ABSTRACT
Introduction: In December 2019, a new variant of a coronavirus led to a pandemic outbreak. Patients with haematological malignancies are at high risk for a severe progression of COVID-19 with high mortality rates. Case report: 54-year-old patient was tested positive for COVID-19 upon admission. The CT scan showed bilateral ground-glass pulmonary opacities. He received dexamethasone and remdesivir. Due to severe thrombocytopenia and detection of blasts in peripheral blood a bone marrow biopsy was done. Cytological and molecular results confirmed the diagnosis intermediate risk APL. We started a therapy with arsenic trioxide and all-trans retinoic acid (ATO/ATRA). The white blood cells (WBC) increased and the respiratory situation worsened. The patient developed a thrombophlebitis. Bleeding complications appeared as an epistaxis, which required an intervention. 28 days after starting the induction, the bone marrow biopsy showed < 5% blasts. A complete peripheral remission was documented on day 50. Discussion: A major concern in treating APL is the differentiation syndrome, which can ultimately result in pulmonary failure. This patient presented with severely impaired lung function due to simultaneous COVID-19 pneumonitis. Therapy of APL had to consider both clinical conditions. Key decisions were (beyond antiviral therapy and supportive measures) a consequent dosing of glucocorticoids and early cytoreductive therapy using hydroxyurea (HU). The pulmonary function was critical during days 7-15 after start of APL therapy, consistent with differentiation syndrome being the main cause of worsening, and clinically met by stop of ATO/ATRA. Another concern was coagulation dysfunction, given the high risk of thromboembolic complications associated with COVID-19, the severe thrombocytopenia and plasmatic coagulation disorder caused by APL. In this case - besides supportive platelet transfusions - we treated by low dose heparin only when a thrombophlebitis occurred. Overall in this patient presenting with COVID-19 and simultaneously APL, the most challenging problem was overcoming pulmonary worsening in the initial phase of APL therapy.