A familiar set of neurobehavioral symptoms often attributed to Lyme disease, such as fatigue and cognitive difficulties, is not specific to Lyme disease and is not indicative of nervous system infection or inflammation, according to researchers.
In addition, biomarkers in blood associated with these symptoms are the same whether patients have active, prior or no history of Lyme disease, they wrote in Clinical Infectious Diseases. The researchers said their work helps to illustrate the complexities of understanding the symptom complex and avoiding unnecessary antibiotic treatment.
“Misattribution of nonspecific symptoms to Lyme disease in general, and neuroborreliosis in particular, has contributed substantially to widespread concerns about ‘chronic Lyme disease,’ a poorly defined nonantibiotic responsive symptom complex,” researcher John J. Halperin, MD, chair of neurosciences at Overlook Medical Center in Summit, New Jersey, and medical director of the Atlantic Neuroscience Institute, and colleagues wrote.
Not only are neurobehavioral symptoms common with non-Lyme illnesses, Halperin told Infectious Disease News, but they do not signal nervous system infection of any kind.
“It’s a state commonly unrelated to Lyme,” Halperin, said. “We know that, at any given time, 2% of the United States population is affected by this to a significant extent. And obviously, 2% of the U.S. population does not have Lyme. One question is, when we do see it in someone with Lyme, does it reflect infection of the nervous system or some other alteration of the nervous system function? Some have suggested there’s an aberrant immune response within the nervous system that causes it, so we were trying to sort out the possibilities.”
Previous European studies showed elevated levels of the cytokine CXCL13 and other biomarkers in central nervous system (CNS) infection. Halperin and colleagues tested whether these biomarkers would identify CNS disease attributable to Lyme in U.S. patients as well.
They analyzed samples from 74 patients who had undergone lumbar puncture for possible Lyme neuroborreliosis (LNB). Patients included those who had Lyme disease concurrent with symptoms; those who had Lyme previously and later had symptoms; and those who had symptoms and a non-Lyme illness. Symptoms included encephalopathy and headache, in addition to common neurobehavioral symptoms.
The researchers found that several serum inflammatory biomarkers were similarly elevated in patients with confirmed LNB, those with possible early LNB and those with non-Lyme neuroinflammation.
Halperin said the data add to evidence that much of the chronic symptomology so often blamed on Lyme disease in fact has other origins, requiring further research. – by Joe Green
Disclosures: Halperin reports that he has been an expert witness defending physicians in cases related to possible Lyme disease.