Lyme Testing: Why Standard ELISA Fails

At a Glance

Lyme disease is one of the most contentious areas in medicine, and much of the controversy stems from diagnosis. The standard approach is a two-tier system: an ELISA (enzyme-linked immunosorbent assay) antibody screen, followed by Western blot confirmation. It was designed to maximize specificity, meaning few false positives. The price is lower sensitivity, meaning more true cases missed, particularly in chronic Lyme disease.

I treat patients with Lyme disease routinely at St. George Hospital, many of whom have been told they do not have Lyme disease based on negative standard testing. Their previous physicians were right to follow standard protocols. Those protocols, though, have limitations that are well documented in the scientific literature and poorly communicated in routine clinical practice.

The Standard Two-Tier System

ELISA (Enzyme-Linked Immunosorbent Assay)

The ELISA screens for antibodies (IgM and IgG) against Borrelia burgdorferi. If positive or equivocal, a Western blot is performed for confirmation.

The limitations are well-documented:

Antibody timing. ELISA detects antibodies, which take two to six weeks to develop after infection. In early Lyme disease, when treatment is most effective, up to 50% of patients test negative on ELISA because they have not yet produced sufficient antibodies. Evidence level: documented in the CDC’s own publications.

Antibody production in chronic infection. In chronic Lyme disease, some patients produce insufficient antibodies to trigger a positive ELISA. This can occur due to immune suppression by the organism, bacterial biofilm formation, intracellular sequestration, or prior antibiotic treatment that partially suppressed but did not eradicate the infection.

Strain variability. Standard ELISA kits typically use antigens from a single Borrelia strain (B31). Borrelia burgdorferi sensu lato includes multiple genospecies (B. afzelii, B. garinii, B. spielmanii in Europe) with antigenic variation. A patient infected with a strain that differs from the test antigen may test negative despite active infection.

Seronegative Lyme disease. Clinical Lyme disease with negative standard serology is documented in the medical literature as a known limitation of antibody-based testing.

Western Blot

The Western blot identifies antibodies against specific Borrelia proteins (bands). CDC surveillance criteria require specific band patterns for positive interpretation. These criteria suit epidemiological surveillance, where specificity comes first. In diagnosing an individual patient, sensitivity may matter more, so the same criteria can be too strict.

Several diagnostically significant bands (OspA at 31 kDa, OspB at 34 kDa) were removed from the CDC interpretive criteria because they were used in early Lyme vaccine development. This decision was reasonable in the context of vaccine-era surveillance but reduces the test’s diagnostic sensitivity in the post-vaccine era.

Advanced Testing Approaches

ELISpot (Enzyme-Linked Immunospot)

The ELISpot assay measures cellular immune responses rather than antibody levels. It detects individual T cells that respond to Borrelia antigens by measuring cytokine (IFN-gamma) secretion at the single-cell level.

Advantages:

• Detects cellular immunity, which may persist even when antibody levels are low
• Higher analytical sensitivity than ELISA
• Can distinguish between active infection and past exposure (active T cell responses indicate ongoing antigenic stimulation)
• Not affected by the timing limitations that apply to early antibody responses

Limitations:

• Not yet widely standardized across laboratories
• Some specificity concerns (potential cross-reactivity with other spirochetes)
• Not endorsed by all infectious disease societies (though this reflects institutional conservatism as much as scientific evidence)

Evidence level: controlled studies demonstrating higher sensitivity than standard serology; clinical validation in multiple European laboratories. The ELISpot is part of standard diagnostic workup at specialized Lyme disease centers in Germany.

In my clinical experience, the ELISpot identifies Borrelia-reactive T cells in a significant proportion of patients with clinical Lyme disease who test negative on standard serology. Not every negative ELISA is wrong, but the ELISpot adds information that standard serology misses.

CD57+ NK Cells

As discussed in the NK cells article, low CD57+ NK cell counts (below 60 cells/mcL) have been observed in chronic Lyme disease and may serve as a marker of disease activity and treatment response.

I use CD57 as one data point among many. A low CD57 count is not specific to Lyme disease and should never be used as a standalone diagnostic test, but alongside a clinical picture consistent with Lyme disease it adds supportive evidence.

Evidence level: clinical observation and retrospective studies. Further controlled research is warranted.

PCR (Polymerase Chain Reaction)

PCR detects Borrelia DNA directly. It is highly specific when positive, but sensitivity is limited by the low concentration of Borrelia in blood and most tissues. PCR from synovial fluid in Lyme arthritis has reasonable sensitivity; PCR from blood has low sensitivity (Borrelia’s blood concentration is typically very low).

Culture

Borrelia culture from patient samples is technically possible but requires specialized media, prolonged incubation (weeks to months), and has low sensitivity. It is primarily a research tool rather than a routine clinical test.

Co-Infection Testing

Tick-borne infections rarely occur in isolation. The same tick that transmits Borrelia burgdorferi can transmit:

• Babesia (babesiosis): test with PCR and antibody panel; blood smear has low sensitivity
• Anaplasma (anaplasmosis): PCR and antibody panel
• Ehrlichia (ehrlichiosis): PCR and antibody panel
• Bartonella co-infection: PCR, antibody panel, and increasingly, digital PCR for improved sensitivity
• Rickettsia: antibody panel

Co-infections can alter the clinical picture significantly and may require different treatment approaches. Testing for co-infections should be standard practice in any patient being evaluated for tick-borne disease.

My Diagnostic Approach

When I evaluate a patient for suspected Lyme disease at St. George Hospital, the workup includes:

• Detailed clinical history: tick exposure, rash history, symptom timeline, prior treatment
• Standard serology (ELISA and Western blot): as a baseline, understanding its limitations
• ELISpot for Borrelia-specific T cell reactivity
• Lymphocyte subset panel including CD57+ NK cells and NK cell function
• Co-infection panel (Babesia, Anaplasma, Bartonella, Rickettsia)
• Inflammatory markers (CRP, cytokines) to assess current inflammatory burden
• Comprehensive metabolic assessment to identify complicating factors

No single test is definitive for Lyme disease. The diagnosis is clinical, supported by laboratory findings. In my assessment, a patient with classic symptoms, documented tick exposure, positive ELISpot, low CD57 and negative standard serology has Lyme disease, whatever the ELISA says.

What I tell my patients: Lyme disease testing is imperfect. The standard tests miss cases, and the advanced tests have their own limits. The best diagnostic approach combines multiple testing modalities with careful clinical assessment. Any physician who relies solely on ELISA results to rule out Lyme disease is applying an incomplete diagnostic standard.

Clinical Perspective: Dr. med. univ. Julian Douwes

For every patient with suspected Lyme disease I order five tests: ELISpot (Borrelia-specific T-cell reactivity), a CD57+ NK cell count, a full co-infection panel covering Babesia, Bartonella and Anaplasma by both PCR and serology, and an inflammatory marker panel including TNF-alpha, IL-6 and C-reactive protein. I order the standard ELISA and Western blot as well, but I never use a negative result to rule out the diagnosis.

At St. George Hospital, which has treated over twelve thousand Lyme patients, roughly 30-40% of those with confirmed clinical Lyme disease and positive ELISpot results had negative or equivocal standard serology (an institutional observation, not a published study). The most common diagnostic error I see in referred patients is a single negative ELISA followed by “you do not have Lyme disease”. That is an incomplete workup, and it should not end the investigation.

This reflects my clinical experience and professional opinion. It is not a substitute for individual medical advice.

Related Reading

• All Lyme Testing Articles
• Explore All Diagnostics Topics
• iSpot Lyme T-Cell Test: A Better Way to Detect Borrelia?
• Lyme Disease False Negatives: Why Standard Tests Miss Chronic Lyme
• Western Blot vs ELISA: Lyme Testing Accuracy Compared