New Test Could Help Diagnose Lyme Disease Sooner and Determine Treatment Efficacy

Traditional tests for Lyme disease, caused by a bite from an infected tick, can stay positive for prolonged periods of time after treatment, making it difficult for clinicians to diagnose persistent Lyme disease cases. Lyme disease frequently goes undetected unless a person notices the telltale rash that forms around the bite. Caused by the bacterium Borrelia burgdorferi, Lyme disease can often be treated with antibiotics, but the disease’s effects can persist in 10 to 20% of cases. Lyme disease can lead to debilitating long-term complications including arthritis, fatigue, mental impairment, and in the most severe cases, attacks on the heart and brain tissue. Scientists and clinicians have been making efforts to develop tests that identify the disease sooner, show when people are cured of infection, and can diagnose reinfection. Now, researchers have identified just such a testing mechanism.

The testing mechanism identified by researchers at Tufts University School of Medicine (Medford, MA, USA) detects a type of antibody that infected individuals produce against a substance the Lyme bacteria acquires from the host in order to grow. The researchers believe tests to detect these autoantibodies - antibodies that mistakenly target and react with a person's own tissues or organs - could provide clinicians with a way to diagnose the disease sooner, know whether treatment with antibiotics is working, and identify patients who have been reinfected. During their research, the scientists discovered that both animals and patients infected with the Lyme bacterium developed autoantibodies to multiple phospholipids. Because autoantibodies can be damaging to the host, these autoantibodies are tightly regulated and tend to disappear quickly once the stimulating factor is removed.

While current testing makes it difficult to diagnose reinfection or successful treatment, “the anti-phospholipid autoantibodies - because of their quick increase and quick resolution with treatment - can fill these gaps as a novel additional test,” said Peter Gwynne of the school’s Department of Molecular Biology and Microbiology. “They may make it possible to tell whether treatment has eradicated the Lyme disease bacteria. And they therefore also make it possible to tell if a patient with a prior infection now has a new infection.” The researchers have a provisional patent pending describing the use of antiphospholipid antibodies in the diagnosis of Lyme disease. Their hope is that if their discovery is borne out by further research, a diagnostic company could begin development of a commercially available version of their test within a couple of years.

However, a bigger question is whether these autoantibodies may identify a subset of patients who will develop persistent symptoms of Lyme disease after treatment. Up to 20% of patients can develop persistent symptoms after Lyme disease. Diagnosis of these patients is currently only by clinical symptoms, making it likely that patients with different causes of their symptoms are grouped together. And treatment trials in patients with persistent Lyme disease are unlikely to show benefit if that occurs.

“Anti-phospholipid antibodies are commonly seen in autoimmune diseases like lupus, and are associated with blood clots and persistent inflammation that causes other disease conditions. Many of the persistent symptoms in patients who continue to have symptoms after being diagnosed with Lyme disease are similar to those autoimmune diseases,” said Linden Hu of the school’s Department of Molecular Biology and Microbiology. “If there ends up being a link between having persistent Lyme symptoms and these autoantibodies, this would be the first test that could be used to distinguish a group of patients who have persistent Lyme disease. It would allow us to test specific new therapies targeted to a defined mechanism.”

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Tufts University School of Medicine