RESUMEN
The vascular niche is a microenvironment located around capillaries and is mainly composed of endothelial cells, pericytes, macrophages, lymphocytes, mesenchymal stem cells, and hematopoietic stem cells. Studies have found that the vascular niche not only functions to regulate cell growth and differentiation in normal tissues, but also has an important role in regulating fibrosis in various organs and tissues in disease states. Coronavirus disease 2019 (COVID-19) is a systemic disease that broke out in 2019, caused by SARS-CoV-2 infection, which results in pulmonary inflammation, systemic multi-organ damage, and an inflammatory cytokine storm. Recently, the vascular niche has been found to play a role in COVID-19-related multi-organ damage. In this review, we introduce the important role of the vascular niche in organ fibrosis and COVID-19-related organ damage, summarize some of the cellular signaling pathways in the vascular niche that promote fibrosis, and discuss the treatment of organ fibrosis in Traditional Chinese medicine and Western medicine.
RESUMEN
BACKGROUND: Critical patients with the coronavirus disease 2019 (COVID-19), even those whose nucleic acid test results had turned negative and those receiving maximal medical support, have been noted to progress to irreversible fatal respiratory failure. Lung transplantation (LT) as the sole therapy for end-stage pulmonary fibrosis related to acute respiratory distress syndrome has been considered as the ultimate rescue therapy for these patients. METHODS: From February 10 to March 10, 2020, three male patients were urgently assessed and listed for transplantation. After conducting a full ethical review and after obtaining assent from the family of the patients, we performed three LT procedures for COVID-19 patients with illness durations of more than one month and extremely high sequential organ failure assessment scores. RESULTS: Two of the three recipients survived post-LT and started participating in a rehabilitation program. Pearls of the LT team collaboration and perioperative logistics were summarized and continually improved. The pathological results of the explanted lungs were concordant with the critical clinical manifestation, and provided insight towards better understanding of the disease. Government health affair systems, virology detection tools, and modern communication technology all play key roles towards the survival of the patients and their rehabilitation. CONCLUSIONS: LT can be performed in end-stage patients with respiratory failure due to COVID-19-related pulmonary fibrosis. If confirmed positive-turned-negative virology status without organ dysfunction that could contraindicate LT, LT provided the final option for these patients to avoid certain death, with proper protection of transplant surgeons and medical staffs. By ensuring instant seamless care for both patients and medical teams, the goal of reducing the mortality rate and salvaging the lives of patients with COVID-19 can be attained.