Autoimmune and CTD Flashcards
Name two genetic CTD
- Marfans Syndrome - autosomal dominant, faulty collagen that leads to many skeletal changes, Signs = tall, long fingers and toes, chest deformities
- Ehlers Danlos Syndrome = skin hyperelastiicty
Name 5 Autoimmune CTD
- SLE
- Systemic Sclerosis
- Sjögren’s Syndrome (SjS)
- Dermatomyositis/ Polymyositis
- Mixed CTD
Describe pathophysiology of Autoimmune CTD
- Inflammation leading organs scarring +/- failure
- Early systemic involvement may not give rise to any Sx
- Any systems can be affected: commonly skin, joints, kidney, lungs, blood cells and nervous systems
- Although there is no cure and damage is irreversible, inflammation can be treated with immunosuppressive drugs.
What is Raynaud’s Phenomenon?
- Peripheral digital ischaemia.
- Finger or toes change colour from PALE (ischaemia, lack of blood flow) –> BLUE (lack of oxygen) –> RED (blood flow returns)
- It can lead to tissue necrosis.
Primary and Secondary causes of Raynaud’s Phenomenon
- Primary (aka Raynaud’s disease)
- Idiopathic
- Younger age, no underlying disease - Secondary
- CTD (SLE, Scleroderma, derma-polymyositis, RA, primary SjS)
- Drugs = Beta-blockers (slows HR, lower BP)
- Vascular damage: atherosclerosis, frost bite, DIY vibrating tools
Management of Raynaud’s Phenomenon
- Smoking cessation
- Avoid exposure to cold
- Change occupation/DIY habit
- Topical glyceryl trinitrate (vasodilator)
- CCB
What is Mixed CTD and how may they present?
Combined features of systemic sclerosis, SLE, polymyositis
Presentation
- Raynaud’s Phenomenon
- arthralgias, swollen joints
- Dysphagia: oesophageal dysfunction
- muscle weakness
- dactylitis
Pathophysiology of SLE
- SLE is an antigen driven immune mediated disease characterised by activation of autoreactive T and B-cells resulting in production of pathogenic autoantibodies and tissue insult.
- Antigen-antibody complexes are formed and circulate the body until it is able to deposit or stick onto vessels or organs.
- Deposited complexes then initiate inflammatory and complement systems which causes cell damage and death (type 3 hypersensitivity).
- Some SLE individuals develop antibodies against RBC, WBC, platelets causing pancytopenia. This is a Type 2 hypersensitivity reaction.
How are SLE Sx non-specific
Presentation can vary greatly between patients.
- Sx can present suddenly or gradually over time.
- Sx can be general = Joint pain, Rash, Fever, Weight loss
- Sx can be specific depending on organ/tissue damaged
Diagnosis criteria of SLE
Dx: must meet 4 of the 11 key Sx and lab findings
SOAP BRAIN MD
S = Serositis, Pleuritis, Pericarditis, Peritonitis O = oral ulcers A = arthritis P = Photosensitivity B = blood: anaemia, thrombocytopenia, leukopenia R = Renal damage A = +ANA I = Immunological: anti-dsDNA, anti-smith, anti-phospholipid N = Neurological: seizures, peripheral neuropathy M = alar rash D = discoid rash
Investigation of SLE
Serology
- ANA
- Anti-dsDNA, Anti-smith, Anti-phospholipids
- Complements: Dec in C3, C4
Management of SLE - conservative, maintenance, flare-ups
Conservative
(1.) UV protection: Avoid sunlight, cover up, high factor sunblock
Maintenance
(1. ) NSAIDs for joint and muscle pains, headaches
(2. ) Immunosuppressants depending on severity and systems affected, consider:
- Corticosteroids
- Hydroxychloroquine
- Azathioprine
- methotrexate
- Belimumab (add on therapy for autoantibody +ve disease where high activity)
Flare-up Mx
- Hydroxychloroquine or low dose steroids for MILD flares (topical for skin)
- DMARDs or mycophenolate for MODERATE flares (organ involvement)
What is Sjorgen’s syndrome? RF? Aetiology? Triggers?
(1. ) AI: immune cells attack exocrine/secretary glands including: saliva, tears, vaginal.
(2. ) As a result, glands do not function leading to dry eyes, mouth, GI tract - leading to irritation of eyes, difficulty swallowing, difficulties having sex.
(3. ) Usually develop as a complication of other autoimmune diseases such as lupus or RA
RF = female of child bearing age, Africa/Asian ethnicity in Europe, Fx of SLE, smoking, sun exposure
Aetiology
- unknown
- genetic (HLA genes) and environmental factors (exocrine gland infection) have a role
Triggers = UV light, Oestrogen, Medication - isoniazid, hydralazine, procainamide, quinidine, etc (Drug-induced Lupus), Smoking, Bacteria, viral infections
Pathophysiology of Sjs
(1. ) In Sjogren’s, ANAs are raised these are anti-SSA & anti-SSB.
(2. ) Antibodies and T-cells enter circulation and reach glands, where cytokines release and inflammation occurs.
(3. ) Cytokines activate fibroblasts in tissue, which produce fibrous tissue that replaces damaged tissue.
(4. ) The end result is a loss secretory cells in the glands.
(5. ) Primary Sjs, occurs alone = sicca syndrome.
- Secondary Sjs occurs with other AI conditions such as RA, SLE, Scleroderma, Primary biliary cirrhosis
Sx of SjS
Dryness of various systems, the following may be present;
(1. ) Keratoconjunctivitis: redness and itching of eye
(2. ) Xerostomia: complain of swallowing difficulty
(3. ) Ulceration, perforation of nasal septum
(4. ) Difficulty speaking
(5. ) Enlargement glands e.g. parotid can cause pinching of nerves
(6. ) Infection is more common due to dryness of epithelium
(7. ) Dryness of skin and vagina
Other Clinical features
- Arthritis
- Rash
- Neurological features
- Vasculitis
- Inc risk of lymphoma
