【正文】 pecially C4, C2, and other early ponents) are also associated with an increased risk of SLE. Environmental factors ? UV exposure ? Microbial response ? Drugs Pathophysiology ? SLE is an autoimmune disorder that involves multisystem microvascular inflammation with the generation of autoantibodies. ? Many immune disturbances, both innate and acquired, occur in SLE, as noted in image 1 In SLE, many geicsusceptibility factors, environmental triggers, antigenantibody responses, Bcell and Tcell interactions, and immune clearance processes interact to generate and perpetuate autoimmunity. One proposed mechanism for the development of autoantibodies involves: ? A defect in apoptosis that causes increased cell death and a disturbance in immune tolerance. ? The redistribution of cellular antigens during apoptosis leads to a display of plasma and nuclear antigens on the cell surface. Thus, dysregulated (intolerant) lymphocytes begin targeting normally protected intracellular antigens. ? Immune plexes form in the microvasculature, leading to plement activation and inflammation. ? Antibodyantigen plexes deposit on the basement membranes of skin and kidneys. CLINICAL ? The presentation and course of SLE is highly variable, ranging from indolent to fulminant. ? The natural history of SLE varies from relatively benign disease to rapidly progressive and even fatal disease. ? The disease often waxes and wanes in individual patients throughout life. ? Patients with isolated skin and musculoskeletal involvement have higher survival rates than those with renal and central nervous system (CNS) disease. Constitutional Nonspecific fatigue, fever, arthralgia and weight changes are the most frequent symptoms in new cases or recurrent active SLE flares. ? Fatigue: the most mon constitutional symptom, can be due to active SLE, medications, lifestyle habits, or affective disorders. ? Fever: another mon yet nonspecific symptom, may also be due to many causes. Active SLE, infection, and drug fever are the most mon etiologies. ? Weight loss: may occur with active disease. Weight gain may also be due to corticosteroid treatment or active disease such as nephrotic syndrome anasarca. ? Lymphadenopathy or splenomegaly may be found. Musculoskeletal ? Arthralgia, myalgia, and arthritis represent the most mon presenting symptoms in SLE. ? Smalljoint arthritis of the hands, wrists, and knees are involved most frequently. ? Jaccoud arthropathy is the term for the nonerosive hand deformities due to chronic arthritis and tendonitis that develop in 10% of patients with SLE. This may mimic rheumatoid arthritis (RA) ulnar deviation and phalangeal subluxations. ? Myositis that manifests as weakness rarely occurs and is more monly related to overlap syndromes or corticosteroidinduced myopathy. Dermatologic Cutaneous manifestations of SLE prise 3 diagnostic criteria and multiple other clues to a potential diagnosis of lupus. ? Malar rash describes an erythematous rash over the cheeks and nasal bridge lasts from days to weeks occasionally painful or pruritic. ? photosensitive rash may be elicited from patients if they have any unusual rash or symptom exacerbation after sun exposure. Photosensitive SLE rashes are often macular and typically occur on the face , arms, or extremities, which are sunexposed regions. ? Discoid lesions often develop in sunexposed areas but are plaquelike lesions with follicular plugging and scarring. ? They may be part of systemic lupus or may represent discoid lupus without an involvement, which is a separate diagnostic entity. Erythema annular centrifugum: unique nonscarring erythematous papules or plaques with central spa ri ng or a m ore c on f lu e nt app e a ran c e. Oral ulcers may be noted, with palatal ulcers being most specific for SLE. Raynaud phenomenon is a painful triphasic blue, white, and red color change at the distal digital tips. It is not a specific finding for SLE, but it may be seen in up to 2030% of patients with SLE. ? Other skin lesions related to but not specific to SLE include Livedo reticularis, alopecia, panniculitis (lupus profundus), bullous lesions, vasculitic purpura, nail fold infarcts and urticaria. Renal The kidney is the most monly involved visceral an in SLE. ? Although only approximately 50% of patients develop clinically evident renal disease, biopsy studies demonstrate some degree of renal involvement in almost all patients. ? Glomerular disease usually develops within the first few years after onset and is usually asymptomatic. ? Acute nephritic disease may manifest as hypertension and hematuria. ? Nephrotic syndrome may cause edema, weight gain, or hyperlipidemia. ? Acute or chronic renal failure may cause symptoms related to uremia and fluid overload. Neuropsychiatric ? Headache is the most mon neurological symptom, often with migraine or plex migraine features. ? Mood disorders such as anxiety and depression are frequently reported. ? Cognitive disorders may be variably apparent in patients with SLE. Formal neuropsychiatric testing reveals deficits in 2167% of patients with SLE, which may be caused by true encephalopathy, neurological damage, medication effects, depression, or some other process. ? Psychosis related to SLE may manifest as paranoia or hallucinations. ? D