Systemic Lupus Erythematosus (SLE)

00:01 Systemic lupus erythematosus is the classical non organ specific autoimmune disease.

00:06 Like the vast majority of autoimmune diseases, there are numerous susceptibility genes involved that lead to the failure of immunological tolerance against self antigens.

00:19 There are a number of environmental triggers.

00:22 For example, UV radiation can cause apoptotic cell death of cells and tissues in the individual.

00:32 These apoptotic cells are not cleared properly and there is the development of autoantibodies.

00:41 Typical of SLE are anti-nuclear antibodies or ANA.

00:47 And there is the development of anti-double stranded DNA, anti-histone, anti-Ro, anti-La, anti-Smith (Sm), anti-ribonucleoprotein and anti-phospholipid antibodies.

01:02 For example, the lupus anticoagulant and anti-cardiolipin.

01:09 These immune complexes of autoantibody and self antigen can be endocytosed by B-cells and the antigens act as DAMPS (Damage Associated Molecular Patterns) that are recognized by endosomal Pattern Recognition Receptors within the B-cells. Dendritic cells also become activated, and the activated dendritic cells secrete the type I interferons - interferon-α and interferon-β, which can help in the activation of the B-lymphocyte. So ultimately there is activation of lymphocytes and of dendritic cells, and the further production of autoantibodies.

02:00 There’s a persistent high level anti-nuclear IgG antibody production.

02:06 The clinical features of SLE are many because of its nature being a systemic disease.

02:14 Immune complexes get trapped in locations in the body where there is very little space.

02:21 For example, the glomeruli of the kidney and the small blood vessels in the skin.

02:26 This can lead to renal failure, serosal inflammation affecting the pleura and pericardium and vasculitis.

02:35 Thrombotic disease also occurs due to the anti-cardiolipin autoantibodies.

02:42 And there is impaired hematopoiesis with the development of antiplatelet autoantibodies and antilymphocyte autoantibodies.

02:52 And finally, immune complexes get deposited within the CNS.

02:57 There are antineuronal autoantibodies leading to neurological and psychiatric morbidity.

03:04 Here you can see the classic butterfly rash that is seen on the cheeks of an individual with SLE.

03:11 This is due to damage to the small blood vessels in the skin of the cheeks.