PRP in Pigmentary Disorders

A review of the literature supporting Platelet-rich Plasma treatment for Vitiligo, Melasma and Psoriasis.

Vitiligo

Vitiligo is an autoimmune disorder that targets melanocytes in the skin causing discolored patches in different areas of the body. Intradermal PRP injections are used in combination with UVB and CO2 laser treatments (Mercuri et al. 2020). The fertile environment of PRP that is rich in growth factors and cytokines help restore and promote normal cellular functions. PRP on its own was found to have poor results compared to fractional CO2 or excimer laser and PRP combination (Yin et al. 2021). Six clinical studies regarding the use of PRP in vitiligo have been identified, with a total of 253 patients. The mean time of follow-up of treated patients was 6 months. In all reports, all treated patients showed a stable vitiligo, and a significantly higher improvement in the PRP groups was always observed compared to control groups, regardless of the combined treatment associated with PRP. Regarding the side effects, PRP in vitiligo patients is safe, without important and specific side effects. Pain at the injection site was the main side effect, although it can be avoided by applying an anesthetic cream (Mercuri, S R et al. 2020).

Melanocytes undergo melanogenesis and synthesis of melanin, which is essential for photoprotection. Melanin production is initiated and regulated by a number of signaling systems and transcription factors, including the tyrosine kinase receptor KIT, its ligand SCF and MITF. Keratinocyte and fibroblast proliferation is stimulated by growth factors found in PRP. PRP accelerates proliferation and migration of fibroblasts through up-regulation of cyclin E and Cyclin- dependent kinase 4, which is important in cell migration and proliferation (Abd EL-Azim et al. 2017).

Melasma

Melasma is an acquired hyperpigmentation disorder that is prevalent among females and patients with darker skin types. The pathogenesis of melasma has been mostly linked to genetics, light exposure, and hormonal causes (Handel, Miot, & Miot, 2014). The treatment of melasma is often a challenge posed by clinicians, due to the common observation of incomplete responses and frequent relapses. Hence, it has become common to adopt combination therapies for melasma (Ogbechie-Godec & Elbuluk, 2017).

PRP has been receiving growing evidence as a new treatment approach for melasma. Particularly, growth factors like TGF-𝛃1 help inhibit melanogenesis in a concentration-dependent manner by delaying the activation of the extracellular kinase (Garg & Bansal, 2021; Kim, Park, & Park, 2004). Upon PRP activation, TGF-𝛃1 is also believed to stimulate basement membrane healing, leading to a pigment lightening effect (Hofny et al., 2018). PDGF mediated collagen synthesis helps achieve an increase in skin volume due to the activation of the formation process of blood vessels as well as collagen and extracellular matrix components (Papakonstantinou, Roth, & Karakoulakis, 2012). The increase in the extracellular matrix components also allows for the improvement of the appearance and texture of the skin (Cayirli, Caliskan, Acikgoz, Erbil, & Erturk, 2014; Kim, Park, & Park, 2004).

In a study conducted by Hofny et al. (2019), 20 adult patients with melasma were administered autologous PRP treatment. The results showed that there was an increase in the expression of TGF-β protein in the lesional skin of melasma patients post-PRP treatment which was associated with clinical improvement. Melasma patients’ epidermis was also free of basal cell hyperpigmentation following PRP injections. Similar findings were observed in other studies exploring hyperpigmentation (Mehryan et al., 2014).

In another study by Sirithanabadeekul et al. (2019), 10 female patients with melasma received an intradermal PRP injection on one side of the face and saline on the other. Over four treatment sessions were administered to the patients every two weeks. The results showed an improvement of melanin levels in the PRP treatment condition compared to the control condition after six weeks. There was also reduced skin pigmentation in the PRP treatment condition. The side effects of the treatment were mild and patients reported they only lasted a few days.

Traditionally, treatments for melasma included chemical peels, topical lightening substances, laser therapies, and dermabrasion. However, these methods have not produced satisfactory or long lasting results (Ogbechie-Godec & Elbuluk, 2017). The use of microneedling and PRP has started showing promising results with melasma patients and patients with ethnic skin (Talakoub & Wesley, 2009)

Psoriasis

Psoriasis is a chronic skin disease that causes patches of dry itchy skin on different areas of the body. This disease can not be cured but certain treatments may help reduce erythema and future flare ups. Platelet rich plasma is effective in the stimulation and acceleration of soft tissue healing and in combination with other treatments, has been an option in managing psoriasis. Studies showed that PRP exerts an anti-inflammatory effect which could be mediated by the presence of HGF among other growth factors (Chakravdhanula et al. 2016). The inflammatory effect is exhibited by the suppression of cytokine release and resisting the inflammatory response. This can be of benefit to counter psoriasis which is characterized by an extensive inflammatory response and release of various cytokines (Atwa et al., 2018). TNFa is a pathogenic cytokine in psoriasis that is produced by different immune cells and also by keratinocytes. TNFa stimulates inflammation and keratinocytes in psoriasis. PRP reduces chemotaxis by inhibiting chemokine transactivation and CXCR4-receptor expression, thus controlling local inflammation (Mao-ying Lin et al., 2020).

A clinical trial was conducted to observe the effects of PRP in combination with treatments such as MTX. PRP was prepared from the patient’s peripheral blood through a 2-stage centrifugation process. All patients in combinational therapy received a single shot of PRP if % BSA falls within certain ranges in their first sitting and subsequently followed with folitrax-15 for 4 weeks, while patients in mono-therapy group received only folitrax-15 for 4 weeks. PRP showed greater efficacy as a combinational modality with MTX for managing hard-to-treat psoriasis, regardless of age, gender, PASI score, disease duration or prior systemic treatment. Patients treated with PRP and MTX showed substantial improvement in terms of reduction in erythema, induration and desquamation at each visit and were significant when compared with patients treated only with MTX (Chakravdhanula et al. 2016). In addition, Patients with chronic plaque psoriasis treated with PRP and methotrexate showed a significant improvement in erythema, induration, and desquamation at each visit compared to patients treated with methotrexate alone (Mao-ying Lin et al. 2020).

In a study conducted by Atwa et al. (2018), PRP was injected intradermally at the plaque site of 24 psoriatic patients once per week for 10 weeks. The results revealed that IL17 expression was more reduced among patients who received the treatment compared to controls who were injected with saline who did not exhibit any changes in IL17 expression. This indicates the presence of an anti-inflammatory effect of PRP treatments on psoriasis.

Refrences