EISOR Delivery: Regional experience with sharing equipe, equipment & expertise to increase cDCD donor pool in time of pandemic.

Donation after circulatory death (DCD) programs are expanding in Europe, in the attempt to expand donors pool. Even in controlled DCD donors, however, a protracted warm ischemia time occurring in the perimortem period might damage organs, making these unsuitable for transplantation. Implementing a strategy of extracorporeal interval support for organ retrieval (EISOR), a regional reperfusion with normothermic, oxygenated blood provides a physiologic environment allowing extensive assessment of potential grafts, and potentially promotes recovery of native function. Here we report the results of a multi-center retrospective cohort study including 29 Maastricht Category III controlled DCD donors undergoing extracorporeal support in a regional DCD/EISOR Training Center, and in the network of referring In-Training Centers, under the liaison of the regional Transplant Coordination Center during COVID-19 pandemic, between March 2020 and November 2021. The study aims to understand whether a mobile, experienced EISOR team implementing a consistent technique and sharing its equipe, expertise and equipment in a regional network of hospitals, might be effective and efficient in implementing the regional DCD program activity even in a highly stressed healthcare system.

Covid-19 Interstitial Pneumonia: Histological and Immunohistochemical Features on Cryobiopsies.

BACKGROUND: The pathogenetic steps leading to Covid-19 interstitial pneumonia remain to be clarified. Most postmortem studies to date reveal diffuse alveolar damage as the most relevant histologic pattern. Antemortem lung biopsy may however provide more precise data regarding the earlier stages of the disease, providing a basis for novel treatment approaches. OBJECTIVES: To ascertain the morphological and immunohistochemical features of lung samples obtained in patients with moderate Covid-19 pneumonia. METHODS: Transbronchial lung cryobiopsy was carried out in 12 Covid-19 patients within 20 days of symptom onset. RESULTS: Histopathologic changes included spots of patchy acute lung injury with alveolar type II cell hyperplasia, with no evidence of hyaline membranes. Strong nuclear expression of phosphorylated STAT3 was observed in >50% of AECII. Interalveolar capillaries showed enlarged lumen and were in part arranged in superposed rows. Pulmonary venules were characterized by luminal enlargement, thickened walls, and perivascular CD4+ T-cell infiltration. A strong nuclear expression of phosphorylated STAT3, associated with PD-L1 and IDO expression, was observed in endothelial cells of venules and interstitial capillaries. Alveolar spaces macrophages exhibited a peculiar phenotype (CD68, CD11c, CD14, CD205, CD206, CD123/IL3AR, and PD-L1). CONCLUSIONS: Morphologically distinct features were identified in early stages of Covid-19 pneumonia, with epithelial and endothelial cell abnormalities different from either classical interstitial lung diseases or diffuse alveolar damage. Alveolar type II cell hyperplasia was a prominent event in the majority of cases. Inflammatory cells expressed peculiar phenotypes. No evidence of hyaline membranes and endothelial changes characterized by IDO expression might in part explain the compliance and the characteristic pulmonary vasoplegia observed in less-advanced Covid-19 pneumonia.