1. Senior Talk Collins Okolie PGY3
AMYLOIDOSIS
Senior Talk
Collins Okolie PGY3

2. OBJECTIVES Definition Mechanism of formation
Characteristics common to all amyloid subtypes
Classification
Clinical Importance/Symptoms
Diagnosis and Treatment
Take home message

3. Definition
A medical condition resulting from aggregation of extracellularly deposited abnormal proteins called amyloid fibrils that cause damage to organs and tissues.
These fibrils are insoluble, linear, rigid and measures approximately 7.5 to 10mm in width

4. Mechanism of formation
Amyloid fibrils arise from misfolded proteins. Alpha helix to beta pleated sheet
Proteins are deposited extracellularly
Proteins aggregate and form fibrils called amyloid fibrils.
Misfolded proteins may result from point mutations.
Deposited as localized vs systemic
-localized; close to cells producing it.
-Systemic; distant sites from these cells producing these abnormal proteins.

5. In 1854 Rudolph Virchow named it amyloid based on color after staining these proteins with iodine and sulfuric acid. Meaning cellulose or starch

6. Characteristics common to all amyloid subtypes
Hematoxylin and Eosin (HE) staining results in amorphous eosinophilic appearance when viewed on light microscopy.

7. Amorphous eosinophilic interstitial amyloid observed on renal biopsy
Picture was adapted from Bruce A Baethge. Amyloidosis Overview.

8. Congo red staining results in bright green fluorescence/birefringe apple green color when viewed under polarized light.

9. Congo red staining of a cardiac biopsy specimen containing amyloid, viewed under polarized light
Picture was adapted from Bruce A Baethge. Amyloidosis Overview.

10. Electron microscopy shows regular fibrillar structure
X-ray diffraction shows beta pleated sheet structure

11. Classification: Historical vs Modern
Historical (Clinical): Primary, Secondary, multiple myeloma associated, Familial.
Modern (Biochemical): Since 1960’s based on ability to solubilize fibrils and immunostain for protein subtypes.
23 different human subtypes named based on A for amyloid followed the precursor protein e.g AL, AH.

12. Table was adapted from Harrison's principles of internal medicine 16th edition vol II, chapter 310-Amyloidosis

13. Further Clinical Manifestations
CNS/Neuro: Neuropathy both autonomic and peripheral, dementia. Corneal deposits also.
Cardiac:
-Cardiomyopathy typically restrictive
-Heart failure predominantly right sided
-Angina
-Sudden death
-Syncope/pre-syncope
-ECG Abnormalities and Conduction disease
-Arrhythmia
-Cardiac tamponade occasionally, though uncommon.
-Hypotension

14. CARDIAC AMYLOID
Adapted from K. Shah et al, Archives of internal medicine 2006.

15. Pulmonary: -Pleural effusions
-Parenchymal nodules
-Tracheal and bronchial infiltration causing hoarseness, airway obstruction and dysphagia.
Renal: Proteinuria, nephrotic syndrome, renal failure leading to kidney transplant or dialysis.

16. Heme: Bleeding abnormalities
Musc: Hypertrophy of muscles, macroglossia
Skin: Nodules, plaques, easy bruising
GI: Organomegaly (Hepatomegaly, splenomegaly), gastroparesis, abnormal bowel movement usually constipation, malabsorption

17. Liver amyloid
Adapted from amyloid images

18. Diagnosis
Unexplained medical disorder and you suspect amyloidosis: e.g heart failure, proteinuria, hepatic dysfunction
Check ECG, TTE, BNP, UPEP, SPEP
Ultimately, you need Tissue biopsy: Abd fat pad, rectal, salivary gland, endomyocardium.
Bone marrow biopsy

19. Treatment
Treatment of this medical disorder is limited and research is still in progress.
Treatment differs depending on subtype.
AL and AH
-High dose mephalan plus dexamethasone/prednisone
-In selected candidates autologous stem cell transplant is an option.
- The goal with treatment is to get rid of clonal plasma cells that lead to immunoglobulin protein

20. AA: Treat the infection or chronic inflammatory condition causing apo serum A protein elevation.
Familial Mediterranean fever: Colchicine
Other conditions are treated conservatively or require organ transplant
Prognosis is poor with this medical disorder.

21. TAKE HOME MESSAGE Can affect any organ system
Hematoxylin and Eosin (HE) and Congo stain only tells you these are amyloid fibrils
Need to immunostain to determine subtype
Different subtypes are treated differently.
A lot still have to be known about the therapy as prognosis is poor for this disease.

22. References
Rajkumar, S. V. and M. A. Gertz. “Advances in the Treatment of Amyloidosis.” NEJM :
Merlini G and V Bellotti. Molecular Mechanisms of Amyloidosis. New England Journal of Medicine 2003, August: 349:583
Baethge B. Amyloidosis Overview.
Bogov B, Lubomirova M and Kiperova B. Biopsy of subcutaneous fatty tissue for diagnosis of systemic amyloidosis. Hippokratia Oct;12(4):236-9.
Dember LM. Modern Treatment of Amyloidosis: Unresolved questions. J Am Soc Nephrol Dec 10.
Gorevic, Shah, K. B., et al. Amyloidosis and the Heart. Archives of Internal Medicine :
P. D. An overview of amyloidosis. UpToDate.com
J D Sipe and Alan Cohen. Amyloidosis. Harrison’s Principles of Internal Medicine. Chapter 30, page 2024
Images and tables were obtained from Harrison’s, Archives of internal medicine, emedicine and google as sited on each image.