The cytokines B-lymphocyte stimulator (BLyS), also known as B-cell activating factor (BAFF), interleukin 6, interleukin 17, interleukin 18, type I interferons, and tumor necrosis factor α (TNFα) are involved in the inflammatory process and are potential therapeutic targets.SLE is associated with low C3 levels in the complement system. Cell death signaling
Apoptosis is increased in monocytes and keratinocytes
Expression of Fas by B cells and T cells is increased
There are correlations between the apoptotic rates of lymphocytes and disease activity. Necrosis is increased in T lymphocytes.Tingible body macrophages (TBMs) – large phagocytic cells in the germinal centers of secondary lymph nodes – express CD68 protein. These cells normally engulf B cells that have undergone apoptosis after somatic hypermutation. In some people with SLE, significantly fewer TBMs can be found, and these cells rarely contain material from apoptotic B cells. Also, uningested apoptotic nuclei can be found outside of TBMs. This material may present a threat to the tolerization of B cells and T cells. Dendritic cells in the germinal center may endocytose such antigenic material and present it to T cells, activating them. Also, apoptotic chromatin and nuclei may attach to the surfaces of follicular dendritic cells and make this material available for activating other B cells that may have randomly acquired self-protein specificity through somatic hypermutation. Necrosis, a pro-inflammatory form of cell death, is increased in T lymphocytes, due to mitochondrial dysfunction, oxidative stress, and depletion of ATP. Clearance deficiency
Impaired clearance of dying cells is a potential pathway for the development of this systemic autoimmune disease.
Atherosclerosis also occurs more often and advances more rapidly than in the general population.Steroids are sometimes prescribed as an anti-inflammatory treatment for lupus; however, they can increase ones risk for heart disease, high cholesterol, and atherosclerosis. Lungs
SLE can cause pleuritic pain as well as inflammation of the pleurae known as pleurisy, which can rarely give rise to shrinking lung syndrome involving a reduced lung volume. Other associated lung conditions include pneumonitis, chronic diffuse interstitial lung disease, pulmonary hypertension, pulmonary emboli, and pulmonary hemorrhage. Kidneys
Painless passage of blood or protein in the urine may often be the only presenting sign of kidney involvement. Acute or chronic renal impairment may develop with lupus nephritis, leading to acute or end-stage kidney failure. Because of early recognition and management of SLE with immunosuppressive drugs or corticosteroids, end-stage renal failure occurs in less than 5% of cases; except in the black population, where the risk is many times higher. The histological hallmark of SLE is membranous glomerulonephritis with "wire loop" abnormalities. This finding is due to immune complex deposition along the glomerular basement membrane, leading to a typical granular appearance in immunofluorescence testing. Neuropsychiatric
Neuropsychiatric syndromes can result when SLE affects the central or peripheral nervous system. The American College of Rheumatology defines 19 neuropsychiatric syndromes in systemic lupus erythematosus.