ABSTRACT
Rationale: The leading cause of death in coronavirus disease 2019 (COVID-19) is severe pneumonia, with many patients developing acute respiratory distress syndrome (ARDS) and diffuse alveolar damage (DAD). Whether DAD in fatal COVID-19 is distinct from other causes of DAD remains unknown. Objective: To compare lung parenchymal and vascular alterations between patients with fatal COVID-19 pneumonia and other DAD-causing etiologies using a multidimensional approach. Methods: This autopsy cohort consisted of consecutive patients with COVID-19 pneumonia (n = 20) and with respiratory failure and histologic DAD (n = 21; non-COVID-19 viral and nonviral etiologies). Premortem chest computed tomography (CT) scans were evaluated for vascular changes. Postmortem lung tissues were compared using histopathological and computational analyses. Machine-learning-derived morphometric analysis of the microvasculature was performed, with a random forest classifier quantifying vascular congestion (CVasc) in different microscopic compartments. Respiratory mechanics and gas-exchange parameters were evaluated longitudinally in patients with ARDS. Measurements and Main Results: In premortem CT, patients with COVID-19 showed more dilated vasculature when all lung segments were evaluated (P = 0.001) compared with controls with DAD. Histopathology revealed vasculopathic changes, including hemangiomatosis-like changes (P = 0.043), thromboemboli (P = 0.0038), pulmonary infarcts (P = 0.047), and perivascular inflammation (P < 0.001). Generalized estimating equations revealed significant regional differences in the lung microarchitecture among all DAD-causing entities. COVID-19 showed a larger overall CVasc range (P = 0.002). Alveolar-septal congestion was associated with a significantly shorter time to death from symptom onset (P = 0.03), length of hospital stay (P = 0.02), and increased ventilatory ratio [an estimate for pulmonary dead space fraction (Vd); p = 0.043] in all cases of ARDS. Conclusions: Severe COVID-19 pneumonia is characterized by significant vasculopathy and aberrant alveolar-septal congestion. Our findings also highlight the role that vascular alterations may play in Vd and clinical outcomes in ARDS in general.
Subject(s)
COVID-19 , Pneumonia , Respiratory Distress Syndrome , Vascular Diseases , COVID-19/complications , Humans , Lung/diagnostic imaging , Lung/pathology , Pulmonary Alveoli/pathology , Respiratory Distress Syndrome/etiologyABSTRACT
BACKGROUND: Patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may present or eventually develop central nervous system and ophthalmic signs and symptoms. Varying reports have emerged regarding isolation of viral RNA from these tissue sites, as well as largely autopsy-based histopathologic descriptions of the brain and the eye in patients with COVID-19. EVIDENCE ACQUISITION: A primary literature search was performed in literature databases such as PubMed, Google Scholar, and Cochrane Library. Keywords were used alone and in combination including the following: SARS CoV-2, COVID-19, eye, brain, central nervous system, histopathology, autopsy, ocular pathology, aqueous, tears, vitreous, neuropathology, and encephalitis. RESULTS: The reported ophthalmic pathologic and neuropathologic findings in patients with SARS-CoV-2 are varied and inconclusive regarding the role of direct viral infection vs secondary pathology. The authors own experience with autopsy neuropathology in COVID-19 patients is also described. There is a particular paucity of data regarding the histopathology of the eye. However, it is likely that the ocular surface is a potential site for inoculation and the tears a source of spread of viral particles. CONCLUSIONS: Additional large postmortem studies are needed to clarify the role of SARS-CoV in the ophthalmic and neuropathologic manifestations of COVID-19.
Subject(s)
Brain/diagnostic imaging , COVID-19/complications , Eye Diseases/diagnosis , Eye/diagnostic imaging , Nervous System Diseases/diagnosis , COVID-19/epidemiology , Eye Diseases/etiology , Humans , Nervous System Diseases/etiology , PandemicsSubject(s)
Cerebral Amyloid Angiopathy/diagnosis , Cognitive Dysfunction/etiology , Frontal Lobe/pathology , Biopsy , Brain/diagnostic imaging , Cerebral Amyloid Angiopathy/complications , Cerebral Hemorrhage/diagnostic imaging , Diagnosis, Differential , Female , Headache/etiology , Humans , Magnetic Resonance Imaging , Memory Disorders/etiology , Meningoencephalitis/diagnosis , Middle AgedABSTRACT
We evaluated the incidence, distribution, and histopathologic correlates of microvascular brain lesions in patients with severe COVID-19. Sixteen consecutive patients admitted to the intensive care unit with severe COVID-19 undergoing brain MRI for evaluation of coma or neurologic deficits were retrospectively identified. Eleven patients had punctate susceptibility-weighted imaging (SWI) lesions in the subcortical and deep white matter, eight patients had >10 SWI lesions, and four patients had lesions involving the corpus callosum. The distribution of SWI lesions was similar to that seen in patients with hypoxic respiratory failure, sepsis, and disseminated intravascular coagulation. Brain autopsy in one patient revealed that SWI lesions corresponded to widespread microvascular injury, characterized by perivascular and parenchymal petechial hemorrhages and microscopic ischemic lesions. Collectively, these radiologic and histopathologic findings add to growing evidence that patients with severe COVID-19 are at risk for multifocal microvascular hemorrhagic and ischemic lesions in the subcortical and deep white matter.