Advantages and limitations of the Lyme antibody index

Differentiates between intrathecal synthesis versus passive
diffusion of specific anti-Borrelia antibodies in CSF.
Need for submission of CSF and serum samples collected around the same time. There are no FDA-cleared assays for determining a Lyme AI.
High sensitivity (>95%) in patients with ≥6 weeks of symptoms,
according to studies performed in European patients with CNSLD.
Assays, methods and cutoffs for establishing the Lyme AI are not standardized and vary between laboratories
in the United States.
The performance characteristics of these assays in the U.S. patients with CNSLD are not described
Available through very few laboratories in the United States, mostly reference commercial labs.
Sensitivity ranges from 70% to 90% in patients with <6 weeks of symptoms.
False-positive results may occur, particularly in patients with neurosyphilis.
Remains positive for months to years following resolution of disease and therefore cannot be used as a
standalone test to establish acute vs past infection or to establish cure.
Lyme AI results cannot be relied upon solely to make a diagnosis of CNSLD