[VITT]Vaccine-Induced Immune Thrombotic Thrombocytopenia

Backg round:

Vaccines are a critical tool in the management of the COVID-19 pandemic resulting from SARS-CoV-2.

Recently,

AstraZeneca vaccine can be associated with development of aprothrombotic disorder that clinically resembles heparin-induced thrombocytopenia (HIT).

Diagnosis of Vaccine-Induced

Prothrombotic Immune

Thrombocytopenia (VIPIT)/Vaccine-

nduced Immune Thrombotic

Thrombocytopenia (VITT):

Patients preented with the following

symptoms should be asked about their vaccine

history of :

[ ] a persistent and severe headache

[ ] focal neurological symptoms or visual changes,

[ ] including blurred or double vision, or episodes

[ ] suspicious for seizure

[ ] . shortness of breath

[ ] . abdominal or chest pain

[ ] . swelling and redness in a limb

[ ] . pallor and coldness in a limb

[ ] unusual bleeding, multiple small bruises, reddish or purplish spots or blood blisters under the skin.

And vaccination falls within the period of 4 - 28 days prior to presentation,

platelet count is less than 150

the patient should be evaluated at their

nearest emergency department for suspected VIPIT/VITT.

Patients with suspected VIPIT/VITT should

have

a D-dimer level and a blood film.

In cases where there is strong clinical suspicion of VIPIT/VITT;

patients should have diagnostic imaging to Investigate for blood clots (including appropriate Imaging to rule out cerebral vein sinus thrombosis(CVST),or other

Note

It is not known whether VIPIT/VITT is associated with arterial thromboses, but arterial clots should be considered if patients have consistent symptoms.

Low platelet count,

abnormal coagulation parameters,

a normal blood film (apart From thrombocytopenia), with or without confirmation of a blood clot on diagnostic imaging makes the diagnosis of VIPIT/VITT presumptive.

Then

The confirmatory diagnosis of VIPIT/VITT is made by testing for HIT.

Management of VIPIT/VITT;

presumptive and confirmed VIPIT/VITT should be treated similarly to HIT.

[ ] No heparin

[ ] . No platelet transfusions

[ ] . First line anticoagulants: direct oral factor Xa inhibitors (e.g., rivaroxaban, apixaban, edoxaban)

[ ] Consult hematologist

[ ] IVIG lg/kg daily for at least 2 days

References:

Https://pdf.hres.ca /dpd.pm/00060240.PDF Accessed 2021

New England Journal of Medicine. DOI:

1O.1056/NEJMoa2104840

Nazy 1, Sachs UJ, Arnold DM, et al. (2021 ).