What is the protocol for preparing endometrial Platelet-Rich Plasma (PRP)?

Endometrial PRP Preparation Protocol

Prepare endometrial PRP by collecting autologous blood in trisodium citrate anticoagulant, centrifuging at 170-200g for 10 minutes at room temperature, and infusing 0.5-1 mL of the platelet-rich supernatant into the uterine cavity, typically on day 10 of hormone replacement therapy. 1, 2

Blood Collection Requirements

• Collect autologous blood at the time of therapeutic application in a sterile clinical setting 3
• Use plastic collection tubes to prevent contact activation 4
• Anticoagulant selection is critical:
  • Use trisodium citrate as first choice (most widely used with minimal negative effects) 1, 3
  • Acceptable alternatives include ACD (acid citrate dextrose) or CPD (citrate phosphate dextrose), including ACD-A and CPD-A formulations 1, 3
  • Never use EDTA - it causes platelet swelling and premature activation 1, 4, 5
• Process blood within 1 hour of collection at room temperature 4, 5

Centrifugation Protocol

• Single low-speed centrifugation at 170-200g for 10 minutes at room temperature provides optimal platelet yield for endometrial applications 1, 4, 3
• This produces a relatively pure PRP preparation with good yield 3, 5
• Maintain room temperature throughout processing to avoid cold-induced platelet activation 4
• Collect the platelet-rich supernatant carefully, avoiding the buffy coat layer 1

Clinical Application for Endometrial Therapy

• Infuse 0.5-1 mL of prepared PRP directly into the uterine cavity 2
• Timing: Perform intrauterine infusion on day 10 of hormone replacement therapy cycle 2
• If endometrial thickness fails to increase after 72 hours, repeat PRP infusion 1-2 additional times in the same cycle 2
• Use freshly prepared PRP within 4 hours for optimal results 4, 5
• Do not store at 4°C as this may cause premature cold activation 4, 5

Activation Considerations

• For endometrial applications, activation may not be required prior to intrauterine infusion as the endometrial tissue itself may provide natural activation 1, 4
• If activation is used, document the specific method (calcium chloride, autologous thrombin, or collagen type I) 1, 4
• The activation procedure significantly impacts growth factor release kinetics 4

Quality Control Parameters

Document the following for each preparation: 1

• Volume of autologous blood collected 1
• Baseline platelet concentration in whole blood 1
• Final platelet concentration in PRP preparation 1
• Purity of preparation (contaminating RBCs and WBCs) 1
• Platelet activation status prior to clinical use 1

Common Pitfalls to Avoid

• Do not use pneumatic tube transport for blood samples - this significantly alters platelet function 1
• Avoid freeze-thaw cycles - use only fresh PRP for endometrial applications 2, 6
• Do not aspirate from the top surface of plasma where light platelets accumulate, nor disturb the buffy coat 1
• Never delay processing beyond 1 hour as this compromises platelet viability 4, 5

Clinical Context

• This protocol is specifically designed for thin endometrium (≤7 mm) refractory to standard hormone replacement therapy 2, 7
• PRP promotes endometrial growth through supraphysiologic concentrations of growth factors including VEGF, PDGF, TGF, and EGF 8, 9, 6
• The autologous nature minimizes risks of disease transmission and immunogenic reactions 6