Characterized by scaly white or erythematous plaques, psoriasis is a chronic autoimmune dermatological disease most often appearing on the scalp, genitalia, lumbosacral area, and extensor surfaces of the limbs.
Affecting an estimated 125 million people worldwide, the condition most commonly is observed in those between the ages of 15 and 25 years of age.
The most recent advancements in the development of biological treatment have revolutionized the treatment of the condition for those with moderate to severe psoriasis, achieving clear or nearly clear skin with long-term success.
However, these treatments in their current form have not been proven to cure psoriasis completely. Additionally, a growing number of those suffering from severe psoriasis are not responding to these current therapeutic treatment options.
Recently, stem cell therapy, including regulatory T-cells, hematopoietic stem cell transplantation, and mesenchymal stromal cells (MSCs) have been used in patients with recalcitrant psoriasis. In this review, Naik discusses stem cell treatment options available for psoriasis.
Regulatory T-cells, or Tregs, regulate or suppress other immunocytes by modulating their responses to the endogenous environment and antigens, which helps to avoid autoimmune reactions and chronic inflammation. Several treatments for psoriasis, including many biologics currently being used, appear to increase the number of Tregs and their performance in patients with psoriasis. This finding led Naik to conclude that, despite their high cost, Treg-based therapies may have the ability to interfere with the pathogenesis of psoriasis.
MSCs have been found to have a significant role in adaptive immunity. This immune-enhancing activity typically occurs in partnership with a number of immune cells, including neutrophils, dendritic cells, monocytes, natural killer cells, macrophages, B-cells, and T-cells. While several Phase I and II studies have not demonstrated significant toxicity, the author calls for more extensive controlled trials to better understand the efficacy and long-term safety of MSCs in this application.
The favorable results observed when using hematopoietic stem cells (HSCT) in a wide range of autoimmune conditions, including lymphoma, leukemia, lupus, diabetes, rheumatoid arthritis, and multiple sclerosis, led to interest in using these cells in patients with psoriasis. Interestingly, improvements in psoriasis have been observed in patients who have undergone allogeneic (rather than autologous) HSCT, suggesting that hematopoietic stem cells could contribute as a primary cause of psoriasis.
Naik concludes that the application of stem cells in the treatment of psoriasis raises hope for the development of a safe and effective therapy for those suffering from severe forms of the condition. While more data is required before clinical application, MSCs could be a promising therapy for the treatment of psoriasis.
Source: Naik PP. Stem cell therapy as a potential treatment option for psoriasis. An Bras Dermatol. 2022;97(4):471-477. doi:10.1016/j.abd.2021.10.002
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