systemic lupus erythematosus (SLE)
Last edited 08/2021 and last reviewed 08/2021
Systemic lupus erythematosus is the classic prototype of a chronic, multisystem, inflammatory connective tissue disorder of autoimmune origin (1,2).
- often follows a relapsing and remitting pattern (3)
- the disease is characterised by the presence of a wide spectrum of autoantibodies (2)
- 98% of SLE patients have antinuclear antibodies (ANA) but are non-specific
- anti-double-stranded DNA (dsDNA) seen in around 70% of cases is highly specific for SLE
- other autoantibodies present in SLE patients include - anti-Smith, anti-ribosomal P and anti-proliferating cell nuclear antigen (PCNA) (3)
- it is non-organ specific and characterised by vasculitis
- due to its broad clinical presentation the disease may vary from rash and arthritis through anaemia and thrombocytopenia to serositis, nephritis, seizures, and psychosis (4)
- SLE, as a chronic inflammatory disorder, is thought to be driven
by autoantibodies that target multiple organ systems including
joints, skin, and kidneys
- SLE is characterized by pathogenic autoantibodies that target specific tissues, however many additional cell types (for example B cells, T cells) and cytokines (for example type I interferon (IFN-I)-a) are involved in the inflammatory response (5)
- dysregulation of both adaptive and innate immunity plays a
role in the pathogenesis of SLE
- adaptive immunity and SLE
- B cells play a central role in the pathogenesis of SLE, mainly by producing autoantibodies but also by producing cytokines and by presenting antigens to T cells
- SLE can occur secondary to defective proteins that regulate T cells in the dysfunctional
clearance of immune cells
- thus part of the pathology of SLE may be due to loss of the immune tolerance and the persistence of attractive B- and T-cell populations
- inate immunity and SLE
- dysregulation of the innate immune system also contributes to SLE
- immune complexes of autoantibodies with endogenous
RNA and DNA can be taken up by plasmacytoid dendritic cells
- leads to activation of toll-like receptor (TLR)7 and TLR9, respectively, and
generates IFN-I
- IFN-I can lead to further augmentation of
adaptive immunity by enhancing the antigen-presenting function
of monocytes and dendritic cells and activating B cells
- IFN-I can lead to further augmentation of
adaptive immunity by enhancing the antigen-presenting function
of monocytes and dendritic cells and activating B cells
- leads to activation of toll-like receptor (TLR)7 and TLR9, respectively, and
generates IFN-I
- adaptive immunity and SLE
Some of the clinical variants of lupus erythematous include the following (6):
- systemic lupus erythematosus (SLE)
- cutaneous lupus erythematosus (CLE) (including subacute cutaneous lupus erythematosus (SCLE) and discoid lupus erythematosus (DLE))
- child-onset lupus erythematosus
- neonatal lupus erythematosus
- drug-induced lupus erythematosus (DILE)
Reference:
- (1) Madhok R, Wu O. Systemic lupus erythematosus. Am Fam Physician. 2007;76(9):1351-3.
- (2) Manson JJ, Rahman A. Systemic lupus erythematosus. Orphanet J Rare Dis. 2006 Mar;1:6.
- (3) Arthritis Research UK. Reports on Rheumatic Diseases. Topical Reviews No 2, spring 2013. Overview of management of systemic lupus erythematosus.
- (4) Rahman A, Isenberg DA. Systemic lupus erythematosus. N Engl J Med. 2008;358(9):929-39.
- (5) Dema B, Charles M. Advances in mechanisms of systemic lupus erythematosus. Discov Med. 2014 May;17(95):247-55
- (6) Yazdany J, Dall'Era M. Definition and Classification of Lupus and Lupus Related Disorders. Chapter 2. In: Wallace D, Hahn BH, editors(s). Dubois' Lupus Erythematosus. Ninth edition. Elsevier Inc, 2019:15-22.