What test is commonly used to diagnose Lyme disease?

The diagnosis of Lyme disease primarily relies on serological testing for antibodies. This is because Lyme disease is caused by the bacterium Borrelia burgdorferi, which is transmitted through tick bites. When a person becomes infected, their immune system produces antibodies in response to the infection.

Serological tests specifically measure the presence of these antibodies, typically IgM and IgG, which indicate an immune response to the infection. The most common serological tests used include enzyme-linked immunosorbent assays (ELISA) followed by Western blot tests for confirmation if the initial test yields positive or inconclusive results. This two-step approach enhances the accuracy of the diagnosis.

The other options are not standard diagnostic tools for Lyme disease. A skin biopsy is not typically performed because Lyme disease's clinical features are well defined and can often be diagnosed based on symptoms and exposure history. Bone marrow biopsy is invasive and not relevant for Lyme disease, as it is used primarily for hematological conditions. Magnetic resonance imaging (MRI) is useful in identifying complications of Lyme disease, such as Lyme-related neurological issues, but it is not a diagnostic test for the infection itself. Thus, serological testing for antibodies is the most direct and widely accepted method for diagnosing Lyme disease.