Fig. 5From: Human placenta-derived mesenchymal stem cells transplantation in patients with acute respiratory distress syndrome (ARDS) caused by COVID-19 (phase I clinical trial): safety profile assessmentAlteration of CD4+ and CD8+ cells in patients with COVID-19 on day − 1 (before) and + 1 (after) PL-MSC transfusion were statistically insignificant (P ≥ 0.05)Back to article page