Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) targets multiple organs and causes severe coagulopathy. Histopathological organ changes might not only be attributable to a direct virus-induced effect, but also the immune response. The aims of this study were to assess the duration of viral presence, identify the extent of inflammatory response, and investigate the underlying cause of coagulopathy. Methods This prospective autopsy cohort study was done at Amsterdam University Medical Centers (UMC), the Netherlands. With informed consent from relatives, full body autopsy was done on 21 patients with COVID-19 for whom autopsy was requested between March 9 and May 18, 2020. In addition to histopathological evaluation of organ damage, the presence of SARS-CoV-2 nucleocapsid protein and the composition of the immune infiltrate and thrombi were assessed, and all were linked to disease course. Findings Our cohort (n=21) included 16 (76%) men, and median age was 68 years (range 41–78). Median disease course (time from onset of symptoms to death) was 22 days (range 5–44 days). In 11 patients tested for SARS-CoV-2 tropism, SARS-CoV-2 infected cells were present in multiple organs, most abundantly in the lungs, but presence in the lungs became sporadic with increased disease course. Other SARS-CoV-2-positive organs included the upper respiratory tract, heart, kidneys, and gastrointestinal tract. In histological analyses of organs (sampled from nine to 21 patients per organ), an extensive inflammatory response was present in the lungs, heart, liver, kidneys, and brain. In the brain, extensive inflammation was seen in the olfactory bulbs and medulla oblongata. Thrombi and neutrophilic plugs were present in the lungs, heart, kidneys, liver, spleen, and brain and were most frequently observed late in the disease course (15 patients with thrombi, median disease course 22 days [5–44]; ten patients with neutrophilic plugs, 21 days [5–44]). Neutrophilic plugs were observed in two forms: solely composed of neutrophils with neutrophil extracellular traps (NETs), or as aggregates of NETs and platelets.. Interpretation In patients with lethal COVID-19, an extensive systemic inflammatory response was present, with a continued presence of neutrophils and NETs. However, SARS-CoV-2-infected cells were only sporadically present at late stages of COVID-19. This suggests a maladaptive immune response and substantiates the evidence for immunomodulation as a target in the treatment of severe COVID-19. Funding Amsterdam UMC Corona Research Fund.

Background General anesthesia during infancy is associated with neurocognitive abnormalities. Potential mechanisms include anesthetic neurotoxicity, surgical disease, and cerebral hypoxia–ischemia. This study aimed to determine the incidence of low cerebral oxygenation and associated factors during general anesthesia in infants. Methods This multicenter study enrolled 453 infants aged less than 6 months having general anesthesia for 30 min or more. Regional cerebral oxygenation was measured by near-infrared spectroscopy. We defined events (more than 3 min) for low cerebral oxygenation as mild (60 to 69% or 11 to 20% below baseline), moderate (50 to 59% or 21 to 30% below baseline), or severe (less than 50% or more than 30% below baseline); for low mean arterial pressure as mild (36 to 45 mmHg), moderate (26 to 35 mmHg), or severe (less than 25 mmHg); and low pulse oximetry saturation as mild (80 to 89%), moderate (70 to 79%), or severe (less than 70%). Results The incidences of mild, moderate, and severe low cerebral oxygenation were 43%, 11%, and 2%, respectively; mild, moderate, and severe low mean arterial pressure were 62%, 36%, and 13%, respectively; and mild, moderate, and severe low arterial saturation were 15%, 4%, and 2%, respectively. Severe low oxygen saturation measured by pulse oximetry was associated with mild and moderate cerebral desaturation; American Society of Anesthesiology Physical Status III or IV versus I was associated with moderate cerebral desaturation. Severe low cerebral saturation events were too infrequent to analyze. Conclusions Mild and moderate low cerebral saturation occurred frequently, whereas severe low cerebral saturation was uncommon. Low mean arterial pressure was common and not well associated with low cerebral saturation. Unrecognized severe desaturation lasting 3 min or longer in infants seems unlikely to explain the subsequent development of neurocognitive abnormalities.

SARS-CoV-2 may cause acute respiratory disease, but the infection can also initiate neurological symptoms. Here we show that SARS-CoV-2 infection causes brain inflammation in the macaque model. An increased metabolic activity in the pituitary gland of two macaques was observed by longitudinal positron emission tomography-computed tomography (PET-CT). Post-mortem analysis demonstrated infiltration of T-cells and activated microglia in the brain, and viral RNA was detected in brain tissues from one animal. We observed Lewy bodies in brains of all rhesus macaques. These data emphasize the virus' capability to induce neuropathology in this nonhuman primate model for SARS-CoV-2 infection. As in humans Lewy body formation is an indication for the development of Parkinson's disease, this data represents a warning for potential long-term neurological effects after SARS-CoV-2 infection.