| Autor: |
Magro, C.M., Mulvey, J.J., Laurence, J., Sanders, S., Crowson, A.N., Grossman, M., Harp, J., Nuovo, G. |
| Předmět: |
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| Zdroj: |
British Journal of Dermatology; Jan2021, Vol. 184 Issue 1, p141-150, 10p |
| Abstrakt: |
Background: There are two distinctive acral manifestations of COVID‐19 embodying disparate clinical phenotypes. One is perniosis occurring in mildly symptomatic patients, typically children and young adults; the second is the thrombotic retiform purpura of critically ill adults with COVID‐19. Objectives: To compare the clinical and pathological profiles of these two different cutaneous manifestations of COVID‐19. Methods: We compared the light microscopic, phenotypic, cytokine and SARS‐CoV‐2 protein and RNA profiles of COVID‐19‐associated perniosis with that of thrombotic retiform purpura in critical patients with COVID‐19. Results: Biopsies of COVID‐19‐associated perniosis exhibited vasocentric and eccrinotropic T‐cell‐ and monocyte‐derived CD11c+, CD14+ and CD123+ dendritic cell infiltrates. Both COVID‐associated and idiopathic perniosis showed striking expression of the type I interferon‐inducible myxovirus resistance protein A (MXA), an established marker for type I interferon signalling in tissue. SARS‐CoV‐2 RNA, interleukin‐6 and caspase 3 were minimally expressed and confined to mononuclear inflammatory cells. The biopsies from livedo/retiform purpura showed pauci‐inflammatory vascular thrombosis without any MXA decoration. Blood vessels exhibited extensive complement deposition with endothelial cell localization of SARS‐CoV‐2 protein, interleukin‐6 and caspase 3; SARS‐CoV‐2 RNA was not seen. Conclusions: COVID‐19‐associated perniosis represents a virally triggered exaggerated immune reaction with significant type I interferon signaling. This is important to SARS‐CoV‐2 eradication and has implications in regards to a more generalized highly inflammatory response. We hypothesize that in the thrombotic retiform purpura of critically ill patients with COVID‐19, the vascular thrombosis in the skin and other organ systems is associated with a minimal interferon response. This allows excessive viral replication with release of viral proteins that localize to extrapulmonary endothelium and trigger extensive complement activation. What is already known about this topic? Acral perniotic‐like lesions are seen in mildly symptomatic patients with COVID‐19 – typically children – while acral retiform purpura associated with pauci‐inflammatory thrombosis is a manifestation of patients who are critically ill with COVID‐19. What does this study add? This study emphasizes that the disparate clinical and pathological manifestations of two distinct forms of acral disease in the setting of COVID‐19 are reflective of differences in interferon signalling.In the mild perniotic presentation, interferon signalling is robust, inflammation is striking and viral load in tissue samples is expectedly minimal.In contrast, in retiform purpura of severe COVID‐19, interferon signalling is absent, viral protein localization to endothelium is extensive and complement deposition with vascular thrombosis is impressive. Linked Comment:Bessis. Br J Dermatol 2021; 184:11–12. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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