Tuesday, May 20, 2008

Why is Lyme different from other bacteria

This is the $64,000 question. What makes it special. Bacteria are either pathogenic, meaning they have the ability to cause disease, or they are non pathogens: they don't make you sick. Some bacteria are a little of each. For example, Group A Beta hemolytic streptoccoci can live peacefully in your throat, a situation doctors call colonization, or it can make you sick as hell with a raging tonsillitis, rheumatic fever or worse- necrotizing fasciitis, the dreaded "flesh eating germ." Bacteria can behave in unpredictable ways. For the most part, they either make you sick or they don't. They don't cause something in between. Or do they? Chronic Lyme is about a new paradigm in infectious diseases. Here the germ just makes you a little sick, to varying degrees. It is well established that some bacteria are hard to eradicate. Colonization with Strep or Staph, including MRSA is difficult to eradicate. The mycobaterium which causes tuberculosis is notoriously difficult to treat. Infectious disease specialist here have no qualms about recommending a two year course of three antibiotics to treat the problem. Of course with TB you are either sick or not, not somewhere in the middle. Most persons harboring tuberculosis are considered not sick. The germ is walled off and dormant. Medication to prevent activation is not warranted if you are past a certain age because the risk of liver toxicity from the medicine exceeds the potential benefit of treating a germ which is not currently making you sick. Physicians must follow the dictum: First do no harm.

The whole notion that germs which do not make you obviously sick are making you sick in subtle, less obvious ways is not accepted by current medical paradigms. In other words, the germ is not causing a raging fever or causing you to cough up horrible foul colored and foul smelling sputum. In fact to the casual observer you do not look sick at all. But you know something is wrong. You have symptoms. The process is frequently insidious. It waxes and wanes. You frequently dismiss the symptoms and try to push through them. You chalk it up to the normal aging process, even if you are only 25 years old.
The notion that chronic bacterial infections cause illness is not described in medical texts. It is not included in standard lecture series given to medical professionals. Diseases are categorized for physcians into clear groups. They are inherited disorders, neoplastic disorders, degenerative disorders, automimmune disorders, disorders particular to an organ system, disorders of the glandular system, disorders of self-regulation or homeostasis, degenerative disorders, disorders of aging, disorders of an unknown cause, neurological disorders or infectious disorders which present with a very specific set of symptoms. Specific diagnostic tests and treatment protocols are codified in conventional medical texts. (I am sure I have left out many other categories of disease, this list is only for informational purposes). Slow viral diseases are well accepted. HIV has a long latency period. Hepatitis C may be present for 30 years before your liver begins to fail.But there is no category of chronic bacterial infections which make you sick in subtle ways. Enter Lyme disease.

The immune system left to its own devices is unable to eliminate spirochetes, the cork screw shaped germs which include Borrelia, the Lyme species. We know this from the Tuskeegee experiment. This is a horrendous chapter in the history of medicine. A cohort of African Americans with syphilis, not treated and followed over time, ended up with the ravages of third stage syphilis, including brain and other end organ damage. Lyme is like syphilis on steroids.

Lyme is bigger, badder and smarter than T. pallidum, the syphilis germ. It has a lot more genes: 132 vs 20. It has the ability to mold its surface proteins to avoid the immune system and to morph into three distinct forms in a fashion reminiscent of a shape shifting alien monster from science fiction stories. It is known to have a proclivity for attacking the brain and the nervous system. It reproduces slowly and spreads throughout the body without much interference from that pesky immune system. And this is no mean feat. The human immune system is a remarkable highly evolved and effective masterpiece of biological engineering. For a bacteria to so effectively ignore these defenses is no mean feat. And yet it does these things. And much research has been done showing just how it does it.

The spirochete starts its tricks shortly after the tick bites the host, you. When your blood flows into the tick it carries antibodies which would normally destroy the germ. It has the ability to upregulate and down regulate surface proteins to help it avoid the immune system. In other words, it can make proteins on its surface appear and disappear at will in order to provide the optimal protection from your immune system. Once it enters your tissues it drills into tissues and cells where it is relatively protected. It spends very little time out in the open, in fluid compartments like the blood stream where it could fall easy prey to the immune system. When conditions are right it becomes an inhabitant of the inside of your cells. When it is intracellular it looses it cell wall. It stops being a spirochete and becomes something called an L-form. At other times it quickly converts to a cystic, spore like structure which also protects it from the immune system. Over time, as the infection becomes firmly established it makes other changes in your immune system. It somehow lowers the numbers of Natural Killer T cells, an important part of the germ killing cell mediated immune response. It increases the amount of active vitamin D which suppresses an anti-germ response of the helper T cells. It sequesters itself in various niches which are difficult to access. . Germs evolve in ways to ensure their survival. Some bacteria, viruses and parasites make us sick, others do not. Lyme is a parasite which ultimately can make us very sick over time.

No comments: