Histo: Connective tissue disease, amyloid, sarcoid, Immune related multisystem disorders Flashcards
Give an example of an autoimmune disease that is:
- Organ-specific with a specific antigen
- Organ-specific without a specific antigen
- Multisystem disease
- Organ-specific with a specific antigen: Pernicious anaemia
- Organ-specific without a specific antigen: Primary biliary cirrhosis
- Multisystem disease: Rheumatoid arthritis, Sjogren syndrome, SLE
What are the main features of SLE?
- Serositis (recurrent inflammation of pleura/pericardial sac - recurrent pleuritic chest pain)
- Oral ulcers
- ANA
- Photosensitivity
- Bloods (pancytopenia: MAHA, ITP, leucopenia)
- Renal (proteinuria)
- Arthritis
- Immunological (anti-dsDNA)
- Neurological (psychiatric, seizures)
- Malar rash
- Discoid rash
NOTE: SOAP BRAIN MD
What units are used for ANA levels?
It is a titre - the highest dilution at which you can see the fluorescence (e.g. 1:1000 is a higher level than 1:10)
List three autoantibodies found in SLE. Which is most specific?
Anti-nuclear antibodies (ANA):
* Anti-dsDNA
* Anti-smith (against ribonucleoproteins) - most specific but low sensitivity
* Anti-histone - drug-related (e.g. hydralazine)
Which autoantibody is present and specific to drug-related SLE
anti-histone antibody
Describe the appearance of skin histology in SLE.
- Lymphocytic infiltration of the dermis
- Vacuolisation (dissolution of the cells) of the basal epidermis
- Extravasation of RBCs into upper dermis causes the typical rash seen.
- Immunofluorescence will show immune complex deposition at the epidermis-dermis junction
Describe the appearance of renal histology in SLE.
Glomerular capillaries are thickened (wire-loop capillaries) due to immune complex deposition.
NOTE: this can be visualised by immunofluorescence
What is the name of non-infective endocarditis associated with SLE?
Libman-Sacks endocarditis
Patient with SLE can present with endocarditis (e.g. new onset murmur, stroke, embolic event but not grow anything on cultures - the vegetation is made up of lymphocytes, neutrophils, fibrin etc)
What is scleroderma?
A condition characterised by excess collagen in the skin and fibrosis
What are the two types of scleroderma? Name the antibodies that they are associated with.
- Diffuse - involves the trunk (anti-Scl70 antibodies (aka anti-topoisomerase II))
- Limited - only affects distal to the elbows and knees (anti-centromere)
What are the main features of limited cutaneous systemic sclerosis?
- Calcinosis (painful deposits of Ca in tips of fingers)
- Raynaud’s phenomenon
- Esophageal dysmotility (difficulty eating)
- Sclerodactyly (tight skin in fingers - hard to stretch)
- Telangiectasia
CREST syndrome
What are the main features of diffuse scleroderma
- Skin changes (tightness) can occur anywhere (including truncal involvement!).
- Tendon friction
- Raynauld’s phenomenon
- Widespread organ involvement: early heart, GI and renal disease. Associated with pulmonary fibrosis.
What pattern of ANA immunofluorescence is seen in scleroderma?
Systemic = Nucleolar
CREST = Centromere pattern
Describe the skin histology in scleroderma.
Increased depth and amount of collagen.
Describe the vascular histology in scleroderma.
Tunica Intima proliferation and collagen deposition gives an onion skin appearance.
What is a major consequence of vascular damage in scleroderma?
Renal hypertensive crisis
What is mixed connective tissue disease?
What antibody is associated?
A condition characterised by the overlap of several connective tissue diseases (SLE, scleroderma, polymyositis and dermatomyositis)
Antibody: Anti-RNP (ribonucleoprotein)
What ANA immunofluorescence pattern is seen in mixed connective tissue disease?
Speckled
What is dermatomyositis and polymyositis?
Which antibodies is associated?
A condition characterised by proximal muscle pain and weakness and inflammation on muscle biopsy.
If associated with skin changes = dermatomyositis.
Antibody = Anti-Jo 1
What is commonly associated with dermatomyositis and polymyositis
MALIGNANCY
Dermatomyositis = ovarian, pancreatic, NHL
Polymyositis = lung, bladder, NHL
Classical blood results seen in dermatomyositis / polymyositis
High CK
High myoglobin
High LDH
Clinical feature of polymyositis and dermatomyositis
Both have proximal muscle weakness –> difficulty performing gross motor tasks (e.g. getting up from a chair, climbind steps, combing hair).
Dermatomyositis has additional associated skin changes:
- grotton papules (erythema of knuckles w raised scaly eruption)
- Heliotrope rash with eyelid oedema
- Systemic v shaped rash
What is sarcoidosis of the skin called?
Lupus pernio
List some features of sarcoidosis.
- Arthritis
- Lupus pernio
- Erythema nodosum
- Bilateral hilar lymphadenopathy
- Pulmonary fibrosis
- Lymphadenopathy
- Inflammation of layers of the heart
- Uveitis
- Meningitis
- Hepatitis, cirrhosis
- Bilateral parotid enlargement
