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Cord Blood Collection and Banking: Overview and Efforts to Minimize
Microbial Contamination
John P. Miller, M.D., Ph.D.
VP and Senior Medical Director, NMDP
May, 2009
Background: Cord Blood Banking and Transplantation
• Recruitment: prenatal or at L&D suite
• Collection: in utero or ex utero
• Processing: manual or automated
plasma depletion +/- RBC depletion
• Cryopreservation: 6%HES/10% DMSO
• Storage: liquid or vapor phase of LN2
• Transport: Dry Shipper -196 to -150 C
• Thawing: with or without washing
• Infusion: ASAP
Cord Blood Recruitment and Collection
Collection Set-up and PreparationEx Utero
Venipuncture and Completing the Collection
Final Product
Steps in cord blood processing
• Receipt, inspection• Initial sampling: TNC, ABO/Rh• Centrifuge soft spin: sedimentation of RBCs with
HES• Hard spin to concentrate HPCs• Product analysis: TNC, viability, culture, CD34, CFU• Cryopreservation• Distribution/shipping• Thawing and washing• Infusing
Cord blood receipt and inspection Rinse into transfer bag with HES
Inspection:Product intact, with no leaks clots or discoloration
Soft spin to pellet RBCsExpress “buffy coat” from RBC pellet
RBCs separated fromBuffy Coat and Plasma After Soft Spin
Hard spin to pellet RBCs and WBCsExpress cell poor plasma from RBC pellet
Transfer to Freezing Bag and Place in CBU Freezing Cassette
Controlled Rate Freezing and Storage in LN2
Potential Sources of Microbial Contamination of Cord Blood
• Cross-placental transmission• Contamination of cord or placenta during
delivery• Contamination during the collection
procedure
Procedures to Minimize the Risk of Microbial Contamination
Organizational level
• NMDP Standards• NMDP Participation Criteria• NMDP membership process• AABB and FACT Standards and
accreditation
Procedures to Minimize the Risk of Microbial Contamination
At the CBU level:
• Maternal health history screening for RCD• Maternal IDM testing for RCD• Review maternal prenatal and delivery history/exam for risk
of transmissible disease, e.g. chorioamnionitis, sepsis • Review of infant history and exam• Examination of cord and placenta, e.g. tears, infection• Preparation of cord for venipuncture• Aseptic Processing- one unit at a time• Time from delivery to cryopreservation• Bacterial and fungal cultures of final product prior to
cryopreservation• Post-discharge infant follow-up (bact and genetic)• Adverse event reporting and investigation
Procedures to Minimize the Risk of Microbial Contamination
Specific to Neisseria and Chlamydia: HHQ
Donor is eligible with history of treatment for chlamydia for either type of delivery
Microbial contamination:Literature Review
• Contamination of CBU occurs at 2-5%1-3
• Culture Method: BacT-Alert or Bactec, Culture NOS organisms include:– Staphylococcus sp.– Streptococcus sp., including enterococcus– Corynebacterium sp.– E. coli– Bacteroides fragilis
• No Neisseria gonorrhea or Chlamydia trachomatis
• 1Bertolini 1995, 2M-Reboredo 2000, 3Donaldson 2000
Microbial contamination:NMDP banks through March 2004
• 356 CBUs had positive cultures (0.7%, n=51,842)• Culture Method: BacT-Alert or Bactec• Common organisms include:
– Staphylococcus sp.– Streptococcus sp., including enterococcus– Corynebacterium sp.– Bacillus sp.– E. coli– Bacteroides fragilis– No ID Aerobes and Anaerobes– Mixed flora
• No Neisseria gonorrhea or Chlamydia trachomatis
Microbial contamination:NMDP banks through March 2004
33.0
11.3
11.5
17.28.5
6.2
4.8
4.8
2.8
Summary
• Steps to minimize bacterial contamination of CBUs include maternal and infant screening, IDM testing, examination of the cord and placenta, preparation for venipuncture, aseptic processing and culture
• Rates of cord blood bacterial contamination are lower than reported in the literature (about 0.7%)
• No cases of contamination with Neisseria or Chlamydia have been reported
Questions?
• ?????