Bronchoalveolar lavage-detected SARS-CoV-2 infection in presence of serial negative nasopharyngeal swabs: a case report.

We describe a case of a SARS coronavirus 2 (SARS-CoV-2) infection in a Swiss 54-years-old immunocompromised patient (lymphoma, therapy with the anti-CD20 antibody Rituximab® ), with initial scarce respiratory symptoms but typical coronavirus disease 2019 (COVID-19) radiological presentation, and symptoms onset during a holiday trip to Texas (USA). Three nasopharyngeal swabs in the 96 hours following hospital admission were negative, despite a CT thorax suggestive for an early stage of infection. COVID-infection was finally confirmed in the bronchoalveolar lavage (BAL) fluid, performed for exclusion of an alternative diagnosis in immunocompromised. In the BAL an increased cellularity with marked lymphocytosis of 35%, a reduced CD4/CD8 ratio of 0.1 and borderline neutrophilia of 3% were found. This finding might be due to the concomitant therapy with anti-CD20 antibodies, but the presence of lymphocytosis in the BAL despite peripheral lymphopenia with decreased CD4/CD8 T-cells ratio are described here for the first time in a SARS-CoV-2 infection. Persistent gastrointestinal symptoms (diarrhea), fever and initially headache were the predominant symptoms. The respiratory symptoms were scarce (variable mild dyspnea mMRC1). The respiratory conditions worsened during the hospital stay, with tachypnea up to 35/min, increased need for supplemental oxygen up to 8 L/min and worsening lung infiltrates on CT thorax on day 5. A therapy with hydroxychloroquine (HCQ) and an immunoglobulin-supplementation were given, with clinical and respiratory improvement, without need for intensive care or any ventilator support, and hospital discharge on day 16. Our case highlights some diagnostic and therapeutical challenges occurring in patients with COVID-19 infection. As take-home message, in the presence of clinical and radiological findings compatible with SARS-CoV-2 infection we outline the importance of treating patients accordingly, also in presence of repeated negative nasopharyngeal swabs. In selected patients as in our case a bronchoscopic BAL should be considered to exclude other infections, but in our opinion not primarily to confirming COVID-19 infection. Our unique finding of a lymphocytosis in the BAL during a COVID-19 infection needs further investigations. 2021 Annals of Translational Medicine. All rights reserved.