Atopic dermatitis, also known as eczema, is a chronic or relapsing inflammatory skin disease, resulting in dry, itchy, crusty, red skin. This condition is caused by a dysregulation of the skin immune system due to genetic and environmental factors and typically starts in childhood with changing severity over the years. In developed countries, atopic dermatitis affects up to 20% of children and 3% of adults. The current treatments available for patients with moderate-to-severe atopic dermatitis are topical steroids (such as corticosteroid creams) and systemic immunosuppressant drugs. However, on one hand, the efficacy of creams is limited and is accompanied by side effects with long-term application and on the other hand, the systemic immunosuppressant drugs have been reported to carry the risk of severe toxicity and side effects.
Since stem cell therapy (SCT) has been proven to be a promising therapy for some intractable diseases through several proof-of concept studies, and particularly
Mesenchymal Stem Cells (MSCs) have been used for the treatment of immune disorders thanks to their immunomodulatory properties, their effect for the treatment of atopic dermatitis has recently been explored.
First, a preclinical study conducted by the Seoul National University (South Korea) demonstrated the mechanisms by which human umbilical cord blood-derived MSCs (hUCB-MSCs) interact with the skin immune system and can alleviate the inflammatory reaction when applied subcutaneously.
This year, the same group, in collaboration with the Seoul St. Mary’s Hospital, proved that these findings can be successfully applied in a clinical trial. Their study includes a total of 34 patients: 7 for a phase 1 trial and 27 for a phase 2a trial. Participants were distributed in two treatment groups: low-dose or high-dose allogenic MSCs subcutaneous administration. In the phase 2a trial, this group assignment was randomized. After the single dose injection, the patients were evaluated every 2 weeks up to 12 weeks. At every study visit, severity of their disease was assessed by means of standard scoring parameters (SCORAD: Scoring Atopic Dermatitis and EASI: Eczema Area and Severity Index).
This first-in-class clinical study shows that single subcutaneous injection of hUCBMSCs improves disease symptoms. This improvement was quantified and confirmed by both scoring parameters. In particular, fifty-five percent of patients in high dose hUCBMSC- treated group showed a 50% reduction in the EASI score. Interestingly, the hUCBMSC treatment resulted in a dose-dependent disease severity reduction: the highest dose showed better improvement of the disease severity. Importantly, along with these results, the treatment showed a consistent reduction in the level of crucial allergy severity biomarkers (total serum IgE and blood eosinophil counts). No severe or serious adverse events were observed in the study. The safety assessment results indicate that the hUCBMSCs were well tolerated.
Larger clinical trials, involving a placebo group, are planned to make up the limitations of this study and reinforce its results before an effective treatment may become available to the general public. However, these results offer hope and reveal the potential of cord blood stem cell therapy in another common condition.