Is there any cause of Lupus

Hey Surfguru

Your reference above is to PV which is different to Lupus (SLE).

http://en.wikipedia.org/wiki/Systemic_lupus_erythematosus

Transmission of Lupus Erythematosus

"In SLE, the body's immune system produces antibodies against itself, particularly against proteins in the cell nucleus. SLE is triggered by environmental factors that are unknown (but probably include viruses) in people with certain combinations of genes in their immune system."

Genetics

"The first mechanism may arise genetically. Research indicates that SLE may have a genetic link. Lupus does run in families, but no single "lupus gene" has yet been identified. Instead, multiple genes appear to influence a person's chance of developing lupus when triggered by environmental factors. The most important genes are located on chromosome 6, where mutations may occur randomly (de novo) or may be inherited. Additionally, people with SLE have an altered RUNX-1 binding site, which may be either cause or contributor (or both) to the condition. Altered binding sites for RUNX-1 have also been found in people with psoriasis and rheumatoid arthritis. "

Environmental triggers
"The second mechanism may be due to environmental factors. These factors may not only exacerbate existing lupus conditions but also trigger the initial onset. They include certain medications (such as some antidepressants and antibiotics), extreme stress, exposure to sunlight, hormones, and infections. Some researchers have sought to find a connection between certain infectious agents (viruses and bacteria), but no pathogen can be consistently linked to the disease. UV radiation has been shown to trigger the photosensitive lupus rash, but some evidence also suggests that UV light is capable of altering the structure of the DNA, leading to the creation of autoantibodies. Some researchers have found that women with silicone gel-filled breast implants have produced antibodies to their own collagen, but it is not known how often these antibodies occur in the general population, and there is no data that show that these antibodies cause connective tissue diseases such as lupus. "

Drug reactions
"Drug-induced lupus erythematosus is a reversible condition that usually occurs in patients being treated for a long-term illness. Drug-induced lupus mimics systemic lupus. However, symptoms of drug-induced lupus generally disappear once a patient is taken off the medication that triggered the episode. There are about 400 medications currently in use that can cause this condition, though the most common drugs are procainamide, hydralazine, quinidine and Phenytoin. "

Non-SLE forms of lupus
"Discoid (cutaneous) lupus is limited to skin symptoms and is diagnosed by biopsy of skin rash on the face, neck, or scalp. Often an antinuclear antibody (ANA) test for discoid patients is negative or a low-titer positive. About 1"5% of discoid lupus patients eventually develop SLE. "

http://en.wikipedia.org/wiki/Lupus_erythematosus