Patient’s Own Stem Cells Mend Heart

[Guest guest]

13 Jan 2005 20:59:23 -0000

Patient's Own Stem Cells Mend Heart

 

press-release

 

 

 

The Institute of Science in Society Science Society

Sustainability http://www.i-sis.org.uk

 

General Enquiries sam Website/Mailing List

press-release ISIS Director m.w.ho

========================================================

 

 

ISIS Press Release 13/01/05

 

Patient's Own Stem Cells Mend Heart

*****************************

 

Adult stem cells proving themselves in the clinic. Dr. Mae-

Wan Ho reports

 

A fully referenced version of this paper is posted on ISIS

members' website

http://www.i-sis.org.uk/full/POSCMHFull.php.

Details here http://www.i-sis.org.uk/membership.php

 

From lab to clinic

 

Over the past three years, adult stem cell research has been

moving from the lab to the clinic with a string of promising

outcomes in treating conditions such as chronic arthritis,

severe systemic lupus erythematosus, Crohn's disease,

cancer, and repairing damaged heart after heart attack (see

" Hushing up adult stem cells " , SiS 13/14

http://www.i-sis.org.uk/isisnews/sis13.php; " Human cloning &

the stem cell debate " , SiS 16

http://www.i-sis.org.uk/isisnews/sis16.php).

 

Follow-up research in several laboratories have now

confirmed that stem cells in the bone marrow or circulating

in the bloodstream are indeed both safe and effective in

heart repair, helping to recover the heart's ability to

contract properly to deliver oxygen and nutrients to the

rest of the body.

 

Non-surgical treatment with patient's own cells

 

After a heart attack, the muscle cells at the periphery of

the damaged area tend to overgrow in order to make up for

the dead or damaged cells. But this initiates a further loss

of muscle cells, causing the damaged area to expand and to

be replaced by useless scar tissue, eventually ending in

heart failure. Many drugs are aimed at preventing this

process of `cardiac remodelling' after a heart attack, so as

to stop the heart muscle cells from overgrowth and dying.

 

Researchers at Heinrich-Heine-University of Dusseldorf in

Germany, who reported the first success in repairing a

patient's damaged heart three years ago, have since treated

ten more patients, all male, by transplanting the patients'

own bone marrow cells (BMCs). The BMCs, collected the day

before, purified and expanded in culture overnight, were

introduced into the blocked (infarct) artery that

precipitated the heart attack during balloon dilatation of

the artery that's part of the standard treatment. Another 10

male patients, who refused the cell therapy, were treated

with the standard therapy only.

 

After 3 months follow-up, the damaged region was found to

have decreased significantly in the group receiving BMC

therapy, from 30+13 to 12+7%, and significantly smaller than

the standard therapy group. Similarly, the damaged wall

movement velocity increased significantly only in the cell

therapy group, from 2.0+1.1 to 4.0+2.6cm/s. There were also

significant improvements in the cell therapy group that

reflected the heart's ability to contract properly and

deliver blood to the body.

 

The regeneration of healthy muscle tissue in the damaged

area was accompanied by the formation of new blood vessels.

An important contribution to the success of the treatment,

the researchers pointed out, was the use of a non-surgical

procedure thus avoiding risks associated with surgical

operations. The introduction of cells through the infarct

artery also ensured that cells would be transported to areas

requiring tissue regeneration.

 

Stem cells from blood just as effective

 

In a further study, the same researchers compared the effect

of BMCs with progenitor cells purified directly from the

blood. In this protocol, 20 patients were randomly assigned

to receive either of the treatments twenty-four hours after

heart attack.

 

Patients receiving BMCs had their bone marrow aspirated on

the morning of the day of cell transplant, and the cells

were used directly after purification without expansion in

culture. Those receiving blood progenitor cells had 250ml of

blood collected immediately after random assignment.

Mononuclear cells were purified and cultured for 3 days

before being re-infused into the infarct artery.

 

Both treatment groups improved significantly in the measured

parameters of heart function after 4 months; there were no

difference between the two groups in the extent of

improvement.

 

In contrast, the control group (of 11) who did not receive

cell therapy showed no significant improvement in any of the

same parameter at 4 months.

 

A randomised trial

 

Another research team at Hannover Medical School in Germany

carried out a randomised trial on the BMC therapy. Here, 60

patients were randomly assigned in equal numbers to either a

control group that received optimum post-infarct medical

treatment, or BMC (direct, no expansion in vitro) transplant

at about 5 days after similar coronary intervention. The

endpoint measurement was the change in global left ventricle

ejection fraction (LVEF) from baseline to 6 months' follow-

up, as determined by cardiac MRI (magnetic resonance

imaging).

 

Global LVEF at baseline, determined at about three and a

half days after post-infarct medical treatment was 51.3

+9.3% in controls and 50.0 +10.0% in the BMC group. After 6

months, however, mean global LVEF had increased only 0.7% in

controls compared to 6.7% in the cell group.

 

The researchers concluded: " The effects of cell transfer

were over and above benefits associated with established

strategies to promote functional recovery after acute

myocardial infarction " , which included both physical and

pharmacological interventions.

 

Mechanisms debated

 

Other researchers have cast doubt on whether the ability of

bone marrow cells to mend damaged heart depends on the stem

cells found in the bone marrow developing into heart muscle

cells or capillaries (fine blood vessels) or both; but that

does not detract from the positive results obtained in the

trials.

 

Researchers at Columbia University, New York, recently

isolated from adult human bone marrow, endothelial

progenitor cells or angioblasts that migrate to ischemic

(blood-flow deprived) myocardium (muscle wall of the heart),

where they induce new blood vessel formation and prevent

myocardial remodelling.

 

They have now shown in experiments on rats that increasing

the number of human angioblasts to the infarct area induced

a dose-dependent new blood vessel formation with development

of progressively larger-sized capillaries. This results in

sustained improvement in cardiac function by protecting

against cell death, and inducing proliferation and

regeneration of the rat heart muscle cells.

 

The researchers suggest that in the cardiac remodelling

process after heart attack, those heart muscle cells that

overgrow to compensate for the dead cells eventually die

because the capillary network cannot provide the increase in

blood flow necessary for the cells to survive.

 

Thus, agents (possibly chemical) that increase bone marrow

angioblasts homing in on the heart muscle to form new blood

vessels could effectively induce endogenous heart-muscle

cells to enter the cell cycle and help the heart regenerate

and recover.

 

 

========================================================

This article can be found on the I-SIS website at

http://www.i-sis.org.uk/POSCMH.php

 

If you like this original article from the Institute of

Science in Society, and would like to continue receiving

articles of this calibre, please consider making a donation

or purchase on our website

 

http://www.i-sis.org.uk/donations.

 

ISIS is an independent, not-for-profit organisation

dedicated to providing critical public information on

cutting edge science, and to promoting social accountability

and ecological sustainability in science.

 

If you would prefer to receive future mailings as HTML

please let us know. If you would like to be removed from our

mailing list at

 

http://www.i-sis.org.uk/mailinglist/.php

========================================================

CONTACT DETAILS

 

The Institute of Science in Society, PO Box 32097, London

NW1 OXR

 

telephone: [44 1994 231623] [44 20 8452 2729] [44 20

7272 5636]

 

General Enquiries sam Website/Mailing List

press-release ISIS Director m.w.ho

 

MATERIAL ON THIS SITE MAY BE REPRODUCED FOR ANY PROFIT FREE

PURPOSES WITHOUT PERMISSION, ON CONDITION THAT IT IS

ACCREDITED ACCORDINGLY AND CONTAINS A LINK TO http://www.i-

sis.org.uk/.

ANY COMMERCIAL USE MUST BE AGREED WITH ISIS