Matrix Metalloproteinase Content and Activity in Low-Platelet, Low-Leukocyte and High-Platelet, High-Leukocyte Platelet Rich Plasma (PRP) and the Biologic Response to PRP by Human Ligament Fibroblasts

Abstract

The results of this study demonstrate that PRP therapy delivers ng/mL-range concentrations of catabolic proteases, which could perpetuate inflammation and inhibit tissue healing.

Biologic response of human anterior cruciate ligamentocytes on collagen‐patches to platelet‐rich plasma formulations with and without leucocytes

“…On the contrary, in vitro studies show that the lowest tested PRP concentration, which was 1× PRP and 0.5 × 10 6 platelets per microliter had the highest proliferation rate. In our sample, both protocols yielded a 4× PRP concentration similar to studies using the same protocols . After dilution to 0.1× and 0.8× metabolic cellular activity and DNA content increased in all groups except the negative control but in the 0.1× group ECM decreased over time.…”

“…In our sample, both protocols yielded a 4Â PRP concentration similar to studies using the same protocols. 5,14 After dilution to 0.1Â and 0.8Â metabolic cellular activity and DNA content increased in all groups except the negative control but in the 0.1Â group ECM decreased over time. Since human muscle, bone and tendon cells, although all part of the musculoskeletal system, react very differently to PRP, 15 it is assumed that each cell type has a different optimal concentration and in the case of LCs lower doses of platelets are effective.…”

Effect of intralesional platelet-rich plasma (PRP) treatment on clinical and ultrasonographic parameters in equine naturally occurring superficial digital flexor tendinopathies – a randomized prospective controlled clinical trial

“…MMPs and IL-1, that may influence tendon healing negatively [27, 73, 74], so that a low leucocyte content seems to be preferable to enhance anabolic effects during tendon healing.…”

PRP in OA knee – update, current confusions and future options

“…We raised our concern regarding this previously [25]. The initial hypothesis that leucocytes could be proinflammatory inside the joint (due to supposed deleterious effects of proteases and reactive oxygen species released from white cells) has been subsequently corroborated.Pifer et al [26] showed in an in vivo study that PRP with leucocytes contains MMP-2, -3 and -9, which is released over a period of at least six days, and can be deleterious.Braun et al [27] compared the effects of leucocyte-rich PRP (LR-PRP), leucocyte-poor PRP (LP-PRP), red blood cell (RBC) concentrate and platelet-poor plasma (PPP) and concluded that “Treatment of synovial cells with LR-PRP and RBCs resulted in significant cell death and proinflammatory mediator production”.Dragoo et al [28], in a rabbit study, showed that the (LR-PRP) group had more undesirable side effects owing to greater inflammatory reactions following injection at the lesion site than at the LP-PRP group.Filardo et al [29] – These authors were the only ones to conduct a clinical trial comparing two different PRP preparations: high-concentrate leucocyte-rich PRP versus low concentrate leucocyte-free PRP. They treated 144 patients and evaluated up to 12 months and comparable positive results were obtained in both treatments, with the only difference being that the PRP leucocyte group suffered from more swelling and pain reaction immediately after the injections.…”

“…Pifer et al [26] showed in an in vivo study that PRP with leucocytes contains MMP-2, -3 and -9, which is released over a period of at least six days, and can be deleterious.…”