Showing posts with label Stem cell. Show all posts
Showing posts with label Stem cell. Show all posts

the "Berlin Patient " - German Doctors believe the man have been cured of HIV Infection as a Result of the Treatment with Stem Cell Transplant

By sulthan on Saturday, January 15, 2011

The 'Berlin patient' is an HIV-positive man who developed acute myeloid leukaemia, received successful treatment and subsequently experienced a relapse in 2007 that required a transplant of stem cells.
  • While the highly lethal technique used on the man known as the "Berlin Patient" would not work for most of the 33 million people with HIV worldwide, scientists say the research shows important progress toward a universal cure.
"Our results strongly suggest that cure of HIV has been achieved in this patient," said the study in the peer-reviewed journal Blood, a publication of the American Society of Hematology.

Before the stem cell transplant the patient received chemotherapy treatment that destroyed most immune cells and total body irradiation, and also received immunosuppressive drugs to prevent rejection of the stem cells.
Antiretroviral therapy was halted on the day of the transplant, and the patient had to receive a second stem cell transplant 13 days after the first one, due to a further relapse of leukaemia.

The patient continued to receive immunosuppressive treatment to prevent rejection for 38 months, and at 5, 24 and 29 months post-transplant colon biopsies were taken to investigate possible graft-versus-host disease in the intestine. At each investigation additional samples were taken to check for signs of HIV infection in the abundant immune cells of the gut wall.

One of the challenges for any approach to curing HIV infection is long-lived immune system cells, which need to be cleared before a patient can be cured. In the case of the Berlin patient CCR5-bearing macrophages could not be detected after 38 months, suggesting that chemotherapy had destroyed these longer-lived cells, and that they had also been replaced by donor cells.
The German researchers and San Francisco-based immunologist Professor Jay Levy believe that the findings point to the importance of suppressing the production of CCR5-bearing cells, either through transplants or gene therapy.
The patient did not resume antiretroviral therapy after the transplant.
Nevertheless HIV remained undetectable by both viral load testing (RNA) and tests for viral DNA within cells, and HIV antibody levels declined to the point that the patient has no antibody reactivity to HIV core antibodies, and only very low levels of antibodies to the HIV envelope proteins.
Seventeen months after the transplant the patient developed a neurological condition, which required a brain biopsy and lumbar puncture to sample the cerebrospinal fluid for diagnostic purposes. HIV was also undetectable in the brain and the CSF.
An additional indication that HIV is not present lies in the fact that the patient’s CD4 cells are vulnerable to infection with virus that targets the CXCR4 receptor. If any virus with this preference was still present, the researchers argue, it would be able to swiftly infect the large population of memory CD4 cells that has emerged.

The `Berlin patient`, Timothy Ray Brown, a US citizen who lives in Berlin, was interviewed this week by German news magazine Stern.
His course of treatment for leukaemia was gruelling and lengthy. Brown suffered two relapses and underwent two stem cell transplants, as well as a serious neurological disorder that flared up when he seemed to be on the road to recovery.
HIV virus on microscope
The neurological problem led to temporary blindness and memory problems. Brown is still undergoing physiotherapy to help restore his coordination and gait, as well as speech therapy.
Friends have noticed a personality change too: he is much more blunt, possibly a disinhibition that is related to the neurological problems.
On being asked if it would have been better to live with HIV than to have beaten it in this way he says “Perhaps. Perhaps it would have been better, but I don’t ask those sorts of questions anymore.”
Timothy Brown is now considering a move from Berlin to Barcelona or San Francisco, and, reports Stern magazine, enjoying a drink and a cigarette.
Stern also interviewed Dr Gero Hütter, who was in charge of Timothy Brown’s treatment. Dr Hütter told Stern that as a scientist he was “in the right place, at the right time” and that “for me it is important to have overthrown the dogma that HIV can never be cured. Something like this is the greatest thing one can achieve in medical research”.



http://aidsmap.com/page/1577949/http://bloodjournal.hematologylibrary.org/cgi/content/short/blood-2010-09-309591v1
http://www.nytimes.com/1998/06/21/magazine/the-berlin-patient.html
http://www.webmd.com/hiv-aids/news/20101215/hiv-aids-cure-faq
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Gene Activity May Affect Acute Myeloid Leukemia Outcome

By sulthan on Tuesday, December 21, 2010

http://health-care-org.blogspot.com/

For acute myeloid leukemia patients, overactive genes in their leukemic stem cells (LSC) can translate into a more difficult struggle to overcome their disease and achieve prolonged remission, new research reveals. "In many cancers, specific subpopulations of cells appear to be uniquely capable of initiating and maintaining tumors," the study authors explained in their report. The researchers identified 52 LSC genes that, when highly active, appear to prompt worse outcomes among acute myeloid leukemia (AML) patients.

Between 2005 and 2007, study author Andrew J. Gentles, of Stanford University in Palo Alto, Calif., and colleagues examined gene activity in a group of AML patients as well as healthy individuals. Separate data concerning AML tumors in four groups of patients (totaling more than 1,000) was also analyzed. In one of the patient groups, the investigators found that higher activity levels among 52 LSC genes meant a 78 percent risk of death within a three-year period. This compared with a 57 percent risk of death in the same time frame for AML patients with lower gene activity among these specific "signature" genes.

In another AML patient group, the research team observed that higher gene activity prompted an 81 percent risk for experiencing a disease set-back over three years, compared with just a 48 percent risk among patients with low gene activity. What's more, Gentles and his colleagues found that higher activity among these 52 LSC genes generally meant a poorer response to chemotherapy treatment and lower remission rates.
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Docs Claim Transplant Cured Man of HIV, But Experts Urge Caution

By sulthan on Wednesday, December 15, 2010

http://health-care-org.blogspot.com/

In a rare case, a man living in Germany who had both leukemia and AIDS no longer has any detectable HIV cells in his blood following a stem cell transplant for his leukemia three years ago. But experts were quick to caution that the case does not have practical implications for the treatment of AIDS worldwide. As it turns out, the donor for that transplant carried a rare mutation in a gene that increases immunity against the most common form of HIV.

First reported in 2009, this follow-up study, published online in the journal Blood, confirms that the recipient patient is still free of both leukemia and HIV three years after the transplant. But one expert issued strong words of caution in interpreting the finding. "Our phones have been ringing off the hook," said Dr. Margaret Fischl, director of the AIDS clinical research unit at the University of Miami Miller School of Medicine. "We are having patients calling us and asking if they can stop their antiretroviral therapy and the answer is uncategorically no."

The theory is that if you could wipe out every infected cell you could cure HIV, Fischl said, but this is a unique case. The patient had intense chemotherapy and radiation, then relapsed and was given a second transplant from the same donor. The donor was unique in that he had a gene that could fight the most common form of HIV. This mutation is seen in about one in every million people, Fischl explained.
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Researchers Turn Stem Cells Into Intestinal Tissue in Lab

By sulthan on Tuesday, December 14, 2010

http://health-care-org.blogspot.com/

Researchers say they've turned human stem cells into functioning human intestinal tissue in a laboratory setting. The study team described its accomplishment as a "significant step" forward in efforts to better understand the function and development of the human intestine. They also expressed hope that the innovation will spur the development of new strategies to combat intestinal diseases, while opening up new avenues for the generation of transplantation tissue.

"The hope is that our ability to turn stem cells into intestinal tissue will eventually be therapeutically beneficial for people with diseases such as necrotizing enterocolitis, inflammatory bowel disease and short bowel syndromes," explained study senior author James Wells, a researcher in the division of developmental biology at Cincinnati Children's Hospital Medical Center, in a hospital news release. Wells and his colleagues report their findings in the Dec. 12 online issue of Nature.

The authors used two types of so-called "pluripotent" stem cells -- cells that have the chameleon-like ability to differentiate into any one of about 200 distinct cell types. Human embryonic stem cells, which are known to have such transformative abilities, were one type. For the other, the researchers looked to "induced" stem cells cells harvested from patients and reprogrammed in the lab to function as pluripotent stem cells. Though less well-tested than embryonic stem cells, induced cells theoretically have the advantage of minimizing the risk for cell rejection when replanted back into the host patient.
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