Leukocyte- and Platelet-rich Fibrin Treatment of Chronic Lower Extremity Ulcer in a Patient with Systemic Lupus Erythematosus: A Case Report

Chronic lower extremity ulcer is a known complication in patients with autoimmune disease. The overall prevalence of lower extremity ulcers in patients with autoimmune disease ranges from approximately 4% to 10% depending on the disease and population studied; in the general population, the prevalence is approximately 1%.^1-3 Approximately 20% to 23% of chronic lower extremity ulcers are associated with autoimmune diseases or vasculitis.⁴

Management of autoimmune-associated ulcers is challenging owing to the larger wound area,³ longer duration of wound healing,³ and higher socioeconomic costs⁴ compared with ulcers in patients who do not have an autoimmune disease. The effectiveness of standard wound care for autoimmune-associated ulcers is not satisfactory.^1,3 Shanmugam et al³ performed split-thickness skin graft in the management of lower extremity ulcer, and a significantly lower response rate was found in subjects with autoimmune diseases compared with those without autoimmune diseases (P=.0002). Those authors speculated that the inflammatory status in the setting of autoimmune diseases may affect angiogenesis and new tissue formation, resulting in prolonged healing and failure of skin grafts.

Autologous platelet concentrates (also known as PRP), or concentrated platelets in a small volume of plasma, have been widely used in mammalian regenerative medicine for over 3 decades.^5-7 The second-generation platelet concentrate L-PRF has been used in multifarious skin ulcers owing to its ease of use and low cost relative to certain adjunctive treatments such as stem cell-based therapy and bioengineered tissue.⁷ In particular, it has been suggested that leukocytes contained in L-PRF may play an important role in wound healing by releasing anti-inflammatory molecules to reduce inflammation in autoimmune-associated ulcers.⁸ However, few published studies report the application of L-PRF in the management of such ulcers. The case of a patient with SLE-related refractory leg ulcer is reported herein. Complete epithelialization was achieved after 15 weeks of L-PRF therapy (Figure 1).

A 26-year-old Chinese male patient had been diagnosed with SLE in 2012 and treated with prednisone and leflunomide. In September 2018, the patient had an accidental fall while walking and sustained a skin abrasion on the right lower extremity, without constant bleeding or swelling. He was treated with a conventional dressing change in a local hospital. After a 5-month treatment period, however, the ulcer area had gradually increased in size from 1 cm × 1 cm to 3.5 cm × 2.5 cm (Figure 2A). In January 2019, the patient presented to the Rheumatology Department at Tongji Hospital, Wuhan, China, for further treatment. He denied a history of diabetes mellitus, hypertension, or tuberculosis and was a nonsmoker. Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

The patient presented with moon face and mild obesity. The ulcer on the right lower extremity extended deep to the superficial fascia and measured 3.5 cm × 2.5 cm × 0.7 cm in size, with coagulative necrosis inside the wound. The surrounding skin showed inflammatory manifestations, including redness, tenderness, and increased temperature (Figure 2A). The laboratory results are shown in Table 1. The nuclear speckled-type antinuclear antibody titer was 1:320, and the cytoplasm speckled-type titer was 1:100. Vascular Doppler ultrasound and plain radiographs of the lower extremities showed no obvious abnormalities. Prednisone was increased to 30 mg per day and leflunomide to 30 mg per day. Standard of care, including debridement and dressing changes with gauze bandage, was routinely performed 3 times per week. The ulcer area increased to approximately 10 cm × 5.7 cm after 3 months of conventional treatment.

The patient was then referred to the endocrinology department for L-PRF treatment. An ulcer secretion sample was collected for microbial culture and drug sensitivity tests. Enterococcus faecium and hemolytic Staphylococcus aureus were identified. The patient was treated with linezolid for 8 days, and the results of follow-up bacterial cultures of the secretion were negative for these species.

When the wound bed was clean and healthy (Figure 2A), the patient received L-PRF treatment. Venous blood was drawn in dry glass tubes without any anticoagulants, and the volume was calculated according to 0.6 mL/cm² of wound area to obtain sufficient PRF clot for wound coverage. Thereafter, the whole blood was centrifuged at 400 g for 12 minutes at room temperature and was separated into 3 layers: red blood cell layer, L-PRF layer, and poor platelet plasma, as described in a previously published study by the corresponding author⁹ (Figure 1). The L-PRF clot, which was rich in fibrin, platelets, and leukocytes, was harvested as described in previously published studies^9,10 and placed to cover the surface of the ulcer after that surface was washed with sterile saline. Subsequently, petroleum gauze was applied over the L-PRF. This patient received L-PRF treatment once a week. The ulcer healed after 15 treatments, with a healing rate of 3.8 cm² per week (Figure 2).

Wound healing involves the 4 overlapping phases of hemostasis, inflammation, proliferation, and remodeling.¹¹ Chronic wounds are stalled in the inflammatory phase owing to disease-specific pathogenic factors.¹² A wide variety of factors may contribute to the development of refractory ulcers in patients with autoimmune disorders such as rheumatoid arthritis and SLE, including immune complex-mediated vasculitis, arteriovenous abnormalities owing to possible prothrombotic states, bacterial infection secondary to immunosuppressants, and immune dysregulation.^{4, 12}

It is increasingly being recognized that immune dysregulation may also significantly hinder the healing of chronic ulcers, with considerable involvement of immune cells and cytokines in proinflammatory processes.¹³ Histopathologic examination of SLE skin lesions identified various infiltrating cells, including T cells, B cells, dendritic cells, and macrophages.¹⁴ Of note, the M1 phenotype of macrophages plays a pro-inflammatory role in the early stages of wound healing and the M2 phenotype exhibits a pro-healing effect at later stages.¹⁵ In patients with SLE, the markers of M1 macrophages are significantly increased, including interferon-γ (P<.05),¹⁶ monocyte chemoattractant protein-1 (P=.08),¹⁷ and interferon-γ-inducible protein 10 (P<.05);¹⁸ while the markers of M2 macrophages are decreased including MHCII (P=.0003),¹⁹ CD204 type A scavenger receptor (P<.05),²⁰ and P2Y12 (P<.05).²¹ Deng et al²² reported that macrophage-depleted mice were resistant to lupus serum IgG–induced skin inflammation. Accordingly, it is speculated that the imbalance, with more M1 macrophages than M2 macrophages, may lead to prolonged inflammation and delayed tissue repair.¹⁵

In the case reported in the present study, the refractory leg ulcer had been present for more than 8 months. The patient had no history of diabetes or tuberculosis. No prothrombotic or vascular abnormalities were observed. The authors of the present case report hypothesized that immune dysregulation may have been a primary causal factor contributing to the recalcitrant wounds in this patient.

Treatment of refractory autoimmune-associated ulcers is challenging. The basic therapeutic measures should focus on proper control of autoimmune and inflammatory disease. However, time to healing is more than 1 year in a large majority of cases.⁴ PRP treatment has been shown to have positive effects on recalcitrant lower extremity ulcers in patients with various pathologic conditions, including venous leg ulcer, diabetic foot ulcer, and pressure ulcer (Table 2).^{10, 23-37} Compared with standard of care, PRP can significantly accelerate wound epithelialization. Collectively, the healing rate of diabetic foot ulcers, pressure ulcers, and venous leg ulcers has reportedly ranged from 0.28 cm² to 1.93 cm² per week (Table 2).^10,23-37 The patient in the present case study received L-PRF treatment once a week and achieved a healing rate of 3.8 cm² per week. This case demonstrated an obvious advantage of L-PRF treatment from among the therapeutic approaches for autoimmune-associated ulcers.

The literature on the application of PRP in autoimmune-associated ulcers is limited. It is known that macrophages play an important role in the healing process.¹⁵ Thus, the imbalance of M1 and M2 in patients with SLE may contribute to the development of skin ulceration. Notably, L-PRF contains a considerable array of host immune cells, especially leukocytes and a small fraction of stem cells, which act as an immune regulatory node with anti-inflammatory and antimicrobial capabilities.³⁸ Neutrophils can secrete a wide variety of cytokines, such as MIP-1α and MIP-1β, which are responsible for the chemotaxis, proliferation, and polarization of macrophages.³⁹ Thus, it is assumed that the beneficial effect of L-PRF owing to the inclusion of leukocytes may be partially mediated by the regulation of macrophages.⁸

This study is limited because it reports a single case in which L-PRF treatment was applied. Case series and RCTs are needed to provide stronger evidence, and such future studies are planned. In addition, pathological examination of wound tissue in this case was not performed owing to the patient’s physical, financial, and psychological burdens.

Management of autoimmune-associated ulcers is challenging, and therapeutic strategies are limited. Innovative use of L-PRF was applied to the case in the present study because of the poor efficacy of conventional therapy. The ulcer was completely epithelialized after 15 weeks of treatment, which demonstrated excellent efficacy of L-PRF in autoimmune-associated ulcers. It has been speculated that leukocytes in L-PRF may contribute to the promotion of wound healing in part by regulating the macrophage imbalance. Further pathological analysis during the period of L-PRF treatment may be of great significance to identify the underlying mechanisms. Case series and RCTs would be useful to further evaluate the clinical application of L-PRF in refractory ulcers in patients with autoimmune diseases.