Histo: Systemic Disease

Question 1

What can JCV infection in HIV positive patients lead to?

Answer 1

Progressive multifocal leukoencephalopathy

Question 2

What is the most common opportunistic infection in HIV positive patients?

Answer 2

CMV

Question 3

Which herpes virus causes kaposi sarcoma?

Answer 3

HHV8

Question 4

What is the main histological finding in sarcoidosis?

Answer 4

Non-caseating granulomas

Question 5

How does end-stage sarcoidosis appear on CXR?

Answer 5

‘Honeycomb’ lung

Question 6

What is a granuloma made up of?

Answer 6

Lymphoid cells and giant cells

Question 7

What colour does IgG4 stain when positive?

Answer 7

Brown

Question 8

Recall 3 diseases caused by IgG4 inflammation

Answer 8

Riedel thyroiditis
Autoimmune pancreatitis
Inflammatory pseudotumours

Question 9

What is the structure of amyloid?

Answer 9

Beta pleated sheet that forms non-branching fibrils

Question 10

What is the cause of AA amyloidosis?

What is the cause of AL amyloidosis?

Answer 10

AA: Derived from serum Amyloid A protein - produced in chronic inflammation

AL: Derived from light chain component of immunoglobulins

Question 11

Which conditions are particularly implicated in the development of AA amyloidosis?

Answer 11

Crohn’s
Rheumatoid arthritis

Question 12

What conditions can cause AL amyloidosis?

Answer 12

Myeloma
B cell neoplasms

Question 13

What is the link between transthyretin and amyloidosis?

Answer 13

Transthyretin mutation leads to misfolding of the protein -> can lead to cardiac amyloid deposition

Question 14

What stain can be used for amyloid?

Answer 14

Congo red - gives green birefringence under polarised light

Question 15

What does amyloid always contain?

Answer 15

P-component