Lung pathology in COVID-19: A systematic review

Abstract

Sparse literature is available regarding autopsy findings of coronavirus disease 2019 (COVID-19) despite high mortality due to its highly contagious nature and lack of robust infrastructure for appropriate handling of the infected cases. Based on clinical findings and various diagnostic tests, it is evident that it holds the potential to affect multiple organ systems of the body preferably lungs and immune and coagulation systems. Cytokine storm-induced thrombotic complication such as disseminated intravascular coagulation is a significant feature in severe cases of COVID-19. This review captures the current information on lung histopathology in COVID-19 infection and severe respiratory failure. In COVID-19, lungs are affected bilaterally, become edematous and red/tan mottled to maroon in color with firm consistency. Distinct parenchymal changes, firm thrombi in the peripheral pulmonary vessels along with diffuse alveolar damage, have been the most consistent feature of COVID-19-related lung pathology. Electron microscopy has also been used to demonstrate viral particles.

Long-COVID and Post-COVID Health Complications: An Up-to-Date Review on Clinical Conditions and Their Possible Molecular Mechanisms

“…In addition, this viral infection can lead to destabilization of the liver, which signals a state of maximum alertness for the whole organism, and generates an increase in plasma biochemical markers of tissue aggression produced in response to tissue-damaging agents. Table 2 summarizes all post-and long-term COVID-19 symptoms for each human body system described in this review [6,9,34,50,56,96,99,118,121,122]. Viral infection leads to an aggressive immunological reaction, which directly and indirectly compromises the cardiopulmonary system.…”

“…The COVID-19 pandemic did not distinguish between different socioeconomic levels, sex or age groups [4,5]. Initially, efforts were focused on controlling the infectious process in order to prevent lung attack and respiratory insufficiency [6], since acute pulmonary and respiratory impairment was observed (similar to other SARS variants) [7]. In infected individuals, altered levels of oxygenation in arterial blood and the depletion of gas exchange caused severe deficiencies and losses of pulmonary capacitance, compromising the basic functions of life [6,8].…”

The Emerging Role of Neutrophils in the Pathogenesis of Thrombosis in COVID-19

“…Studies on lung histopathology in COVID-19 infection and severe respiratory failure have demonstrated the presence of distinct alveolar damage and thrombi formation in the peripheral pulmonary vessels. Interestingly, visualization of neutrophil-rich inflammation and neutrophil extra-cellular traps at the site of infection confirmed the role of neutrophils in COVID-19related immune responses [67,68]. Veras et al ascertained that SARS-CoV-2 can induce NET formation through healthy neutrophils, which depends on angiotensin-converting enzyme 2 or hypercitrullination [69].…”

Combining initial chest CT with clinical variables in differentiating coronavirus disease 2019 (COVID-19) pneumonia from influenza pneumonia

“…So far, many virological, pathogenesis, pathological and pathophysiological studies have gradually lifted the veil of COVID-19 for us 23 – 33 , and may also explain the differences in clinical and CT features between influenza pneumonia and COVID-19 showed by our study.…”

“…This was caused by the pathological changes of COVID-19. In the lungs of COVID-19, terminal bronchi were obstructed by bronchial exudate, viscous secretions, and inflammatory exudate 23 – 27 . Such pathological changes rarely occur in influenza pneumonia.…”