From two Italian studies on autopsies comes the confirmation “in the field” of the mechanisms underlying the Vaccine-Induced Immune Thrombotic Thrombocytopenia, or VITTIt all stems from antibodies that bind PF-4, the potent platelet activating factor, hypothesized as a possible cause and now actually found in the tissues of people affected by the disease. The data also confirm the extreme rarity of VITT and above all the possibility of diagnosing it in time and treating it so that it is not fatal.
Two studies
The studies, published on Haematologica e Diagnostics, were led on a man of 50 and a woman of 37, both subjected to autopsy after the death from VITT in Sicily in March. The analyzes confirmed the presence of a very extensive venous thrombosis, but also an immune response that led to the inflammatory process and vascular damage: the cascade of events after the administration of the vaccine starts from the immune activation that leads to the formation of new antibodies or to the activation of existing ones against PF-4; these then cause an uncontrolled activation of the platelets from which the disseminated venous thrombosis derives, with an over-consumption of the platelets themselves and the appearance of cerebral hemorrhage. “The tests on some samples, conducted for the first time in autopsy studies, verify and confirm the VITT and the presence in the body of antibodies that bind PF-4: these anti-Pf-4 complexes were identified only last month by British and German colleagues and in our study they have been shown to be responsible for extensive venous thrombosis in atypical locations such as the veins of the liver, intestine and brain – explains Paolo Zamboni, vascular surgeon at the University of Ferrara who participated in the investigations together with the coagulation expert of the IRCCS Ca ‘Granda Ospedale Maggiore Policlinico of Milan Pier Mannuccio Mannucci and colleagues from the Universities of Catania, Foggia and Palermo -. VITT, if not diagnosed in time, leads to a dramatic consumption of platelets which can be followed by fatal cerebral hemorrhages ».
Very rare cases
Studies confirm the correlation with the vaccine, but point out that VITT can be recognized by typical warning symptoms such as severe headache, pain in the neck and abdomen, pain and / or swelling in the limbs; if suspected, the disease can be diagnosed through simple tests such as blood counts with platelet counts and analysis in the blood of parameters such as fibrinogen and D-dimer. If there is a confirmation, timely diagnosis allows you to intervene and avoid the worst with an intravenous gamma globulin treatment associated with the anti-inflammatory prednisolone and the antithrombotic fondaparinux. “Cases are very rare, about three per million, and serious or even fatal outcomes can be averted with an early diagnosis and therapy that are already available – underlines Zamboni -. Knowing exactly what happens is a big step towards reducing the climate of doubt and hesitation created by the news of the first cases of adverse vaccination events: the knowledge of the mechanisms of the disease and the awareness of the existence of valid countermeasures are elements of reassurance with respect to the vaccination campaign, which is the tool that will allow us to overcome the pandemic ».
May 27, 2021 (change May 29, 2021 | 08:30)
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