The following is a repost from the Daily Kos. Go to this link to see over 100 comments and counting on this post there:
http://www.dailykos.com/story/2011/05/05/973226/-Researchers-on-Persistence-in-Lyme-Disease
Over the years I've had to hear the criticism from well-meaning strangers and some friends that Lyme Literate Doctors or LLMDs are treating a disease that does not exist, and that doctors who treat Lyme disease with long-term antibiotics are taking unfair advantage of patients.
Sometimes the discussion can get a little heated with their concern for me, as they think I may be making a mistake. I take a deep breath, and then I say to them, "I hear that you're concerned, and I can see you have issues with these doctors, but what if there is evidence that Lyme disease can infect individual patients for more than 3-4 weeks? Is it not reasonable to treat them with longer term antibiotics when there is evidence they have an existing infection?"
Usually they nod at this point, wondering where I'm going to go with the discussion next. So I ask, pointedly, "Other than looking at case studies, what about researchers who think Lyme disease may be able to persist, or at least have enough doubt that they know more research is needed to find out why a significant portion of the population who contracts Lyme disease has persisting symptoms? What's in it for them?"
I usually get a thoughtful look, and a lot of silence. So I continue.
"I'll tell you what's in it for them:
The pursuit of scientific knowledge. Some people just want to know what really is going on with Borrelia
burgdorferi, and they are working on figuring it out. Not without putting themselves in a position of controversy, either - but most continue to do the benchwork they need to do and publish."
Indeed, many people who are new to the controversy over Lyme disease being a chronic, persistent infection have heard about the doctors, heard about the IDSA; may have heard about various bills before their state senates and heard about the film,
Under Our Skin.
But not everyone has heard about the research that can leave one questioning the common idea that Lyme disease is easy to treat and cure. Not everyone has read
Cure Unknown, even though it is practically considered the Lyme patient community's go-to guide.
"Here,
read this," a patient at a support group leans over a table, handing
Cure Unknown to a newcomer, "Borrow it for as long as you want - we have more than one copy in the group, and it will help you understand the controversy."
I've seen this act take place a number of times, and for many patients it is their first exposure to the story of Lyme disease, how Dr. Willy Burgdorfer discovered the spirochete that caused Polly Murray and her family grief, the creation of Lyme disease support groups, the story of Dr. Joe Burrascano's Senate testimony in the early 1990's, and the ongoing controversy over Lyme disease.
It is also often their first exposure to researchers who are working to understand Lyme disease, and find out how the organism operates, and why some patients continue to have persistent symptoms after 21-28 days of oral antibiotics.
Some of this research is what I will cover here.
Beagles With Borrelia
Dr. Reinhard Straubinger, a researcher at Cornell University, New York, placed infected ticks on 19 beagles and allowed them to feed. Two months later, he tested the dogs and found 18 were infected with Borrelia
burgdorferi, one was uninfected.
He then gave 12 of the infected dogs doxycycline or amoxicillin, and left 6 dogs untreated. Eleven of the twelve infected dogs had developed lameness and recovered on antibiotics, and their antibody response declined. Four of six untreated dogs went on to develop arthritis.
Six months later, all the dogs were necropsied. All the treated dogs still had spirochetes in their tissues, albeit at a reduced load - but had a persisting infection, as if they had not been treated.[1]
Straubinger observed that in untreated dogs, their antibodies had consistently risen throughout the study - but treated dogs had a "dip" in their antibodies. Their antibodies initially decreased during treatment, but as time went on, they were on the rise six months after initial infection - probably due to the surviving spirochetes, according to Straubinger.
Straubinger went on to do a similar study as a controlled study with 16 beagles who were treated with different kinds of antibiotics after four months of disseminated infection. He then went on to treat 12 of the dogs with antibiotics for one month. After
a little over a year, he performed a necropsy on them and found that spirochetes were detected in low levels in multiple tissues regardless of antibiotic choice.[2]
Of Mice and Men
Dr. Stephen Barthold and Dr. Emir Hodzig, of the University of California at Davis, have done a number of well-known studies on mice.
In 2008, he treated one group of mice with ceftriaxone three weeks after infection with Borrelia burgdorferi (Bb) and treated another group of mice with ceftriaxone much later on - four months after initial infection.[3]
Each of these two groups had their own control group of mice which were not treated with antibiotics.
All the mice were tested. The results: One month after treatment, none of the mice had clinical signs of Lyme disease, nor could cultures detect Bb.
But two of five mice had positive Bb cultures. Three months later, one mouse transmitted living spirochetes to 9 uninfected ticks. Five mice were examined one month after treatment and their tissues were positive for Bb DNA.
To add to the story, three months after treatment, tissue of two of these mice still had positive tissue samples, two could transmit living spirochetes to uninfected ticks, and one mouse could transmit an infection to another via a skin graft.
After the mice were necropsied three months after treatment, small numbers of spirochetes were still found in collagen-rich areas of the mice's tissues in their hearts, tendons, and ligaments. It didn't matter how soon they'd been treated, either:
all of them had spirochetes.
In his abstract, Dr. Barthold states:
"...when some of the antibiotic-treated mice were fed on by Ixodes scapularis ticks (xenodiagnosis), spirochetes were acquired by the ticks, as determined based upon PCR results, and ticks from those cohorts transmitted spirochetes to naïve SCID mice, which became PCR positive but culture negative. Results indicated that following antibiotic treatment, mice remained infected with nondividing but infectious spirochetes, particularly when antibiotic treatment was commenced during the chronic stage of infection."
These live spirochetes could be transmitted, but oddly, Dr. Barthold could not get them to grow in culture.
Are these spirochetes pathogenic, though? Do they cause disease, can they
replicate? Barthold states in his abstract that they are nondividing but infectious.
Trial of Tigecycline
After these experiments, in 2010 Barthold and Hodzic went on to test the effectiveness Tigecycline on persisting Borrelia
burgdorferi in mice.[4]
In his paper, Barthold states:
"Clinical assumptions are complicated by the ephemeral, variably recurrent, and diverse nature of both objective clinical signs and subjective symptoms of Lyme borreliosis. What is not known is whether or not antibiotic treatment completely eradicates the infection, and this has generated debate among the medical and lay communities."
He admits to the controversy over the persistence of Lyme disease after antibiotic treatment, and also states it is not known if it completely eradicates infection.
He continues:
"Antibiotics are likely to kill most B. burgdorferi organisms, but the immune system is needed to fully eliminate the remaining spirochetes. However, therein lies the challenge, since Borrelia burgdorferi has evolved to persistently infect fully immunocompetent hosts. Persistent infection has been shown to be the rule, rather than the norm, in a variety of laboratory animal species, including mice, rats, Peromyscus leucopus, hamsters, gerbils, guinea pigs, rabbits, dogs, and nonhuman primates. Based upon culture and/or PCR, persistent infections have also been documented in humans from both Europe and the United States Therefore, the “mop up” phase, which is dependent upon the immune system, is likely to be ineffective against an agent such as B. burgdorferi, which is highly effective at evading host clearance."
In the study itself, a new first-in-class antibiotic, tigecycline (glycylcycline), was evaluated during the early dissemination (1 week), early immune (3 weeks), or late persistent (4 months) phases of Borrelia burgdorferi infection in C3H mice (mice bred to emphasize joint inflammation).
Mice were treated with high or low doses of tigecycline, saline, or ceftriaxone. After 3 months of treatment, infection was assessed using cultures, quantitative ospA real-time PCR, and subcutaneous transplantation of joint and heart tissue into SCID mice (severely compromised immune deficient mice).
The result was that tissues from all saline-treated mice were culture and ospA PCR positive, tissues from all antibiotic-treated mice were culture negative, and some of the tissues from most of the mice treated with antibiotics were ospA PCR positive, although the DNA marker load was markedly decreased compared to that in saline-treated mice.
Antibiotic treatment during the early stage of infection appeared to be more effective than treatment that began during later stages of infection.
The viability of noncultivable spirochetes in antibiotic-treated mice (demonstrable by PCR) was confirmed by transplantation of tissue grafts from treated mice into SCID mice, with dissemination of spirochetal DNA to multiple recipient tissues, and by xenodiagnosis, including acquisition by ticks, transmission by ticks to SCID mice, and survival through molting into nymphs and then into adults.
Furthermore, PCR-positive heart base tissue from antibiotic-treated mice revealed RNA transcription of several B. burgdorferi genes.
These results extended previous studies with ceftriaxone, indicating that antibiotic treatment is unable to clear persisting spirochetes, which remain viable and infectious, but are nondividing or slowly dividing.
Dr. Staubinger, Dr. Barthold, Dr. Hodzic, and their teams are not considered researchers on the fringe, but mainstream researchers who have approached the issue of persistence with an open mind.
One person everyone might want to listen to regarding the possibility of Borrelia
burgdorferi's ability to persist in its host is its very own discoverer, who stated the following during an interview:
"I am a believer in persistent infections because people suffering with Lyme disease, ten or fifteen or twenty years later, get sick [again]. Because it appears that this organism has the ability to be sequestered in tissues and [it] is possible that it could reappear, bringing back the clinical manifestations it caused in the first place. These are controversial issues for microbiologists, as well as the physicians who are asked to treat patients."
~ Dr. William Burgdorfer, discoverer of the Borrelia burgdorferi spirochete, 2009
So we know the spirochetes persist. Researchers know they do. The evidence we need to consistently provide is of their infectious nature after antibiotics have been used. Why this issue of persistence is considered controversial remains a question, given that syphilis can enter a latent, dormant state in its host.
In 2009, Gary Wormser, who denies the existence of Chronic Lyme disease, wrote his own critique of some of these studies:
"What are causes of the attenuation of the spirochetes that persist posttreatment? Are they in the process of dying? Are they producing mRNA, and if so, which mRNA? Are they motile? Can they replicate? Are they genetically altered? Can they regain pathogenicity? "
In his own conclusion, he states, "The biological nature of these spirochetes is unclear," along with some caveats about the likelihood of their being pathogenic.[5]
He thinks they
are not infectious. Other researchers - like Barthold - think they
are infectious. Patients who have experienced relapsing-remitting symptoms definitely think they
are, and would like to put this issue to rest and find treatment that is 100% effective. In the meantime, antibiotics are the treatment of choice.
This is why I push for more research. The research that has already been done is noteworthy and requires further investigation, and only by determining the truth can the controversy be put to rest.
My future directions suggested for researchers:
1) Use non-murine models for study - higher order mammals with more collagenous tissue around their brains
2) After animals have been treated with antibiotics and spirochetes found in tissue, instead of killing them, study them for a few years and repeatedly expose infected host animals to stress (in accordance with study design for ethical treatment of animals).
3) Periodically retest animals for antibodies, PCR, and culture, including CSF and ultimately, brain tissue. Use advanced testing methods in development.
Who knows, maybe it will happen - at the end of Barthold's Tigecycline study he stated, "Further studies are under way in the mouse model to determine if the postantibiotic-persistent organisms return to a cultivable and pathogenic state or if they eventually die out."
References:
1. Straubinger RK, Summers BA, Chang YF, Appel MJ.
Persistence of Borrelia burgdorferi in experimentally infected dogs after antibiotic treatment.
J Clin Microbiol. 1997 Jan;35(1):111-6.
2. Straubinger RK.
PCR-Based quantification of Borrelia burgdorferi organisms in canine tissues over a 500-Day postinfection period. J Clin Microbiol. 2000 Jun;38(6):2191-9.
3. Hodzic E, Feng S, Holden K, Freet KJ, Barthold SW.
Persistence of Borrelia burgdorferi following antibiotic treatment in mice. Antimicrob Agents Chemother. 2008 May;52(5):1728-36. Epub 2008 Mar 3.
4. Stephen W. Barthold, Emir Hodzic, Denise M. Imai, Sunlian Feng, Xiaohua Yang,
and Benjamin J. Luft
Ineffectiveness of Tigecycline against Persistent Borrelia burgdorferi. Antimicrobial Agents and Chemotherapy, Feb. 2010, p. 643–651.
5. Gary P. Wormser, Ira Schwartz.
Antibiotic Treatment of Animals Infected with Borrelia burgdorferi.
Clin Microbiol Rev. 2009 Jul;22(3):387-95.
