Could the new Lyme disease test help prevent chronic infections?

Lyme disease is the most common vector-borne disease in the US – new CDC estimate shows that about 476,000 Americans are diagnosed with Lyme disease each year – and it’s caused by bacteria Borrelia burgdorferi. It is primarily transmitted to humans through the bite of an infected person Ixodes fleas; also known as black-legged tick or deer tick.

Although transmission does not occur instantly when a tick bites a person – in fact, it must be attached to a person for 36 to 48 hours or more to transmit the disease – it often takes a person a long time to realize that the tick is attached to them, with some not even noticing. completely to the point of involuntarily descending.

This is due to the fact that small ticks, especially nymphs, are young ticks between the larval and adult stages and are at the highest risk of transmitting Lyme disease. It is about the size of a poppy seed and very abundant.

If a person contracts the disease, a common initial indication is a ‘bull’s eye’ rash which usually develops near the tick bite site. As the rash gets bigger, it will disappear in the center and develop a red circle on the outside. Other early symptoms may include fever, headache, tiredness and joint stiffness.

These symptoms can lead a person to seek tests, and, if the result is positive, two to four weeks of treatment with antibiotics usually follows. For many people, this is enough to clear up the infection; but it doesn’t work for everyone and some people continue to experience symptoms.

“We don’t know if the symptoms are still due to an active infection, nerve damage, or some sort of autoimmune reaction. There are no current tests that can determine this. It’s similar to long COVID – no one really knows what causes it or what to do about it.”

Stella Huyshe-Shires, head of Lyme Disease Action

What is chronic Lyme disease?

While treatment works for most people, in about 10 to 20% of people treated with the recommended dose of antibiotics, Lyme disease symptoms persist, even after they finish treatment. This is known as post-treatment Lyme disease, and the symptoms, such as fatigue, joint or muscle pain, and cognitive dysfunction, can last up to six months or longer.

It’s not known why some people develop Lyme disease post-treatment. “We don’t know if the symptoms are still due to an active infection, nerve damage, or some sort of autoimmune reaction. There are no current tests that can determine this. It’s akin to long COVID – nobody really knows what causes it or what to do about it,” explains Stella Huyshe-Shires, chair of Lyme Disease Action.

Additionally, an unknown number of people who contract the disease remain undiagnosed and untreated for years, or even a lifetime. When this occurs, the disease is allowed to spread, potentially reaching the joints, heart, and central nervous system (CNS), and can result in severe and debilitating symptoms, such as arthritis, facial weakness and paralysis – known as Bell’s palsy – and numbness. and pain in the arms and legs.

How the new Lyme disease test can help prevent chronic infections

When it comes to Lyme disease, early diagnosis is critical, because the sooner someone is treated with antibiotics, the less likely they are to develop persistent symptoms.

However, due to the fact that people may not realize they have been bitten by a tick, and because the symptoms of Lyme disease can be similar to those of other conditions, it can be very difficult to diagnose.

In addition, if someone were to get tested, the currently available tests could potentially miss the infection.

The main type of test for Lyme disease today is a blood test that looks for antibodies to Lyme disease bacteria, which follows a two-tier system.

Tier one involves a conventional enzyme-linked immunoassay (ELISA) test, and if the result is borderline or positive, the sample is sent to a specialist reference laboratory for further testing. The second level test is an immunoblot – or Western blot – which confirms Lyme disease and also helps identify a false positive level one result.

But if the antibodies haven’t developed sufficiently — it takes several weeks for the body to make enough antibodies to show a positive result — the test can come up as negative even though a person has an active Lyme disease infection.

Likewise, the presence of antibodies is possible No indicates active infection. “Once a person has developed the antibodies on which current tests are based, those antibodies can persist for years, even if the person has recovered. So that person will still be tested positive. You can get Lyme disease more than once, and this makes it difficult to use current tests to determine: ‘is it Lyme disease?’” says Huyshe-Shires.

And, according to Mollie Jewett, associate professor and head of the Division of Immunity and Pathogenesis at the Burnett School of Biomedical Sciences, UCF School of Medicine in the US, another problem with current tests is that they may not be standardized across diagnostic laboratories, plus expertise. necessary for accurate interpretation of results, and is somewhat subjective.

Therefore, developing a new standard active test that can directly detect Lyme disease bacteria, not just antibodies to the bacteria, could greatly improve the accuracy of the test, and allow people to be diagnosed earlier. This means fewer people go undiagnosed and potentially receive treatment in the early stages, making it less likely that their symptoms will become chronic.

The challenge of making a more effective test for Lyme disease

All well and good says that a new test for Lyme disease is needed, but actually developing one is quite a difficult task. As Huyshe-Shires points out, creating a test that detects active disease may rely on very new technologies for discovering biomarkers, and this is something that won’t happen overnight.

In addition, Jewett explains that developing an active test is very challenging because of the temporary time window in which Lyme disease bacteria are present at detectable levels in the blood.

“Biology of B. burgdorferi is such that bacteria do not grow in the blood. It is only temporarily in the blood in the first seven to 14 days after infection. After that the bacteria spread to other places in the body such as joints, heart and nervous system. This is a site of infection that is a feature of Lyme disease,” he said.

“A direct diagnostic test for Lyme disease, therefore, must be very sensitive to be able to detect the bacteria even if it is only present in small amounts in the blood. I like to use the fishing analogy – the best diagnostic tests are for direct detection B. burgdorferi requires lots of hooks in the water (sensitivity) and optimal bait to catch what you’re fishing for (specificity). It is also very important that anyone can become a successful fisherman (diagnostic tests must be objective and easy to interpret).

Active test for Lyme disease

Despite the challenges, researchers are working to produce a new Lyme disease test that detects active infection, and is faster and more accurate.

For example, Jewett is involved in developing rapid tests that can detect the disease several weeks earlier than current tests, which would address the “diagnostic blind spot” that occurs before at least 14 days after infection – where there are not enough antibodies for current tests to pick up infection. It will also eliminate the need to visit a diagnostic laboratory and wait for the results.

“The test we developed to detect it directly B. burgdorferi has the potential to address this “diagnostic blind spot” allowing people to be diagnosed with Lyme disease earlier, and therefore, allowing them to receive the right treatment more quickly,” explains Jewett.

“In addition to immediately detecting B. burgdorferi With our test, our team is developing a point-of-care diagnostic kit that can be used in a doctor’s office to run tests and provide diagnostic test results in as little as 15 minutes. Tests currently have to be sent to a diagnostic company and results are not available for several days.”

Another type of new Lyme disease test

There may also be new tests which, while not always detecting active infections, are still more accurate than the tests we currently have.

One example is a testing mechanism identified by researchers at Tufts University School of Medicine, which detects antibodies an infected individual produces against substances that Lyme disease bacteria acquire from a host to grow, known as autoantibodies – antibodies that mistakenly target and react with a person’s tissues or organs.

Researchers believe that tests to detect this could offer a way to diagnose Lyme disease more quickly, tell if treatment with antibiotics is working, and identify people who have been reinfected.

In addition, biotech company EpitogenX is working to adapt its COVID-19 testing technology to make testing for Lyme disease better.

Dr Abdo Alnabulsi, chief executive officer (CEO) of EpitogenX, stated: “We are working on a serology-based antibody test to detect Lyme disease. This test will be developed using our proprietary technology ‘EpitoGen’, a multiplexing biological system where several biomarker targets can be assembled into a single chimeric antigen. We will also use our internal AI systems to identify antigenic regions in Lyme pathogens.”

“Our technology’s ability to display multiple biomarker targets means the test will be highly sensitive and specific for Lyme. The test will be available as a laboratory-based (ELISA) and as a point-of-care lateral flow version.

Alnabulsi also added that both test versions would be easier to use and less expensive than existing platforms, making it possible for worldwide adoption.

New treatments on the horizon for Lyme disease

Of course, the surest way to prevent chronic Lyme disease is with medications that can prevent or cure Lyme disease infection.

Fortunately, there may be new treatments in vaccine form, with Valneva and Pfizer’s VLA15 vaccines currently in advanced clinical development.

VLA 15 is a multivalent recombinant protein vaccine that targets outer surface protein A B. burgdorferi. It targets six Borrelia serotypes which represent the most common pathogenic strains found in the US and Europe.

The vaccine is currently being tested in a phase 3 study, called VALOR, to assess its efficacy, safety, tolerability and immunogenicity in participants aged five and older.

The study started in August 2022, and spanned 29 months. During the first year, as part of the main series, participants will receive three doses of VLA15. They will then receive a booster dose approximately one year after the completion of basic immunization.

The vaccine received fast-track designation from the US Food and Drug Administration (FDA) in 2017, and Pfizer could potentially submit a Biological Licensing Application (BLA) to the FDA, and a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) in 2025, while awaiting successful completion of the VALOR study.

If a vaccine is approved for use, along with a new rapid Lyme disease test, it could be a breakthrough step in preventing people from developing chronic Lyme disease.

New technology regarding Lyme disease test (supported by IN-PART)

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