# Thrombotic Microangiopathy Post-COVID-19 Vaccination

## TL;DR

This paper reports two cases of thrombotic microangiopathy following COVID-19 vaccination and discusses possible immune-related causes.

## Contribution

The novelty lies in presenting real-world case reports of thrombotic microangiopathy post-COVID-19 vaccination and discussing its potential immune-mediated pathophysiology.

## Key findings

- Two patients developed thrombotic microangiopathy after receiving the COVID-19 vaccine.
- Exaggerated pro-inflammatory and immune-mediated processes are suggested as possible causes of post-vaccination thrombosis.
- There is a need for better understanding and management of thrombotic complications following vaccination.

## Abstract

The emergence of COVID-19 has caused a wide spectrum of symptoms, ranging from asymptomatic to devastating symptoms, leading to death. One of the most serious complications of COVID-19 is the thromboembolic phenomenon, which has led to increased morbidity and mortality. Several vaccines were developed to protect against this infection and used widely across the globe. However, thromboembolic events were observed in the vaccinated population and were certainly the most commonly reported events following the COVID-19 vaccination. Although the thrombotic complications of COVID-19 were poorly understood, hyper-inflammatory responses were thought to be one of the main explanations for this infection sequel. In the setting of COVID-19 vaccines, there is still no clear understanding of the thrombosis pathophysiology, and, again, exaggerated pro-inflammatory and immune-mediated processes seem to be leading causes. Definitely, with the rise in reported cases of serious complications and increased awareness of these phenomena, we learn new theories and explanations that help us understand and manage those patients. We report the case report of two patients we managed over the last three years who presented with thrombotic microangiopathy following the COVID-19 vaccination.