Lung Histopathology in Coronavirus Disease 2019 as Compared With Severe Acute Respiratory Sydrome and H1N1 Influenza

Abstract

Background Patients with severe Coronavirus Disease 2019 (COVID-19) have respiratory failure with hypoxemia and acute bilateral pulmonary infiltrates, consistent with acute respiratory distress syndrome (ARDS). It has been suggested that respiratory failure in COVID-19 represents a novel pathologic entity. Research Question How does the lung histopathology described in COVID-19 compare to the lung histopathology described in SARS and H1N1 influenza? Study Design and Methods: We conducted a systematic review to characterize the lung histopathologic features of COVID-19 and compare them against findings of other recent viral pandemics, H1N1 influenza and SARS. We systematically searched MEDLINE and PubMed for studies published up to June 24, 2020 using search terms for COVID-19, H1N1 influenza and SARS with keywords for pathology, biopsy, and autopsy. Using PRISMA-IPD guidelines, our systematic review analysis included 26 articles representing 171 COVID-19 patients; 20 articles representing 287 H1N1 patients; and eight articles representing 64 SARS patients. Results In COVID-19, acute phase diffuse alveolar damage (DAD) was reported in 88% of patients, which was similar to the proportion of cases with DAD in both H1N1 (90%) and SARS (98%). Pulmonary microthrombi were reported in 57% of COVID-19 and 58% of SARS patients, as compared to 24% of H1N1 influenza patients. Interpretation DAD, the histologic correlate of ARDS, is the predominant histopathologic pattern identified in lung pathology from patients with COVID-19, H1N1 influenza and SARS. Microthrombi were reported more frequently in both patients with COVID-19 and SARS as compared to H1N1 influenza. Future work is needed to validate this histopathologic finding and, if confirmed, elucidate the mechanistic underpinnings and characterize any associations with clinically important outcomes.

Use of the COVID-19 Reporting and Data System (CO-RADS) classification and chest computed tomography involvement score (CT-IS) in COVID-19 pneumonia

“…Chest CT takes a considerable part in the timely detection of lung infection abnormalities in the early phase for diagnosis of COVID-19 [ 6 ]. Also, recent studies have reported that chest CT could have higher sensitivity than RT-PCR in diagnosing COVID-19 [ 7 , 8 ]. The Fleischner Society stated that chest CT scanning is essential in diagnosing COVID-19 patients when the symptoms worsen or RT-PCR is unavailable [ 9 ].…”

“…This classification varies from very low (CO-RADS 1) to very high (CO-RADS 5). Besides, a technically inadequate examination is encoding as CO-RADS 0 and if a positive RT-PCR result was proven during the examination, it encodes as CO-RADS 6 (Table 1 ) [ 8 ].…”

Bilirubin Levels as Potential Indicators of Disease Severity in Coronavirus Disease Patients: A Retrospective Cohort Study

“…Lungs are recognized as the primary target organs for COVID-19 (4). However, COVID-19 patients frequently show evidence of damage to other organs.…”

A Novel Swine Model of the Acute Respiratory Distress Syndrome Using Clinically-Relevant Injury Exposures

“…pneumonia or aspiration) (21). Even SARS-CoV-2, a pandemic respiratory virus that causes ARDS in its most severe form, provokes both epithelial and endothelial lung injury as assessed via post-mortem examination (27,28). We believe this trend has important experimental implications, as "single-hit exposures" (such as intratracheal endotoxin in mice) are unlikely to fully recapitulate the complex pathophysiology of human ARDS.…”