Knee OA · high-inflammatory phenotype
PRP + Protein-Rich Plasma.
An autologous combination protocol, concentrated PRP plus a plasma-protein fraction enriched for α2-macroglobulin (A2M) and fibrinogen, for selected mild-to-moderate knee OA patients with a high-inflammatory profile.
PRP + PROTEIN
What is PRP + Protein?
Standard PRP delivers concentrated platelets and growth factors. The protein-rich plasma (PRP-PRP) fraction is concentrated from your own plasma to enrich for α2-macroglobulin, fibrinogen, and other plasma proteins.
The combined injectate aims to address both the biologic signaling side of OA (PRP component) and the protease-driven cartilage degradation side (A2M-rich PPP), particularly in patients whose OA phenotype is more inflammatory than mechanical.
Autologous PRP
From your blood · two-spin · Lp-PRP
Leukocyte-poor PRP, prepared in our on-site lab. Concentrated platelets deliver growth factors and signaling proteins that recruit endogenous repair processes and modulate local inflammation.
Protein-Rich Plasma fraction
From your PPP · ultrafiltration · A2M-concentrated
Platelet-poor plasma processed through ultrafiltration to concentrate large-molecular-weight plasma proteins, most notably alpha-2-macroglobulin, a broad-spectrum protease inhibitor relevant to cartilage breakdown in OA.
Regulatory Disclosure
PRP and plasma-derived protein concentrates are autologous blood products. These products are not approved by the U.S. Food and Drug Administration (FDA) as drugs or biologics for the treatment of osteoarthritis. Clinical use is based on physician judgment, current evidence, and individualized patient evaluation. No outcomes can be guaranteed.
The procedure
What to expect during a visit
Both fractions are prepared from the same venous draw. The procedure takes about 2 hours, mostly lab processing time.
Intake & screening
Patient selection screens for autoimmune arthritis and confirms inflammatory phenotype.
Blood collection
Single venous draw into anticoagulated tubes; volume sized for both PRP and protein fractions.
PRP preparation
Two-spin centrifugation produces Lp-PRP from the cellular fraction.
Protein concentration
Platelet-poor plasma undergoes ultrafiltration to concentrate A2M-rich protein fraction.
Image-guided delivery
Combined PRP + protein fraction delivered intra-articularly under ultrasound guidance.
Why α2-macroglobulin matters
How α2-macroglobulin protects cartilage.
In OA, the cartilage extracellular matrix is degraded by matrix metalloproteinases (MMPs) and ADAMTS proteases activated by local inflammation. The catabolic environment outpaces the chondrocytes' anabolic response and the joint surface progressively loses material.
α2-Macroglobulin is a 720 kDa plasma protein that acts as a broad-spectrum protease inhibitor, trapping and neutralizing MMPs, ADAMTS-4, ADAMTS-5, and other catabolic enzymes implicated in cartilage breakdown. Concentrating it from your own plasma may shift the local balance away from net catabolism, especially in inflammatory OA phenotypes.
Wang et al. (2014) demonstrated A2M's protective effect against cartilage degradation in rat OA models. Clinical evidence in humans is emerging.
Is this you?
When PRP + Protein is the right protocol.
This isn't a default OA protocol, patient selection is deliberate. We screen for autoimmune arthritis and lean toward this approach when the OA phenotype reads as inflammatory rather than mechanical.
✓ Likely a fit
- Mild-to-moderate knee OA (K-L grade 2–3) with inflammatory features
- Elevated synovitis on MRI or clinical exam
- Symptoms despite PT, activity modification, and conservative care
- Cleared for autoimmune arthritis (RA, gout, psoriatic) by labs/exam
- Realistic expectations: meaningful response over 3–4 months
Frequently asked
PRP + Protein-Rich Plasma, in clinical depth.
How is this different from PRP alone or PRP + HA? +
Standard PRP delivers biologic signaling. PRP+HA adds mechanical viscosupplementation. PRP+Protein adds a protease-inhibition mechanism via concentrated α2-macroglobulin, targeting the enzymatic side of cartilage breakdown. Each is appropriate for a different OA phenotype.
Why screen for autoimmune arthritis first? +
Autoimmune arthritides (rheumatoid, psoriatic, gout) are not osteoarthritis: they have different pathophysiology and require different management. Misidentifying them as OA can delay appropriate disease-modifying therapy. Screening with appropriate labs and clinical assessment is a deliberate guard-rail in our protocol.
What does α2-macroglobulin actually do? +
A2M is a 720 kDa plasma protein that acts as a broad-spectrum protease inhibitor: it traps and neutralizes MMPs, ADAMTSs, and other enzymes that break down cartilage in OA. By concentrating it from your own plasma and delivering it intra-articularly, we aim to shift the local balance toward less net cartilage degradation.
How long until I know if it's working? +
Plan for a 3–4 month assessment window. Symptoms typically improve gradually; we follow-up functionally at 6 and 12 weeks and do a comprehensive reassessment at 3–4 months. Response is variable and depends on phenotype, severity, and adherence to post-procedure guidance.
Does insurance cover this? +
No. Both the PRP and protein-fraction components are considered investigational/not medically necessary by most insurers and are out-of-pocket. We provide transparent pricing during consultation and supply documentation for HSA/FSA reimbursement where applicable.
Related therapies
Other paths for knee OA.
Schedule a knee OA consultation
Find out if this combination fits your knee.
Dr. Glowney reviews your imaging, labs, and OA phenotype, and recommends the protocol most likely to help. Sometimes that's this combination; sometimes it's plain PRP, BMAC, or a different path entirely.
Or call 720-550-6175