PRP subtypes classified by white-cell content, thought to alter clinical effect.
Platelet-rich plasma preparations differ in how many white blood cells they retain after centrifugation. Leukocyte-rich PRP (LR-PRP) keeps most of the neutrophils and other leukocytes from the drawn blood, which are thought to drive a stronger initial inflammatory and pro-catabolic signal. Leukocyte-poor PRP (LP-PRP) is processed to strip most of these cells out, producing a formulation with a comparatively milder inflammatory profile.
The leukocyte content is one of the few variables clinicians can reason about when choosing or interpreting a PRP product, since it plausibly affects how a joint or tendon responds to injection. It shapes conversations with patients and referrers about why one clinic's or supplier's PRP might behave differently from another's, and it's a factor worth asking about when a patient reports a prior PRP injection that flared or didn't help. It also matters when appraising research, since a trial's findings may not generalise across preparations with different leukocyte content.
In practice this is determined by the commercial separation system and protocol used (e.g. single- versus double-spin centrifugation, or specific kit chemistry), not by point-of-care testing in most clinics. Some systems report an approximate leukocyte concentration or fold-increase relative to whole blood, but this is rarely verified at the bedside. The hypothesised application split — leukocyte-poor for intra-articular use where inflammation may be less desirable, leukocyte-rich for tendinopathy where a stronger initial inflammatory stimulus is hypothesised to aid healing — is a common clinical heuristic rather than an established, evidence-based protocol.
Comparative clinical evidence between LR-PRP and LP-PRP remains limited, and many studies don't report leukocyte content at all, which makes cross-trial comparison and replication difficult. Terminology and thresholds for what counts as "rich" versus "poor" are not standardised across manufacturers, so two products both labelled LP-PRP may differ meaningfully in composition. Clinicians should avoid treating the tendon-versus-joint targeting rule as settled practice and should be cautious extrapolating efficacy claims from one preparation type to another.
This guide was auto-drafted and is pending editorial review.