4.1 EPCs
Until now, the clinical application of EPCs in PAH has been rare (Table 3). The search results from clinicaltrials show that only China and Canada have achieved EPC therapy trials using human patients. Of the 31 idiopathic PAH patients in the Chinese trial, 16 patients were randomly selected to receive conventional therapy, and 15 patients were randomly selected to receive EPC infusion plus conventional therapy. This trial lasted for 12 weeks, and the frequency and degree of adverse events were similar between the 2 groups (p >0.05)(X. X. Wang et al., 2007). However, the cell infusion group exhibited a significant improvement in mean distance walked in 6 minutes, mPAP, pulmonary vascular resistance, and cardiac output. The Canadian trial was more radical because they used gene-edited EPCs in patients who were refractory to conventional therapy. They injected seven patients with eNOS-EPCs, but the number of patients was far less than that in the Chinese trial, and there were five female subjects but only two male subjects. Similar to the Chinese trial, the infusion of EPCs was well tolerated in the cell infusion group, and there was a significant increase in the mean distance walked in 6 minutes over all 6 months. However, it is worth noting that some improvements (such as hemodynamics) disappeared after 3 months, which may be due to the short duration of EPCs(Granton et al., 2015).