SARS-CoV-2, the etiologic agent of COVID-19, is a global pandemic with substantial mortality dominated by acute respiratory distress syndrome. We systematically evaluated lungs of 68 autopsies from 3 institutions in heavily hit areas (2 USA, 1 Italy). Detailed evaluation of several compartments (airways, alveolar walls, airspaces, and vasculature) was performed to determine the range of histologic features. The cohort consisted of 47 males and 21 females with a median age of 73 years (range 30-96). Co-morbidities were present in most patients with 60% reporting at least three conditions. Tracheobronchitis was frequently present, independent from intubation or superimposed pneumonia. Diffuse alveolar damage (DAD) was seen in 87% of cases. Later phases of DAD were less frequent and correlated with longer duration of disease. Large vessel thrombi were seen in 42% of cases but platelet (CD61 positive) and/or fibrin microthrombi were present at least focally in 84%. Ultrastructurally, small vessels showed basal membrane reduplication and significant endothelial swelling with cytoplasmic vacuolization. In a subset of cases, virus was detected using different tools (immunohistochemistry for SARS-CoV-2 viral spike protein, RNA in situ hybridization, lung viral culture, and electron microscopy). Virus was seen in airway epithelium and type 2 pneumocytes. IHC or in situ detection, as well as viable form (lung culture positive) was associated with the presence of hyaline membranes, usually within 2 weeks but up to 4 weeks after initial diagnosis. COVID-19 pneumonia is a heterogeneous disease (tracheobronchitis, DAD, and vascular injury), but with consistent features in three centers. The pulmonary vasculature, with capillary microthrombi and inflammation, as well as macrothrombi, is commonly involved. Viral infection in areas of ongoing active injury contributes to persistent and temporally heterogeneous lung damage.

Since its initial recognition in December 2019, Coronavirus disease 19 (COVID-19) has quickly spread to a pandemic infectious disease. The causative agent has been recognized as a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily affecting the respiratory tract. To date, no vaccines are available nor any specific treatment. To limit the number of infections, strict directives have been issued by governments that have been translated into equally rigorous guidelines notably for post-mortem examinations by international and national scientific societies. The recommendations for biosafety control required during specimen collection and handling have strongly limited the practice of autopsies of the COVID-19 patients to a few adequate laboratories. A full pathological examination has always been considered an important tool to better understand the pathophysiology of diseases, especially when the knowledge of an emerging disorder is limited and the impact on the healthcare system is significant. The first evidence of diffuse alveolar damage in the context of an acute respiratory distress syndrome has now been joined by the latest findings that report a more complex scenario in COVID-19, including a vascular involvement and a wide spectrum of associated pathologies. Ancillary tools such as electron microscopy and molecular biology used on autoptic tissue samples from autopsy are also significantly contributing to confirm and/or identify new aspects useful for a deeper knowledge of the pathogenetic mechanisms. This article will review and summarize the pathological findings described in COVID-19 until now, chiefly focusing on the respiratory tract, highlighting the importance of autopsy towards a better knowledge of this disease.

TME enriched with cytotoxic T lymphocytes is associated with higher levels of macrophages and PD-L1 expression on tumor cells and with aggressive histopathological features, lower response to chemotherapy and shorter survival. The role of chemotherapy as a tumor immunogenicity inducer should be confirmed in a larger validation set.

Functional foods provide health benefits if they are consumed on a regular basis as part of a varied diet. In this review, we discuss the availability and role of functional foods in pet nutrition with a focus on dogs and cats. Indeed, functional foods modify gastrointestinal physiology, promote changes in biochemical parameters, improve brain functions and may reduce or minimize the risk of developing specific pathologies. This evidence derives largely from clinical studies while only limited evidence is available from studies in dogs and cats. Therefore, functional food consumption should be further investigated in pet nutrition to understand how dietary interventions can be used for disease prevention and treatment.

A simple and reproducible multiparametric PGS effectively predicted survival in patients with MPM.