Histo: Connective tissue disease, amyloid, sarcoid, Immune related multisystem disorders Pt.1

Question 1

Give an example of an autoimmune disease that is:

1. Organ-specific with a specific antigen
2. Organ-specific without a specific antigen
3. Multisystem disease

Answer 1

1. Organ-specific with a specific antigen: pernicious anaemia
2. Organ-specific without a specific antigen: primary biliary cirrhosis
3. Multisystem disease: rheumatoid arthritis, Sjogren syndrome, SLE

Question 2

What are the main features of SLE?

Answer 2

SOAP

• Serositis
• Oral ulcers
• ANA
• Photosensitivity

Brain

• Bloods (low counts)
• Renal (proteinuria)
• Arthritis
• Immunological (anti-dsDNA)
• Neurological (psychiatric, seizures)

MD

• Malar rash
• Discoid rash

SOAP BRAIN MD

Question 3

What units are used for ANA levels?

Answer 3

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)

Question 4

List three autoantibodies found in SLE. Which is most specific?

Answer 4

• Anti-dsDNA
• Anti-Smith (Sm, against ribonucleoproteins) - most specific but low sensitivity
• Anti-histone - drug-related (e.g. hydralazine)

Question 5

How is anti-dsDNA measured?

Answer 5

ELISA

Crithidia luciliae

• Incubate the patient’s serum with Crithidia Luciliae (protozoan)
• It has a big organism with dsDNA (kinetoplast) so if the patient has anti-dsDNA antibodies it will bind to the dsDNA in the kinetoplast

Question 6

What can be seen on blood film in SLE?

Answer 6

LE (lupus erythromatosus) cell - neutrophil or macrocyte that has engulfed nuclear material of another cell

Question 7

Describe the appearance of skin histology in SLE.
What would immunofluorescence show?

Answer 7

• Lymphocytic infiltration of the dermis
• Vacuolisation (dissolution of the cells) of the basal epidermis
• Extravasation of blood causes a rash

NOTE: immunofluorescence will show immune complex deposition at the epidermis-dermis junction

Question 8

Describe the appearance of renal histology in SLE.

Answer 8

Thickened pink glomerular capillaries (wire-loop capillaries) due to immune complex deposition.

NOTE: immune complex deposition can be visualised by immunofluorescence

This is what a normal glomerulus looks like

Question 9

What is the name of non-infective endocarditis associated with SLE?

Answer 9

Libman-Sacks endocarditis

NOTE: the vegetation is made up of fibrin, lymphocytes, neutrophils, histocytes

Question 10

What is scleroderma?

Answer 10

An autoimmune condition characterised by excess collagen deposition and fibrosis

Question 11

What is the localised skin-only form of scleroderma called?

Answer 11

Morphoea (sclerosis of skin only)

Question 12

What are the two types of scleroderma?
Name the antibodies that they are associated with.

Answer 12

Diffuse

• Involves the trunk and proximal limbs
• Anti-Scl70 antibodies (anti-topoisomerase)

Limited (CREST syndrome)

• Only affects skin distal to the elbows and knees
• Anti-centromere antibodies

Question 13

What are the main features of limited cutaneous systemic sclerosis (CREST syndrome)?

Answer 13

• Calcinosis
• Raynaud’s phenomenon
• Esophageal dysmotility
• Sclerodactyly
• Telangiectasia

Question 14

What pattern of ANA immunofluorescence is seen in scleroderma?

Answer 14

Nucleolar

Question 15

Describe the skin histology in scleroderma.

Answer 15

Increased depth and amount of collagen (results in reduced skin elasticity)

Question 16

How does scleroderma cause gastric and oesophageal dysmotility?

Answer 16

Collagen deposition (fibrosis) with the submucosa - affects muscle contraction

Question 17

Describe the vascular histology in scleroderma.

Answer 17

Intimal proliferation gives an onion skin appearance.

Question 18

What is a major consequence of vascular damage in scleroderma?

Answer 18

Renal hypertensive crisis

Question 19

What is mixed connective tissue disease?

Answer 19

A condition characterised by the overlap of several connective tissue diseases including SLE, scleroderma, polymyositis and dermatomyositis

Question 20

What ANA immunofluorescence pattern is seen in mixed connective tissue disease?

Answer 20

Speckled