Some thoughts about antibody levels ...

Discussion in 'Fibromyalgia Main Forum' started by matthewson, Feb 3, 2007.

  1. matthewson

    matthewson New Member

    being used as treatment markers for anti-biotic/ antiviral therapy.

    I see a lot of posts about antibody levels and that this one or that is high and I just wanted to post on what my experience has been working in Blood Banking.

    If a patient has been transfused with a unit of blood and they develop an antibody to one of the many antigens on the surface of a red blood cell, they become sensitized to that antigen and produce antibodies to it. Initially the reaction can be quite strong, that if you were to titer it out, it would be quite high.

    Some people, years later, have lesser amounts of antibodies to that antigen, and yet some people still have the same high levels that they had initially after the exposure. Now, these people will never again be transfused with blood that contains that antigen, because we test for all common antibodies before we give anyone blood. So, since red blood cells only last about 120 days in the system before they are filtered out by the liver, there are NO red blood cells with that antigen that produced the antibody response in their system at all PERIOD!

    So, why is it that some Dr's rely on antibody titers and I am assuming they are monitoring the IgG antibodies to previous infections to treat with anti-virals or antibiotics? Could someone please tell me what the rationale is that these Dr's are using IgG titers as markers so to speak to gauge how anti-biotic/anti-viral therapy is working? I would be interested to hear this.

    What got me to thinking about this is Swedeboys post about being tested for EBV antibody levels every year. My first thought was "Why"? He also said that they have not changed in I don't remember how many years.

    I am going to post some info from Webmd that I found quite interesting about this topic. This if from an article on Chlamydia pneumoniae.

    One expert, though, cautions that antibody levels may not be the most reliable means for determining associations between infection and heart disease. "Antibody [levels] are not very specific in telling who has just been exposed, who is currently infected, or who was chronically infected," says Ignatius W, Fong, MD, professor of medicine at the University of Toronto and head of the division of infectious diseases at St. Michael's Hospital, also in Toronto.


    "What you get is a mishmash of patients you look at who may have a combination of previous exposure but are not persistently infected, some who are persistently or chronically infected -- which we think are the ones that will have it in the circulating blood cells and are more at risk for having atherosclerosis -- and the antibody [tests] cannot differentiate them; you can get an overlap and conflicting data from various studies," Fong says.


    Siskovick acknowledges that measuring antibody levels essentially gives a snapshot only of prior infections, when "what we're really interested in is chronic infection, reinfection, reactivation of infection, and so on." But because they did not have any way to accurately gauge infections by other means, they designed their study to ask whether previous infection as reflected by the presence of antibodies was related to the risk of heart attack and death from a heart attack in older adults. The signs, Siskovick and colleagues contend, indicate that the answer to that question is probably yes.

    Oops! I thought this post didn't make it on and I retyped it and then I just deleted the second post that was the full one!

    Anyway, I would like anyone's thoughts on this as this has me in a quandry. Basically, everyone's immune system responds differently with regards to amounts of antibodies to offending antigens and I have trouble seeing how these Dr's are using antibody titers to gauge if a treatment is working or not. As you can see from my example in blood banking, there would be no offending antigen left in the system after 120 days, yet the antibody (IgG) response in each individual would be different.

    Thanks for any and all reponses.

    Take care, Sally[This Message was Edited on 02/04/2007]
    [This Message was Edited on 02/04/2007]
  2. u34rb

    u34rb New Member

    matthewson,

    Sally,

    "red blood cells only last about 120 days in the system before they are filtered out by the liver, there are NO red blood cells with that antigen that produced the antibody response in their system at all PERIOD!".

    Perhaps my experience with IgG may be the answer. Every year my IgG is measured because I have a MGUS, Monoclonal Gammopathy of Unknown Significance. And every year a value is returned. Does this mean that several years ago I was infected or (if my blood cells are replaced every 120 days) I am still infected with a chronic pathogen?

    Well, it seems that both statements may be true! And the reason is that I probably have a clone based somewhere in my bone marrow pumping out the IgG. Either because it got switched on some years ago and forgot to switch itself off, or I have a current chronic infection which it is responding to.

    In other words, my IgG is a marker for either past or present infection.

    I would really very much like to make sense of the "unknown significance" since if I could make it 'significant' I might solve the riddle of my chronic illness!

    I am excited to find out if I have any Ig sub class deficiences.
  3. matthewson

    matthewson New Member

    Any other thoughts on this?
  4. matthewson

    matthewson New Member

    Anyone else?