Mesenchymal Stem Cells: a Potential Treatment Approach for Refractory Chronic Spontaneous Urticaria.

The etiopathogenesis of chronic spontaneous urticaria (CSU) is not fully elucidated, and almost 30-40% of patients are resistant to treatments; therefore, there is still a need for the development of new and effective treatments. This study aimed to develop experimental cellular therapy for CSU patients resistant to current treatment options. Autologous adipose tissue mesenchymal stem cells (MSC) were administered to 10 refractory CSU patients who were then followed up for six months. The efficacy of treatment was evaluated according to the weekly urticaria activity scores (UAS7) and drug use scores (DUS7). To observe the effect of treatment on immune cells, CD4+ T cell subsets were analyzed by flow cytometry, and the serum IFN-γ, TNF-α, IL2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17a, IL-21, IL-22, TGF-β1, PGE2, IDO and anti-FcεRI levels were measured using the Luminex and ELISA methods. The values obtained were compared with 10 control refractory CSU patients and five healthy controls. We found that the T cell subsets and inflammatory molecules were not affected by MSC treatment during the follow-up period. In control patients, a significant decrease was detected only at the Th2 subset, TGF-β1, PGE2, IDO and anti-FcεRI levels on the 14th day of treatment. The UAS7 and DUS7 values of the MSC-treated patients significantly decreased during the follow-up period, but in control patients, a significant but temporary decrease was seen. According to our findings, unlike conventional treatment, MSC therapy resulted in longer and more effective recovery. Our data indicate that MSCs may be an alternative and effective approach for treatment-resistant CSU patients. Graphical Abstract.