Administration of mesenchymal stem cells during ECMO results in a rapid decline in oxygenator performance.

Mesenchymal stem cells (MSCs) have attracted attention as a potential therapy for Acute Respiratory Distress Syndrome (ARDS). At the same time, the use of extracorporeal membrane oxygenation (ECMO) has increased among patients with severe ARDS. To date, early clinical trials of MSCs in ARDS have excluded patients supported by ECMO. Here we provide evidence from an ex-vivo model of ECMO to suggest that the intravascular administration of MSCs during ECMO may adversely impact the function of a membrane oxygenator. The addition of clinical grade MSCs resulted in a reduction of flow through the circuit in comparison to controls (0.6 ±0.35 L min-1vs 4.12 ± 0.03 L min-1, at 240 minutes) and an increase in the transoygenator pressure gradient (101±9 mmHg vs 21±4 mmHg, at 240 minutes). Subsequent immunohistochemistry analysis demonstrated quantities of MSCs highly adherent to membrane oxygenator fibres. This study highlights the potential harm associated with MSC therapy during ECMO and suggests further areas of research required to advance the translation of cell therapy in this population.