Leukocyte rich PRP keeps more white blood cells

The clinic separates blood into layers for PRP

The clinic puts some blood into a machine that spins it into layers. Staff collect a platelet-heavy layer. Their choice of layer sets how many white blood cells remain.

A rich mixture keeps more white blood cells. A poor mixture leaves most of them out. Rich and poor only describe the white-cell amount. The words don't rank the quality of care.

Ask whether the planned PRP is rich or poor in white blood cells so you know what is planned.

Joints and tendons may call for different mixtures

Knee studies have often favored PRP with fewer white blood cells. Some tendon studies have used PRP with more white blood cells. Neither finding proves that one mixture fits every body part. A knee joint and an elbow tendon do different jobs.

The injury also matters. Long-term joint wear differs from a new tendon tear. Tell the doctor how long your ache has lasted and whether strength has changed.

The doctor considers the white-cell amount when choosing a PRP mixture for the sore tissue.

A clear visit ends with a clear answer

Ask how the clinic will prepare the PRP and why that mixture suits the joint or tendon. The doctor can name the sore tissue and its likely cause. The visit should also cover expected soreness, price, and care during the first days.

You don't need a lesson about the machine. Write down regular medicines and earlier care. Name one daily task that now hurts. It may be walking to the mailbox, lifting a pan, or sleeping on one side.

After examining the sore tissue, the doctor can tell you whether PRP is reasonable.

Sources

1. In a controlled laboratory study, blood from five healthy donors was processed through three commercial PRP systems (MTF Cascade, Arteriocyte Magellan, Biomet GPS III). Platelet, red-cell and TGF-beta1 concentrations did not differ significantly between systems, but white-cell counts and PDGF-alpha-beta, PDGF-beta-beta and VEGF concentrations differed significantly across all three. Cascade produced leukocyte-poor PRP while GPS III and Magellan produced leukocyte-rich PRP with correspondingly higher white cells and growth factors.

   Castillo TN, Pouliot MA, Kim HJ, et al. — Comparison of growth factor and platelet concentration from commercial platelet-rich plasma separation systems. American Journal of Sports Medicine, 2011. DOI: 10.1177/0363546510387517.

2. Three healthy adults each donated 181 mL of blood which was processed through four commercial PRP kits (GPS III, Smart-Prep2, Magellan, ACP). The three kits that draw from the buffy-coat layer produced platelet concentrations 3-6 times baseline and white-cell concentrations 3-6 times baseline; the one kit drawing from plasma produced platelet concentrations only 1.5 times baseline. The authors concluded that the lack of standardisation of PRP preparation has contributed, at least in part, to the varying clinical efficacy reported for PRP.

   Fitzpatrick J, Bulsara MK, McCrory PR, et al. — Analysis of Platelet-Rich Plasma Extraction: Variations in Platelet and Blood Components Between 4 Common Commercial Kits. Orthopaedic Journal of Sports Medicine, 2017. DOI: 10.1177/2325967116675272.

3. A systematic review of 105 clinical PRP studies in orthopaedics published 2006-2016 found that only 11 (10%) described the preparation protocol clearly enough for another investigator to repeat it, and only 17 (16%) reported any quantitative metric of the final PRP composition. The authors concluded that the current reporting of PRP preparation and composition does not allow the PRP products actually delivered to patients to be compared between studies.

   Chahla J, Cinque ME, Piuzzi NS, et al. — A Call for Standardization in Platelet-Rich Plasma Preparation Protocols and Composition Reporting: A Systematic Review of the Clinical Orthopaedic Literature. Journal of Bone and Joint Surgery (American), 2017. DOI: 10.2106/JBJS.16.01374.

4. A narrative review of PRP concluded that the literature suggests leukocyte-rich PRP is more beneficial in tendinopathies while pure (leukocyte-poor) PRP is more beneficial in cartilage pathology - but stated plainly that different PRP preparations have not been directly compared head-to-head in ANY pathology, and that the PRP type used is frequently not even stated in published research.

   Collins T, Alexander D, Barkatali B — Platelet-rich plasma: a narrative review. EFORT Open Reviews, 2021. DOI: 10.1302/2058-5241.6.200017.

5. The American Academy of Physical Medicine and Rehabilitation convened a technical expert panel that ran a structured literature review (2023, updated through June 2025) and a modified Delphi process, and issued five evidence-based clinical recommendations plus 11 consensus-based best practices for PRP in knee osteoarthritis. The statement is explicit that orthobiologic therapies 'remain an evolving area of practice' and that robust, dose-dependent randomized controlled trials are still needed to establish PRP's clinical effects.

   Borg-Stein J, Jayaram P, Colorado BS, et al. — AAPM&R guidance statement on platelet rich plasma for knee osteoarthritis. PM&R, 2026. DOI: 10.1002/pmrj.70144.