Injections of platelet‐rich plasma prepared by automatic blood cell separator combined with topical 5% minoxidil in the treatment of male androgenetic alopecia

Abstract Background Platelet‐rich plasma (PRP) has been increasingly accepted as a potential therapy in the treatment of androgenetic alopecia (AGA), However, there remains a dearth of data on the effectiveness of PRP prepared by automatic blood cell separator with a combination of topical minoxidil for the treatment of AGA. Objective To evaluate the efficacy and safety of PRP prepared by automatic blood cell separator combined with topical 5% minoxidil therapy in male AGA. Methods Thirty male patients with mild/moderate AGA were enrolled in a randomized double‐blind controlled study. Patients were randomly divided into two treatment arms: (group A) PRP prepared by automatic blood cell separator combined with topical 5% minoxidil group; (group B) PRP prepared by automatic blood cell separator combined with a topical placebo group. Trichoscopic assessments regarding hair density/quantity and mean hair diameter were performed at baseline and follow‐up. Clinical efficacy of global photography and patient satisfaction were conducted to verify the therapeutic efficacy of the treatment, and the occurrence of adverse reactions was recorded. Results We detected a significant increase in all patients in hair density and quantity after PRP treatment (p < 0.05), and there was no significant difference in mean hair diameter. Although hair density/quantity was more pronounced in group A than in group B, the difference between groups was not statistically significant (p > 0.05). In terms of clinical efficacy and patient satisfaction, group A was superior to group B, and no serious adverse reactions occurred. Conclusion We hereby conclude that the injections of PRP prepared by an automated method are effective and safe in the treatment of mild‐to‐moderate male AGA patients, and its combination with topical 5% minoxidil therapy was superior to PRP monotherapy with better clinical efficacy and higher patient satisfaction.


INTRODUCTION
Androgenetic alopecia (AGA) is the most common type of noncicatricial alopecia in dermatology clinics. AGA has genetic susceptibility, which can occur in both men and women and has a certain influence on patients' mental health and social interaction, leading to the occurrence of anxiety, depression, and other adverse psychological conditions. 1 At present, the pathogenesis of AGA remains unclear, androgen and heredity are the primary pathogenic factors. Current treatments for AGA include drug therapy, laser therapy, microneedle therapy, hair transplantation, and platelet-rich plasma (PRP) therapy.
The United States Food and Drug Administration-approved treatments for AGA include oral finasteride and topical minoxidil. 2 However, there are several adverse reactions of topical minoxidil, including dermatitis, scalp irritation, and prone to relapse after withdrawal, which requires long-term use to maintain the efficacy. In addition, oral finasteride has side effects such as decreased libido, which limits clinical application. PRP with various growth factors is a concentrated platelet solution derived from the separation of plasma prepared from autologous venous blood, and it is enriched with various growth factors involved in the regulation of cell proliferation and differentiation and the induction of angiogenesis. 3 PRP has been widely used with high safety and few adverse reactions. 4 Studies have shown that PRP plays a positive role in the hair growth cycle and promotes hair regeneration, which can be used as a combined treatment for AGA. 5,6 Most previous studies have used traditional manual methods to prepare PRP, while blood samples prepared by automatic procedures have higher platelet concentrations than that by manual methods. 7 The aim of this study was to evaluate the efficacy and safety of PRP prepared by automatic blood cell separator with a combination of topical 5% minoxidil therapy for male AGA.

Intervention and treatment protocol
Minoxidil and placebo were blinded by SAS9.4 software. Patients and researchers were blinded to the treatments. All patients were randomized by assigning blinded drugs and then allocated into two treatment arms: Group A (PRP+M): PRP prepared by automatic blood cell separator combined with topical 5% minoxidil therapy.   (Table 2).

Topical therapies
The usage and dosage of topical drugs were the same in both groups.
Topical application started the next day after injection. Keep scalp dried before application, apply 1ml from the center to the periphery of the alopecia area, spray twice a day, then massage the scalp for 3-5 min.

Evaluation and assessment
For each patient, trichoscopic images were captured and measured by dermoscopy (Beijing Dermat Technology Co., LTD.). Trichoscopy

Statistics
Statistical software SPSS23.0 was used for statistical analysis with mean ± standard deviation (x ± s). Comparison between the two groups was conducted by student t-test. p < 0.05 indicates that the difference is statistically significant.

RESULTS
The clinical efficacy of the two groups was evaluated in the 4th week after the last PRP injection. According to the comparison of hair images, we detected that hair became thicker, and hair color deepened and increased hair coverage after PRP therapy. According to the photographs of three enrolled patients, it was found that the global appearance and hair quality were improved in visual assessment ( Figure 1 Figure 2, 3) In terms of patient self-satisfaction evaluation, five patients in group A were very satisfied, eight were satisfied and two were dissatisfied.
The overall satisfaction was 86% (13/15). In group B, two patients were very satisfied, nine were satisfied and four were dissatisfied. The overall satisfaction was 73% (11/15). The overall satisfaction of group A was higher than group B, indicating that PRP combined with the topical 5% minoxidil group has higher satisfaction. The adverse reactions of PRP injection therapy were transient pain at the injection site and a burning sensation, which could be relieved after ice application and tolerated.
Spot bleeding and erythema may subside spontaneously without a scar after injection. In the course of treatment, no serious adverse reactions occurred, except for one patient who experienced mild dizziness and nausea during injection, which was self-alleviated after a few minutes. The primary outcome of our study was the effectiveness of the treatment demonstrated by physicians assessing the improvement in hair growth under trichography and photography. Secondary outcomes, as discussed above, were measured by patient self-satisfaction and the occurrence of adverse reactions. The outcomes demonstrated the safety and effectiveness of the automated method prepared PRP injection combined with topical 5% minoxidil therapy.

DISCUSSION
AGA affects up to 50% of females and 80% of males. 9 It starts after puberty and presents progressive development. Male pattern alopecia is based on the recession of the hairline, the top bald hair as a typical performance, part of the "horseshoe" appearance. 10 AGA usually accompanies by scalp greasy, increased dandruff, pruritus, and other symptoms. AGA is a polygenic disease with complex inheritance, the exact etiology and pathogenesis remain unclear.
Androgen as the main pathogenic factor of AGA, leads to gradual

F I G U R E 3
Comparison of average dermoscopic hair density and hair diameter before and after treatment.
In this study, PRP prepared by an automatic blood cell separator was determined to be 3-5 times higher than the concentration of whole blood platelets. The platelet enrichment of the automated methodprepared PRP was high while the granulocyte content was low, so this kind of PRP with high purification quality may have better hair regeneration ability. In addition, the automated method prepared PRP has the advantages of one-time automatic collection, convenient operation, high safety, stable quality, and long-term storage under freezing.
Besides, other blood components can be transfused back into the body during the procedure of PRP preparation, which can avoid blood waste.
In this study, all enrolled patients received injections of automated method-prepared PRP. The results showed that the average hair density and hair counts of all patients after 3 months of treatment were significantly higher than that of pretreatment (p < 0.05). However, there was no significant difference in the average hair diameter before There are still some limitations in this study. On the one hand, due to the small sample size of this experiment, AGA patients of different severity have not been grouped and stratified compared, and for a short follow-up period, the long-term efficacy of PRP injection therapy could not be assessed. On the other hand, there is no unified standard for PRP preparation, concentration, injection method, course of treatment, and treatment interval of PRP, which may lead to bias in the efficacy evaluation. Therefore, further expansion of the sample size and longer follow-ups are still needed to explore and determine the method to achieve optimal hair regrowth conditions.
In conclusion, our study provides further evidence that PRP injection is safe and effective for the treatment of mild/moderate AGA, and PRP prepared by automatic blood cell separators has high purification quality and high platelet concentration. The injection of automated method-prepared PRP combined with topical 5% minoxidil therapy was superior to PRP monotherapy in terms of patient satisfaction and clinical efficacy for the treatment of mild/moderate male AGA, it is worthy of clinical promotion.