Sunday, December 02, 2012

Chronic Myelogenous Leukemia



Chronic myelogenous leukemia (also called chronic myeloid 

leukemia) is a rare cancer that affects bone marrow. That's 

where blood cells are produced. CML leads to the production 

of many abnormal white blood cells, which do not fight infection 

as well as normal white blood cells. As they build up in the 

blood and bone marrow, the abnormal cells crowd out healthy 

white blood cells, red blood cells, and platelets.


The Philadelphia Chromosome

People with CML have an abnormal chromosome called the 

Philadelphia chromosome. Chromosomes carry genes, which 

tell cells what to do. In CML, pieces of chromosomes 9 and 22 

break and switch places. The changed chromosome 22 is 

called the Philadelphia chromosome. It carries a new gene 

called bcr-abl. Bcr-abl calls for a protein (tyrosine kinase) to be 

made, triggering stem cells to create abnormal white blood 

cells found in CML.

Chronic Phase

The chronic phase is the first period of CML.  
Most people in this phase don't have any 
symptoms. They're usually diagnosed during 
a routine blood test. Because there are only a 
small number of abnormal white blood cells in 
the blood and bone marrow, the body is still 
able to fight infection. Even though you might 
not feel sick now, it's important to get treated 
so CML doesn't progress to the next phase.

Accelerated Phase

During the accelerated phase, you may 
develop symptoms such as fatigue, weight loss, shortness of breath, or fever. This means the number of abnormal blood cells has increased. Once in this phase, it may become harder to achieve remission with CML treatments. The accelerated CML phase can lead to the most serious and aggressive phase of the cancer, blast phase.

Blast Phase

By the blast phase of CML, the number of 
abnormal blood cells in the bone marrow and 
blood is high. Meanwhile, the number of 
healthy red and white blood cells and 
platelets has dropped. With fewer disease-
fighting white blood cells, you're more likely to 
get infections. You may have anaemia or 
uncontrolled bleeding. This stage is severe 
and life-threatening.

Targeting the Abnormal CML Protein

The chronic phase of CML is first treated with 
targeted drugs called tyrosine kinase inhibitors (TKIs). They kill off CML blood cells by blocking the protein produced by the abnormal gene bcr-abl. Side effects can include rashes and swollen skin, nausea, muscle cramps, and diarrhea. When TKIs can't control the disease, there are other treatment options.

Stem Cell Transplant

A stem cell transplant is an option for some 
people who don't respond to TKIs. First, you 
get high doses of chemotherapy drugs to kill 
blood-forming cells (stem cells) in your bone 
marrow. Then, you receive stem cells from a 
matched donor, called an allogeneic 
transplant. These cells will form new, healthy 
blood cells. A stem cell transplant is the only 
way to cure CML. But newer treatments that 
target bcr-abl can also normalize the 
Philadelphia chromosome and help many 
people with CML achieve remission.

The best candidates for a stem cell transplant:
Are younger rather than older patients
Are in the chronic phase of CML
Are in overall good health
Have a matched stem cell donor (preferably a close relative, such as a brother or sister)

Treatment Options
If TKIs aren't working and you're not a 
candidate for a stem cell transplant, other 
treatment options include:
Chemotherapy drugs taken by mouth to kill 
abnormal cells throughout your body, such as 
hydroxyurea or busulfan
Biological therapies, like interferon, that 
stimulate your own immune system to fight off 
the cancer

Continuous Monitoring Is Necessary
When you have CML, you'll see your doctor at least every few months to monitor treatment and check for side effects. CML tests include:
Complete blood count and bone marrow tests to measure red and white blood cells and platelets
Fluorescent in situ hybridization (FISH) test to see how many cells contain the Philadelphia chromosome
Polymerase chain reaction (PCR) test to look for the bcr-abl gene.

Questions About Your CML Treatment

Here are a few questions to ask your doctor while you're undergoing treatment for CML:
What CML phase am I in?
What are my treatment options and what side effects might I experience?
Should I get a second opinion?
Can I enroll in a clinical trial of an experimental treatment?

How to Cope with CML
During your treatment for CML, here are a few ways to help yourself feel better:
Go to all of your check-ups so your doctor can change treatment if it's not working.
Tell your doctor about any side effects you're experiencing.
If you're struggling with your illness, get support from friends, family members, or your medical team.


Signs Your Treatment Is Working
When you go for regular checkups, your doctor will be looking for these signs that your treatment is working:
Hematologic response: An improvement in the number of healthy white blood cells and platelets
Cytogenic response: Fewer Philadelphia chromosome-positive cells in your blood and bone marrow

You are considered to be in CML remission when:
Your blood cell count is normal (complete hematologic response).
No cells with the Philadelphia chromosome can be found in your blood or bone marrow (complete cytogenic response).
None of the abnormal gene can be found in your blood (complete molecular response).
Being in remission isn't the same as being cured. A stem cell transplant is the only proven cure for CML.

Signs of Relapse

CML can come back even after it has been successfully treated. Signs of relapse include fatigue or weakness, weight loss, fever, night sweats, bone pain, swelling or pain on the left side (a sign of an enlarged spleen), and a feeling of fullness in the belly. If you have any of these symptoms, call your doctor.


Why Isn't My Treatment Working?

CML therapy works well for most people, but not everyone. Reasons why treatment might stop working include:
The cancer cells change (mutate).
Not enough medication is getting into your bloodstream.
If your treatment isn't effective, your doctor may adjust your drug doses or switch you to another therapy.













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Sunday, March 11, 2012

Stem cells transplant trick immune system to accept organs



Of 8 kidney transplant patients who have been treated with this new approach of stem cell transplant, 5 have managed to avoid taking anti-rejection drugs a year after their surgery. One patient is totally free of anti-rejection drugs nearly 2 years after her kidney transplant.

With conventional transplants, recipients need to take pills to suppress immune system for the rest of their lives. These drugs can cause side effects, including high blood pressure, diabetes, infection, heart disease & cancer. This new approach would potentially offer a better quality of life & fewer health risks for recipients.
But some experts say the procedure, in which patients undergo a bone marrow transplant from an unmatched organ donor, is too risky, especially given the relative of kidney transplants. According to one Dr., since the current treatment is so stable, it really has to be safe. The new approach was done by Noble laureates of 1960, who discovered that the immune system in animals can be trained to acquire tolerance of foreign tissue. But it has been a long road to bring this about in people. To get recipients to accept the organ, the team needs to “condition” them by suppressing their bone marrow with chemotherapy & radiation before transplanting the donor’s bone marrow. Bone marrow contains immature blood forming stem cells that give rise to all blood cells, including immune system.
“The idea here is to try to use donor-derived stem cells to achieve engraftment, a state we call chimerism” said a doctor. “Here what we’re trying to do is get donor & recipient cells to peacefully co-exist”.
About a month before transplant surgery, kidney donors must inject themselves with a medication for several days that forces stem cells & other key cells called “facilitating cells” into their blood stream, from where they can be collected & sent off to the University of Louisville for processing.
The doctor said that these facilitating cells are naturally occurring cells that help create amore favourable environment for the stem cells & allow engraftment to occur safely.

Ildstad has developed a process for enriching these cells & formed a company called Regenerex LLC, which is developing the patented technology.
Meanwhile, the transplant recipient is given radiation & chemotherapy to suppress the immune system, a process intended to prepare them for accepting the donor’s stem cells.
The patients then undergoes a kidney transplant, & a day later, get transplanted with the enriched mix of the donor’s stem cells & facilitating cells with the hope offorming 2 bone marrow systems that can exist & function in one person.
Following these procedures, the recipient starts off taking anti-rejection drugs, but is gradually weaned off them with the goal of stopping entirely a year after the transplant.
The doctor said, patients developed tolerance to the graft, eliminating the need for anti-rejection drugs, even when donor recipients were mismatched & unrelated. The team is enrolling patients in the clinical trials, which aims to include 40 subjects.


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Tuesday, October 04, 2011

Stem Cell Treatment May Relieve Angina

Drugs, angioplasty, and coronary artery bypass graft (CABG) surgery are the main treatments for angina -- chest pain caused by blocked coronary arteries.


The new treatment came from the discovery about a decade ago that CD34+ stem cells stimulate the formation of new blood vessels. Coronary artery disease involves not only the blockage of major arteries, but the death of small vessels, or capillaries, of the heart muscle. This treatment targets these small vessels that have been damaged. The stem cells have shown the ability to repair and replace them in animal models. 


Patients were given a drug for several days to increase the number of CD34+ stem cells in the blood. Blood was collected and processed to collect the stem cells, and then, using a catheter threaded into the heart, the researchers injected the CD34+ cells into areas of the muscle that had been identified as oxygen-deprived areas. The patients received 10 such injections during a single catheterization procedure.

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