Autoimmune diseases & chronic inflammation Flashcards
Which gene region is the most common genetic susceptibility in?
HLA region
How does autoimmunity cause clinical disease? (3)
- Auto-reactive B cells & auto-antibodies
- Auto-reactive T cells
- General inflammation
How do auto-reactive B cells and auto-antibodies cause clinical disease?
Directly cytotoxic»_space; activate complement and interfere with normal physiological function
How do auto-reactive T cells cause clinical disease?
Directly cytotoxic»_space; inflammatory cytokine production
What are the 2 types of autoimmune disease?
- Organ specific (eg. thyroid)
- Systemic (eg. connective tissue)
What is Hashimotos thyroiditis?
Thyroid follicle destruction»_space; 1* hypothyroidism
What is Graves’ disease?
Thyroid gland over-stimulation by anti-TSH autoantibody»_space; hyperthyroidism
What are scleroderma, polymyositis and Sjogrens syndrome?
Connective tissue diseases
What are non-specific diagnostic tests for autoimmune diseases?
Inflammatory markers (ESR/CRP/albumin)
What are disease-specific diagnostic tests for autoimmune diseases?
Autoantibodies, HLA typing
What is rheumatoid factor (RF)?
Antibody (IgM, IgG, IgA) directed against Fc portion of IgG
- increased with rheumatoid arthritis, but not specific
What is Anti-CCP (ACPA)
Useful prognostic marker for rheumatoid arthritis
-more specific than RF
What is systemic lupus erythematosus?
Connective tissue disease»_space; malar rash, mouth ulcers, alopecia, pleural effusion.
What is the test for systemic lupus erythematosus?
Anti-nuclear antibodies
What is the treatment for systemic lupus erythematosus?
Immunosuppression
What is ANCA vasculitis?
Inflammation of small vessels (polyangitis)
What are the 3 forms of ANCA vasculitis?
Microscopic
Granulomatosis
Eosinophilic granulomatosus
What is the test for Raynaud’s?
Anticentromere antibodies»_space; ANA positive
What is a granuloma?
A mass of granulation tissue where lots of macrophages clump together
How long do people suffer from chronic liver disease?
6+ months
What is cirrhosis (liver)?
Nodule formation & fibrosis
What are the consequences of cirrhosis?
Portal hypertension
Bleeding oesophageal varices
Oedema
^Infection
What are ascites?
Accumulation of fluid in peritoneal cavity
-marker of late-stage liver disease
What layers of skin are affected with skin ulcers?
Epidermis and dermis
What are the causes of leg ulcers?
Vascular (90%)
Other (eg. inflammation, infection, neuropathy)
What are the risk factors for venous leg ulcers?
Valve incompetence, DVT, obesity, immobility
What are the risk factors for arterial leg ulcers?
Diabetes, smoking, ^BP, obesity
What is the difference in presentation of venous and arterial leg ulcers?
Venous - relatively painless & superficial
Arterial - painful, leg cramp, paraesthesia
What are the main causes of neuropathic leg ulcers?
Diabetes
B12 deficiency
Alcohol
What are rare causes of leg ulcers? (3)
- Pustule (rapid breakdown)
- Pyoderma gangrenosum
- Malignancy
What is healing by 1st intention? (leg ulcers)
Restoration by fibrous adhesion»_space; thin scar without granulation tissue
What is healing by 2nd intention? (leg ulcers)
Wounds with lots of tissue loss; >> phagocytosis removes debris >> granulation tissue fills in defects >> organisation >>fibrous scar >> scar contraction to close wound
What is ankle brachial pressue indices(ABPI)?
Ratio of systolic BP in foot:arm.
-1.0 = non significant arterial disease
How are leg ulcers managed?
Treat underlying cause (debride necrotic tissue), ulcer & any infection
What are the 3 types of thrombosis?
Arterial
Cardiac
Venous (main»_space;P.E.)
Where do venous thrombi normally occur?
Sites of vascular stasis
-95% around valves in legs
What are thrombi composed of?
Platelets, fibrin, RBCs
What are the potential outcomes of DVT? (4)
Propagation
Embolisation
Dissolution
Organisation & recanalisation
What are the main types of emboli?
Thrombus (99%) Atheromas Infective Tumour Gas Fat
What are the symptoms of a pulmonary embolus? (4)
Sharp chest pain Breathlessness Coughing Fainting (Swollen leg if DVT)
What is the 2-level wells score?
DVT & P.E. diagnosis chart
- 2+ points suggests DVT likely
- 4+ points suggests P.E. likely
What are the tests for a pulmonary embolus?
Chest x-ray Bloods (D-dimer) CT pulmomary angiogram VQ scan Doppler ultrasound
What is D-dimer?
A protein in blood when a clot has broken down
How are pulmonary emboli managed?
PHARMACOLOGICAL - low weight heparin, vitamin K antagonist, anticoagulants
MECHANICAL - compression stockings, IVC filter
What is a paradoxical embolism?
Cerebral infarction from thrombus in deep calf that passes through a patent foramen ovale
