AstraZeneca: cause of cerebral vein thrombosis clarified
Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.
More posts by Christiane Fux All content is checked by medical journalists.The AstraZeneca vaccine can cause extremely rare thromboses in the brain. Now we know how they arise - and how they can be treated.
After vaccinations with the Covid-19 vaccine from AstraZeneca, isolated cases of rare cerebral vein thrombosis have occurred. Researchers from Greifswald, Vienna and Graz have now not only discovered the mechanism on which the incidents are based - they have also presented an effective therapy.
"People no longer have to be afraid of this vaccination," said the head of transfusion medicine in Greifswald, Andreas Greinacher, in a press conference.
Antibodies cause platelets to clump together
The blood tests of seven affected patients showed that special antibodies may form in response to the vaccination. These attach to the blood platelets (thrombocytes) and activate them. This mechanism is usually activated when it comes to sealing vascular damage. In this way, however, it causes the blood to clump and thus promotes the formation of clots.
The researchers are not yet able to say whether the reaction is triggered by components of the vaccination itself or is due to the general activation of the immune system by the vaccination. It is also unclear whether the cerebral vein thromboses might not also have other causes in isolated cases.
Treatment with intravenous immunoglobulins
However, medicine has known the mechanism described for a long time from a rare autoimmune disease, heparin-induced thrombocytopenia (HIT). Doctors usually treat these with high-dose intravenous immunoglobulins (IVIG), which neutralize problematic antibodies, for two consecutive days.
Based on tests with blood samples from those affected, the Greifswald researchers assume that patients with cerebral vein thrombosis should also respond to the treatment. Greinacher said people very, very rarely vaccinated would continue to develop this complication. "But when it occurs, we now know how to treat these patients and specifically address this complication."
Test if you have symptoms
If symptoms occur four to 14 days after the vaccination, tests for the special antibodies can be used to quickly find out whether the reaction is HIT-like. After that, the risk of complications will "most likely" decrease, according to the scientist.
This applies to both cerebral vein thromboses, which are associated with headaches and punctiform hemorrhages on the extremities, as well as signs of deep vein thrombosis in the legs, which can also be caused by the mechanism. These, too, should not be treated with anticoagulants such as heparin, as is usually the case with clots, but with IVIG.
