From the Guidelines
The initial serology for suspected Lyme disease is a two-tier testing approach consisting of an enzyme-linked immunosorbent assay (ELISA) followed by a Western blot if the ELISA is positive or equivocal. This standardized approach is recommended for all patients with clinical symptoms suggestive of Lyme disease, as stated in the study by 1. The ELISA detects antibodies against Borrelia burgdorferi, the bacterium that causes Lyme disease, and serves as a sensitive screening test. If the ELISA is positive or borderline, the more specific Western blot is performed to confirm the diagnosis by identifying antibodies to specific proteins of B. burgdorferi.
Some key points to consider when ordering serology for Lyme disease include:
- The sensitivity of the two-tiered testing approach is low (30%–40%) during early infection, but increases to 70%–100% for disseminated Lyme disease, as noted in the study by 1.
- The specificity of the two-tiered testing approach is high (>95%) during all stages of disease, as stated in the study by 1.
- Antibodies may not be detectable in the first few weeks of infection, so patients with early Lyme disease and the characteristic erythema migrans rash can be treated empirically without waiting for serologic confirmation, as mentioned in the study by 1.
- Once a patient develops antibodies, they may persist for months or years, so serology cannot distinguish between active and past infection, as noted in the study by 1.
- The test should only be ordered when there is a reasonable clinical suspicion of Lyme disease based on symptoms and potential exposure to ticks in endemic areas, as stated in the study by 1.
It's also important to note that the two-tiered testing approach has been the standard for Lyme disease diagnosis since 1994, as discussed in the study by 1, and has been shown to maximize clinical utility and specificity. Overall, the two-tiered testing approach is a valuable and highly specific clinical tool for diagnosis of disseminated Lyme disease, as stated in the study by 1.
From the Research
Initial Serology for Suspected Lyme Disease
The initial serology for suspected Lyme disease typically involves a two-tiered testing approach, which includes an enzyme-linked immunosorbent assay (ELISA) as the first-tier test, followed by a Western blot as the second-tier test 2, 3, 4.
- The first-tier test, usually an ELISA, is used to detect the presence of IgM and IgG antibodies against Borrelia burgdorferi, the bacteria that causes Lyme disease 3, 5.
- The ELISA test can be performed using various antigens, including whole cell sonicate, recombinant proteins, or synthetic peptides 3, 5, 6.
- Some studies have evaluated the performance of newer tests, such as the Quidel Sofia 2 Lyme test, which is a lateral flow method that can provide rapid results 2.
- The second-tier test, usually a Western blot, is used to confirm the presence of specific antibodies against B. burgdorferi and to rule out false-positive results from the first-tier test 3, 4, 5.
Types of ELISA Tests
There are different types of ELISA tests that can be used for the diagnosis of Lyme disease, including:
- ELISA using whole cell sonicate antigen 4
- ELISA using recombinant antigens, such as OspC, OspF, and p41-G 3, 6
- ELISA using synthetic peptides, such as the OspC7 peptide 5
Comparison of ELISA Tests
Studies have compared the performance of different ELISA tests, including the Quidel Sofia 2 Lyme test, with the standard two-tiered testing approach 2, 3, 5.
- The Quidel Sofia 2 Lyme test has been shown to have substantial agreement with the Zeus VlsE1/pepC10 IgG/IgM test, with an overall agreement of 89.9% 2.
- The DbpA/C6-OspC ELISA has been shown to be equivalent to the two-tier test method in identifying sera from negative-control subjects and in detecting stage II and III LD patient sera, but was better at detecting anti-Borrelia antibodies in stage I LD patients 3.
- The OspC7 peptide ELISA has been shown to be more sensitive than the Western blot procedure in detecting IgM antibodies in patients with early Lyme disease 5.