Monday, July 25, 2011

Lyme tests old and new

My recommendations for Lyme testing have not changed.

Some new tests have been introduced, unfortunately there are no published studies demonstating their validity. One test is called an immune tolerance test. It measures T cell proliferation after exposure to select Lyme antigens. There exist very few studies regarding such lymphocyte proliferation tests for diagnosing Lyme. Oddly, the background paper published by the manufacturer, describing the underpinnings of this technology, cites an old Wormser study in the foot notes. The Wormser study using somewhat different methods concluded the test was insensitive but specific.

A second test measures an array of cytokines levels in response to antigenic stimulation. This test is also offered without any validation.

I suspect the problem may relate to the way the immune system responds to Lyme infection. The early immune response to Lyme infection, the cell mediated response, is measured here. Lyme bacteria are known to be very immungenic. Early Lyme infections are associated with dramatic immune responses. This is why for example, early EM rashes frequently show marked inflammation. It is also why early Lyme may be associated with fever and a flu like illness(mini-cytokine storm).

I think the concept of a cell mediated immune assay for the diagnosis of Lyme is right.

Such a test has been developed for tuberculosis. It measures a direct cytokine response to antigen presentation.

A new test for Lyme is sorely needed. Current tests remain clearly inadequate.

When I test my patients I continue to skip the ELISA and go right to the Western Blot. Although there are some patient who are ELISA positive and WB negative, these patients generally show some reactivity on WB assays.

Various labs seem to offer complete Lyme Western Blots. These include: IgeneX, Clongen, MDL, and SUNY. The SUNY Lyme lab presents some bands not seen from the other laboratories. Western Blot testing may also be available through the Mayo Clinic I have been informed. (I only have direct experience with IgeneX and Clongen although I have seen reports from other labs)

I like the C6 peptide test. This is a very specific ELISA test. It has a lot of false negatives because the antigen tested can easily change its epitope. Any value greater than 0.1 needs to be considered. With values of 0.4 and greater, I am fairly comfortable suggesting the patient has had prior exposure to Bb even in the face of a negative WB.

Co-infection testing is indispensible. Any positive results significantly increase the likelihood that a co-infection (here Borrelia) is also present.

The best test still remains a careful history and physical examination of the patient.

Sunday, July 24, 2011

Everything you thought you knew about cyst busters is wrong

Eva Sapi's recent research calls into question everything we thought we knew about Lyme "cysts." In fact it destroys the old thinking.

We have heard about cell wall antibiotics, intracellular antibiotics and cyst-busters. Think again.

She investigated the effect of various antibiotics on Lyme spirochetes and round body forms - also know as cystic forms.

Doxycycline worked according to plan. Doxy inhibits protein synthesis - it kills bacteria, including Lyme, by action within the cytoplasm, inhibiting the manufacture of proteins required for the bacteria's survival. Doxy and others are commonly referred to as intracellular antibiotics.

Spirochete loads decreased by about 90% while cyst levels increased by 200% - just as expected.

Then amoxicillin data was presented. Amoxicillin inhibits the formation of bacterial cell walls. Amox and similar drugs should then only be effective in killing spirochetes with an intact cell wall. This is where the results start deviating from the plotted course.

Amoxicillin killed 90% of spirochete forms - OK, but -- it also killed 68% of the cystic forms! Amoxicillin and other cell wall drugs are not cyst busters - only specific anti-parasite drugs kill cysts - or so we thought.

Well lets think again for a second: what are cysts? Are they balled up forms of spirochetes with a different kind of membrane - or blebs (also described) expressed through the spirochete membrane? Maybe the former retain much of the cell wall from the original spirochete - maybe that is why amoxicillin works here.

This would seem to clear up a nagging question raised by others. Are cysts and L-forms really the same thing? These results show that cysts cannot represent a version of L-forms or spheroplasts which result when gram negatives shed their cell walls. If this were the case a cell wall drug would be ineffective. Cysts and L-forms are distinct and different forms. (There may be a hole in this reasoning. I will explain later).

OK So we have learned something new: cell wall antibiotics can also kill some cyst forms which are not L-forms.

Let's look at some more data. Tigecyline is a not a cyst drug either. Wrong. Tigecycline kills 90% of spirochetes, good so far, but it also kills 90% of cysts! Tigecycline is an intracellular antibiotic similar to doxycycline! Another fly in the ointment.

OK. Cysts with their lower metabolic rate, still need ribosomal proteins to survive, just not at the levels of intact spirochetes. Tigecyline is a more powerful drug, higher levels are delivered into the cytoplasm of the cysts. This makes sense. Cyst forms are still essentially a pleomorphic version of Lyme bacteria with somewhat different features. In this scenario, cysts could be L-forms. But we have already shown that this is not true because amoxicillin can kill them. Right?

Amoxil is a cell wall drug. I thought so. Kersten, (antimicrobial agents and chemotherapy, May 1995, p. 1127-1133) states that Beta-lactam antibiotics, which include amox, penicillin and Rocephin, have been shown to cause a specific loss of total intracellular RNA in the absence of cell wall hydrolysis. In other words, amoxil could possibly work in part as an intracellular agent. If this is right cyst forms of Lyme could still be L-forms. So perhaps we have not shown that L-forms and cyst forms are different after all.

The question remains unanswered.

Let's get to the Cyst-busters. It takes antiparasitic drugs, so we thought, to kill the cysts. Cyst-busters, anti-parasite drugs, kill parasites (and Lyme cysts) not bacteria. The so called cyst-busters were heretofore used in combination or cycled with other antibiotics. Previous thinking was that typical antibiotics would kill spirochetes and/or L-forms and that cyst busters would disrupt only the cystic forms.

Cyst-busters do not kill intact spirochetes - so we are told. Very wrong this time.

I cannot cover the whole Sapi study. The most exciting finding is that Tindamax (tinidazole) - our premier Cyst-buster, is the most effective drug overall. This "cyst-buster" kills 90% of cysts and spirochetes: by far the best drug. We don't know it's effect on L-forms, but we can guess. Tindamax probably works by an intracellular mechanism. If this is true it should be equally effective against L-forms.

It gets even better. Tindamax is the only drug which does a great job on biofilm colonies as well!
(not to be discussed now). More on biofilms later.

Tindamax passes the blood brain barrier and penetrates well into most tissues. It has been effective in my patients with neurocognitive deficits - neuroborreliosis.

Recently I tried it on another sort of patient. This patient has had intractable Lyme arthritis of his knees. This young athlete had been extensively treated with IV Rocephin followed by a year of typical oral antibiotics. Knee effusions have persisted - until I prescribed Tindamax. Now, after two months, the fluid in his knees has evaporated. His knees are dry and painless for the first time in over one year.

This raises the question: should Tindamax be used as mono-therapy? Well, I cannot endorse blanket use at this time. Tindamax has a black box warning. It has been associated with cancer in some laboratory animals. Perhaps there are more compelling reasons to use Tindamax, but this will have to wait for another post.

My nagging question:

Why does penicillin kill Lyme? It shouldn't. Lyme is a gram negative bacteria. While certain Beta-lactam antibiotics can kill gram negative bacteria, penicillin cannot. Penicillin is only active against gram positive bacteria.

Maybe this other mechanism alluded to above, the alternative intracellular RNA mechanism is significant and explains why penicillin kills Lyme spirochetes. Maybe not.

We need to continually reevaluate things which we have assumed to be true, because many of them are not.