Final answer:
Patients with Lyme arthritis should demonstrate positive findings for antibodies to Borrelia burgdorferi.
Step-by-step explanation:
Patients with Lyme arthritis should demonstrate positive findings for antibodies to Borrelia burgdorferi. A presumptive diagnosis of Lyme disease can be made based on the presence of a bull's-eye rash at the site of infection, in addition to other associated symptoms. Serological tests like ELISA and Western blot can be used to detect serum antibodies produced in response to the bacteria that causes Lyme disease.