Treatment of Chronic Haemophilic Synovitis with PRP: Clinical and In Vitro Studies

Abstract

Intra-articular blood, iron and hemosiderin, hydroxyl radical cytokines, and neo-angiogenesis cause synovial inflammation, which leads to cartilage and joint damage. Platelet-rich plasma (PRP) inhibits most of the mediators that produce and maintain synovitis. We compile here our work showing the clinical effectiveness of intra-articular PRP injections and their potential role in stopping articular cartilage damage due to bleeding and its possible repair. A total of 116 joints, including knees (63%), elbows (19.8%), and ankles (17.2%), were treated with intra-articular injections of PRP. Moreover, we also show here the number of extracellular DNA traps (ETs) and the PRP effect in the synovial fluid of patients at the time of treatment and six months after. Clinically, it is demonstrated that PRP is effective in reducing bleeding episodes (p < 0.001) and pain (p < 0.0001) and improving the hemophilia joint health score (HJHS) (p < 0.001) at one year of follow-up. Furthermore, our results demonstrate that PRP inhibits ET formation in vitro and reconstitutes the immune system's cellular components in the synovial fluid of patients after treatment. We conclude that PRP can be considered an effective, safe, and easy treatment for hemophilic synovitis.

Keywords: hemophilia; joint; platelet; synovitis.

Figure 1

VAS values before treatment and 3, 6, and 12 months after PRP treatment. We compare the results before treatment vs. 3 months after treatment, before treatment vs. 6 months after treatment, and before treatment vs. twelve months after treatment. The results are statistically significant (* p < 0.001).

Figure 2

Joints with and without bleeding episodes before treatment and 3, 6, and 12 months after PRP treatment. The results show statistically significant differences before vs. the three different post-treatment periods evaluated (* p < 0.001).

Figure 3

Hemophilia joint health score (HJHS) before treatment and 3, 6, and 12 months after PRP treatment. The differences before and after treatment are statistically significant (*p < 0.001).

Figure 4

Presence of ETs in synovial fluid of patients with CHS. (A) The presence of ETs in 22 SF samples was analyzed after being stained with propidium iodide (DNA is colored in red) and anti-human elastase (elastase is colored in green) using fluorescence confocal microscopy (60X). Representative images of attached cells stained with irrelevant antibody isotype or PMA-stimulated neutrophils were used as negative (I) or positive ET release control (II) signals. The incipient release of DNA strands (red) with bound elastase (green) is indicated with white arrows in panels (III,IV). Massive and complete DNA release is shown in panel (V). (B) Quantification of cell-free DNA and (C) DNA-EL complex measured in the 22 SF samples. (D) Statistical associations between these last two parameters were analyzed by Spearman’s correlation and linear regression models. As presented in Oneto et al. [19].

Figure 5

The synovial fluid of patients with CHS contains soluble ET inducer factors that are inhibited by plasma. In vitro ET induction was evaluated by stimulating healthy neutrophils with 10% of SF for 2 h, in the presence or absence of PRP or PPP. Neutrophils incubated with 10% of medium without SF were used as controls for unstimulated neutrophils. After fixation, cells were stained with PI (red) and anti-human elastase (green). Representative fluorescence confocal microscopy images (60X) of NETs induced by SF samples (N = 18). DNA-EL levels were quantified in supernatants by ELISA and expressed as fold changes of unstimulated neutrophils (n = 18, * p < 0.05, *** p < 0.001 vs. SF-stimulated neutrophils (SF) without PRP/PPP, Kruskal–Wallis test). As presented in Oneto et al. [19].

Figure 6

Synovial fluid analysis before and after PRP treatment of patients with CHS. (A,B) Synovial fluid samples were spread on glass coverslips, fixed, and stained with Giemsa. Images were obtained by optical microscopy in different fields of slides and represent the cellular composition (black arrows) of synovial fluid from the same patient before and after 6 months of PRP treatment (magnification 400X, scale bar 20 μm). (C) Converted MeHb (g/dL) was calculated based on the concentration of stock buffered Hb solution quantified using a hematology analyzer (n = 7, * p < 0.05, ** p < 0.01, *** p < 0.001 vs. saline). As shown in Caviglia et al. [20].