Lupus _Systemic Lupus Erythematosus_- Causes, Pathogenesis, Signs & Symptoms, Diagnosis, Treatment

SLE is an auto immune disorder characterized by the presence of Antibodies to nuclear, and cytoplasmic antigens, Multisystem inflammation, Variable clinical manifestations, And a relapsing and remitting course. And the disease commonly affects women of childbearing age.
First let’s discuss about the etiology & pathogenesis of the disease. The specific cause of S L E is not known. However, genetic predisposition & environmental triggers, such as UV light from sun exposure, Infections, and certain drugs play a role in the pathogenesis. It is important to note that both of these factors should be there to get the disease.
Individuals with genetic predisposition for S L E have several defects in their normal physiology. Including defects in apoptosis & increased cell death. Defective clearance of apoptotic bodies. Hyperactive T & B lymphocytes. High ratio of CD4 + T cells to CD8 + T cells. Defective immune complex clearance. And impaired self tolerance.
Increased apoptosis & defective clearance of apoptotic bodies lead to accumulation & persistence of apoptotic debris. Which triggers the formation of autoantibodies against certain components in these apoptotic bodies, mainly to double stranded DNA. Then these antibodies will bind with their respective antigens & form antigen antibody complexes.
As these individuals also have a defect in clearance of immune complexes, they tend to accumulate in various tissues & organs in the body, mainly in the vasculature. Upon deposition, these complexes then activate the complement system, leading to inflammation of the affected site. Immune complexes can also deposit in the basement membranes of the cells in kidney, causing kidney injury. In addition, autoantibodies are targeted against many healthy tissues in the body, causing direct damage. Major victims are cardiac phospholipids, & beta 2 glycoproteins.
Clinical presentation of SLE can be highly variable. And there is evidence of multisystem involvement. Classic dermatologic finding in SLE is the malar rash, which resembles the shape of a butterfly on the face. In addition, patients may also have a particular type of rash called discoid lupus. And they also have photo sensitivity. Constitutional symptoms such as fever; Weight loss; And fatigue are also common among these individuals.
Musculoskeletal symptoms include arthralgias & myalgias. And avascular necrosis of bone. Pulmonary symptoms include pleural effusions; Interstitial lung disease; And pulmonary hypertension. Renal manifestations of SLE include, acute kidney injury; and chronic kidney disease.
Hematologic manifestations include leukopenia & thrombocytopenia; and hemolytic anemia. Neuropsychiatric manifestations include seizures; and psychosis. Cardiac manifestations include pericarditis; and myocarditis.
Diagnosis of SLE is based on the clinical findings and laboratory evidence of the disease. Currently used criteria for the diagnosis of SLE are published in 2019 by the European league against rheumatism, and American college of rheumatology. According to this, first there should be an anti nuclear antigen titer of at least 1 to 80. If not, patient is not considered as having SLE. If present, 22 additive weighted criteria are considered. Which include 7 clinical domains, and 3 immunologic domains. Each criterion is assigned points, ranging from 2 to 10. Patients with at least one clinical criterion, and 10 or more points are considered to have SLE.

Treatment of S L E depends on disease severity & manifestations. Hydroxychloroquine has a central role in the management of the disease, as it decreases flares & prolongs the life of the patient. For cutaneous, musculoskeletal, and serosal involvement, non steroidal anti inflammatory drugs, or short courses of steroids can be used. Long term treatment with corticosteroids is required when the central nervous system, or kidneys are involved.

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