From the Guidelines
The diagnostic tests for Lyme disease typically involve a 2-tiered serologic analysis, consisting of an enzyme-linked immunoassay or immunofluorescence assay, followed by reflexive immunoblotting, as recommended by current guidelines 1. The 2-tiered testing approach is the most accurate method for confirming the diagnosis of Lyme disease, with a high specificity of >95% during all stages of the disease 1.
Key Points to Consider
- The sensitivity of the 2-tiered testing is low (30%–40%) during early infection, but increases to 70%–100% for disseminated Lyme disease 1.
- Patients with a lesion consistent with erythema migrans and a history of exposure to Lyme-endemic areas can be diagnosed without laboratory testing 1.
- Other diagnostic tests, such as polymerase chain reaction (PCR) tests, may be used in certain cases, but their use is limited 1.
Diagnostic Approach
The diagnostic approach for Lyme disease typically involves:
- Clinical evaluation, including a physical examination and medical history
- Laboratory testing, using the 2-tiered serologic analysis
- Interpretation of test results, taking into account the patient's symptoms, exposure history, and stage of disease It is essential to note that early treatment with antibiotics, such as doxycycline, is most effective, and prompt medical attention is recommended if Lyme disease is suspected 1.
From the Research
Diagnostic Tests for Lyme Disease
The diagnostic tests for Lyme disease (Lyme borreliosis) include:
- Indirect immunofluorescence assay (IIFA) 2
- Enzyme-linked immunosorbent assay (ELISA) 2, 3, 4, 5, 6
- Immunoblotting 2, 3, 4, 5
- Western blot 4
Comparison of Diagnostic Tests
Studies have compared the effectiveness of different diagnostic tests for Lyme disease, including:
- IIFA vs. ELISA: IIFA produced the highest percentage of positive results, which were then confirmed by immunoblot, but not by ELISA 2
- Immunoblotting vs. ELISA: Immunoblotting is superior to indirect ELISA for diagnosing early Lyme disease 3
- ELISA vs. IFA: ELISA was better suited for testing large numbers of specimens and easier to interpret than IFA 6
Two-Tier Serologic Testing Protocol
The Centers for Disease Control and Prevention recommends a two-tier serologic testing protocol using an ELISA initially, followed by the more specific Western blot to confirm the diagnosis when the assay samples are positive or equivocal 4
Limitations of Diagnostic Tests
The laboratory diagnosis of Lyme disease is based upon the detection of antibodies generated against Borrelia burgdorferi, but this system is insensitive for diagnosing early infection 5