Ch 4 PRP

Question 1

What is regenerative medicine?

RRR, goals (3)

Answer 1

interdisciplinary field of research and clinical therapy

focused on repair, replacement, or regeneration of cells, tissues, and organs

goals
restoring structure and function to the affected tissue or organ

reduction of inflammation and pain

improved healing of injured tissues

inc stem cell, Gene therapy, PRP

Question 2

when analysed in the context of RCT, a clear positive effect for platelet-rich plasma becomes less apparent

Answer 2

case series without control groups, involve relatively low sample sizes, are underpowered, and exhibit enrollment bias

Question 3

what is PRP

how much higher?

Answer 3

plasma fraction of
autologous blood with a concentration of platelets and growth factors/cytokines that is higher than baseline

At least 3-5 times higher

Question 4

How does PRP act?

Answer 4

proliferation of MSC and fibroblasts

TGF-B > collagen type 1 production in tendons

Question 5

Platelet role

promote (6)

Answer 5

hemostasis and wound healing

alpha granules > growth factors and cytokines

promote:
1.cell recruitment
2. cell migration,
3. cell proliferation,
4. angiogenesis
5. osteogenesis
6. recruit, stimulate, and provide a scaffold for stem cells

Question 6

what cytokines and GF platelets have? (9)

Answer 6

platelet-derived growth factor (PDGF)

transforming growth factor (TGF-a), (TGF-b)

vascular endothelial growth factor (VEGF),

fibroblastic growth factor (bFGF),

epidermal growth factor (EGF)

connective tissue growth factor (CTGF),

insulin-like growth factor (IGF),

hepatocyte growth factor (HGF),

keratinocyte growth factor
(KGF)

Question 7

what does PDGF do?

Answer 7

Mitogenic for mesenchymal cells and osteoblasts.

Stimulates chemotaxis pf WBC and fibroblasts

Question 8

TGF-a, TGF-b

Answer 8

Stimulates undifferentiated mesenchymal cell proliferation.

Regulates endothelial, fibroblastic, and osteoblastic mitogenesis

Regulates collagen synthesis and collagenase secretion

Question 9

TNF

Answer 9

Regulates monocyte migration, fibroblast proliferation,
macrophage activation

angiogenesis.

Question 10

VEGF

Answer 10

Stimulates angiogenesis and mitogenesis for endothelial cells

Question 11

FGF

Answer 11

Promotes growth and differentiation of chondrocytes and osteoblasts.
Mitogenic for mesenchymal cells,

Question 12

IGF - 1

Answer 12

Chemotactic for fibroblasts and promotes protein synthesis

Question 13

What else does PRP contain?PRP for wound healing

Answer 13

Clotting factors
Plasma proteins
antibacterial and fungicidal effects
membrane glycoproteins (influence inflammation)
800 unique proteins

Depending on prep > leukocyte- and platelet-rich plasma (L-PRP)

Question 14

reasons fo variability in product? (6)

Answer 14

Individual donor variability

concurrent drug therapy

coagulation state

venipuncture technique

processing and isolation method

degree of platelet activation

Question 15

studies have demonstrated marked variability

major challenge for PRP therapy

Answer 15

Carr 2016
Canine platelet-rich plasma systems: a prospective analysis.
Front Vet Sci.

Franklin 2015
Characteristics of canine platelet-rich plasma prepared with five commercially available systems.
Am J Vet Res.

Question 16

OA

recent studies > PRP seems to be beneficial in dogs with OA

Answer 16

alpha granules > modulate inflammation and promote tissue healing

treated with a single injection of
PRP may have improvement in validated client survey results and subjective pain
and gait scores as well as objective kinetic gait

ihibit nuclear factor κB and decrease expression of cyclooxygenase-2, which are both important mediators of the inflammatory component of osteoarthritis.

Question 16

wound healing

4 functions

Answer 16

people and dogs

promotes wound epithelialization,

reduces scar formation,

exhibits antimicrobial activity,

stimulates angiogenesis

Question 17

moderate (2–3x) and high (4–6x) platelet concentrations are
beneficial for soft tissue and bone healing

Answer 17

still no consensus on the ideal platelet concentration for specific applications.

Question 18

Multiple studies have investigated the compositional differences of commercially available
PRP systems, but there is still no overall consensus on optimal component
concentrations

Answer 18

Franklin 2015
Characteristics of canine platelet-rich plasma prepared with five commercially available systems. Am J Vet Res

Question 19

crucial to deliver PRP directly to the site of tissue injury for it to be most effective;
therefore, appropriate intra-articular injection technique and ultrasound-guided soft
tissue injection techniques are crucial for success

Answer 19

Venator 2020 (12 dogs, clinical)
Assessment of a Single Intra-Articular
Stifle Injection of Pure Platelet Rich Plasma on Symmetry Indices in Dogs with Unilateral or Bilateral Stifle Osteoarthritis from Long-Term Medically Managed CCL Disease. Vet Med (Auckl)

Ho 2015
Single ultrasound-guided platelet-rich
plasma injection for treatment of supraspinatus tendinopathy in dogs. Can Vet J

Question 20

Alves 2021

Answer 20

dogs with moderate and severe osteoarthritis
that were treated with 2 intra-articular injections of PRP 14 days apart found that
the PRP group had significantly better clinical metrology instruments than saline control
group at multiple time points, some up to 180 days

Question 21

CCL

venator 2020

Answer 21

CCL injury and have also
shown that PRP has beneficial effects in improving pain, lameness, effusion, and/or
overall inflammation within the stifle

6 dogs > ACP-treated knees showed evidence of ACL repair and less severe synovitis.

experimental and clinical studies

Question 22

soft tissue injury

still limited evidence available

Answer 22

Tendons and ligaments > poor self-repair capability.
Histologic > tendinosis is not an acute inflammatory condition, failure of normal tendon repair mechanism

shown to have a beneficial immunomodulatory effect on tenocytes to stimulate
the secretion of angiogenic proteins in injured tenocytes

Question 23

Ho 2015

Answer 23

canine study showed that dogs with supraspinatus
tendinopathy treated with a single PRP ultrasound-guided injection had subjective
improvement in lameness and function in 40% of dogs with improved tendon fiber
pattern and in 60% of dogs with improved tendon echogenicity 6 weeks following
treatment.46

Question 24

How is PRP osteopromotive?

Chondropromotive?

augment bone grafts

Answer 24

Stimulates the production of osteoclast-like cells
Platelets contain a number of grwoth factors to initiate bone healing - PDGF, TGF-B, VEGF, BMP
Chondro:
- Significant increased in chondrocyte proliferation and celular accumulation of GAGs and collagen tpe 2 in porcine chondrocytes with platelet lysate

Question 25

List 2 contraindications of PRP treatment

Answer 25

Thrombocytopaenia
Coagulation defects

Question 26

in the human
literature it has been proposed that platelet concentration greater than 6x baseline
(or >1800 x 103 platelets/m) may be detrimental and lead to cellular apoptosis

Answer 26

Most recent studies agree that it is best to reduce RBC in PRP as they have been
shown to have a deleterious inflammatory effect.

Question 27

limitations (3)

Answer 27

Deficits in basic science research,

inherent variability in “product” due to discrepancies between donors and preparation systems

inability to completely assess individual platelet-rich plasma samples prior to clinical application

Question 28

soft tissue and bone repair is a temporally complex series of interactions between the injured tissue composed of a diverse population of cells and a dynamic extracellular matrix, recruited leukocytes, and an untold number of growth factors and cytokines.

As such, the ideal platelet number, growth factor concentration, and proper delivery timeline necessary to successfully treat specific diseases remain unknown

Answer 28

ome studies report outcomes after single injections of platelet-rich plasma,25,67,74,92 whereas others have utilized a series of platelet-rich plasma injections.87 Due to differences in preparation systems and dosing regimens, it is difficult to collectively make comparisons and draw conclusions regarding the ideal dosing schedule from these studies.