Myeloid cell differentiation within extracorporeal membrane oxygenators in patients with ARDS

Extracorporeal membrane oxygenation is a last-resort rescue therapy for patients with acute respiratory distress syndrome (ARDS). The membrane oxygenator (MO) is prone to coagulation and dysfunction. Studies have shown that circulating cells can be retained within the MO, however, it is unclear what their cellular identity is. Here, we used single cell-RNA sequencing to characterize MO-resident and incoming venous PBMCs from ARDS patients. We find that MO contain both undifferentiated monocytes and differentiated macrophages, characterized by increased SPP1 expression. These results indicate that myeloid retention and differentiation occurs within MO, which might contribute to MO dysfunction.