WAZZUP?! - New and Notable
"Immunology in Health and Disease: An Outline for the Layman"
"Plants That Allergy Sufferers Should Avoid", The New York Times, Sunday, July 7, 2002, Cuttings, in Sports (Sec 8), p13.
This web site contains discussions regarding the more common allergic disorders and their consequences. However, our Immune System - that collection of cells, tissues and organs including various types of white blood cells, thymus, lymph nodes, intestinal Peyer’s patches and spleen, is the seat of many other functions in health and disease. Thus, in addition to its role in defense against infections, the Immune System is deeply involved in autoimmune disorders, transplantation, cancer, the aging process and in both normal pregnancy and in infertility. In fact, human life is not possible without a normally functioning Immune Sustem.
1) Autoimmune Disorders:
It is vital to our survival that our Immune
System recognizes the difference between “self” and “non-self”. Otherwise,
this system would destroy itself and its host during fetal life.
It is now understood that we all harbor a small number of B and T lymphocytes
that can react against self, and that their number and activity are
controlled partly by hormones and partly by genetic predisposition.
When a sufficient number of self-attacking cells develop, the result is a group of diseases called “autoimmune diseases”. The type and consequences of the disease produced depend upon the type of body tissue attacked. When the skin is attacked, autoimmune bullous (blister) diseases result. When the kidney is attacked, nephritis (like Goodpasteur’s Syndrome) results. When joint tissue is attacked, various types of arthritis result. When many different tissues are attacked, including the blood system itself, “Lupus” (Systemic Lupus Erythematosis) results. These diseases are more common in women, and at least some tend to run in families. Treatment involves supprression of the destructive immune reaction while maintaining the normal immune responses - a tricky challenge.
Medical science can now transplant several
different foreign (donor) tissues into recipient (host) bodies: lung, liver,
kidney, pancreas, skin, cornea....In such cases, however, the medical team
must overcome the natural tendency of the recipient immune system to reject
the foreign donor tissue. The closer the genetic match, the easier
the task. In the case of identical twins, there is no problem whatsoever.
But in all other cases, immunosuppressive drugs must be used. The
most important of these are steroids - cortisone, but there are many others.
The problem is in giving enough to protect the transplanted tissue, but
not enough to knock out the host defenses, which are always at least
partly suppressed by these agents. In fact, long-term use of immunosuppressive
agents - as is necessary for long-term protection of transplants,
leads to an increased susceptibility to infections, and to cancers, as
discussed below. There is even a special problem wherein the transplanted
tissue itself contains too many competent immune cells from the donor.
In that case, a “graft versus host” reaction can result, as the transplant
attacks the recipient host. Not healthy.
Even in the best of circumstances, the results are only partial. For example, the average 10 year survival of kidney transplants (except between identical twins) is about 40 %. However, medical science is getting progressively better at modulating these immune reactions so as to enable more and safer transplantations to be performed.
Our Immune System is vital in tumor surveillance, and in the removal of pre-malignant cells from our bodies - on a daily basis. Thus, in primary or in secondary immunodeficiency diseases, there is an increased incidence of cancers. The most well-known example of this, unfortunately, is AIDS, whose virus (HIV) attacks normal lymphocytes. Among the many consequences are Kaposi’s Sarcoma, Non-Hodgkin’s Lymphoma, and cervical cancer. On a more global scale, the immune system is affected by psychological states including anxiety, stress, and especially resentment, all of which suppress the immune system. There is a message here for all of us.
4) The Aging Process:
Aging itself is associated with - and
may indeed be partly caused by “immune senescence”, wherein our lymphocytes
gradually die off in a pre-programmed process called “apoptosis”, or “programmed
cell death”. The speed of the process is genetically controlled,
but it proceeds in all of us.
Can we do anything about this process to delay it? The only manipulation found - in mice - to delay the aging process is substantial reduction in caloric intake while maintaining nutrition. Vitamin supplementation has been suggested in the form of Vitamin A, C, D, E, B6, B12, and also iron and zinc, although there is no clear evidence concerning the effectiveness of these agents for this purpose. Thymic (remember that?) extract is also being tested.
In any case, something must be happening to the process of aging in humans. In the 1600’s, the average life expectance was in the 20’s. In 1900 it was age 47. Now the average life expectance is nearly 80 years. In fact, of all the people who have EVER lived on Earth since Adam and Eve and who have reached the age of 65, more than half are alive today! Maybe there is a chance to beat the grim reaper...if not the tax collector.
5) Fertility and Infertility:
Not only is our immune system responsible for
our health - and for some of our miseries. It is also vital to whether
we enter the world at all, and to whether we reproduce. For normal
pregnancy to be successful, maternal immunosuppression is necessary in
order to tolerate the “foreign” (partly paternal) graft represented
in the fetus. Conversely, some of the problems of persistent infertility
and of ”recurrent pregnancy loss” which are increasing in our young population
have their origin in the Immune System.
The well-known general problems include age of female partner, sexually transmitted diseases, chromosomal abnormalities in utero, environmental toxins and co-existing diseases. Less well-identified issues include a global (but not geographic) reduction in the quality of sperm, the increasing finding of anti-sperm antibodies in the female partner (possibily due to delay in permitting conception in the face of prolonged sexual contacts - a process of sensitization), and increasing types and duration of stressors in modern life. These latter issues all have immunologic implications, in addition to the issue of anti-cardiolipin antibodies found in the blood of some women with auto-immune diseases.
So Allergy / Immunology involves not only “sneeze and wheeze”. It may actually be as close to the “Meaning of Life” as we get - short of “Love thy God...and Love thy neighbor as thyself”.