Conference misery::feline_v1

1064.0. "FeLV and AIDS - could their be a connection?" by DISSRV::GERRY (Go ahead, make me PURRR...) Tue Jan 26 1988 15:51

    This is an article published in PET HEALTH NEWS - Jan/Feb 1988
    It has been recopied here without permission.  I thought it might
    be of interest to other Feliners.
    
    
    FeLV Studies May Prove Helpful to AIDS Research
    
    Researchers at the University of Illinois College of Veterinary
    Medicine may gain a greater understanding of the human AIDS virus
    through a study currently being conducted on Feline Leukemia Virus
    (FeLV).  Although FeLV does NOT infect humans, the similarities
    between it and the human AIDS virus make it an accurate model for
    studying AIDS.  
    
    FeLV is not to be confused with Feline T-lymphotropic Lentivirus
    (FTLV), the agent that causes an AIDS-like illness in cats.  FTLV
    was discovered earlier this year by a veterinary team at the Universit
    of California at Davis.  Although both FeLV and FTLV are the same
    types of viruses, there is no known link between the two.
    
    Wayne Tompkins, Ph.D. and Mary Tompkins, D.V.M., of the University
    of Illinois College of Veterinary Medicine, are currently studying
    how FeLV affects cats.  Working with a grant of $750,000 from the
    National Institutes of Health, originating through the National
    Institute of Allergies and Infectious Diseases, the doctors hope
    that what they learn about treating and preventing FeLV in cats
    may also bring insight to the ongoing research on AIDS in humans.
    Cats, like humans, contract their immune-system diseases naturally,
    and studies so far have shown that the viruses affect their immune
    systems in similar ways as the AIDS virus affects humans.
    
    FeLV attacks and cripples a cat's immunity.  It prevents the immune
    system from fighting off almost any sort of infection, even infections
    caused by simple bacteria, viruses or fungi.  The AIDS virus attacks
    humans in much the same way.  In both cases, most patients die not
    from the original virus, but from secondary illnesses that their
    disabled immune systems cannot conquer.  The incubation periods
    for both diseases can last for years, so an infected cat, or human,
    may be stricken at any time after exposure to the virus.
    
    According to Dr. Mary Tompkins, a specialist in feline immunology,
    about 1 percent of the cats in the United States, and up to 30 percent
    of the cats that live in multi-cat households, are infected with
    FeLV.  Some of these may be carriers without actualy exhibiting
    signs of the disease, but even carriers suffer from impaired immune
    systems.  About 50 percent of infected cats will develop signs of
    the disease within two years after exposure to the virus.  There
    is a vaccine against FeLV, but many cat owners still have not had
    their cats vaccinated.  
    
    The goal of the Tompkins team is to isolate the individual components
    of the feline immune system in order to learn which specific cogs
    in the system are being adversely affected by the virus.  Once they
    understand the structural foundation of the condition, they hope
    to be able to develop treatments and preventive methods to combat
    infection.  Success in reaching this goal could mean success for
    researchers of the human AIDS virus as well.
    
    The body levies various lines of defense against invasions of viruses
    like FeLV.  The first stage involves legions of immune cells, called
    macrophages, which attempt to destroy and swallow infectious agents.
    If these fail, as they usually do against FeLV, the macrophages
    call for the assistance of "T-helper cells," which produce the
    substances interleukin 2 and interferon.  These substances then
    call "killer cells" to the site to "pacify" the invading viruses.
    
    In an immune system that is infected with FeLV or AIDS, the T-helper
    cells are either greatly weakened or entirely ineffective.  This
    allows the infection to spread unchecked.  The Tompkinses hope to
    learn where the actual defect in the immune system is located. 
    They will isolate each of the different types of cells involved
    in the immunity process to discover which are directly attacked
    by the virus.  The Tompkinses' work will focus most heavily on the
    relationship between the macrophages and the T-helper cells, and
    the agents they produce to create immunity against infection.
    
    The Tompkinses' studies thus far have shown that the T-helper cells
    within most cats with FeLV are unable to produce interlukin 2. 
    They have also identified infected cats that are producing interleukin
    2 but that are experiencing no killer cell activity against the
    virus.  Still other cats do not produce either interleukin 2 or
    killer cells.  In all cases, the immune systems are somehow being
    blocked.
    
    The Tompkinses hope that the results of their research will also
    identify what causes the cat's immune system to turn the carrier
    stage of the disease suddenly into an active case of FeLV.  They
    plan to devise a system by which they can track the activities of
    all the involved cells through each stage of the disease.  Eventually
    the doctors hope to discover ways to correct the problem, perhaps
    by learning to activate the immune system through other channels
    within the cat's body.  If they are successful, their findings may
    contribute to human AIDS research.
    
    
                                                  

    Cin,
    
    Closer to home Dr. Max Essex of the Harvard School of Public Health
    has been studying FeLV for more than 12 years and relating his findings
    to human disease including AIDS.  He is part of the US team working
    on the problem.
    
    Frank

    Thanks to both of you for these informative notes. I had heard
    from my vet that there were similarities between AIDS and FeLV
    but didn't actually know what they were other than the immune
    system was affected, and that cats frequently develop tumors. 
    (An aside - I was told by my vet that tests now show that 10% of 
    the cats who have been identified as having FeLV
    through the test in the New Jersey lab eventually throw off the disease
    entirely - a fact just very recently published.)
                                 
    Again, thanks for putting in the time to re-print the article.
    
    Pat
                                                    

    Last fall I attended an informational seminar about AIDS and the
    doctor speaking told us of the similarities between AIDS and FeLV.
    
    Apparently several groups studying AIDS have approached the drug
    company that markets the FeLV vaccine for help.  This drug company
    will NOT share their knowledge of the disease/vaccine with anyone.
    
    Can you imagine witholding data of this magnitude for the sake of
    a few dollars (apparently they have patented their vaccine and don't
    want to share it's "secret") when it could help lessen the threat
    we face from AIDS?  The doctor said it was a foreign drug company
    and as such, safe from prosecution in US patent court.
    
    Sue

    re:  .3
    
    I don't think the drug company is hiding *everything* because they
    aren't the only ones who have the information, fortunately.
    
    Dr. Max Essex, at Harvard Medical School, was one of the developers
    of the FeLV vaccine -- he is the researcher referred to in an
    earlier reply to the base note about the current work being done
    on FeLV and human AIDS.
    
    So I suspect that those scientists/vets/etc. on the cutting edge
    of the research have access to pretty good information and people.
    
    I hope so!
    		Penelope

    Re: .3...I don't know where the doctor got his information, but
    Leukocell was introduced over two years ago as the world's first
    feline leukemia virus vaccine by Norden Laboratories, located in
    Lincoln, Nebraska.  I know that Nebraska is still part of the U.S.
    as I've flown over it on numerous occasions.  The vaccine is protected
    by U.S. Patent No. 4,332,793.  I cannot begin to imagine that this
    company, who had so much assistance from researchers in the veterinary
    medicine field, would ever withhold such information.  It's quite
    possible that some other foreign drug company had some information
    they are not willing to share, but I don't think the doctor who
    gave the seminar you attended had his facts straight.
    
    I guess the ad that says the only thing that's spreading faster
    than AIDS is the misinformation about this terrible disease is right.
    I'm also sure that the company wants to protect their patent on
    the vaccine, but I can't imagine they would do anything so cruel.
    Also, didn't Tufts do alot of research on the virus???
    
    BTW, I have no interests in Norden Labs, except that my boys are
    receiving the vaccine.  The information I got for this note was
    taken from one of Norden's ads for the vaccine.

    Mary

    
    
    (I'm glad) I stand corrected!  I wouldn't want to think anyone would
    do such a thing either.
    
    Thanks.