Delayed-onset Organizing Pneumonia Emerging after Recovery from Coronavirus Disease 2019: A Report of Three Cases Diagnosed Using Transbronchial Cryobiopsy and a Review of the Literature

A case of late-onset organizing pneumonia following COVID-19 infection in a post-kidney transplant patient

A 50-year-old man who had undergone a living-donor kidney transplant 12 years prior for chronic renal failure due to autosomal dominant polycystic kidney disease contracted coronavirus disease 19 (COVID-19). He had a positive antigen test, mild symptoms, sore throat, and fever of 37.9 ℃. The patient was treated with molnupiravir for 5 days, and the symptoms disappeared 5 days after onset. However, 10 days after onset, he developed a fever of approximately 37 ℃ and a non-productive cough; 27 days after onset, the patient was hospitalized for anorexia and a worsening respiratory condition. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test results on admission were negative, and no antiviral medications were administered against SARS-CoV-2. Computed tomography revealed extensive ground-glass opacities in both lung fields. The patient was treated with steroid pulse therapy, ceftriaxone, atovaquone, azithromycin, and respiratory management using a high-flow nasal cannula. The combined therapies were successful, and the patient was managed with a nasal oxygen cannula after 3 days. Oxygen administration was discontinued after 6 days of hospitalization, and the patient was discharged after 14 days. Based on the laboratory findings, bacterial, interstitial, and Pneumocystis pneumonia were unlikely. The success of the steroid pulse therapy suggested that respiratory failure was caused by pneumonia due to the immune response after COVID-19 infection.

Organizing pneumonia and COVID-19

Organizing pneumonia (OP) is an interstitial lung disease, and can be cryptogenic, if no cause is identified, or secondary to several conditions. COVID-19-induced persistent inflammation can be associated with interstitial lung disease. We present a review of literature of OP and COVID-19-induced OP with an illustrative case. A 38-year-old man was admitted with COVID-19 that required mechanical ventilation for 56 days. Initial chest computed tomography (CT) revealed diffuse bilateral ground-glass opacities in the lungs with consolidation areas involving 75 % of the parenchyma. After weaning from MV, the patient still required oxygen supplementation. A new chest CT scan also showed extensive diffuse areas of consolidation and ground-glass opacity. OP was hypothesized and 40 mg/day prednisone initiated and continued for six months with resolution of lung functional and image abnormalities. Organizing pneumonia should be included in the differential diagnosis of COVID-19 patients with respiratory symptoms after partial pulmonary recovery.