EmCyte VS RegenLab

Using an underdosed PRP can lead to lackluster and subclinical outcomes, misrepresenting the success of minimally-invasive and cost-effective treatments for patients who wish to delay or avoid surgery for a variety of reasons. Some patients don’t have the ability to take time off for surgery or prefer to avoid the risk of possible postoperative complications altogether; some are simply too young and active.  

For years, Plymouth Medical has sought to compare several PRP devices with independent cell count reviews in order to:

1) shed light on the inherent variability between commercially available kits demonstrating that not all PRP is the same and 

2) establish a better understanding of the cellular composition of therapeutic PRP for various indications. 

Here are a  couple of our comparisons linked below:

• EmCyte PurePRP vs Apex Xcell PRP

• Production of PRP from Different Devices for Aesthetic Purposes: Quality Control Analysis

In light of three recent JAMA publications painting a negative review of PRP (RegenLab) , this blog seeks to compare how RegenLab’s PRP kits (RegenKit-THT) stack up against EmCyte’s single and double spin PRP systems and discuss how a sufficient platelet dose can impact clinical results [1]. 

Platelet Dose

Cole et al. suggest the minimum requirement of clinically therapeutic PRP  must be concentrated at least 5X platelet baseline values [2]. A more recent RCT comparing PRP and HA for KL II-KL III knee OA patients recommended that at least 10 billion platelets must be delivered in a single 8 mL aliquot of PRP [3] for positive outcomes up to 1yr. 

• EmCyte’s PurePRP II double spin system: Provides over 10+ billion platelets in a PRP sample from a 60mL draw

• EmCyte’s AbsolutePRP single spin system: Provides 2.5-5 billion platelets depending on the draw volume.

• RegenLab: 0.49 billion platelets

• Total platelet dose comparison is included in the summary tables below.

Platelet Concentration (X-Factor)

Platelet concentration or X-Factor can only be used as a comparison measure between different PRP preparation systems and protocols as this calculation does not consider injectate volume and total dose of platelets delivered. It accounts for any natural variances in patient platelet baseline levels. For more information, check out our blog post: What is ‘X-Factor’ When Discussing PRP & Why Does it Matter?

• EmCyte’s PurePRP II double spin system: Provides  7X PLT concentration per the validated protocols regardless of blood draw

• EmCyte’s AbsolutePRP single spin system: Provides 2-3X PLT concentration per the validated protocol

• RegenLab: 0.7X PLT concentration [4].

  • In most instances, RegenLab PRP platelet content represents a depletion of platelets from whole blood levels as it doesn’t achieve the expected 2X concentration when producing 5 mL of PRP from 10 mL of whole blood.

• Total platelet concentration comparison is included in the summary tables below.

Kit Efficiency (Platelet Recovery %)

When comparing kits, it is important to look at how effective kits are at recovering platelets (%) from a whole blood sample.

• EmCyte’s PurePRP II double spin system: Recovers on average 78-81% of all platelets loaded in the system from whole blood

• EmCyte’s AbsolutePRP single spin system: Recovers 97% of platelets

• RegenLab recovers only 35% of platelets harvested into the vacutainer.

• Platelet recovery % comparison is included in the summary tables below.

Cost

Despite platelet recovery and purity being important clinically, we believe kit pricing is what mostly drives the adoption of test tube kits such as RegenLab, Eclipse, Selphyl,  and others. However, since these kits are not shown to be effective in recovering therapeutic platelet doses, one must look at the cost per billion platelets or the therapeutic cost of PRP rather than simply the kit price.

• EmCyte’s PurePRP II double spin systems cost per billion platelets averages $24.72 to $39.77

• EmCyte’s AbsolutePRP single spin system: $27.47

• RegenLab: cost of $200.00

• Cost per billion platelets comparison is included in the summary tables below.

Risks of Using an Underdosed PRP Formulation

Last year, the Journal of the American Medical Association (JAMA) published three studies regarding PRP treatment for various orthopedic conditions, leading to an editorial describing PRP as ineffective for knee osteoarthritis (OA), ankle OA, and Achilles tendinopathy [6]. This is unfortunate since the PRP products used in the studies were underdosed, not meeting the minimum requirement of what is considered PRP [2].

The RESTORE Knee OA trial used 3x weekly intra-articular injections of 5 mL of RegenLab PRP, performed under ultrasound guidance using a medial patellofemoral approach [1]. The paper describes the product ranging from 1.6-5X PLT concentration from whole blood platelet levels and is leukocyte poor [1]. Its summary of PRP Characteristics Based on Reporting Recommendations reports the mean platelet volume of their PRP as 325x106/mm3. One of their exclusion criteria is a whole blood platelet count of less than 150x106/mm3 [1]. At best, their PRP was concentrating platelets ~ 2X baseline levels, calculated from [PLT] of PRP / [PLT] of minimum enrolled whole blood.

RegenLab’s white paper data reports RegenLab PRP to perform worse, at 1.6X baseline whole blood platelet levels [4]. Bansal et al. published an RCT comparing PRP and HA for knee OA which recommended that at least 10 billion platelets must be delivered in a single 8 mL aliquot of PRP [3]. The RegenLab study would therefore have been severely underdosed at 1.63 Billion platelets in 5 mL of PRP [1].

It’s important to note that based on Bansal et al.’s multi-center RCT, treating knee OA with anything less than 10 billion platelets in an 8 mL sample or PRP may not result in clinically significant improvement at 1-year post-treatment. [3].  To achieve this PRP formulation, it is imperative that one:

• Harvests a large enough whole blood sample that contains enough platelets to supply the final PRP adequately with  over 10 billion platelets

• Uses an efficient PRP system with a high platelet recovery rate % so that enough platelets are transferred to the final PRP throughout processing

For clinics using a single-spin system such as the EmCyte AbolututePRP Gold, the final PRP may still be underdosed to gain good clinical results for knee OA (despite far superior performance over RegenLab’s system). We believe more studies are needed looking at clinical outcomes across various doses and injection frequency to establish dose-response curves.  One area to investigate may be treatment frequency and timing intervals of injections. This may elucidate if repeat injections of a medium dose (3-5Bn PLT) PRP may have the same positive clinical outcomes as a single, high-dose (10Bn PLT) PRP injection at 1year.  

EmCyte PRP (specifically the neutrophil-poor Protocol A preparation of the GS60 PurePRP II), consistently provides a 6-8X PRP and over 9-13 billion platelets in a 7 mL sample [7], [8]. This would satisfy the established consensus definition of PRP from a platelet concentration factor [2] and dose standpoint [3].  

Testing Data Sources:

EmCyte AbsolutePRP Gold 20 mL: Plymouth Medical Quality Control testing

EmCyte GS30-PURE-II - Mandle Comparison of EmCyte GS30 PurePRP II, EmCyte GS60 PurePRP II, Arteriocyte Magellan, Stryker RegenKit THT, and Eclipse PRP

EmCyte GS60-PURE-II - Report 515 Research Study - BSR Comparison of EmCyte PurePRP II 2015, Harvest/Terumo APC60/Clear PRP, and Arthrex Angel PRP Products

RegenLab RegenKit THT: Mandle Comparison of EmCyte GS30 PurePRP II, EmCyte GS60 PurePRP II, Arteriocyte Magellan, Stryker RegenKit THT, and Eclipse PRP

Citations

[1] Bennell, Kim L., et al. “Effect of Intra-Articular Platelet-Rich Plasma vs Placebo Injection on Pain and Medial Tibial Cartilage Volume in Patients with Knee Osteoarthritis.” JAMA, vol. 326, no. 20, 2021, p. 2021., https://doi.org/10.1001/jama.2021.19415. 

[2] Cole, Brian J., et al. “Platelet-Rich Plasma: Where Are We Now and Where Are We Going?” Sports Health: A Multidisciplinary Approach, vol. 2, no. 3, 2010, pp. 203–210., https://doi.org/10.1177/1941738110366385. 

[3] Bansal, Himanshu, et al. “Platelet-Rich Plasma (PRP) in Osteoarthritis (OA) Knee: Correct Dose Critical for Long Term Clinical Efficacy.” Scientific Reports, vol. 11, no. 1, 2021, https://doi.org/10.1038/s41598-021-83025-2. 

[4] “Regenkit A-PRP.” Regen Lab, 18 July 2022, https://www.regenlab.com/products/regenkit-a-prp-2/. 

[5] Magalon, J, et al. “Depa Classification: A Proposal for Standardising PRP Use and a Retrospective Application of Available Devices.” BMJ Open Sport & Exercise Medicine, vol. 2, no. 1, 2016, https://doi.org/10.1136/bmjsem-2015-000060. 

[6] Katz, Jeffrey N. “Platelet-Rich Plasma for Osteoarthritis and Achilles Tendinitis.” JAMA, vol. 326, no. 20, 2021, p. 2012., https://doi.org/10.1001/jama.2021.19540. 

[7] Mandle, Robert PhD. Research Study: Comparison of EmCyte GS30-PurePRP® II, EmCyte GS60-PurePRP® II, Arteriocyte MAGELLAN, Stryker REGENKIT®THT, and ECLIPSE PRP (2016)

[8] Mandle, Robert PhD. Comparisons of EmCyte PurePRP II, Harvest/Terumo APC60/Clear PRP, and Arthrex Angel PRP Products (2015)

09/17/22