- antinuclear antibodies
- 10:1 more in females
- although lupus has a very characteric presentation, the symptoms are also found in others so diagnosis is based on: some of the less common features, characteric distribution of symptoms and blood tests. - In blood tests, 95% of cases test positive for the ANA although it can be found in healthy people too. A more specific te4st for lupus is to test for anti-double-stranded dna antibodies and anti-SM AB , the levels of which reflect the activity of the disease
- results in complement deficiency where some actually have a genetic deficiency in complement components whilst in others, there is an acquired defect of the system - thought to be the result of its consumption by autoantibodies which initially react to the component C1q. - the lack of efficient complement has a number of consequences 1. immune complexes cannot be cleared and as a result they are deposited in vascular basement membranes or access tissue macrophages 2. It also impairs resistance to infectiom
3. Is impairs selection deletion of autoreactive V cells resulting in the formation of a range of autoantibodies - the complement system is not the only target of autoantibodies in SLE; some act directly on tissues such as the kidneys, red blood cells, platelets and others, including the brain.
- these autoantibodies are so effective because they are able to perpetuate their production through a varierty of bypass mechanisms including impaired clearances of nuclear debris and signalling to B cells. -the clinical features of lupus therefore correspond to the antibody targets seen in the table below:
Tissue| Clinical feature|
- change in mood or personality
- infarct or haemorrhage presenting as stroke
- rise in ICP
- a large proportion of morbidity and mortality in patients with SLE is caused by the neuropsychiatric complications, neuropsychiatric...