Though antibiotics can often clear up symptoms of Lyme disease within a few weeks, some patients experience severe symptoms like nervous system abnormalities, heart rhythm irregularities, and arthritis weeks or even months after infection. At this point, scientists don’t yet completely understand the exact cause of the longer-term symptoms, and they aren’t easy to treat.
But new research out of Johns Hopkins and Stanford University could lay the groundwork to help determine which Lyme disease patients develop post-treatment Lyme disease syndrome (PTLDS), a little-understood and controversial disease.
To investigate, researchers at Hopkins set out to identify the biological “signatures” of particular immune system molecules called mediators; the idea was to determine which parts of the immune response are mobilized in reaction to the disease, particularly in the beginning, when patient symptoms are most acute.
After studying the levels of 65 different molecules, the team’s analysis found two different groups of Lyme disease patients in the early stages of infection: “mediator-high” and “mediator low.” Those in the high-mediator group exhibited more severe symptoms, higher rates of antibody production, and higher liver enzymes before treatment.
They also showed higher levels of three particular mediators, which returned to normal after treatment. Researchers found that patients in the mediator-low group seemed to have been unable to mount a strong immune response to the disease.
The levels of particular mediators and their receptors may be important biomarkers for Lyme disease that could be linked to individual symptoms.
“With this signature in hand we can begin to ask in larger numbers of patients if all or part of this signature stays elevated in some and if these can be related to PTLDS,” says Mark Soloski, senior author of the report and a professor of medicine at Hopkins.
“These biomarkers have the potential to provide insight into disease process but also may be of value in predicting who may develop PTLDS as well as suggest pathways that can be targeted for therapy.”