Educational guide
Leukocyte-rich vs leukocyte-poor PRP
Whether a PRP preparation carries a high or low white-blood-cell fraction is one of the most debated variables in the field. The published literature has not settled it, and the major sources disagree. This page reports what those sources say and why a system that lets the physician select either profile is the practical hedge.
General background on the PRP class. Not a claim about any product sold on this site, not a recommendation for any protocol, and not a statement that any preparation treats any condition.
What the terms mean
A leukocyte-rich (LR) preparation retains a higher concentration of white blood cells, chiefly neutrophils. A leukocyte-poor (LP) preparation reduces that fraction. The distinction is separate from platelet concentration; a system can be high-platelet and either LR or LP depending on how the leukocyte layer is handled.
Different clinical settings have been argued to favor different profiles, which is why the answer is not one-size-fits-all and why the equipment decision matters.
What the literature reports
Five sources, five framings of the same question. Every cell is a report of what the cited source states.
| Source | Type and size | What it reports on LR vs LP |
|---|---|---|
| Riboh et al., AJSM 2016;44(3):792-800 | Network meta-analysis, 9 studies, 1,055 patients | Leukocyte-poor PRP produced better WOMAC scores than hyaluronic acid and placebo; leukocyte-rich did not show that difference. Adverse-reaction rates similar. |
| Abbas et al., JBJS Am 2022;104(6):559-570 | Network meta-analysis, 23 studies, 2,260 patients | No significant difference in outcome measures or local adverse reactions between LP-PRP and LR-PRP; leukocyte concentration does not play a significant role in patient-reported outcomes for knee OA. |
| AAOS Knee OA guideline, 3rd ed., 2021 | Clinical practice guideline | Determining the better choice between LR-PRP and LP-PRP is still inconclusive, but at this time appears to favor LR-PRP. PRP recommendation carries a Limited strength of recommendation. |
| Romandini et al., AJSM 2024;52(13):3212-3222 | Double-blind RCT, 12-month follow-up | Leukocytes did not affect the safety or efficacy of intra-articular PRP for knee OA; LR and LP comparable at all follow-up points, no difference in adverse events. |
| Fitzpatrick et al., AJSM 2017;45(1):226-233 | Meta-analysis of RCTs, tendinopathy | Good evidence to support a single injection of LR-PRP under ultrasound guidance in tendinopathy. Soft-tissue setting, not intra-articular. |
General literature on the PRP class, cited as background. Not outcome data for any product distributed by PRP Direct, and nothing here recommends a protocol or claims any preparation treats any condition. The AAOS statement reads: "Platelet-rich plasma (PRP) may reduce pain and improve function in patients with symptomatic osteoarthritis of the knee," at a Limited strength of recommendation.
The takeaway: buy the choice, not a fixed profile
When the literature disagrees with itself, the equipment should not make the call for you. A device with a fixed leukocyte profile has already decided for every case you will ever run on it. A device that lets the physician select a neutrophil-rich or neutrophil-poor preparation leaves the decision at the chair, and lets a practice change protocol without changing capital equipment. That matters most in a mixed book: joint work alongside tendon and soft-tissue cases, where the sources above point in different directions.
Emcyte reports that PurePRP SP produces either a neutrophil-rich or neutrophil-poor preparation from the same device, with the leukocyte fraction isolated inside the concentrating system so it can be retained or removed. That is a manufacturer-reported device capability. It describes what the device can produce, not how any preparation performs in a patient.
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Request a quotePRP Direct distributes 510(k)-cleared autologous blood-processing devices. Manufacturer specifications are not claims of clinical efficacy of the prepared biologic. This page is general education and is not medical advice; protocol and treatment decisions belong to a licensed clinician.