Abstract
Background
Prolonged shedding/relapse of COVID-19 infection has been reported, particularly in patients who received anti-CD20 agents (eg. rituximab). However, cases of occult COVID-19, in which SARS-CoV-2 persistence in lung parenchyma is diagnosed despite clearance from nasopharyngeal (NP) specimens, are uncommon.
Case summary
We describe two cases of occult COVID-19 in immunocompromised patients. Both patients had received rituximab previously. Both cases initially presented as ground-glass infiltrates on lung imaging; the diagnosis was originally not suspected due to repeated demonstration of negative SARS-CoV-2 from NP specimens, and alternative etiologies were originally considered. Persistence of SARS-CoV-2 in lung parenchyma, however, was demonstrated on bronchoalveolar lavage (BAL) specimens; additionally, isolation of viable SARS-CoV-2 virus and detection of SARS-CoV-2 nucleocapsid and spike-protein antigen in lung tissue on immunohistochemistry close to 3-months from primary infection strongly suggested ongoing viral persistence and replication as a driver of the lung parenchymal changes, which resolved after antiviral treatment.
Discussion
Occult COVID-19 can be a cause of unexplained ground-glass infiltrates on lung imaging; negative NP samples do not rule out SARS-CoV-2 persistence and invasive sampling must be considered. The unsuspected presence of viable virus on BAL, however, highlights that procedurists perfoming aerosol-generating-procedures during an ongoing pandemic wave must also practise appropriate infection-prevention precautions to limit potential exposure.
【저자키워드】 COVID-19, SARS-CoV-2, rituximab, Relapse, Immunocompromise, Viral antigen, Occult COVID-19, 【초록키워드】 immunohistochemistry, pandemic, Immunocompromised patients, Diagnosis, lung, SARS-CoV-2 virus, Antiviral treatment, virus, Antigen, Replication, BAL, COVID-19 infection, persistence, nasopharyngeal, Patient, Isolation, spike-protein, viral persistence, etiology, Precaution, specimens, anti-CD20, Primary infection, Bronchoalveolar lavage, Prolonged, lung parenchyma, changes, occult, lung tissue, SARS-CoV-2 nucleocapsid, clearance, repeated, limit, invasive, highlight, reported, diagnosed, demonstrated, suggested, resolved, parenchymal, 【제목키워드】 detection, Immunocompromised patient, nasopharyngeal, respiratory specimen, pulmonary infiltrate,