Mesenchymal stromal cell therapy for COVID-19-induced ARDS patients: a successful phase 1, control-placebo group, clinical trial

Abstract

Background: Acute respiratory distress syndrome (ARDS) is the devastating complication of the new COVID-19 pandemic, directly correlated with releasing large amounts of inflammatory cytokines. Due to their immunoregulatory features, mesenchymal stromal cells (MSCs) provide a promising approach against this disease. In this regard, this study was designed as a single-center, open-label, phase 1 clinical trial with a control group to examine the safety and explore the possible potency of three injections of umbilical cord-derived MSCs (UC-MSCs) in mild-moderate COVID-19-induced ARDS patients.

Methods: Twenty confirmed COVID-19 patients with mild-to-moderate ARDS degree entered the study and were divided into two groups: control group (standard care) and intervention group (standard care + UC-MSCs). The patients received three intravenous infusions of UC-MSCs (1 × [Formula: see text] cells/kg BW per injection) every other day. Respiratory markers, CRP levels and specific serum cytokines were assessed four times (days of 0, 5, 10 and 17) during the 17-day follow-up period.

Results: During the study, there were no serious adverse effects after cell transplantations. Besides, significant improvement in SPO₂/FIO₂ ratio and serum CRP levels was observed. On the other hand, a significant decrease (P < 0.05) in serum cytokine levels of IL-6, IFN-g, TNF-α, IL-17 A and a significant increase in serum cytokine levels of TGF-B, IL-1B and IL-10 were observed. Also, no significant changes were observed in CT scan images of patients during the study period.

Conclusion: Our obtained results demonstrated that multiple intravenous transplantations of allogenic UC-MSCs in non-severe COVID-19-induced ARDS patients are a safe procedure. In addition, this intervention is a hopeful approach to decline cytokine storm and recover respiratory functions. Indeed, more clinical trials with larger sample sizes are required to confirm these results. Trial registration This clinical trial was registered with the Iranian Registry of Clinical Trials (ID: IRCT20160809029275N1 at 2020.05.30).

Keywords: Acute respiratory distress syndrome; Clinical trial; Mesenchymal stromal cells; Safety.

Fig. 1

Immunophenotypic characterization of human umbilical cord-derived mesenchymal stromal cells by flow cytometry for the expression of mesenchymal (CD73, CD90, CD105) and hematopoietic (CD34, CD 45) stem cells markers. (Dotted line: unstained control, Solid line: a marker of interest)

Fig. 2

A Osteogenic and B adipogenic differentiation of hUC-MSCs (magnification ×100 (A) and ×400 (B) from inverted phase microscope). hUC-MSCs human umbilical cord-derived mesenchymal stromal cells

Fig. 3

Oxygenation changes (SPO2/FIO2 ratio) in the control and intervention groups during the study

Fig. 4

Serum CRP levels in the control and intervention groups during the study

Fig. 5

Schematic before and after lung CT scan of patients. A and B are representative images of a patient in intervention group (before and after treatment)/C and D are representative images of a patient in control group (before and after study)

Fig. 6

A Serum IL-6 levels in the control and intervention groups during the study. B Serum IFN-g levels in the control and intervention groups during the study. C Serum TNF-α levels in the control and intervention groups during the study. D Serum IL-1β levels in the control and intervention groups during the study. E Serum IL-17A levels in the control and intervention groups during the study. F Serum TGF-β levels in the control and intervention groups during the study. G Serum IL-10 levels in the control and intervention groups during the study. All measurements were performed by ELISA method