Systemic Lupus Eryhtematosus Flashcards
defintion
autoimmune disease that can affect any part of the body
who is SLE more common in
9x more common in females and in asians and afro-caribeans
risk factors
UV light, smoking and infection especially EBV
Pathophysiology
- due to defective immune clearance, necrotic cells release their nuclear material which is normaly cleared by the immune system
- but in SLE there is defective immune clearance so the immune system eventually believes the nuclear material are antigens (auto- antigens)
- the immune system stimulates B cells to produce autoantibodies (anti- nuclear antibodies) in response to these auto antigens
- the auto antigens and anti-nuclear antibodies then form an immune complex and migrate into blood vessels
- they eventually become lodged in a vessel wall in an organ triggering a localised inflammatory response which activates the complement system and recruits neutrophils
- the neutrophils produce enzymes which damage the endothelial basement membrane
classical triad of general presentation
- fever
- arthralgia
- malar butterfly rash
Mucocutaneous features
- photosensitivity
- malar butterfly rash which spare the nasolabial folds
- non-scarring alopecia
- discoid lupus erythematous
- painless mouth ulcers
- sjogrens syndrome
neurological features
- depression, psychosis
- seizures
- cranial or peripheral neuropathy
- mononeuritis multiplex
serositis
- pleural effusion and pleurisy
- pericardial effusion and pericarditis
msk features
- non-deforming arthritis which has the same distribution of rheumatoid arthritis but does not cause erosions
- the deforming arthropathy is called JACOUS arhtropathy which is ulnar deviation from 2nd to 5th fingers due to subluxation of MCP joints
- myopathy: weakness, myalgia and myositis
haematological features
- lymphadenopathy (one of the earliest symptoms)
- haemolytic anaemia
- leucopenia
- lymphopenia
- thrombocytopenia
what should you always be suspicious of in SLE
renal disease always do urinalysis or you’ll kill the person
lupus nephritis
- most severe an deadly manifestation of lupus as it causes no symptoms until the kidneys completely fail
- causes a lupus glomerulonephritis causing proteinuria of greater than 500mg
- can also cause hypoalbunaemia, haematuria and hyperlipidaemia
diagnosis of lupus nephritis
first do urinalysis and if there is protein in urine then do renal biopsy
what syndrome is a disease on its own but is most common in people with SLE
anti-phospholipid syndrome
what is anti-phospholipid syndrome
autoimmune disorder which causes recurrent arterial and venous thrombosis
presentation of anti-phospholipid syndrome
recurrent miscarriages and recurrent unexplained thrombosis
clinical signs of anti-phospholipdu syndrome
- livido reticularis
- prolonged APTT (not because deficiency in clotting factors but because the antibodies interfere with phospholipids)
diagnosis of anti-phospholipid syndrome
one of three antibodies must be present on 2 occasions 12 weeks apart
- beta-2-glycoprotein
- lupus anti-coagulant
- anti-cardiolipin
the more antibodies present the higher the risk of thrombosis
management of anti-phospholipid syndrome
life long warfarin but remember warfarin is teratogenic so if person wants to get pregnant you must take the off warfarin and put them on FRAGMIN which is a type of low molecular weight heparin
diagnostic criteria
must meet 4 criteria with one being immunological and one being clinical
antibodies in SLE
- ANA: sensitive but not at all specific
- anti-dsDNA: specific but not completely sensitive
- Anti-Ro
- Anti-Sm
Anti-DsDNA
highly specific for SLE but not everyone with SLE has it, basically means that if you have it you definitely have SLE but if not is doesn’t rule it out
anti-Ro
- associated with cutaneous manifestations and secondary sjogrens
- in pregnancy it causes neonatal lupus which can cause foetal heart block
the higher the titre of antibodies
the more active the disease
