Table 1.
Systems proposed for platelet-rich plasma classification in human regenerative medicine (2010–2020).
| Authors | Variables considered and additional commentaries | Classification system |
|---|---|---|
| DeLong et al. (59) | PAW system • Platelet (PLT) concentration (μL) • Method (exogenous or endogenous) of PLT activation (Ac) • Presence or absence of white blood cells (WBCs): including neutrophils. |
PLT concentration • P1: ≤ to baseline PLT concentrations • P2: >baseline concentrations to 750 × 103 PLT/μL • P3: >750 to 1,250 × 103 PLT/μL • P4: >1,250 × 103 PLT/μL. |
| Methods of PLT activation • Endogenously: no symbols • Exogenous activating (Ac): x. |
||
| WBC • Above (A) to baseline • Below/equal to (B) baseline • Neutrophils: α (above) (below) is added blood levels |
||
| Mishra et al. (63) | Sports medicine PRP classification. • WBC concentration • Activation (Ac): (–) no activation, (+) activation • PLT concentration: A (5x or >blood levels), B <5x blood levels. |
Type 1: WBC↑, Ac (–), A or B. Type 2: WBC↑, Ac (+), A or B. Type 3: WBC↓, Ac (–), A or B. Type 4: WBC↓, Ac (+), A or B. |
| Dohan Ehrenfest et al. (60) | Platelet concentrate classification. • WBC presence and concentration • Fibrin architecture. • Activation (Ac): intrinsic. • No anticoagulant. |
Pure PRP (P-PRP) – or leukocyte-poor PRP: products without WBCs and low-density fibrin network after Ac. Leukocyte and PRP (L-PRP) products: preparations with leukocytes and with a low-density fibrin network after Ac. Pure platelet-rich fibrin (P-PRF) – or Leukocyte- Poor PRF: products without WBCs and high-density fibrin network. Leukocyte- and PRF (L-PRF): products with leukocytes and high-density fibrin web. |
| Mautner et al. (62) | PLRA classification • PLT/μL • WBC/μL (including neutrophils) • Red blood cells (RBCs) • Activation (A) • Volume of PRP (ml) |
P:PLT count per μL |
| L: WBC • (–): <1% of neutrophils in WBC • (+): >1% of neutrophils in WBC |
||
| R: RBC/μL • (–): <1% of RBC in PRP • (+): >1% of RBC in PRP |
||
| A: Activation (No = –, Yes = +) | ||
| PRP injected volume (mL). | ||
| Magalon et al. (61) | DEPA classification • D: dose of injected PLTs/PRP-injected volume • E: % PLT recovered in the PRP. • P: purity of the PRP obtained (relative composition of PLTs, WBCs, and RBCs). • A: activation process. |
D: • (a) Very high dose of injected platelets: >5 billion • (b) High dose of injected platelets: 3 to 5 billion • (c) Medium dose of injected platelets: f 1 to 3 billion • (d) Low dose of injected platelets: <1 billion. |
| E: • (a) High efficiency: if the recovery rate in PLTs is >90% • (b) Medium efficiency: if the recovery rate in PLTs is between 70 and 90% • (c) Low efficiency: recovery rate of PLTs is between 30 and 70% • (d) Poor efficiency: recovery rate is <30% |
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| P: • (a) Very pure PRP: if the percentage of PLTs is >90% • (b) Pure PRP: between 0 and 90% of the PLTs • (c) Heterogeneous PRP: if the percentage of PLTs is between 30 and 70% • (d) Whole-blood PRP: if the percentage of PLTs in the PRP is <30% compared with RBCs and WBCs. |
||
| A: • Ac used for activating PRP. |
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| Kon et al. (65) | PRP coding system. • 6 digits grouped in pairs indicating parameters of PLT composition, purity and Ac: N1 N2 -N3 N4 -N5 N6. |
N1 & N2 indicate the PLT concentration of PRP. |
| N3 & N4 indicate the purity of the PRP, referring to the absence (0) or presence (1) of RBCs and the concentration of WBCs (0, 1, 2, 3.). | ||
| N5 and N6 refer to the activation. • N5 indicates if activation is endogenous (0) or if PRP is activated before its injection (1). • N6 mentions the addition of calcium for activation (0 = no, 1 = yes). |
PLT, platelet; WBC, white blood cell; Activation, Ac.