Negative SARS-CoV-2 antibodies in patients with positive immunohistochemistry for spike protein in pityriasis rosea-like eruptions

SARS-CoV-2-Induced Vasculitic Skin Lesions Are Associated with Massive Spike Protein Depositions in Autophagosomes

In patients infected with severe acute respiratory syndrome coronavirus 2, vasculopathic changes of the skin are associated with a severe prognosis. However, the pathogenesis of this vasculopathy is not conclusively clarified. In this study, 25 prospectively collected skin samples from patients with COVID-19-related skin lesions were examined for vasculopathic changes and, in case of vasculitis, were further analyzed with electron microscopy and immunohistochemistry. Vasculopathy was observed in 76% of all COVID-19-related inflammatory skin lesions. Visual endothelial changes without manifest leukocytoclastic vasculitis were found in 60% of the COVID-19-related skin lesions, whereas leukocytoclastic vasculitis was diagnosed in 16%. In the cases of vasculitis, there were extensive spike protein depositions in microvascular endothelial cells that colocalized with the autophagosome proteins LC3B and LC3C. The autophagy protein complex LC3-associated endocytosis in microvascular endothelial cells seems to be an important pathogenic factor for severe acute respiratory syndrome coronavirus 2-related vasculitis in the skin. On ultrastructural morphology, the vasculitic process was dominated by intracellular vesicle formation and endothelial cell disruption. Direct presence of severe acute respiratory syndrome coronavirus 2 particles in the skin was not observed. Therefore, our results suggest that instead of direct viral infection, dermal vasculitic lesions in COVID-19 are caused by severe acute respiratory syndrome coronavirus 2 spike protein deposition followed by endothelial damage with activation of autophagy.

Pemphigus Vulgaris Possibly Associated with COVID-19 Infection

Pemphigus vulgaris (PV) represents damage to epidermal keratinocytes, resulting in acantholysis due to the production of autoantibodies against desmoglein-1 and desmoglein-3. Autoimmune blistering disorders such as pemphigus vulgaris or bullous pemphigoid that develop following coronavirus disease 2019 (COVID-19) have been reported in several studies. Herein, we report a case of PV onset following COVID-19 infection in a 17-year-old female, demonstrating --the potential pathogenic capacity of SARS-CoV-2 to develop PV.