Systemic Lupus Erythematosus (SLE) is a chronic, systemic pathology with an autoimmune pathogenesis, characterised by variable development and prognosis. From an epidemiological point of view, its frequency varies throughout the world and it affects between 20 to 70 cases out of every 100.000. As is the case with other autoimmune diseases, SLE mainly affects females, particularly when pregnant. Moreover, its frequency is greater in non-Caucasian patients (Afro-American and Afro-Caribbean). The aetiology of SLE has not yet been specified: hitherto unknown, environmental causes, which affect the genetically predisposed, and/or pre-existing modifications to the immune system are considered to be relevant. Other risk factors include: female sex hormones, sunlight, smoking, a vitamin D deficiency and various infections. Moreover, there exist other types of drug-induced SLE, which, however, are considered reversible after the drug in question has been suspended. There are also interesting physiopathological mechanisms regarding the aetiology of SLE: for example, modifications in cellular apoptosis and the production of anti-nuclear, autoantibodies. The latter from immune-complexes which precipitate SLE, causing occlusion of the vascularised areas, such as renal glomeruli. Clinically, SLE affects different organs and initially, it can have a marked, non-specific symptomatology, including: fever, a general feeling of malaise, asthenia, and muscular and joint pain. With the progression of the disease, the clinical symptoms become more indicative, differentiating themselves according to the sex of the patient. Females tend to show arthritic phenomena, psychiatric symptoms with the presence of Raynaud’s disease and leukopenia. Males are typically affected by renal pathologies, peripheral neuropathy and alterations in the skin. Any given pathology can develop in a seesaw fashion and is characterised by acute periods followed by periods of remission. Approximately 70% of patients show dermatological symptoms: frequent in initial or acute stages is the so-called “butterfly rash”, an erythematous skin rash which affects the malar skin bilaterally in the shape of butterfly wings. Hair loss and oral, nasal and genital ulcers can also be affected by the rash. Other clinical symptoms of SLE are:
- Arthritis and widespread joint pain
- Anaemia, leukopenia and alterations in clotting
- Cardiac inflammation (endocarditis, pericarditis and valvular heart disease
- Pleurisy and other inflammatory, interstitial pathologies affecting the lungs
- Glomerulonephritis, leading to renal deficiency
- Peripheral neuropathy, cephalalgia, cognitive dysfunction and convulsions
- Psychiatric symptoms, including anxiety, depression and psychosis
The incidence of SLE in pregnant women increases the possibility of spontaneous miscarriage. Furthermore, there is a form of neonatal Lupus affecting the newborns of mother with SLE; it is usually benign and self-limiting. Diagnosing SLE can be complex and based on a clinical and histopathological evaluation, and laboratory test. The most used of the latter involves researching for antinuclear antibodies (ANA and ENA) and direct immunofluorescence, in which a band-like deposit along the epidermal basement membrane is highlighted. Other examinations deployed in suspect cases are the evaluation of: a complement system, electrolytes, renal function, hepatic enzymes and whole blood count. In 1997 the American College of Rheumatology (ACR) revised its diagnostic criteria for SLE, of which the following may be indicative to confirm a diagnosis:
1. Malar rash
2. Discoid rash
3. Phothosensitivity
4. Oral and/or nasopharyngeal ulcers
5. Non-erosive arthritis
6. Serositis (pleuritis or pericarditis)
7. Kidney dysfunctions (persistent proteinuria)
8. Neurological disorders (convulsions, psychosis)
9. Haematological disorders (haemolytic anaemia, leukopenia, lymphopenia, thrombocytopenia)
10. Immunological disorders (the presence of anti-DNA antibodies and anti-Sm, changes in the number of circulating IgG and IgM)
11. Positivity to anti-nuclear antibodies.
Treatment for SLE involves reducing the number of acute events in terms of frequency and severity. Drugs in current use include: NSAIDs, corticosteroids, immunosuppressants and antimalarial medications. Almost 90% of patients who are treated and monitored for possible, systemic complications can expect a standard quality of life. However, the prognosis is worst for males than females.
