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A drug to treat sickle cell anaemia is safe for use in children and should be made available, US doctors say. Sickle shaped red blood cells are more likely to block blood vessels and die sooner, resulting in pain, organ damage and early death. The study in the Lancet, involving some 200 US babies, found hydroxycarbamide reduced pain and other complications in the half given the drug. A UK expert said the findings were "extremely encouraging". Hydroxycarbamide is already available for use in adults, but its effectiveness had not been tested in young children.
Major effect
In the study, the babies taking the drug had half the number of painful events - pain lasting more than two hours and needing drug treatment. There was an 80% reduction in cases of pain and tenderness in the hands and feet (dactylitis). The study says the only negative effect was mild or moderate neutropenia, in which the number of infection fighting white blood cells falls. The researchers said the study "should have a major effect on guidelines for the management of children with sickle cell anaemia. "Hydroxycarbamide therapy can now be considered for all very young children with sickle cell anaemia."
Organ damage
David Rees, a consultant paediatric haematologist and medical adviser to the Sickle Cell Society, said that while it was "encouraging" that the drug was safe in very young children" the study was "in a way disappointing". He said the primary goals of the study had been to show an impact on spleen or kidney function as "it had been hoped that if you can intervene early you could prevent organ damage", yet this was not the case.
Professor David Weatherall, from the University of Oxford, said: "These findings are extremely encouraging. "Hydroxycarbamide is inexpensive and could certainly be made available in low-income countries in which sickle-cell anaemia is so common." "In view of the early deaths that result from this disease in sub-Saharan Africa, the success of this trial in early infancy is particularly encouraging."
BBC News - Sickle cell anaemia treatment 'effective for children'
With the study, and unpublished findings from his lab, Porteus believes his team has amassed enough proof to start planning the first human clinical trial using the powerful CRISPR-Cas9 gene editing system to correct the genetic mutation that causes sickle cell disease. "We think we have a complete data set to present to the FDA (Food and Drug Administration) to say we've done all pre-clinical experiments to show this is ready for a clinical trial," Porteus told Reuters by phone. CRISPR-Cas9 has quickly become the preferred method of gene editing in research labs because of its ease of use compared with older techniques. CRISPR works as a type of molecular scissors that can selectively trim away unwanted parts of the genome, and replace it with new stretches of DNA.
Research using the powerful technique is plowing ahead even as researchers from the University of California and the Broad Institute battle for control over the CRISPR patent. Oral arguments in the case are expected on Dec. 6 at the U.S. Patent and Trademark Office in Alexandria, Va. In sickle cell disease, the body makes mutant, sickle-shaped hemoglobin, the protein in red blood cells that carries oxygen to the body's tissues. It is caused by a single mutation in a gene that makes a hemoglobin protein. In a study published last month in Science Translational Medicine, a team from the University of California, Berkeley, and colleagues used the CRISPR gene editing tool to snip out the diseased gene and deliver a new stretch of DNA to correct the mutation in human stem cells. In that study, some 25 percent of blood-forming cells were corrected.
Red blood cells in a sickle cell patient, after a bone marrow transplant at the National Institutes of Health Clinical Center in Bethesda, Md. Medical Association.
In the Stanford study, Porteus and colleagues took a different approach. They used CRISPR to snip the gene, but they used a harmless virus to introduce the repair mechanism into cells. After a series of tests in healthy cells, the team tested the gene editing system in blood-forming cells from four patients with sickle cell disease. They showed they could correct the mutation in 30 to 50 percent of these diseased cells. Sixteen weeks after they injected the cells into young mice, the team found the cells were still thriving in the bone marrow. Porteus said the findings were very encouraging because prior studies have shown that if you can correct mutations in 10 percent of cells, that should create enough to cure the disease. Stanford is now scaling up its laboratory processes to support human trials.
The process will involve using chemotherapy to wipe out a patient's blood system but not their immune system, as is done in a stem cell transplant. Then, the team would inject the patient's own corrected stem cells, which the researchers hope would engraft into the bone marrow and produce healthy blood cells. Porteus has equity interest in CRISPR Therapeutics of Cambridge, Massachusetts, but he said the sickle cell work has been independent of it. The university has built a cell manufacturing plant for this purpose. "We hope to develop the entire process here at Stanford," he said. Porteus said the team plans to make an initial submission to the FDA in the next few months to map out the clinical trial, and hopes to treat the first patient in 2018.
Stanford Uses CRISPR to Correct Sickle Cell, Human Trials Planned
In a study of more than 300,000 U.S. adults aged 21 to 90, researchers at Pennsylvania State University's College of Medicine found the prevalence of hearing loss among participants overall was 1.6 percent, compared with 3.4 percent among those with iron-deficiency anemia. The findings were published in the journal JAMA Otolaryngology-Head & Neck Surgery.
The most common forms of hearing loss associated with anemia in the study were sensorineural hearing loss, in which the nerve pathway to the brain is damaged, and conductive hearing loss. In that condition, there is a problem with external sounds being conducted to the middle ear and eardrum. Many patients in the study who had suffered hearing loss had both kinds. However, researchers say, it's possible that correcting anemia with supplemental iron could improve the conditions. That's a future area of study.
A research audiologist conducts a hearing test on a patient at the Phonak US Audiology Research Center in Warrenville, Ill.
Researchers say it makes sense that loss of hearing might be caused by anemia. The inside of the ear is very sensitive to oxygen, and it's possible that the nerves there are not getting enough in someone who is iron-deficient. Iron is an essential element for the production of hemoglobin, the red blood cell protein that carries and releases oxygen throughout the body.
Hearing loss is common as people age. When the loss is sudden, in particular, researchers say doctors ought to consider iron-deficiency anemia as a possible cause. According to the American Speech-Language-Hearing Association, approximately 15 percent of U.S. adults complained of hearing loss in 2014. To the extent that iron deficiency may play a role, experts suggest eating a well-balanced diet, containing an adequate amount of nutrients and iron for optimal health.
Some Hearing Loss May Be Related to Anemia, Study Finds
A French teenager's sickle cell disease has been reversed using a pioneering treatment to change his DNA. The world-first procedure at Necker Children's Hospital in Paris offers hope to millions of people with the blood disorder. Scientists altered the genetic instructions in his bone marrow so it made healthy red blood cells. So far, the therapy has worked for 15 months and the child is no longer on any medication.Sickle cell disease causes normally round red blood cells, which carry oxygen around the body, to become shaped like a sickle.
Healthy red blood cells are round, but the genetic defect makes them sickle shaped
These deformed cells can lock together to block the flow of blood around the body. This can cause intense pain, organ damage and can be fatal. The teenager who received the treatment had so much internal damage he needed to have his spleen removed and his hips replaced. Every month he had to go into hospital to have a blood transfusion to dilute his defective blood. But when he was 13, doctors at the Necker Children's Hospital in Paris did something unique.
'No sign of disease'
Doctors removed his bone marrow - the part of the body that makes blood. They then genetically altered it in a lab to compensate for the defect in his DNA that caused the disease. Sickle cell is caused by a typo in the instructions for making the protein haemoglobin, which is densely packed into red blood cells. A virus was used to infect the bone marrow with new, correct instructions. The corrected bone marrow was then put back into the patient.
The results in the New England Journal of Medicine showed the teenager has been making normal blood since the procedure 15 months ago. Philippe Leboulch, a professor of medicine at the University of Paris, told the BBC News website: "So far the patient has no sign of the disease, no pain, no hospitalisation. He no longer requires a transfusion so we are quite pleased with that. "But of course we need to perform the same therapy in many patients to feel confident that it is robust enough to propose it as a mainstream therapy."
'Given his life back'
Prof Leboulch is nervous about using the word "cure" as this is just the first patient to come through clinical trials. But the study does show the potential power of gene therapy to transform the lives of people with sickle cell. "I think it's very significant, essential they've given him his life back," said Dr Deborah Gill from the gene medicine research group at the University of Oxford.
A normal red blood cell next to a sickle cell
She told the BBC: "I've worked in gene therapy for a long time and we make small steps and know there's years more work. "But here you have someone who has received gene therapy and has complete clinical remission - that's a huge step forward." However, the expensive procedure can only be carried out in cutting-edge hospitals and laboratories, while most sickle cell patients are in Africa. The next big challenge will be to transform this pioneering science into something that really can help millions of people.
What is sickle cell disease?
