A chronic skin disease called atopic dermatitis (AD) involves the formation of skin lesions seen in eczema along with severe pruritus or itching. This condition affects 10% of adults and 20% of children. Abnormal responses of dominant type 2 helper T cells and B-cells leads to high levels of immunoglobulin E (IgE) in the serum causing the allergy. There are current treatment practices for this “itchy” condition using topical corticosteroids and immunosuppressive agents that however is associated with adverse effects such as disturbed growth, cataract and osteoporosis (Eichenfield et al, 2014). The first study of using cell therapy for AD is the 2017-published clinical trial in Stem Cells. 34 adult patients with moderate-to-severe AD received mesenchymal stem cells isolated from human umbilical cord blood (UC-MSCs).
55% of patients who received 5.0 × 107 (termed as high-dose) of the stem cells showed a lowering of AD symptoms by 50% as measured by An Eczema Area and Severity Index (EASI) score. Similarly, the Investigator’s Global Assessment (IGA) score lowered by 33% and the Severity Scoring for Atopic Dermatitis (SCORAD) score decreased by 50%. The levels of IgE in the serum decreased while the pruritus score was decreased by 58%. Neither were any serious adverse effects nor did any patient stop treatment due to any such incident showing the promise of MSCs in treating AD.
A team led by researcher Song reported in 2019, the effects of extracts of UC-MSCs on a mouse model of AD. The clinical symptoms and the levels of serum IgE were lowered in mice that received the stem cell extract. The dermatitis was lowered as seen by dermatitis scores at the histological level. Additionally, key cytokines regulating T-cell responses in AD such as IFN-γ, IL-17, IL-4 and IL-13 were also decreased. The processes of lyophilization and subsequent reconstitution did not affect these therapeutic effects. Thus, future treatment using extracts from mesenchymal stem cells emerge for AD.
Let us look at another aspect of health: cognitive aging is an issue faced with shrinkage and loss of neurons along with decreased plasticity of the synapse. A team led by Cao (2017) reported the beneficial effects of human umbilical cord-derived mesenchymal stem cells on a mouse model of aging. After 3 months of stem cells (once in 2 weeks administrations), aged mice showed improved synaptic plasticity, memory and hippocampal-dependent learning. Thus, the scientific community has evidence in the use of MSCs in treating the manifestations of aging. This becomes significant given that globally, the aged population (60 years or over) reached 962 million in 2017 that is double the population of the aged seen in 1980. By 2050, the number of older persons is pitched to double to reach nearly 2.1 billion (The UN highlight sheet, 2017).
The ease of isolating mesenchymal stem cells from the umbilical cord and cord blood coupled to their immunomodulatory properties opens up the door to treat several chronic diseases such as dermatitis and age-related disorders.
Eichenfield, L. F. et al. Guidelines of care for the management of atopic dermatitis: section 2. Management and treatment of atopic dermatitis with topical therapies. J Am Acad Dermatol 71, 116–132, (2014).
Kim, H. S. et al. Clinical Trial of Human Umbilical Cord Blood-Derived Stem Cells for the Treatment of Moderate-to-Severe Atopic Dermatitis: Phase I/IIa studies. Stem Cells 35, 248–255, (2017).
Song, J., Kang, H.J., Ju, H.M. et al. Umbilical cord-derived mesenchymal stem cell extracts ameliorate atopic dermatitis in mice by reducing the T cell responses. Sci Rep 9, 6623 (2019).
Cao, N., Liao, T., Liu, J. et al. Clinical-grade human umbilical cord-derived mesenchymal stem cells reverse cognitive aging via improving synaptic plasticity and endogenous neurogenesis. Cell Death Dis 8, e2996 (2017).
World Population Ageing 2017 Highlights. The United Nations. Department of Economic and Social Affairs. https://www.un.org/en/development/desa/population/publications/pdf/ageing/WPA2017_Highlights.pdf