Does COVID-19 pneumonia signify secondary organizing pneumonia?: A narrative review comparing the similarities between these two distinct entities

Abstract

Multiple observational studies have described the similarities between COVID-19 pneumonia and organizing pneumonia (OP). These two entities clinically manifest with mild and subacute respiratory symptoms, often with a delayed diagnosis due to the atypical ARDS and silent hypoxemia presentation. Radiological features are often indistinguishable between the two. With the increase in antemortem lung biopsies and autopsies being performed, more histopathological findings of OP and its variant, acute fibrinous and organizing pneumonia (AFOP), are being diagnosed. These entities are known complications of viral infections as a delayed immunological process, explaining the favorable response to corticosteroids. Clinicians should be vigilant to diagnose this under-recognized entity of secondary OP in people with COVID-19 when clinical deterioration occurs, especially with compatible radiologic findings and recent cessation of corticosteroids. Despite the proven benefits of corticosteroids in treating COVID-19, treatment approaches can be more effective as OP often requires higher doses and a more prolonged therapy duration for remission and preventing relapses. The purpose of our narrative review is to compare the similarities between COVID-19 pneumonia and OP, emphasizing the clinical, radiological, and histopathological features based on the evidence available in the literature.

A Case of Rebound Inflammation in a 38-Year-Old Man with Severe COVID-19 Pneumonia Following Cessation of Dexamethasone Therapy

“…Increased corticosteroid doses and treatment duration beyond the usual 10-day course are both recommended to establish remission and avoid relapse. Consistent evidence supports examining secondary OP in persons with past COVID-19 infection who have clinical and radiographic deterioration following recent cessation of corticosteroids, in the absence of evidence of new infection or other causation [ 3 , 11 ]. Secondary OP was a strong possibility in our patient.…”

“…Similarly, Myall et al [ 10 ] reported that 39% of COVID-19 patients had persistent signs and symptoms 4 weeks following discharge. Interstitial lung illness, most often organizing pneumonia [ 3 ], was detected in 35 survivors (4.8%). On imaging, the majority of X-ray or computed tomography images revealed bilateral subpleural ground-class consolidation in the lower or middle section of the lung, or occasionally subpleural and peri-bronchial linear dense consolidation, as well as traction bronchiectasis.…”

“…Chong et al [ 3 ] discussed the clinical, biochemical, and imaging similarities between the 2 entities of COVID-19 pneumonia and secondary organizing pneumonia (OP). Both present clinically as mild-to-subacute respiratory symptoms that are typically discovered years later as a result of atypical acute respiratory distress syndrome (ARDS) and silent hypoxemia.…”

“…Accordingly, immunomodulatory agents that suppress an excessive inflammatory response (eg, corticosteroids) are promising potential therapies for COVID-19. Among available therapies, corticosteroids are widely used in clinical practice and multiple clinical trials showed they lower the mortality rate [ 3 ]. In patients hospitalized with COVID-19, the use of dexamethasone 6 mg daily resulted in lower 28-day mortality rate among those who were receiving respiratory support [ 4 ].…”

“…In patients hospitalized with COVID-19, the use of dexamethasone 6 mg daily resulted in lower 28-day mortality rate among those who were receiving respiratory support [ 4 ]. However, cases of corticosteroid resistance or rebound inflammatory response during corticosteroid tapering or after discontinuation have been reported [ 3 , 5 – 7 ]. This report describes a case of rebound inflammation in a 38-year-old man with severe COVID-19 pneumonia following cessation of dexamethasone therapy, with improvement following reintroduction of dexamethasone.…”