Evaluation of standard and modified two-tiered testing algorithms using well-characterized early Lyme disease samples

Area of Science:

• Infectious Diseases
• Medical Diagnostics
• Immunology

Background:

• Current laboratory diagnosis for Lyme disease (LD) primarily relies on serological testing.
• Two-tiered testing algorithms, including standard (STTT) and modified (MTTT), are FDA-cleared but their performance in early LD is debated.

Purpose of the Study:

• To evaluate the performance of FDA-cleared STTT and MTTT algorithms in diagnosing early Lyme disease.
• To assess the sensitivity and specificity of these algorithms in a well-characterized patient cohort.
• To identify factors influencing the accuracy of serological tests in early LD.

Main Methods:

• Compared four FDA-cleared STTT and MTTT algorithms using serum samples from 251 participants (107 early LD cases, 144 controls).
• Analyzed samples from the U.S. East Coast and Upper Midwest.
• Assessed test performance at initial blood draw and evaluated convalescent samples.

Main Results:

• Algorithm sensitivity at initial draw ranged from 22% to 36%, with specificity from 98% to 100%.
• MTTT algorithms demonstrated higher sensitivity than STTT (P ≤ 0.05).
• Discordance between algorithms was observed; only 22 of 45 laboratory-confirmed cases tested positive across all evaluated algorithms. Early LD cases with erythema migrans and constitutional symptoms were more likely to test positive.

Conclusions:

• Two-tiered serologic testing algorithms are insensitive for diagnosing early Lyme disease, particularly within the first two weeks of symptom onset or in cases without constitutional symptoms.
• Modified two-tiered testing (MTTT) showed improved sensitivity over standard two-tiered testing (STTT), but overall performance remains suboptimal.
• Novel diagnostic approaches are urgently needed to improve the laboratory confirmation of early Lyme disease.