A/43 Flashcards
2 characteristics of SLE
- multisystem disorder
- remitting/relapsing disease : ondulant
What type of autoantibodies can you find in SLE? (3)
- Antinuclear antibodies
- Antibodies to blood cells
- Antibodies to phospholipids
What is the anti-smith antibody?
auti-antibody against double strand DNA, found specifically in SLE
How do we detect ANA in lupus?
immunofluorescence test - different patterns depending on which region of the cell is affected
Limitations of testing for ANA (2)
- low specificity : other autoimmune disorders can also be positive
- 5-15% old healthy people can be positive too
Incidence of SLE (3)
- 1/250 people prevalence
- 9:1 female / male ratio
- Disease of the 30s
What do the antibodies to phospholipids affect in SLE?
blood clotting : patients more prone to venous thrombus and thrombocytopenia
Pathomechanisms of SLE (3)
- Type 3 HS : DNA/antiDNA complexes
- Type 2 HS : antibodies to RBC, platelets
- Antibodies to clotting system
Genetic factors of SLE pathogenesis (4)
- familiar accumulation
- HLA-DR2 and HLA-DR3 are the most prone
- Genetic deffect of C1q, C2, C4
- Deffective clearance of immune complexes
Most affected systems by SLE (7)
- Vessels
- Skin
- Joints
- Kidney
- Heart
- Serosal membranes
- CNS
Morphology of SLE on the vessels
Acute necrotizing vasculitis of small arteries and arterioles
Morphology of SLE on the skin (2)
- Butterfly erythema
- Maculopapular eruption
Morphology of SLE on kidney (2)
- Endothelial, mesangial, epithelial proliferation caused by inflammation
- Glomerulonephritis due to IC deposits
Morphology of SLE on heart (2)
- Libmen-Sacks endocarditis
- AS
Morphology of SLE on CNS (2)
- Cerebral microinfarcts
- Neurologic / psychiatric manifestations
SLE therapy
immunosuppression, steroids
Incidence of RA (2)
- Peak incidence 40-50 years
- 5:1 female / male ratio
What type of auto-antibodies in RA?
anti-citrullinated protein antibodies (ACPA)
What is rheuma factor?
IgM/A autoantibodies against Fc receptor of IgG
What does rheumatoid arthritis mostly cause? (2)
- Non suppurative, proliferative, symmetric synovitis of small joints
- Destruction of articular surface
Factors that affect incidence of RA? (2)
- Genetic factors : HLA-DR4 allele
- Environmental triggers
Pathomechanism of RA? (3)
- CD4 is activated by binding MHCII
- CD4 induces macrophages to release cytokines
- Cytokines induce MMP, RANKL, RF production and proliferation of fibroblasts and synovia
What do MMPs do?
Destroy tissue
What does RANKL do?
Osteoblast proliferation, which leads to bone destruction
2 types of joint issues caused by RA
- pannus
- ankylosis
What is pannus in RA?
hypertrophy of synovia, inflammatory cells, granulation tissue
What is Ankylosis in RA?
Bony bridge on articular surface, fibrous deformity of the joint
Other organ effects of RA (3)
- Subcutaneous rheumatoid nodules
- Acute necrotizing vasculitis
- Lung fibrosis
What is Reynaud’s phenomenon?
Hyperreactivity to cold due to vascular involvement of RA
