Role of Antibodies in Cognitive Dysfunction in Patients With Systemic Lupus Erythematosus

This study will examine the possible relationship between certain antibodies found in patients with systemic lupus erythematosus (SLE) and cognitive (thought processing) impairment in these patients. Antibodies are proteins produced by cells of the immune system to fight foreign invaders such as bacteria and viruses. In autoimmune diseases like SLE, however, the immune system produces antibodies against the body's own healthy tissues. Antibodies targeting the brain may cause cognitive dysfunction. Many patients with SLE have mild to severe cognitive impairment involving, for example, short- or long-term memory, thought processing and relating objects in time and space.

Patients 18 years of age and older with SLE may be eligible for this study. Participants will undergo the following tests and procedures:

• Medical history and physical examination, including blood and urine tests
• Psychiatric interview and questionnaire to assess depression
• Neuropsychological tests - answering questions given by an examiner or filling out a test form or questionnaire
• Tests of cognitive function - answering questions given by an automated computer program or performing tasks using a computer mouse
• Magnetic resonance imaging (MRI) of the brain - a test that uses strong magnetic fields and radio waves to generate images of the brain. The patient lies still on a stretcher inside a cylinder containing a magnetic field. The patient's head is stabilized with a plastic strap and foam pads. During the imaging, a substance called gadolinium-DTPA is injected into an arm vein through a catheter (thin plastic tube). This substance is used to enhance the images.

Patients may also be asked to undergo an optional procedure called a lumbar puncture (spinal tap) to examine the relationship between cognitive impairment and the amount of antibodies in the cerebrospinal fluid (CSF)- fluid that circulates around the brain and spinal cord. For this procedure a small area of skin on the lower back is numbed with a local anesthetic. A needle is then inserted in the space between the bones in the lower back, and about 2 tablespoons of CSF is withdrawn through the needle.