Navigation Links
Anemia treatment may be a double-edged sword
Date:1/30/2008

Erythropoietin has so far been known to doctors as a hormone that boosts red-blood-cell production. Now, a mouse study led by Lois Smith, MD, PhD, an ophthalmologist at Children's Hospital Boston, shows it also keeps blood vessels alive and growing in the eye. The findings not only add a new function to the hormone, but also give doctors a reason to pause before prescribing it to patients with diseases affected by abnormal blood-vessel growth, such as retinopathy and cancer.

The study, published in the February issue of the Journal of Clinical Investigation (online January 24), also found that whether the hormone is a risk or benefit depends on the timing of administration.

Smith and first author Jing Chen, PhD, worked in mice with retinopathy, an eye disease that begins when healthy blood vessels nourishing the retina die. Numerous vessels then grow in, but they are deformed. Ultimately, the deformed vessels may pull the retina off the back of the eye, causing blindness.

The researchers measured erythropoietin produced in the retina as the disease progressed. Production was 3 to 10 times below normal during early-stage retinopathy, when healthy blood vessels died, and 12 to 33 times above normal during late-stage retinopathy, when deformed blood vessels grew into the retina. The researchers concluded that erythropoietin helps blood vessels survive and grow in the retina, with effects that may be healthy or harmful.

Next, the team examined whether giving erythropoietin could treat retinopathy. They injected erythropoietin into the bloodstream either early, as the mice lost healthy blood vessels, or later, when deformed blood vessels began to invade--then compared them with untreated mice.

Boosting erythropoietin early slowed the disease. The mice lost half as many healthy blood vessels, causing about 30 percent fewer deformed vessels to grow in. Raising erythropoietin levels later, when deformed blood vessels were present, appeared to accelerate the disease--slightly more deformed blood vessels grew in.

If similar effects are found in humans, and its use is properly timed, then giving erythropoietin early could slow loss of healthy blood vessels in retinopathy, says Smith. "Right now, there is very little out there to treat blood vessel loss in patients with retinopathy. However, further studies on the restoration of normal levels of erythropoietin are needed to translate these results to patients."

In other diseases, like cancer, in which doctors need to slow blood vessel growth, the hormone could be blocked, although clinical trials would need to confirm this idea, she adds.

But given at the wrong time, erythropoietin may make blood vessels grow in an unhealthy way, says Smith. For example, because it boosts red blood cells, erythropoietin is often prescribed to premature babies and diabetic adults for anemia. Some of these patients also have retinopathy. Giving the hormone at the wrong time might help anemia, but worsen the eye disease.

"We're not saying, 'don't do it.' We're saying, 'think about it,'" says Smith. "Physicians should look at the state of the eye before giving erythropoietin to patients with retinopathy. They should consider not giving it to patients with full-blown retinopathy, in which abnormal vessels are present, because our work suggests it may accelerate the disease. However, if a patient is early on in the disease, then our work suggests erythropoietin may be beneficial."

Cancer patients, who often take erythropoietin for anemia, face a similar potential risk, says Smith. "Since erythropoietin has the potential to make blood vessels in tumors grow, it could make tumors worse, although a clinical trial is required to know if this is true in humans."

Overall, Smith says her mouse studies are a reason for doctors to think and researchers to investigate, not for patients to panic.


'/>"/>

Contact: Keri Stedman
keri.stedman@childrens.harvard.edu
617-919-3110
Children's Hospital Boston
Source:Eurekalert

Related medicine news :

1. FDA Reports New Risks Posed by Anemia Drugs
2. Modeling Simulation Predicts Potential Negative Impact on U.S. Blood Supply if ESA Use Limited for Chemotherapy-Induced Anemia
3. Evidence links anemia drugs with leukemic transformation in patients with primary myelofibrosis
4. New Kind of Stem Cells Reverse Sickle Cell Anemia
5. FDA Approves MIRCERA(R): First Renal Anemia Treatment with Monthly Maintenance Dosing
6. New anemia measure predicts risk of death in dialysis patients
7. FDA Issues New Warnings for Anemia Drugs
8. Simpler Anemia Treatment May Help Kidney Patients
9. Cancer Doctors Across America Stunned at Governments Ruling Restricting Anemia Management Protocols for Cancer Patients, Call Ruling Interference in Practice of Medicine
10. Controversial Anemia Drug Doesnt Cut Need for Transfusions
11. Anemia and tropical diseases; Is pharmacogenomics ready for the clinic?
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/10/2016)... California (PRWEB) , ... February 09, 2016 , ... ... students, faculty and staff helped give free oral screenings to 150 children in ... 5, 2016. , The College of Dental Medicine joined Chinese American Dental Society ...
(Date:2/9/2016)... Fort Lauderdale, Florida (PRWEB) , ... February 09, 2016 , ... ... known as the Taste of South Florida Event, an upscale fundraiser held in South ... to wow sponsors and guests alike. This year the event will be held in ...
(Date:2/9/2016)... MA (PRWEB) , ... February 09, 2016 , ... ... (WCRI) compares the workers’ compensation fee schedule rates and Medicare rates for a ... services covered in the report, Evaluation of the 2015 Fee Schedule Rates ...
(Date:2/9/2016)... ... February 09, 2016 , ... On January 12, 2016 Paul McElwee, a ... they noticed their furnace not producing any heat. Shortly after entering the home, Paul ... exchanger was leaking dangerous levels of carbon monoxide into the home, at 2,000 parts ...
(Date:2/9/2016)... ... February 09, 2016 , ... METTLER TOLEDO ... lab personnel have a basic understanding of the techniques they use so they ... will help them reduce waste and rework to create a leaner overall lab ...
Breaking Medicine News(10 mins):
(Date:2/10/2016)... HALLANDALE, Fla. , Feb. 9, 2016  Until ... sagging were surgery or liposuction. Thankfully, the FDA approved ... freezing them to death. Coolsculpting was originally approved in ... to the thighs and now the chin. With this ... Wellness Center can use a smaller applicator, the CoolMini, ...
(Date:2/10/2016)... , Feb. 9, 2016 On ... Administration (FDA) met with its Arthritis Advisory ... biosimilar of Johnson & Johnson,s Remicade and ... approved in the U.S. The Biologics Prescribers ... groups - Alliance for Patient Access, American ...
(Date:2/10/2016)... CTI BioPharma Corp. (CTI BioPharma) (NASDAQ ... the clinical studies being conducted under the Company,s ... the issuance of the Company,s February 8, 2016, ... by the U.S. Food and Drug Administration (FDA) ... oral communication from the FDA followed by a ...
Breaking Medicine Technology: