Among patients with SARS‐CoV‐2 infection (also known as COVID‐19), pneumonia, respiratory failure and acute respiratory distress syndrome are frequently encountered complications. 1 Although the pathophysiology underlying severe COVID‐19 remains poorly understood, accumulating evidence argues for hyperinflammatory syndrome causing fulminant and fatal cytokines release associated with disease severity and poor outcome. 2 However, the spectrum of complications is broader and includes among others various auto‐immune disorders such as autoimmune thrombocytopenia, Guillain–Barré and antiphospholipid syndrome. 3 , 4 , 5 In this report we describe seven patients from six French and Belgian Hospitals who developed a first episode of autoimmune haemolytic anaemia (AIHA) during a COVID‐19 infection. Patient characteristics are detailed in Table I. Briefly, median age was 62 years (range, 61–89 years), and all patients presented with risk factors for developing a severe form of COVID‐19 such as hypertension, diabetes and chronic renal failure. All patients had both a positive oropharyngeal swab for SARS‐CoV‐2 and typical images of COVID‐19 infection on chest computed tomography scans (25–75% extension). Three patients were admitted in an intensive care unit but only one required invasive ventilation. Treatment for COVID‐19 infection differed according to the standards of each centre. Thus, three patients received hydroxychloroquine, in association with azithromycin for two of them, and one patient received lopinavir and ritonavir. Table I Characteristics of seven patients with autoimmune haemolytic anaemia after the onset of COVID‐19. Patient Age Gender Comorbidity CT‐scan* Oropharyngeal swab (tested by PCR) Haemoglobin (g/l) Reticulocyte count (109/l) Lymphocyte count (109/l) Lactate dehydrogenase (U/l) Haptoglobin (g/l) DAT specificity Optimum temperature Day between COVID‐19 symptoms and AIHA Related pathology AIHA treatment Response #1 61 M Hypertension, chronic renal failure Moderate Positive 60 477 250 1000 100 g/l along with an increase of 20 g/l at least seven days after an infusion with red blood cells. Corticosteroid failure lead to rituximab injection in the third case (patient #6), and one responding patient is scheduled to receive rituximab because of a MZL clone (patient #3). At the time of last follow‐up, all patients were alive and had at least partly recovered from COVID‐19. To conclude, we report seven cases of warm and cold AIHA associated with COVID‐19 disease, all of them occurring after the beginning of the symptoms of the infection and within a timeframe compatible with that of the cytokine storm. Four out of the seven patients had indolent B lymphoid malignancy either already known or discovered because of the haemolytic episode. AIHA is a classical complication of both CLL and MZL, 6 , 7 and viral infections are known to trigger autoimmune cytopenias. 8 Whether the presence of an underlying malignant B lymphoid clone facilitated the onset of AIHA is unknown. Nonetheless, these observations argue for systematically investigating for the presence of a lymphoid clone in patients presenting with COVID‐19 infections and autoimmune cytopenias. Author contributions GL, AQ and FC designed the research study, analyzed the data and wrote the paper. MB, JS, CJ, DR, FM, AM, TB, GD and AD contributed to conception, patient enrollment and data collection.
