Efficiency of mesenchymal stromal cells (MSCs) in the treatment of patients with critical limb-threatening ischemia

Abstract

Relevance. The relevance of the study is determined by the fact that hopes are placed in the cell therapy for patients with critical limb-threatening (CLI) ischemia as a method of the restoration of blood circulation in the affected limb in patients who cannot undergo surgical or endovascular intervention. Aim. To evaluate the efficiency of allogeneic MSCs for the treatment of critical lower limb ischemia (randomized placebo-controlled study).Materials and methods. The study included 34 patients with critical lower limb ischemia (grade 4 according to Pokrovsky). There were 18 patients in the MSC group, and 16 patients in the placebo group). The groups were comparable concerning age, disease duration, and comorbidities. Allogeneic MSCs (phenotype CD73+, CD90+, CD105+, CD45–, CD34–, CD14–) were injected into the posterior calf muscles. Clinical outcome, ankle pressure, transcutaneous oxygen tension (tcpO2), and pain-free walking distance (PFWD) were evaluated. The patients were followed-up for 12–36 months. According to the clinical outcome in each group, the patients were divided into subgroups with «effect (+)» or «effect (–)». In 2 patients, there was an «uncertain clinical outcome». When analyzing the results, these patients were assigned to one or another subgroup.Results. In the MSC and placebo groups, the clinical outcome assessed as «effect (+)» or «effect (–)» did not differ (OR 1.5; 95 % CI 0.34–6.7). With different variants of group formation and with the assignment of patients with an «uncertain clinical outcome» to a one or another subgroup, the final results neither differed. According to instrumental research methods (PFWD, tcpO2, ankle pressure, angiography), there were no differences in the MSC and placebo groups. Conclusion. With different variants of analysis and group formation, no convincing evidence that allogeneic MSCs can be effective for the treatment of critical lower limb ischemia have been obtained.