SARS-CoV-2 organising pneumonia: 'Has there been a widespread failure to identify and treat this prevalent condition in COVID-19?'

Abstract

Reviews of COVID-19 CT imaging along with postmortem lung biopsies and autopsies indicate that the majority of patients with COVID-19 pulmonary involvement have secondary organising pneumonia (OP) or its histological variant, acute fibrinous and organising pneumonia, both well-known complications of viral infections. Further, many publications on COVID-19 have debated the puzzling clinical characteristics of 'silent hypoxemia', 'happy hypoxemics' and 'atypical ARDS', all features consistent with OP. The recent announcement that RECOVERY, a randomised controlled trial comparing dexamethasone to placebo in COVID-19, was terminated early due to excess deaths in the control group further suggests patients present with OP given that corticosteroid therapy is the first-line treatment. Although RECOVERY along with other cohort studies report positive effects with corticosteroids on morbidity and mortality of COVID-19, treatment approaches could be made more effective given that secondary OP often requires prolonged duration and/or careful and monitored tapering of corticosteroid dose, with 'pulse' doses needed for the well-described fulminant subtype. Increasing recognition of this diagnosis will thus lead to more appropriate and effective treatment strategies in COVID-19, which may lead to a further reduction of need for ventilatory support and improved survival.

Keywords: imaging/CT MRI etc; pneumonia; rare lung diseases; viral infection.

Figure 1

Photomicrograph shows immature collagen plugs or Masson bodies (arrows) filling the airspaces. There is mild chronic interstitial inflammation. (H&E, medium power).

Figure 2

37-year-old woman with COVID-19 requiring FiO₂ of 1.0 delivered via heated humidified high-flow nasal cannula for 8 days. On day 8, initiation of treatment with ‘pulse-dose’ methylprednisolone 1000 mg intravenously for 3 days was followed by an abrupt reduction in oxygen needs and eventual discharge on ambient air. (A) Contrast-enhanced thin-section CT image 6 days after onset of symptoms shows peripheral and peri-bronchial ground-glass opacity in both lungs typical of an organising pneumonia pattern of lung injury. (B) Unenhanced CT image 2 weeks after discharge shows marked clearing of ground-glass opacity with small foci of lung consolidation and minimal traction bronchiectasis (arrows) suggesting mild fibrosis.