Dr. Abhay Bhave comments on a recent study that found distinctive pulmonary pathobiologic features in patients who had died from COVID-19 when compared to patient who had died from ARDS secondary to H1N1 influenza virus infection.

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A recent study published in NEJM compared 7 lung samples obtained from autopsied COVID-19 patients with 7 lung samples of autopsied patients who died as a result of acute respiratory syndrome (ARDS) secondary to H1N1 influenza and found widespread thrombosis with microangiopathy in COVID-19 specimens. These lung samples showed alveolar capillary microthrombi found to be 9x more prevalent in COVID-19 as opposed to influenza patients. New vessel growth through intussusceptive angiogenesis was also found to be 2.7x higher in the former.

Key findings

Though the lungs from patients with COVID-19 and influenza shared common morphology such as diffuse alveolar damage and infiltrating perivascular lymphocytes, there were other marked differences noted.