Stem Cells

I have been asking what I think is a simple question but seem not to be able to get an answer.
In Stem Cell therapy they 'harvest' cells which have not 'differentiated' INTO the cells which the
Stem Cell Harvesters / scientists need / patients need.
The PRODUCTION of stem cells in the marrow is stimulated by a bleed.
If one has a bleed the body produces undifferentiated stem cells which THEN become the new cells which are LOST due to the bleed.
Now when one looks at that scenario WHY not simply bleed a person and then the stem cells can become the cells which the body needs.
Either the red blood cells .. the cardiac cells .. Multiple Sclerosis cells .. the Parkinson's cells .. etc .. ?
The NEED induced BY the bleed / blood cell reduction would cause an INCREASE of undifferentiated stem cells .. ?
I have asked that question in a few places and nobody can or will address it.

hiiiiiz dear ironjustice u can ask Andy about this thy have i diea about all this thnx for ur asking

ironjustice,

Much to your credit, nothing you have posted has been simple, and your question actually has a very complex answer, which has nothing to do with bleeding. I'm not familiar with non-thalassemia gene therapies and how they harvest stem cells, but bleeding would not be suitable for thalassemia, as the stem cell harvest from the marrow will always be too limited to be useful, unless a method is used to increase their production to much higher levels. The stem cell mobilization being used in the group led by Dr Sadelain is based on a stimulation using G-CSF (granulocyte colony-stimulating factor) to mobilize the CD34+ cells. With their most recent mobilization in three patients, sufficient quantities of stem cells have been mobilized that make the likelihood of success far higher. I have heard Dr Evangelia Yannaki describe this process at two different conferences, and honestly, it has been the most difficult material to understand. It is highly technical and there are variations that have been tested using hydroxyurea in both splenectomized and non-splenectomized patients. Hydroxyurea is used to try to limit the amount of white cells also produced.

The process of producing enough peripheral stem cells,finding the right vector or "vehicle" to deliver the treated stem cells and also preparing the patients for the transplants is an incredibly involved and complex process. In my opinion, the group led by Sadelain (who has no financial interest in any company that stands to profit from gene therapy) has best answered all the questions and appears posed to produce the best results. By the end of this year, we should have some real answers. The competition among the various groups working on gene therapy and even among the groups working together may be both good and bad, as it should lead to better processes coming out of the competition, but also the possibility is created that this competition is actually slowing down the process and preventing the sharing of results. Let's hope we can get a little more competition towards a common goal of finding a cure for thalassemia.

The process of producing enough peripheral stem cells,finding the right vector or "vehicle" to deliver the treated stem cells and also preparing the patients for the transplants is an incredibly involved and complex process.

That is why I mention the replacement OF these 'elaborate processes BY the body ITSELF producing the UNDIFFERENTIATED stem cells.
When one bleeds the body will produce the 'template' / undifferentiated stem cell / a stem cell which hasn't 'decided' WHAT to become / what is needed BY the body .. at this time.
When one is NOT producing these cells .. when we are NOT anemic / NOT low in iron THEN there are no stem cells at all TO decide whether or not to become ANYTHING because they are simply not there.
Normally being slightly anemic we are producing stem cells to replace the older red blood cells in the body.
WHEN one is in a state of too much iron THEN the body doesn't HAVE to constantly produce new red blood cells and therefore the undifferentiated cells which would BECOME these red blood cells are never or rarely produced .
The slow removal of blood over a period of time  where they removed 50ml of blood  as opposed to the more liberal removal of copious amounts of blood  may afford steady supply of the stem cells.
Imho ...

The slow removal of blood over a period of time 
where they removed 50ml of blood is also shown
to work in polycythemia.

Iron reduction therapy in hepatitis C
EDITOR,—Three papers in the July issue
report on the possible association between
iron and tissue damage in conditions other
than haemochromatosis. Tan et al (Gut
1997;41:14–18) found that gastric cancer
cells are more susceptible to photodynamic
therapy when iron is removed. Boucher et al
(Gut 1997;41:115–20) found that treatment
of hepatitis C with interferon leads to a
decrease in liver iron content. Bacon (Gut
1997;41:127–8) briefly commented on the
association between iron and hepatitis C,
including some evidence that iron depletion
may be beneficial in patients who fail to
respond to interferon á.
Shortly after Bacon et al’s pioneering
report in 1993 on iron reduction therapy in
hepatitis C,1 and mainly because of a lack of
any other option at the time, we started
applying this form of therapy in our growing
population of patients who had failed to
respond to interferon and who had the unfavourable
1b genotype.
The simplest and cheapest way to reduce
body iron stores is repeated drawing of one
unit of whole blood (as for haemochromatosis).
However, we encountered several unexpected
difficulties in our attempts to implement
a phlebotomy programme for patients
with chronic hepatitis C. A small group of
patients are reluctant to undergo repeated
phlebotomy because of ethnic or psychological
reasons (there is a belief that blood equals
life and therefore that blood loss depletes the
body of life giving power). A second group
cannot tolerate blood loss because of recurrent
episodes of faintness and presyncope.
These patients need several hours’ observation,
a chaperone, and sometimes intravenous
fluid before they can be discharged home. In
a third group venous access is a problem. The
large bore needles of standard phlebotomy
bags can be inserted into large straight veins
only. Most female and some male patients do
not have suitable veins and this problem
becomes more serious with age. This obstacle
can be overcome by improvisation with
smaller bore needles but this has the
disadvantage of slower flow, increased stasis
and coagulation within the tubing, sometimes
necessitating reinsertion of the iv line. A
fourth impediment in a busy gastroenterology/
hepatology department is lack of
enthusiasm among nursing staff and a shortage
of beds and space in the recovery room. It
also seems unwise to place patients with
chronic hepatitis C undergoing phlebotomy
and large quantities of potentially hazardous
blood alongside uninfected patients recovering
from endoscopy. This also limits the time
available for phlebotomy.
We devised a simple way to circumvent all
of these difficulties: all new patients with
chronic hepatitis C (unless they have an iron
deficiency) are shown a 50 ml syringe as early
as possible in their workup. They are told that
from now on they should ask for all blood
tests to be taken only with such syringes and
that any surplus blood should be discarded
with the syringe in the biohazard containers.
This also applies when vacutainer tubes are
used. As iron overload in these patients is not
as great as in those with haemochromatosis,
iron depletion can be accomplished in 20–40
phlebotomy sessions (a 50 ml syringe can
contain ~70 ml blood). Thus iron reduction
therapy is achieved more slowly than with
conventional phlebotomy but is integrated
into the routine workup and is accepted by
both patients and staff alike.
We hope that our method may be useful to
other clinicians in the field.
Y LURIE
M BEER GABEL
I LAMBORT
T SOUMATZKY
S D H MALNICK
D D BASS
Kaplan Medical Center,Affiliated to the
Hebrew University Medical School and Hadassah,
PO Box 1, Rehovot 76100, Israel

Even in donors for stem cell transplants, G-CSF is needed to mobilize sufficient stem cells to be used in the transplant, and this is from normal, non-thal donors. Sufficient quantities of stem cells for the transplant are not available without drug induced mobilization. In thals, it is even more difficult to collect sufficient stem cells to be used for gene therapy.

Taking blood from thal majors would not be done. In thal majors, the bone marrow is suppressed as much as possible to prevent the production of blood cells, as they are of negative value and expand the bone marrow, causing weak bones and much pain to the patients. Removing blood over a long period would have no meaning as transfusions would have to continue to keep the patient alive. Bleeding would be totally counter-productive in those who cannot make their own blood. This is why blood-letting which is commonly used to reduce iron load in those with hemochromatosis, is completely contraindicated in thalassemia.

Only with a drug induced mobilization are there sufficient quantities of stem cells collected to be useful. But even with this mobilization, a problem occurs with too many white blood cells being produced. This is another part of the problem that is being addressed, primarily through the use of hydroxyurea.

http://clinicaltrials.gov/ct2/show/NCT00336362  (From 2006).

Before gene transfer methods can be attempted in individuals with beta thalassemia major, a safe method of obtaining blood stem cells needs to be developed. The purpose of this study is to investigate the safety and feasibility of collecting peripheral blood stem cells (PBSC) from individuals with beta thalassemia major. Research participants will be given G-CSF (filgrastim) for several days to increase the number of stem cells in the blood, a process called "mobilization." After mobilization, participants will undergo a procedure called apheresis to remove the white blood cells. Researchers in the laboratory will purify the stem cells from the mixture and test methods of putting a normal globin gene into the stem cells. Half of the participants will receive hydroxyurea (HU) prior to G-CSF mobilization. HU is used in splenectomized patients to attempt to reduce the risk of clotting during mobilization. In non-splenectomized patients, HU is given in an attempt to decrease the size of the spleen.

The results of this research. http://ash.confex.com/ash/2009/webprogram/Paper23321.html

For gene therapy (GT) of thalassemia (TH), high numbers of genetically-modified hematopoietic stem cells (HSCs) are required to effectively compete for niche space in the hypercellular thalassemic bone marrow (bm). Mobilized peripheral blood is the preferable source of HSCs for thalassemia GT due to higher yields of CD34+cells compared to bm harvest. There is limited information on the mobilization efficacy of adult patients with major β-TH as well as on the safety of the procedure in a condition of splenomegaly and extramedullary hemopoiesis. Rare events of splenic rupture or thrombosis with G-CSF in normal donors raise safety concerns for its use in TH where chronic splenomegaly and hypercoagulability exist. Pretreatment of patients with hydroxyurea (HU) could reduce the risk of splenic rupture or thrombosis by decreasing the splenic hemopoiesis and thereby the spleen size in the non-splenectomized (non-SPL), and the circulating cells in the splenectomized (SPL) patients before G-CSF. In an on going mobilization study, we aim to assess the safety and efficacy of G-CSF mobilization with or without HU pretreatment in adult patients with β-TH major...
Overall, it seems that mobilization of SPL thalassemic patients is challenging.  Mobilization is not inherently inefficient in SPL patients but it results from mandatory G-CSF-dose modifications to avoid hyperleukocytosis. Patient-tailored schemes of G-CSF mobilization or alternative ways of mobilization (ie AMD 3100) will be required in order to obtain high numbers of HSCs from SPL patients. HU seems to play a safety role as pretreatment before mobilization, especially in the SPL patients, however the time to G-CSF initiation after HU cessation is critical for a sufficient CD34+cell yield.

As I said, this is anything but a simple process and many years of research has only now brought us to the point where there is sufficient stem cell mobilization to give stem cell therapy a chance to succeed.

The thinning of the blood which happens
when one is bled may also be beneficial.
------
For blood stem cells, the force is strong
Blood flow, nitric oxide boost production of stem cells

By Tina Hesman
Saey Web edition : Wednesday, May 13th, 2009
Blood stem
cells grow with the flow, two new studies show.

The studies, led by independent groups at Children’s Hospital Boston,
report that an embryo’s heartbeat and blood circulation stimulate the
growth of blood stem cells.

The discovery could be a boon to researchers seeking to make blood
stem cells for people with blood cancers, immune system disorders and
other diseases that require bone marrow transplants. In children and
adults, blood stem cells reside in the bone marrow. Only about a third
of patients who require bone marrow transplants have matching donors.

“Basically we cannot offer optimal therapy to two-thirds of patients,”
says Leonard Zon, director of the Stem Cell Program at Children’s
Hospital Boston, and a coauthor of one of the new studies, which
appears online May 13 and in the May 15 Cell.

Scientists can make red and white blood cells easily in the
laboratory, but bone marrow patients need blood stem cells to
constantly replenish their blood supply. Producing these cells, also
called hematopoietic stem cells, is much more difficult, Zon says.

Now, his group suggests that a little force can boost blood stem cell
production in zebrafish embryos. Reporting online May 13 in Nature, a
group led by George Daley, director of the Pediatric Stem Cell
Transplantation Program at Children’s Hospital Boston, demonstrates
that blood flow also triggers hematopoietic stem cell production in
mouse embryos. Both groups found nitric oxide plays an important role.

Daley’s group directly tested the ability of blood flow to turn cells
into hematopoietic stem cells. The team placed mouse embryonic stem
cells in a centrifuge-like device that mimics sheer stress — the
frictional force blood creates when it flows over cells — in a mouse’s
aorta. In early embryos, blood stem cells first form on the floor of
the aorta. Later in development, they migrate to the bone marrow.

Embryonic stem cells exposed to the same magnitude of sheer stress as
found in the mouse aorta produced hematopoietic stem cells. Cells that
were exposed to a different magnitude of sheer stress, such as that in
the human aorta, did not.
A nitric oxide–blocking drug reduced the number of blood stem cells
induced by the sheer stress. Nitric oxide is a chemical produced
naturally in the body and is known to be important in regulating blood
vessel growth and elasticity.

When the researchers gave the nitric oxide–blocker to pregnant mice,
their embryos also had problems making blood stem cells.

Zon’s team used zebrafish embryos, which are transparent, to watch the
stem cells develop. He and his colleagues found that chemicals that
increase blood flow in the tails of zebrafish embryos also boost
activity of RUNX1, a master regulator of blood stem cells. Mutant
embryos that don’t have a heartbeat because of a defect in a heart
muscle protein don’t make hematopoietic stem cells in their tails.

When the researchers gave a nitric oxide compound to the mutant
embryos, however, the embryos produced more blood stem cells. The
nitric oxide–blocker also inhibited blood stem cell production, the
researchers found. Those findings suggest that blood flow may increase
nitric oxide levels, which then boost stem cell production, Zon says.

Intuitively, scientists might expect that mechanical forces play a
role in shaping development, but few biologists have studied this due
to experimental difficulties, says Ihor Lemischka, a stem cell
biologist at Mount Sinai School of Medicine in New York City.

“I think we’ll be seeing more of these types of studies,” Lemischka
says.

It’s still not clear how the cells sense sheer stress, and researchers
are trying to unravel the chain of events between mechanical force and
stem cell production in order to manipulate the process to make blood
stem cells for transplant.

Ironjustice,

Can I ask you to supply links to the original article when possible? I like to make sure that the original credits are seen.

Dear  Andy,

I am writing this post on behalf of one of my friend whose daughter has recently been diagnosed with Multiple Sclerosis which is in the early stages. Incidentally, my friend's daughter too happens to be a Thal carrier. Are there any studies to prove that Multiple Sclerosis has some correlation with thalassemia major or minor?

Whatever little research we have done on Multiple Sclerosis so far suggests that the Multiple Sclerosis is irreversible and disease progression can be delayed and cannot be completely stopped.

Do you have any view on Multiple Sclerosis and its potential cure, medications etc. Can Stem Cell Transplant/Bone Marrow Transplant cure Multiple Sclerosis.

Regards,
Himanshu

Dear Himanshu,

I am sorry to hear about the news your friend has recieved.  I do not know of any correlation between MS and thalassemia.

Novel treatments for MS, that are proving to be effective in the early stages have been recently published.  I will post what I have read soon.

Please convey my best wishes to your frined and your friend's daughter.

Sharmin

I have not seen anything to suggest a connection between thal and MS. There is a good summary about MS and research, including gene therapy at http://www.ms-uk.org/genetics

My late sister had MS that was well controlled under medications currently available. Much progress has been made in treatment.