dose of enoxaparin 40 mg s/c twice daily, with close neuromonitoring in the intensive care unit.

Laboratory results showed thrombocytopenia, with a platelet count of 59 x 109/L, extremely elevated d-dimer of 12600 ng/ml, a fibrinogen level of 1.8 gm/l, and other normal pro-coagulant workups. The individual was diagnosed with VITT.

A brain and cerebral sinus venogram CT scan were conducted and showed extensive superior sagittal sinus thrombosis with bilateral front parietal infarcts. Additionally, an enzyme-linked immunosorbent assay test for platelet factory-4 antibodies was sent to a higher center.

Based on the data and without waiting for the results of the anti PD4 antibody test, the woman was promptly started on IVIG 1 g/kg, with close observation of the platelet level.

The anti PF4 antibody results were positive, and a significant improvement in the individual’s neurological condition was seen within a few days.

Blurred vision, headache, and weakness also improved. By day 10 of admission, the woman could walk without support, and her platelet counts also returned to normal.

Investigators concluded that because VITT has such a high mortality rate, treatment should start before the anti-PF4 antibodies tests confirms positive results, but more research is needed to understand the underlying mechanism of the disorder.

Reference

Sobh O, AlSoofi N, Alatifi A, et al. A rare case of COVID-19 vaccine-induced thrombotic thrombocytopenia in a young patient. Cureus. 14(4);e24355. doi:10.7759/cureus.24355