Umbilical Cord Blood: An Alternate Source of Stem Cells

Susan Parker

Advisor: David Fahringer PA-C

University of Kentucky

College of Health Sciences

Physician Assistant Program

Objectives

Understand the process of stem cell transplants

Discuss methods of retrieval of stem cells Learn benefits and disadvantages of using

umbilical cord stem cells Discuss ethical concerns surrounding

umbilical cord blood use

Stem Cell Transplants Stem cell transplants are indicated for hematopoietic

malignancies, bone marrow failure syndromes, and genetic immunodifiecient disorders.

When a patient needs a stem cell transplant, a suitable donor must be found.

Immune ablation, to reduce GVHD risk, is administered under intense medical supervision in a sterile environment.

The patient’s recovery begins with an extremely weak and vulnerable immune system with a wide range of complications and opportunistic infection risk.

Stem Cell Transplants (cont’d) 6 human leukocyte antigens (HLAs) need to be matched

between donor and recipient to improve post-transplant prognosis

Only 30% of patients will have the ideal situation: related donor with all six HLA matches

If no suitable related donor, the process of searching the National Marrow Donor Program (NMDP) begins.

Currently, there are two sources of stem cells available to patients, bone marrow derived and umbilical cord derived stem cells.

Your Chances of Finding a Donor

10 million registered BM donors worldwide Caucasion has a 50% chance of finding a

donor Minorities are lower, donor programs

targeting subpopulations to increase diversity of donor pool.

Basically, <50% chance of finding a donor under any circumstance.

Bone Marrow Stem Cells

Standard stem cell source for over 40 years Obtained by bone marrow aspiration of the

pelvis of donor Relatively no risk to donor other than pain

(no anesthetics used) From beginning search to actual transplant

takes 3-5 months

Umbilical Cord Stem Cells

First successful transplant in 1988 Relatively low risk to mother and baby Beginning search to transplant in as few as

21 days

Umbilical Cord Collection

Collected after delivery of baby, before delivery of placenta

Contraindicated in moderate-high risk births

Collected under aseptic techniques and stored at -80F

Umbilical Cord Retrieval

Benefits of UCSC over BMSC

Decreased transplant time No chance of donor having acquired disease,

infection, nor the possibility of donor declining procedure

Increased diversity of donor pool, much higher rates of minority donation

UCSC have acceptable mortality rates with 4/6 HLA matches

Faster neutrophil engraftment (lower chance of engraftment)

Best prognoses seen in pediatric patients Non-myeloblative immune destruction has better

outcome with UCSC transplant

Drawbacks of UCSC Longer time to immune system recovery

due to immaturity of cells Leads to increased GVHD and infection

risk (but diseases less severe than with BM) Less effective for adults Cell dose of one sample usually inadequate

for patients with increased body mass Possible unknown genetic conditions of

newborn donor

The Bottom Line Chance of engraftment similar between BM and

UC Decreased severity of complications with UC Pooling of two or more UC samples has promising

results, ex-vivo expansion of cells being researched

Collecting cord blood has variable results due to technique and delivery complications

Best outcome is still with 6/6 HLA matched related bone marrow donor

UC contains mesenchymal stem cells that have shown promise in becoming various types of tissues: neural, cardiac, hepatic, renal, etc.

Ethics of Using UCSC

Alturistic donation – no cost to donor, increased attention to minorities, LOTS of paperwork and stipulations

Private donation - $1500 + $150/month with no guarantee of successful collection or storage

Recommendations for families with known genetic and inherited disorders

Pressure on families during an already stressful life event Targeting middle and upper class mothers and

obstetricians in wealthy areas Not available to all women in all areas

Private Cord Banking: Advertisement

http://www.cryo-cell.com/video_center/angelvision/index.asp

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3786-91 Barker, 2003, J., Weisdorf, D., et al. Rapid and complete donor chimerism in adult recipients of

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Bieback, 2004, K., Kern, S., Kluter, H., Eichler, H. Critical parameters for the isolation of mesenchymal stem cells from umbilical cord blood. Stem Cells. 2004; 22: 625-634.

Fisk, 2005, N., Roberts, I., Markwald, R., Mironov, V. Can Routine Commercial Cord Blood Banking Be Scientifically and Ethically Justified? PloS Medicine. 2005 February;

2(2): 44- 47. Laughlin, 2005, M., Giralt, S., Spitzer, T. Umbilical Cord Blood Transplantation: A New Alternative

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O’Brien, 2006, T., Tiedemann, K., Vowels, M. No longer a biological waste product: umbilical cord blood. MJA. 2006 April; 184(8): 407-410.

Tuch, 2006, B. Stem Cells: A Clinical Update. Family Physician. 2006; 35: 719-721. Wang, 2005, F., Huang, X., Zhang, Y., Chen, Y., Lu, D. Successful transplantation of double unit

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