ND, United States
North Dakota does not have any state legislation around cord blood education, but their Dept. of Health has officially adopted the educational materials from Parent's Guide to Cord Blood Foundation.
- What are TNC, MNC, CD34+, and CFU, and why should I care?
These are all ways of counting cell types, and they tell you whether or not your cord blood collection has lots of stem cells and if they are healthy.
Stem cells happen to be Mono-Nuclear Cells or MNC: when you look at them under a microscope there is only one nucleus. Unfortunately, one of the most difficult aspects of stem cell biology is that you can't identify a stem cell just by looking at it. There are other types of blood cells which are also MNC, such as nucleated red blood cells. The only proof that a cell is a stem cell comes from how it behaves when it multiplies.
Scientists have worked for years to develop various chemical stains which have a high affinity for stem cells. The best known marker for blood-forming stem cells is that they test positive for CD34, a protein found on the surface of stem cells. But, CD34+ counts are not an accurate measure of stem cells: CD34+ results vary between labs, they can vary within a single lab, and only 1-2% of the MNC that have CD34+ are actually stem cells.
The Total Nucleated Cell count or TNC is the test most often reported as a measure of the cell count after cord blood processing. The main advantage of measuring TNC is that the count is highly reproducible within and among labs, so it can be used accurately throughout the blood banking community. Even better, the TNC count can be automated with the use of a device called a flow cytometer.
At present Colony Forming Units or CFU are considered to be the best measure of whether stem cells are "viable", or quite frankly alive. The TNC count includes both living and dead cells. In the CFU test a small portion is watched under controlled conditions to see if stem cells divide and form colonies. This used to be a subjective measure, but recently it has been standardized with technology to image the cells and count colonies in the image. The only remaining problem with the test is that it takes days for colonies to grow.
- Why is it important to ship cord blood with a special courier?
The Parent's Guide to Cord Blood Foundation recommends shipping with a courier that has a division specializing in "Life Sciences" transport. This helps to insure that your critical shipment is not misplaced, arrives promptly, and is maintained within the acceptable temperature range during transport from the hospital to the lab.
The first priority for parents to consider is the cord blood shipping time: Once the cord blood is harvested, the blood cells and stem cells gradually begin to die. Public cord blood banks set a limit of 48 hours on the time between birth and processing the blood for cryogenic storage. It would be a "best practice" if family banks also followed the 48 hour window.
The second priority for parents to consider is the cord blood shipping temperature: The standard procedure for transporting fresh cord blood is to keep it within an ambient temperature range of 15 °C (59 °F) to 25 °C (77 °F). Priority shipping services may guarantee the arrival time, but not the temperature conditions during transit. The cord blood might get too hot or too cold while sitting in the back of a truck, on a loading dock, or in the cargo hold of an airplane. A specialty courier with Life Sciences expertise will carry the cord blood in a controlled environment.
Parents can improve the survival of their child's cells during transit to the cord blood laboratory by selecting a family bank that provides a well insulated shipping container and that provides a specialty courier who maintains the shipment within the desired temperature range. In many countries it is standard practice for the shipping container to have a temperature logger.
In the United States, the post 9/11 security requirements of the Transportation Security Administration (TSA) require that specialty couriers can only offer cord blood shipping through those cord blood banks that are registered with the TSA as a "Known Shipper". Before 9/11, specialty couriers could market their services directly to consumers, and in some countries this is still possible. Parents should check if a Family Bank offers specialty courier services before they sign a contract.
- Are related donors better for transplants?
The overall answer is yes, but this is a complex topic.
The two important measures of patient outcome are: long-term survival, and the impact on quality of life from graft-versus-host disease (GvHD). Sibling donors tend to trigger less GvHD. Also, sibling donors are available faster than searching for an unrelated donor, and patients have better survival when they go to transplant faster after diagnosis.
The exact comparison of outcome between sibling or unrelated donor varies with the patient diagnosis. The NMDP website has a page on this, with numerous references. For many cancers the outcomes are comparable, although sibling donors have a slight edge. The largest study was by Weisdorf et al. 2002, for over 2900 patients with CML leukemia. When correcting for all other factors, the survival with sibling donor vs unrelated donor was 68% vs. 61%. Sibling donors show a significant improvement for pediatric cord blood transplants of hereditary disorders. The European Blood and Marrow Transplantation Group (EBMT) reported 3 year survival rates of 95% from a sibling donor vs. 61% from an unrelated donor.
Weisdorf, D.J. et al. Blood 2002; 99:1971-1977.
Bizzetto, R. et al. (EBMT) Haematologica 2011; 96(01):134-141