Wednesday, November 14, 2018

PTLDS vs chronic Lyme disease

There has been a lot of buzz about Posttreatment Lyme disease syndrome, PTLDS.

A number of papers over the past couple of years have described the syndrome, working towards a common understanding. Mostly the papers have been written by experts on the "I believe in chronic Lyme disease" side of the divide.

It is a narrowly defined entity. 
PTLDS applies specifically to a group of patients with a history of well characterized acute Lyme disease who were treated according to standard guidelines but despite treatment went on to develop chronic symptoms.  
Not included are:  patients who never had acute Lyme but developed chronic symptoms over time,  patients who in retrospect had acute Lyme, e.g. “summer flu” but diagnosis was delayed for months or years,  patients with a wide array of atypical, mysterious symptoms and syndromes (arguably the largest group), patients suffering with other tickborne coinfections,  patients misdiagnosed because CDC surveillance criteria were inappropriately used for purposes of clinical diagnosis,  patients misdiagnosed with a variety of illnesses ranging from fibromyalgia to MS, and patients infected with novel species of borreliosis and others. 

I have referred to the group as CLD, chronic Lyme disease. 

Nonetheless, the PTLDS name is important because it is now part of the EBM fabric. 

Patients who meet the criteria may escape the labels of psychosomatic disorder, fibromyalgia and CFS. (And, between you and me, once a concept becomes part of the EBM repertoire its definition tends to loosen quite a bit). Don't tell anyone. 

PTLDS opens a door. 
There have been only 4 NIH sponsored studies examining retreatment of Lyme patients. The meaning of the studies has been hotly debated for nearly 2 decades. The most important study is  last, published 10 years ago (Fallon 2008). In the double blinded randomized controlled study of a narrowly defined set of patients the results were positive.  The treatment group had substantial, measurable improvements. The "long-term" active therapy was 10 weeks of IV Rocephin. Cognitive improvements and constitutional improvements were present at 12 weeks. No further treatment was prescribed. At 24 weeks cognitive improvement was lost -- not durable with the 10 week treatment, but constitutional improvements persisted. 

The study conclusions have been misinterpreted and abused by those on the other side. 
Fallon writes in 2012: 
“Each of the U.S. treatment trials on PTLDS have concluded with the recommendation the course of therapy tested in each specific trial was not recommend…”
There is a difference however between whether a trial is effective and whether or not a treatment is recommended.”
“…treatment was shown to be effective.”

To state the obvious:  antibiotics don't make you smarter or fix brain dysfunction.

The studies shows a proof of concept. 
Science provides the cover for biological plausibility:  no effort to eradicate Lyme bacteria in mice, dogs or primates has proved effective. Persistence is demonstrated in test tube studies. Even a human study demonstrated persistence. 

The logic SHOULD be clear.  It is not controversial that people touched by Lyme can be miserable and disabled.  It is not controversial that Lyme bacteria persist. It is not controversial that additional courses of antibiotics have led to clinical improvements in patients -- the best CRTs.

The clinical trials have not helped us find an optimal therapy. But that was not really their purpose. Their purpose was to determine if chronic Lyme is real (not known at the time of the studies) and if patients  improve with additional courses of antibiotics. This was the big question of the day. 

Further research will likely be guided by empiric evidence garnered by practicing physicians. 

The optimal therapy for Lyme is a very complex clinical question and it will take many years or decades for us to get there.

PTLDS patients have a real illness. The patients are suffering with a chronic disabling illness robbing them of any vestige of a quality of life.  Antibiotics have the potential to make their lives better,

PTLDS or chronic Lyme disease?  Not exactly equivalent but heading in that direction. Post Lyme syndrome: RIP.

Any serious discussion about Lyme controversies between the two camps should start here. Chronic Lyme disease --  persistent infection is proved by science.

I will be working on a talk on: How to treat Lyme. I hope some will attend.








No comments: