The overall aim of this project is to investigate the different types of immune cells found in the blood of patients with Systemic Lupus Erythematosus (SLE) and healthy donors. We know that the amount of fat on the surface of immune cells is an important factor controlling their behaviour. Immune cells from SLE patients are defective and this is associated with changes in the levels of fat on these cells. This project will investigate the level of fat in the blood and on immune cells from patients with SLE and age matched healthy controls, and measure how changes in the amount of fat can affect the way immune cells behave.

Accelerated atherosclerosis is a serious complication of autoimmunity including patients with both adult and juvenile onset systemic lupus erythematosus (SLE). This suggests that defects in fat levels could contribute to disease pathogenesis. The immune system in patients with SLE does not work normally. In adult patients with SLE we know that many of the immune cells involved in protecting the body from infections or cancer are over-active and actually cause disease. In young people the immune system is still developing and very little is known about what goes wrong in patients that develop juvenile-onset SLE, whether this is the same as adult disease and whether the same treatments are relevant for this group of patients. This project aims to find out whether immune cells from SLE patients with adult-onset disease have the same defects as adult patients with juvenile-onset SLE. We know that an important factor that controls immune cell behaviour is the amount of fat that they have on their surface. We also know that a change in fat on immune cells from adult patients with SLE makes them defective. This project will investigate the level of fat in the blood and in immune cells from adult patients with juvenile-onset SLE and age matched healthy controls, and measure how changes in the amount of fat can affect the way immune cells behave. We will investigate how drugs that control fat levels can help to normalize the behaviour of immune cells from SLE patients.

Inclusion Criteria:

• Diagnosis of SLE according to American College of Rheumatology revised criteria
• Having given written informed consent prior to undertaking any study-related procedures.
• Male and female patients between the ages of 18 and 80 years.

Patients who have met all the above inclusion criteria listed and healthy donors will be screened for the following exclusion criteria:

Exclusion Criteria:

• Under any administrative or legal supervision.
• Conditions/situations such as:
• A concomitant autoimmune disease
• Impossibility to meet specific protocol requirements (e.g. blood sampling).
• Patient is the Investigator or any sub-investigator, research assistant, pharmacist, study coordinator, other staff or relative thereof directly involved in the conduct of the protocol.
• Uncooperative or any condition that could make the patient potentially non-compliant to the study procedures.
• Pregnant or breast-feeding women, currently or in the last three months prior to inclusion.
• Patients who have been vaccinated in the last three months prior to inclusion.

Patients will be approached by the consultant rheumatologist when the patient is attending their normal outpatient clinic appointment.

Healthy donors will be approached in a similar way using information flyers, invitation letters and participant information sheets by a member of the research team.

Healthy volunteers from UCL staff will be made aware of the study and also asked to participate.

All participants are required to indicate in written consent if they agree to the use of any left over samples and associated data for future research use.