Persistent endotheliopathy in the pathogenesis of long COVID syndrome - reply to comment from von Meijenfeldt et al.

We are grateful for the comments and the interesting additional novel data presented by von Meijenfeldt et al. These findings provide further evidence that sustained endotheliopathy and coagulopathy are both common in patients following acute COVID-19. The longitudinal data presented provide additional insights into the duration of specific aspects of COVID-19–induced hemostatic dysfunction. Previous studies have reported elevated D-dimer levels in 25% of patients in the first few months after SARS-CoV-2 infection. Notwithstanding differences in patient cohorts and study design, von Meijenfeldt et al. show that these elevated D-dimer levels after acute COVID appear to normalize by 4 months. Given that convalescent COVID-19 patients commonly present with respiratory symptoms, this observation has important clinical implications with respect to the utility of D-dimer testing in pulmonary embolism testing algorithms.