Gero Hütter
Encyclopedia
Gero Hütter is a German hematologist. Huetter and his medical team transplanted bone marrow deficient in a key HIV receptor to a leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...

 patient, Timothy Ray Brown, who was also infected with human immunodeficiency virus (HIV). Subsequently, the patient's circulating HIV dropped to undetectable levels. The case was widely reported in the media, and Hütter was named one of the "Berliners of the year" for 2008 by the Berliner Morgenpost, a Berlin newspaper.

HIV treatment

In 2009, Hütter, Eckhard Thiel and others from the Charité Hospital
Charité
The Charité - Universitätsmedizin Berlin is the medical school for both the Humboldt University and the Free University of Berlin. After the merger with their fourth campus in 2003, the Charité is one of the largest university hospitals in Europe....

 in Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, published a report on the case in the New England Journal of Medicine. Their patient Timothy Ray Brown, a US citizen living in Berlin, had both acute myelogenous leukemia (AML) and HIV. The physicians found a bone marrow donor with a CCR5-Δ32 mutation in both genomic copies of a gene encoding a cell-surface chemokine receptor
Chemokine receptor
Chemokine receptors are cytokine receptors found on the surface of certain cells, which interact with a type of cytokine called a chemokine. There have been 19 distinct chemokine receptors described in mammals...

 called CCR5
CCR5
C-C chemokine receptor type 5, also known as CCR5, is a protein that in humans is encoded by the CCR5 gene. CCR5 is a member of the beta chemokine receptors family of integral membrane proteins...

. Because "almost all strains of HIV" use the CCR5 receptor to enter a host cell, the mutation confers resistance to HIV infection. The patient himself was heterozygous for CCR5-Δ32. Following the transplant procedure, the patient's CD4+ T-cells
T helper cell
T helper cells are a sub-group of lymphocytes, a type of white blood cell, that play an important role in the immune system, particularly in the adaptive immune system. These cells have no cytotoxic or phagocytic activity; they cannot kill infected host cells or pathogens. Rather, they help other...

 circulating in the blood were homozygous for CCR5-Δ32. The macrophage
Macrophage
Macrophages are cells produced by the differentiation of monocytes in tissues. Human macrophages are about in diameter. Monocytes and macrophages are phagocytes. Macrophages function in both non-specific defense as well as help initiate specific defense mechanisms of vertebrate animals...

s in his bowel, which continued to express wildtype CCR5 (because they hadn't been replaced yet from bone marrow precursors), also had no detectable virus. After 600 days without antiretroviral drug treatment, the patient's blood, bone marrow and bowel HIV levels were below the limit of detection; the virus was thought to be present in other tissues. However, the patient actually had a brain biopsy, in addition to biopsies of his intestines, liver, lymph nodes, bone marrow—basically, every part of the body that can be biopsied. All were negative for virus. There is no virus in this person's body out to two and a half years off of all anti-HIV drugs. His antibody levels—called titers—are declining just the way expected if the patient was vaccinated against HIV and then the levels of antibodies were examined. They'd be very strong in the beginning, but would weaken if they are not re-exposed to the virus. It is believed this patient has no HIV in his body and therefore there is nothing to re-expose him, so the concentration of HIV antibodies in his blood is decreasing. It is predicted that, in a couple of years, his HIV antibody test will be negative.

The mortality risk associated with bone marrow transplants is thought to contraindicate the use of this experimental treatment for HIV-positive individuals without leukemia or lymphoma. Some researchers such as Edward Berger believe that resistance to CCR5 inhibition may emerge if CXCR4
CXCR4
C-X-C chemokine receptor type 4 also known as fusin or CD184 is a protein that in humans is encoded by the CXCR4 gene.- Function :...

 strains of HIV emerge (these use CXCR4 rather than CCR5 as a coreceptor, from which they become independent). Before the treatment though the patient had low levels of the CXCR4 virus but after the treatment this type of HIV could not be detected either which Hütter called "very surprising". People without CCR5 can be more sensitive to some infections such as West Nile virus
West Nile virus
West Nile virus is a virus of the family Flaviviridae. Part of the Japanese encephalitis antigenic complex of viruses, it is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, domestic...

.

Jay Levy, one of the first researchers to isolate and describe HIV in the early 1980s, wrote an editorial accompanying Huetter's publication in the New England Journal of Medicine. Noting the reduction in detectable HIV in the patient's blood and the return of the patient's circulating CD4+ T-cell population to normal levels, with all of the cells expressing the resistant variant of CCR5, Levy cautions that calling this treatment a cure would be premature. This is because HIV is known to hide in latent form in a variety of organs not easily sampled, including the heart and brain. The high risks of a bone marrow transplant also make this treatment risky since many bone marrow patients die. And the CXCR4 virus that was detectable in the blood of the patient before the treatment "could eventually emerge". Levy does believe though that this case "could pave the way for innovative approaches that provide long-lasting viral control with limited toxicities for persons with HIV infection".

As of June 4, 2010, Dr. Huetter's patient was in very good health and had been HIV- and cancer-free (combined) for two years.

Dr. Huetter received an award on June 3, 2010 from the AIDS Policy Project, a national advocacy group focused on an AIDS cure, and San Francisco Supervisor Ross Mirkarimi on behalf of the people of San Francisco.

The text read:
"Dr. Gero Hütter: In recognition of your historic achievement of being the first doctor to functionally cure AIDS/HIV through an innovative procedure that entails a remarkable example of the use of stem cell transplants. We join you with hope that your achievement will globally inspire researchers to explore new techniques and technologies for an AIDS cure. On behalf of the people of San Francisco, the AIDS Policy Project, and all those engaged in the combat against the HIV disease, the City and County of San Francisco extends its highest commendation!" —Supervisor Ross Mirkaraimi, Member, San Francisco Board of Supervisors, June 3, 2010
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK