Ultrastructural findings of lung injury due to Vaccine-induced Immune Thrombotic Thrombocytopenia (VITT) following COVID-19 vaccination: a scanning electron microscopic study

T. CONGIU;D. FANNI;M. PIRAS;C. GEROSA;F. CAU;D. BARCELLONA;D'Aloja Ernesto;R. DEMONTIS;A. CHIGHINE;M. NIOI;P. CONI;A. RAVARINO;G. CERRONE;V. AIMOLA;C. BOTTA;A. SCANO;G. ORRU';F. COGHE;P. VAN EYKEN;G. LA NASA;L. SABA;J. S. SURI;G. FAA;F. MARONGIU

2022-01-01

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Abstract

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare new syndrome occurring after the ChAdOx1 nCoV-19 vaccine immunization. Patients with VITT are characterized by a variable clinical presentation, likewise also the outcome of these patients is very variable. Here we report the lung ultrastructural findings in the course of VITT of a 58-year-old male patient. Alveoli were mainly dilated, irregular in shape, and occupied by a reticular network of fibrin, while interalveolar septa appeared thickened. The proliferation of small capillaries gave rise to plexiform structures and pulmonary capillary hemangiomatosis-like features. Near the alveoli occupied by a dense fibrin network, the medium-sized arteries showed a modified wall and an intraluminal thrombus. This scenario looks quite similar to that found during COVID-19, where the lungs suffer from the attack of the antigen-antibodies complexes and the virus respectively. In both diseases, the final outcome is a severe inflammation, activation of the haemostatic system and fibrinolysis.