AIDS Virus Can Hide In Bone Marrow 118
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kdawson
from the no-one-can-see-us-here dept.
from the no-one-can-see-us-here dept.
suraj.sun writes "The virus that causes AIDS can hide in the bone marrow, avoiding drugs and later awakening to cause illness, according to new research that could point the way toward better treatments for the disease. Dr. Kathleen Collins of the University of Michigan and her colleagues report in this week's edition of the journal Nature Medicine that the HIV virus can infect long-lived bone marrow cells that eventually convert into blood cells. The virus is dormant in the bone marrow cells, she said, but when those progenitor cells develop into blood cells, it can be reactivated and cause renewed infection. The virus kills the new blood cells and then moves on to infect other cells, said. In recent years, drugs have reduced AIDS deaths sharply, but patients need to keep taking the medicines for life or the infection comes back, Dr. Collins said."
Alt Therapies (Score:5, Informative)
IIRC, they did a bone marrow transplant between someone with AIDS/HIV and another person who had a natural immunity to the disease.
The HIV positive patient was 'cured'
http://www.time.com/time/health/article/0,8599,1858843,00.html [time.com]
Is this a viable cure for HIV? Not by a long shot. Even [Berlin-based hematologist Gero] Huetter says bone-marrow transplants, which kill about a third of patients, are so dangerous that "they can't be justified ethically" in anything other than desperate situations like late-stage leukemia.
...
But there might be a glimmer of hope in the case. If the transplant does prove to have been a success and can be replicated, researchers say gene therapists might one day be able to re-engineer a patient's cells to change their bone marrow the same way a transplant does, except without the dangers.
Re:Uh This is a Surprise? (Score:5, Informative)
-10 internet points. It becomes part of the dna for a few select cell types, not EVERY cell type, and certainly you cannot spread this 'bad' DNA to offspring by means of DNA in eggs/sperm. you are implying that a virus competely changes your entire genetic make up. and this is simply not the case. it changes cellular dna to instructs those infected cells to mass produce new hiv. You wont be growing wings anytime soon.
Re:Alt Therapies (Score:1, Informative)
It would be extremely interesting if the actual source of the invincibility AIDS were to be bone marrow rather than blood itself. Perhaps we have gotten it wrong for the last 30 years or so. What a fantastic world it would be with yet another disease conquered.
The article doesn't do a very good job of putting this finding in context. The idea of "reservoirs" of the virus is both fairly old and well established; reasonably soon after HAART treatments were able to knock down the blood virus counts to undetectable levels, researchers tried the risky experiment of stopping treatment only to see the virus instantly rebounds.
Dormant cells in the lymph nodes are currently considered the most important such reservoir. Various other reservoirs were known or hypothesized, which I would have assumed included bone marrow; apparently it's a new discovery. While important, it's not paradigm-shifting, nor does it offer an immediate path for treatment--we can't currently clear out the known reservoirs. This simply makes the challenge of finding a cure higher.
Scientific American had a pretty good overview issue on HIV cures and vaccines about a year and a half ago. I assume this [scientificamerican.com] is the article, but didn't re-read to confirm.
j.
Re:How about a bone marrow transplant? (Score:5, Informative)
I think it's interesting that the cells themselves can hide in the progenitor cell
We're discussing the aids virus, not a cell infected with it. virus != cell.
The issue here is that some (all?) bone marrow stem cells don't progress with the reproduction of the virus while it's a stem cell. Once the stem cell is infected, the virus sits there, dormant, because the cell is not hospitable for it to reproduce in. Then when the stem cell differentiates into a red blood cell, the virus is able to resume its mission, and kicks out a few thousand new virons which re-initiate infection. This someone that was thought to be "cured" becomes reinfected.
Nerve cells have also been known to serve as time capsules for a variety of viruses, though I don't believe they've figured out what triggers reactivation in those cases. These sleepers are really challenging for the immune system to deal with, because from the outside of the cell where the white blood cells etc are milling around, the infected cell looks and behaves normally. It's only detected as a problem after it's fired up the bug factory inside, and by that time it may be too late. Unless the cell behaves abnormally, there's just no way for the immune system to identify the cell as needing to be destroyed. And from there the only thing that can kill it is itself. But again the apoptosis process is usually triggered by abnormalities within the cell - if the virus is dormant there's nothing to trigger that either. The cell doesn't know it's a carrier, nor does the immune system.
Re:How about a bone marrow transplant? (Score:3, Informative)
Anyway, back on the point: I don't think they'd transplant any tissue from an HIV carrier to a healthy person even without the current finding.
Wha?
The OP was talking about killing off the bone marrow in the *infected* patient and then performing a marrow transplant (a common treatment for lymphomas). No idea how you interpreted it as the reverse, what good would that do??
Re:Uh This is a Surprise? (Score:4, Informative)
News at 11 (Score:2, Informative)
As for transplants being the great new cure-all for HIV infection: no. Transplantation substitutes one batch of problems for another batch of medical issues. A good HLA match is still required, and finding someone with the right CCR5 or CXCR5 mutation would make the situation doubly difficult. Then, because the engrafted immune system will recognize the host's antigens as foreign (even with HLA typing), the recipient would still require immunosuppression, putting them at risk for the kinds of infections and tumours that HIV patients tend to get. Not to mention the costs of actually doing and maintaining a transplant patient. Can't do that for millions of people, it's hugely expensive.
What this study probably implies is that autologous stem-cell transplantation (capturing the patient's own stem cells, eradicating their immune system, and putting back the stem cells to reconstitute the patient's immune system -- a treatment sometimes used in some lymphomas) would not be feasible as a last-ditch treatment for HIV/AIDS. It wouldn't solve the problem of HIV hiding in 'privileged' sites such as the brain (microglia) anyways, and being a source for viral replication/release even when virions are banished from the blood.
Re:Alt Therapies (Score:3, Informative)
Depends on how risky you consider anesthesia. That's about the riskiest aspect of donating marrow, followed closely by the risk of local infection.... As for the process, they basically stick a needle into your pelvic bone and draw out some marrow.
http://www.marrow.org/DONOR/When_You_re_Asked_to_Donate_fo/Donation_FAQs/index.html#process [marrow.org]
Re:How about a bone marrow transplant? (Score:3, Informative)
Re:How about a bone marrow transplant? (Score:3, Informative)
Not that there even is an aids virus. I thought it was HIV
AIDS was originally the description of the condition/symptoms of the disease that was later identified as HIV. The terms are now used somewhat interchangeably. (tho admittedly, this is probably poor usage, but at some point you just have to accept it)
Acquired Immuno-Deficiency Syndrome. Basically, something you caught from someone else crippled your immune system. Took them awhile to figure out what it was and actually isolate and classify it. That something was HIV.
The term "AIDS" got its foothold during the time period between when we recognized the disease and figured out what was causing it. You still call a cold a "cold", even though we now know that being exposed to cold damp weather for extended periods isn't actually what is the root cause of your getting sick.
yes, and it works (Score:3, Informative)
We use chemicals, not radiation. The disease is called leukemia; it is cancer of the immune system.
AIDS has been cured this way. The patient already had leukemia. They got the AIDS cure thrown in for free. :-)