Connective tissue diseases Flashcards
What are CTD?
Characterised by presence of auto-antibodies
Characterised by spontaneous over activity of the immune system
SLE - definiton
Systemic auto-immune disease that can affect any part of the body
SLE - epidemiology
M/F, age, ethnicity
More common in females
After puberty
Asians, Afro-carribeans
SLE - causes
Increased oestrogen levels
Silica dust exposure
UV light
SLE - pathogenesis
Defect in apoptosis causes increased cell death.
Debris of dead cells are not effectively cleared which allows the persistence of antigen and immune complex production.
Complement activation and inflammation.
Dead cells release nuclear material which act as potential auto-antigens
T and B cells are stimulated
Auto-antibodies are produced
Deposition of small immune complexes in the skin
SLE - clinical features
Involves a wide range of body systems
General: fever, fatigue, malaise, weight loss
MSK: arthralgia, myalgia, inflammatory arthritis
Muco-cutaneous: Butterfly malar rash which spares naso-labial folds, discoid lupus (circular), painless mouth ulcers, alopecia, raynauds
Resp: pleural effusion, PE, ILD
Renal: lupus nephritis
Neuro: headache, depression
SLE - which type of hypersensitivity reaction is involved?
Type III hypersensitivity (immune complex mediated)
SLE - immunology
Complement binding to immune complexes helps remove antigen from the body
Large complexes can be removed by macrophages (phagocytosis)
Small complexes are not removed as easily so they inset into the small blood vessels and cause symptoms
SLE - investigations
Bloods
- raised inflammatory markers
- FBC: thrombocytopenia, anaemia, leukopenia
Auto-antibodies
- +ve ANA (not specific - can be +ve in other conditions. Usually over 1:160 titre in SLE patients)
- If ANA is +ve, do more specific testing to determine cause
- Anti-dsDNA - levels change depending on flare ups
- Anti-Sm - highly specific
- Anti-Ro
- Anti-RNP
Decreased complement
- Decreased C3 and C4 levels (as complement is consumed by immune processes)
MUST SCREEN FOR ORGAN INVOLVEMENT
Urinalysis - screen for renal disease
Renal biopsy
Imaging - x-ray, CT, MRI
SLE - MILD management
Hydroxychloroquine
- for arthritis, skin manifestations
Topical steroids
NSAIDs
SLE - MODERATE management
Oral steroids
Immunosuppressants
- azathioprine, methotrexate, myclophenolate mofetil)
- to decrease production of auto-antibodies
SLE - SEVERE management
IV steroids
IV immunosuppressants
- cyclophosphamide
Rituximab
APS - definition
Venous or arterial thrombosis and/or adverse pregnancy outcomes
APS - Epidemiology
M/F, age
More common in females
Young patients
APS - clinical features
1 or more otherwise unexplained venous or arterial events
Foetal death after 10 weeks
3 pregnancy losses before 10 weeks
Premature birth (due to severe pre-eclampsia or placental insufficiency)
APS - investigations
Bloods - thrombocytopenia Antibodies - Lupus anticoagulant - IgM or IgG beta 2 glycoproteins - IgM or IgG anticardiolipin antibodies
APS - management
Life long anti-coagulation
LMWH/Aspirin (in patients with recurrent pregnancy loss)
(Do NOT use warfarin, it is teratogenic)
Hydroxychloroquine
Sjogrens syndrome - definition
Characterised by lymphatic infiltrates in exocrine organs. Diminished lacrimal and salivary gland function
Sjogrens syndrome - epidemiology
M/F, age
More common in females
Age 50-60
Sjogrens syndrome - clinical features
Dry eyes Dry mouth Dry throat Vaginal dryness Joint pains Fatigue
Sjogrens syndrome - investigations
Diagnosis based on ocular dryness - Schrimmers test (to assess tear production) Auto-antibodies - +ve Anti-Ro - +ve Anti-La
Sjogrens syndrome - management
Lubricating eye drops
Saliva replacement
Systemic sclerosis - definition
Excessive collagen deposition
Systemic sclerosis - DIFFUSE form clinical features
Early organ involvement
skin changes: proximal to forearms, involves torso
ILD
Systemic sclerosis - DIFFUSE form auto-antibodies
Anti-Scl-70
Systemic sclerosis - LIMITED form clinical features
Skin changes: distal to elbows, face, feet
Systemic sclerosis - LIMITED form auto-antibodies
Anti-centromere
Systemical sclerosis - general features
Tightening of the skin Raynauds Calcinosis Sclerodactyly Telangectasia
Systemic sclerosis - management
Raynauds: CCB
Renal involvement: ACE inhibitors
Mixed CTD - definition
Features of SLE, polymyositis, systemic sclerosis
Mixed CTD - clinical features
Raynauds Arthralgia Myositis Sclerodactyly Pulmonary hypertension ILD
Mixed CTD - auto-antibodies
Anti-RNP
