PEER-REVIEW | HAIR RESTORATION | by the age of 30, 50% by age 50, and 80% by age 70. In
women, 13% of premenopausal women have some evidence of pattern hair loss. However, the incidence increases in women around the time of the menopause and may affect 70% of women over the age of 65 years3
.
Physiological consideration The process begins by performing a blood sample on an anti-coagulated tube with separating gel. The tubes are then centrifuged for a few minutes (speed and time depend on the kit protocol). Owing to their density the red cells fall to the bottom of the tube. On the upper-part of the tube the plasma and the platelets can be found. Once in the dermal layer, platelets are activated, they
inflate and the growth factors are released. Platelet activation is a natural reaction when a traumatic process occurs in tissue (injection or injure). Activation can also be provided by adjunction of CaCl2 or thrombin. In this series, the authors’ did not use any activator. The most important growth factors for hair application are: ■ Platelet derived growth factor (PDGF) stimulates the growth of dermal mesenchyme4
■ Vascular endothelial growth factor (VEGF) creates neoangiogenesis, as well as increases and improves hair growth and hair size 5–8
■ Epidermal growth factor (EGF) stimulates mitosis of epithelial cells and fibroblast, and improves the rate of anagen, the active growth phase of hair follicles 9, 10
■ Insulin like growth factor (IGF) slows down apoptosis11
Epidermal growth factor
■ Fibroblast growth factor (FGF) stimulates the proliferation and differentiation of keratinocytes and endothelial cells12
(EGF) stimulates mitosis of epithelial cells and fibroblast, and improves the rate of anagen, the active growth phase of hair follicles.
■ Nerve growth factor (NGF) strongly stimulates hair growth and slows down apoptosis. NGF has a modulating effect on the hair depending on the receptor with which it interacts. NGF also acts as stress-mediators. This is certainly a good way to explain the correlation between stress and hair loss13
.
Previous studies There are three applications in the hair-loss field: androgenic alopecia, alopecia areata, and hair graft. Regarding PRP evaluation in androgenic alopecia, there are five published studies. The first study from Sorbellini et al14
exhibited an in
vitro study conducted on 50 patients. Twelve follicles were taken from each patient, four follicles were induced with PRP, four in Ringer’s solution, and four in standard solution. The mitotic activity was then measured. According to the results, the PRP group showed a significant increase of mitotic activity and a reduction of apoptosis. The purpose of the next study by Takikawa et al15
was
to determine whether there was a difference between simple PRP injections and PRP containing deltaparine
26 ❚ March 2015 |
prime-journal.com Figure 2 Dermaroller Figure 1
Tropocells® PRP kit (Estar Medical, Holon, Israel)
and protamine microparticles, which acted as carriers for growth factors in
the PRP. The study was conducted on 26 volunteers with thin hair who received five local treatments. PRP improved hair density in 16% at 12 weeks. There was no significant difference on the hair density improvement with or without deltaparine. In the third study, Greco and Brandt16 demonstrated that infusing growth
factors into the scalp did reverse miniaturisation over an 8 month period when compared to control. They observed an increase of 9.7% in average hair shaft diameter at 4 months and then 6.1% at 8 months in the treatment group. In the fourth study by Sciavone et al,
researchers explored the possible clinical benefit of injecting platelet- derived growth factors into the scalp of patients using a specific autologous blood concentrate. Two injections of a leukocyte platelet-rich plasma (L-PRP) with the addition of concentrated plasmatic proteins were administered at baseline and after
3 months in 64 patients. Macrophotographs were taken at baseline and after 6 months, and two independent evaluators rated them using the Jaeschke rating of clinical change. Some improvement was seen in all patients by one evaluator and in 62 by the other17 In the fifth study, Li et al showed that injection of mice
.
with activated PRP induced faster telogen to anagen transition than in control mice18
.
Objective of the evaluation This article intends to retrospectively evaluate a cohort of 70 patients with progressive androgenic alopecia. These patients underwent a combination therapy with injection of platelet extracts prepared using a PRP kit, and a rotary single-use multipuncture instrument (dermaroller).
Materials and methods PRP was prepared using the PRP kit (Tropocells® PRP kit (Estar Medical, Holon, Israel) (Figure 1) through a one step procedure. A total of 30 ml of blood was transferred to PRP tubes containing acid-citrate dextrose modified solution (additive/blood ratio of 1:5.67) and separating gel (1:5). Two tubes have been used for each procedure (60 cc). The PRP tube
was then centrifuged (1500 g for 10 minutes at room temperature) resulting in blood separation into three
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