laboratory abnormalities that may be seen in Lyme disease
In patients with CNS involvement (neuroborreliosis), cerebrospinal fluid (CSF) analysis typically shows a lymphocytic pleocytosis, mildly elevated protein concentration (100–200 mg/dL) and normal glucose concentration. Additionally, a high IgG index and oligoclonal bands may be present. Specific testing includes intrathecal antibodies against Borrelia . The most sensitive and specific application of this test is through the calculation of an antibody index (the ratio of Borrelia /total antibody in the CSF versus the same ratio in the serum). PCR testing of CSF may also be performed, but the sensitivity is very low (<20%).
During episodes of arthritis, synovial fluid white cell counts range from 500 to 110,000/mm 3 , with a polymorphonuclear predominance. PCR has detected B. burgdorferi DNA in synovial fluid and synovial tissue in research settings, but it is not used routinely in clinical practice.