Investigation performed at the Department of Orthopedic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Am J Sports Med. 2020 Apr;48(5):1189-1199. doi: 10.1177/0363546520906142. Epub 2020 Mar 5.
Tendinopathy is still a great challenge in clinical practice, and the role of platelet-rich plasma (PRP) is controversial. The influence of leukocytes on tendinopathy at an early stage has not been defined so far.
To compare the effects of leukocyte-rich PRP (Lr-PRP) and leukocyte-poor PRP (Lp-PRP) on Achilles tendinopathy when applied at an early stage.
Controlled laboratory study.
A rabbit Achilles tendinopathy model was induced by a collagenase injection. A week later, treatments were applied randomly on local Achilles tendon lesions: (1) 200 μL of Lr-PRP (16 legs), (2) 200 μL of Lp-PRP (16 legs), and (3) 200 μL of saline (16 legs). At 3 and 6 weeks after the collagenase injection, outcomes were evaluated by histology, magnetic resonance imaging (MRI), real-time polymerase chain reaction analysis, immunohistochemistry, and transmission electron microscopy (TEM).
The Lr-PRP group had a lower T2 signal intensity ( = .0377) and smaller diameter ( = .0193) and cross-sectional area ( = .0194) than the Lp-PRP group on MRI. Histologically, the Lr-PRP group had better scores than the Lp-PRP group ( = .0284 and = .0188, respectively). Compared with the Lp-PRP group, higher gene expression and more protein synthesis of collagen I ( = .0160 and = .0309, respectively) and CD163 ( < .0001 and = .0411, respectively) were found in the Lr-PRP group. Considering TEM and biomechanical testing, the Lr-PRP group demonstrated more mature collagen fibers ( < .0001), a larger fiber diameter ( = .0005), a higher failure load ( = .00417), and higher tensile stress ( < .0001) than the Lp-PRP group.
Lr-PRP had more beneficial effects than Lp-PRP when delivered at an early stage during tendon repair.
Here, we showed that tendinopathy influenced the curative effects of PRP in vivo. An early-stage application of Lr-PRP had more benefits for the repair of tendinopathy than Lp-PRP in a rabbit model, which will supplement guidelines of PRP treatment on tendinopathy clinically.
腱病仍然是临床实践中的一大挑战，而富血小板血浆（PRP）的作用仍存在争议。白细胞对早期腱病的影响目前尚未明确。
比较富含白细胞的 PRP（Lr-PRP）和贫白细胞 PRP（Lp-PRP）在早期应用于跟腱病时的效果。
对照实验室研究。
通过胶原酶注射诱导兔跟腱病模型。1 周后，将以下治疗方法随机应用于局部跟腱病变：（1）200 μL Lr-PRP（16 条腿），（2）200 μL Lp-PRP（16 条腿），和（3）200 μL 生理盐水（16 条腿）。在胶原酶注射后 3 周和 6 周，通过组织学、磁共振成像（MRI）、实时聚合酶链反应分析、免疫组织化学和透射电子显微镜（TEM）评估结果。
与 Lp-PRP 组相比，Lr-PRP 组的 T2 信号强度较低（ =.0377），直径（ =.0193）和横截面积（ =.0194）较小。组织学上，Lr-PRP 组的评分优于 Lp-PRP 组（ =.0284 和 =.0188，分别）。与 Lp-PRP 组相比，Lr-PRP 组中胶原蛋白 I 的基因表达和蛋白合成更高（ =.0160 和 =.0309，分别），CD163 更高（ <.0001 和 =.0411，分别）。考虑到 TEM 和生物力学测试，Lr-PRP 组的胶原纤维更成熟（ <.0001），纤维直径更大（ =.0005），断裂负荷更高（ =.00417），拉伸应力更高（ <.0001）。
在腱修复过程中，早期应用 Lr-PRP 比应用 Lp-PRP 更有益。
本研究表明腱病会影响体内 PRP 的治疗效果。在兔模型中，早期应用 Lr-PRP 比 Lp-PRP 更有利于腱病的修复，这将为临床上 PRP 治疗腱病提供补充指南。
