This study is designed to establish a population of patients with Lyme disease for evaluation, treatment and follow-up to learn more about the infection.

Patients with active Lyme disease may be eligible for this study.

Participants will have a medical history and physical examination and diagnostic evaluations as appropriate to their individual condition. Laboratory tests may include routing blood and urine tests, X-rays, or other imaging studies, body fluid or tissue cultures, skin biopsy and tests for allergic or immune responses. Treatment will include only medications approved by the Food and Drug Administration, given according to accepted dose schedules and ways of taking the medicines. All diagnostic tests and treatments will be according to standard medical practice for the disease. No experimental procedures will be offered under this protocol.

Patients will be followed as needed for evaluation and treatment of their condition. In general, they will be asked to return at the end of therapy, then 3, 6 and 12 months later, and then every 6 to 12 months. More frequent visits may be required or less frequent visits may be allowed, depending on the individual's condition.

Participants may be asked to undergo the following additional procedures for research purposes:

• Extra blood draws to study Lyme disease and other inflammatory conditions. Blood will be drawn from arm veins. The total amount drawn during any 6-week period will not exceed 450 cc (30 tablespoons) for adults and 7 cc (1/2 tablespoon) per kilogram (2.2 pounds) of body weight for children under 18 years of age.
• Leukapheresis to collect large numbers of white blood cells. Whole blood is collected through a needle in an arm vein, similar to donating blood. The blood circulates through a machine that separates it into its components, and the white cells are removed. The rest of the blood is returned to the body through the same needle. Only adults 18 years of age and older will be asked to undergo leukapheresis.