Episode 611: Why Lyme Disease Tests Miss Patients – Dr. Liz Horn on Breakthrough Research | LIVE from ILADS

What if the biggest obstacle to diagnosing Lyme disease isn't a lack of symptoms—but the limitations of the tests doctors rely on?

In this LIVE from ILADS interview, Tick Boot Camp co-host Rich sits down with Dr. Liz Horn, PhD, Principal Investigator of the Lyme Disease Biobank, a research program of the Bay Area Lyme Foundation, to explore why Lyme disease testing remains challenging and how new diagnostic technologies could change the future of patient care.

Recorded at the 2025 International Lyme and Associated Diseases Society (ILADS) Conference in San Antonio, Texas, the conversation covers early Lyme disease testing, antibody detection, FDA-cleared diagnostics, persistent symptoms after treatment, tissue donation, and the research needed to better understand Borrelia and other tick-borne pathogens.

Dr. Horn explains how researchers are using donated blood, urine, and human tissue samples to develop more accurate tests, investigate persistent symptoms, and study what tick-borne pathogens may be doing inside the body.

She also shares encouraging developments involving IGeneX, emerging multiplex antibody tests, and a growing research network that gives patients meaningful opportunities to contribute to scientific progress.

Her message is hopeful: Better Lyme disease diagnostics are possible, and patients can play an important role in making them a reality.

Meet Dr. Liz Horn, PhD

Dr. Liz Horn is the Principal Investigator of the Lyme Disease Biobank, a research initiative of the Bay Area Lyme Foundation.

She began working on the biobank in 2013, with biological sample collection beginning in 2014.

The program was created to address a major obstacle in Lyme disease research: scientists often lack access to well-characterized patient samples needed to develop and validate diagnostic tests.

Dr. Horn explains that a survey conducted in January 2025 found that approximately 85% of participating researchers still lacked some of the samples they needed.

Through the biobank, her team collects, processes, and distributes samples to qualified researchers investigating Lyme disease and associated infections.

At the time of the interview, the program had enrolled more than 1,250 participants and supported over 115 research projects.

Why Lyme Disease Testing Remains So Difficult

Dr. Horn explains that most commonly used Lyme disease diagnostic tests do not directly detect the bacteria responsible for the infection.

Instead, they measure the body's immune response.

This distinction is especially important during early infection, when the immune system may not yet have produced detectable antibodies.

She describes two major categories of diagnostic testing.

Direct Testing: Looking for Borrelia Itself

A direct test attempts to identify the pathogen or its genetic material.

For Lyme disease, that means detecting evidence of Borrelia rather than measuring the immune system's response to it.

Dr. Horn explains that researchers still need better direct detection methods.

The development of reliable direct tests could provide new opportunities for diagnosing infection, particularly in situations where antibody testing is inconclusive.

Indirect Testing: Looking for Antibodies

Indirect tests, including commonly used Lyme disease serology tests, measure antibodies produced in response to infection.

The challenge is that antibodies take time to develop.

Dr. Horn explains that a person may have Lyme disease before their immune response becomes detectable through laboratory testing.

This creates a diagnostic window during which an infected patient may test negative.

A negative Lyme disease antibody test early after infection does not necessarily rule out Lyme disease.

For more information about testing limitations, explore Tick Boot Camp's Lyme disease testing resources.

Why Two Lyme Disease Tests Can Produce Different Results

One of the interview's most revealing discussions concerns differences between laboratory assays.

Dr. Horn explains that two FDA-cleared first-tier antibody tests may not identify exactly the same patients.

A sample that tests negative using one assay may test positive using another.

This means the specific test used by a laboratory can influence whether an infection is detected.

Dr. Horn describes how the Lyme Disease Biobank's well-characterized samples help researchers evaluate these differences.

Her work underscores why test sensitivity, specificity, timing, and clinical context all matter when interpreting Lyme disease results.

New Lyme Disease Tests: IGeneX and Multiplex Antibody Technology

Dr. Horn discusses several promising diagnostic developments supported by biobank samples.

IGeneX and FDA-Cleared Lyme Disease Testing

She highlights an IGeneX diagnostic assay that received FDA clearance with the help of clinical samples provided by the Lyme Disease Biobank.

These samples allowed researchers to evaluate how the test performed in people with documented clinical histories.

Dr. Horn emphasizes that access to carefully characterized samples is essential for developing and validating new diagnostic technologies.

FDA clearance does not mean a test is perfect or appropriate for every clinical situation, but it represents an important regulatory milestone.

Multiplex Testing: Looking at More Than One Antibody Target

Dr. Horn also describes research involving a company referred to in the interview as Embios.

Its experimental approach examines multiple Borrelia antibody targets rather than relying on a single target.

She explains that Borrelia expresses different proteins, known as antigens, that may trigger different antibody responses.

A multiplex test can examine several antibody targets simultaneously.

Dr. Horn uses a simple analogy:

Looking at one target is like taking one photograph. Looking at ten targets provides ten different snapshots.

Researchers hope this broader approach may improve the ability to detect Lyme disease at different stages of infection.

However, these approaches still require rigorous validation to establish their accuracy and clinical usefulness.

Could New Lyme Tests Detect Infection Earlier?

Dr. Horn discusses research involving two experimental single-tier serology tests.

According to the findings she describes, these approaches showed promise for identifying Lyme disease earlier than some conventional testing methods.

She references the possibility of detecting infection approximately one week after symptom onset in certain study settings.

That would represent a meaningful advance for patients who currently face uncertainty during the early stages of infection.

However, these findings do not mean that every patient can currently obtain a reliable positive test one week after infection.

Larger studies, regulatory review, and clinical validation are necessary before new diagnostic approaches can become widely adopted.

Why Some Patients Don't Develop the Expected IgG Antibody Response

Dr. Horn describes research involving patients who received treatment for early Lyme disease.

She explains that clinicians often expect an IgG antibody response to develop as time passes.

However, her research found that some treated patients did not develop the anticipated detectable IgG response.

This process, known as seroconversion, can be affected by the timing of infection and treatment.

Dr. Horn explains that antibiotic treatment may change the development of measurable antibodies.

This is particularly important when interpreting follow-up testing.

The absence of a later positive IgG test does not necessarily mean an earlier Lyme disease diagnosis was incorrect.

Likewise, antibody results alone cannot reliably establish whether an infection remains active after treatment.

One in Five Patients Still Had Symptoms Three Months Later

Dr. Horn discusses a study involving patients with early Lyme disease who were followed after treatment.

She reports that approximately 20% continued experiencing symptoms three months later, despite receiving treatment early in their illness.

These patients had been evaluated at clinical sites experienced in recognizing early Lyme disease.

The finding raises important questions about why some people experience persistent symptoms even after timely diagnosis and treatment.

Dr. Horn believes further research is needed to understand the biological mechanisms involved and develop better tools for evaluating patients who remain ill.

Persistent symptoms after Lyme disease treatment are real and deserve appropriate medical attention, but they do not by themselves establish that live Borrelia bacteria remain present.

For additional research and patient perspectives, explore Tick Boot Camp's Lyme Persists educational resources.

What Is the Lyme Disease Biobank?

Rich asks Dr. Horn to explain the biobank in practical terms for patients and caregivers.

She describes it as a collection of biological samples donated by people who participate voluntarily in research.

The program includes samples from individuals with early Lyme disease and people experiencing persistent symptoms.

Depending on the study, participants may provide:

• Blood samples
• Urine samples
• Information about symptoms and medical history
• Follow-up samples over time
• Certain tissues collected during qualifying surgical procedures

These materials are processed and made available to researchers developing diagnostic tests and investigating disease mechanisms.

Dr. Horn explains that scientists benefit from knowing the clinical background associated with each sample.

Without that information, it becomes much harder to determine whether a diagnostic test accurately identifies the patient population it is intended to serve.

The Lyme Disease Tissue Bank: Studying Borrelia and Bartonella Inside the Body

One of the most important initiatives discussed is the Lyme Disease Tissue Bank, launched in 2019.

The program collects selected tissues donated after death by people who had Lyme disease or other tick-borne infections.

At the time of the interview, Dr. Horn reports that 27 individuals had donated tissues, including brain tissue.

Additional tissue types may include:

• Heart
• Liver
• Spleen
• Bladder
• Muscle
• Peripheral nerves and other nervous system tissues

These donations allow researchers to investigate where pathogens or their components may be found and how they might relate to disease processes.

Dr. Horn emphasizes that the program is not a whole-body donation program.

Instead, it coordinates the recovery of specific tissues for scientific study.

Participants interested in postmortem donation must register in advance so arrangements can be made.

The program can coordinate donations across much of the United States.

How Tissue Donations Could Help Explain Persistent Lyme Symptoms

Dr. Horn believes studying human tissue may help answer questions that cannot be resolved through blood testing alone.

Researchers are interested in understanding whether Borrelia, Bartonella, or other pathogens—or evidence of their prior presence—can be identified in specific tissues.

The findings could help scientists investigate disease mechanisms, improve diagnostic methods, and identify future research priorities.

The tissue bank also provides an opportunity to study neurological and other organ-specific complications associated with tick-borne illnesses.

However, finding bacterial material in tissue does not automatically establish active infection or prove that the organism caused a particular symptom.

These questions require careful scientific investigation.

More Than 115 Research Projects Supported

Dr. Horn explains that the biobank has supported more than 115 research projects.

Not every project produces a successful diagnostic test.

Some experimental approaches fail to demonstrate adequate accuracy.

She emphasizes that these negative findings are still valuable.

They help researchers identify which approaches are unlikely to work and avoid repeating unsuccessful experiments.

The biobank also asks participating researchers to share performance data from their studies.

This allows the program to build knowledge about how different tests perform using its samples.

Dr. Horn believes this collaborative model accelerates research by allowing scientists to focus on developing and evaluating new technologies rather than independently recruiting every patient needed for early investigations.

How Lyme Disease Patients Can Contribute to Research

Near the end of the interview, Rich asks how Tick Boot Camp listeners can help advance Lyme disease research.

Dr. Horn explains that participation opportunities depend on the specific study and the patient's circumstances.

Donate Blood or Urine

Eligible participants in certain geographic areas, including the San Francisco Bay Area, may be able to donate biological samples through participating clinical sites.

The process typically involves informed consent, health-history questions, and sample collection.

Consider Tissue Donation

Some individuals may be eligible to contribute tissue collected during specific surgical procedures.

Dr. Horn also discusses the possibility of registering for postmortem tissue donation.

These contributions can support research into the effects of tick-borne pathogens on different organs and tissues.

Support Patient-Powered Research

Rich also highlights MyLymeData, a patient-powered research initiative that allows people affected by Lyme disease to share information about their experiences.

These opportunities provide ways for patients to contribute to research, even when their own health circumstances limit other forms of advocacy.

For current eligibility requirements and donation information, visit the Lyme Disease Biobank or contact the Bay Area Lyme Foundation.

When Will Better Lyme Disease Tests Become Available?

Rich asks Dr. Horn when patients might begin seeing significant improvements in Lyme disease diagnostics.

Speaking in 2025, she expresses optimism that better tests could begin emerging within approximately two years, with additional progress over the following five years.

She credits the availability of well-characterized samples, collaboration among research groups, and growing interest in new diagnostic technologies.

These are research expectations rather than guaranteed development or approval timelines.

Still, her message is encouraging.

The tools needed to improve Lyme disease testing are being developed, and patients are helping make that work possible.

Key Takeaways

• Current Lyme disease tests have important limitations. Antibody tests may miss infections before a detectable immune response develops.
• Direct detection remains a major research priority. Scientists need better methods for identifying Borrelia itself.
• Different FDA-cleared tests may produce different results. The choice of assay can influence detection.
• Multiplex antibody testing shows promise. Evaluating multiple Borrelia antigens may improve diagnostic performance.
• Early treatment can affect antibody development. Some treated patients may not develop the expected later IgG response.
• Persistent symptoms require more research. Dr. Horn discusses findings showing that approximately one in five early-treated patients still reported symptoms after three months.
• Patient donations are advancing science. Blood, urine, and tissue samples help researchers investigate diagnostic and biological questions.
• The Lyme Disease Biobank supports collaboration. More than 115 research projects had used its resources at the time of the interview.
• Patients can help drive progress. Voluntary research participation and advocacy can contribute to the development of better diagnostic tools.

About This LIVE from ILADS Interview

Recorded at the 2025 International Lyme and Associated Diseases Society Conference in San Antonio, Texas, this conversation features Dr. Liz Horn, PhD, Principal Investigator of the Lyme Disease Biobank.

Rich and Dr. Horn discuss the limitations of Lyme disease testing, new diagnostic technologies, FDA-cleared assays, persistent symptoms after treatment, and how donated biological samples are helping advance scientific research.

They also explore opportunities for patients to contribute to studies that may improve the future of Lyme disease diagnosis and care.

Discover additional interviews with researchers and healthcare professionals through Tick Boot Camp's LIVE from ILADS podcast series.