AMYLOIDOSIS pathology pptx ssr medical college

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1. AMYLOIDOSIS DR. RAMA SRIVASTAVA

2. DEFINITION Amyloidosis is a condition associated with a number of disorders in which extracellular deposits of fibrillar proteins are responsible for tissue damage and functional compromise.

3. Amyloid is an abnormal proteinaceous substance deposited between cells in various tissues of the body in a variety of clinical settings.

4. These abnormal fibrils are produced by aggregation of misfolded proteins ( which are soluble in their normal folded configuration) Amyloidosis is fundamentally a disorder of protein misfolding .

5. PATHOGENESIS OF AMYLOIDOSIS Factors that contribute to misfolding &aggregation of proteins are : a. When it’s concentration reaches abnormally high levels – Ageing (Senile amyloidosis) Increased production( eg . Chronic inflammation) Impaired excretion ( eg . Long term hemodialysis) b. Mutant protein (Hereditary amyloidosis) c. Defective proteolysis ( eg . Alzheimer’s disease)

6. Appearance of AMYLOID With light microscope & routine stain (H&E) – Amorphous, eosinophilic, hyaline extracellular substance. (Other hyaline substances – collagen, fibrin) CONGO RED STAIN – Light microscope – pink or red color to amyloid deposits. Polarization microscopy – Apple green birefringence.

7. CARDIAC AMYLOIDOSIS

8. RENAL AMYLOIDOSIS H&E CONGO RED

9. PHYSICAL NATURE OF AMYLOID 95% - FIBRILLAR protein – By Electron microscopy – Non branching fibrils of indefinite length and a diameter of 7.5 - 10 nm. X – ray crystallography – Characteristic cross β pleated sheet conformation is seen. This is responsible for distinctive staining and birefringence of Congo red stained amyloid. 5% - P component (SAP), proteoglycans & glycosaminoglycans – staining similar to starch(amylose) – named AMYLOID.

10. BETA PLEATED SHEET CONFORMATION(EM)

11. ELECTRON MICROSCOPY- NON BRANCHING FIBRILS.

12. CONGO RED STAIN(POLARIZED LIGHT)- APPLE GREEN BIREFRINGENCE SEEN.

13. IMMUNOFLUROSCENT STAIN AMYLOID DEPOSITS SHOW GREEN FLUROSCENCE.

14. PAS + ve AMYLOID

15. CHEMICAL NATURE OF AMYLOID Of the 23 biochemically distinct forms of amyloid that have been recognized, following 3 are the most common : AL (Amyloid light chain protein) AA (Amyloid associated protein) A β amyloid. Other typres – ATTR (Amyloid transthyretin) A β 2m (Amyloid β 2 microglobulin ) Acal (Amyloid calcitonin) AIAPP (Islet amyloid polypeptide) AANF (Amyloid atrial natriuretic factor)

16. AL type of amyloid AL protein is produced by plasma cells . It is made up of - complete immunoglobulin light chain or - amino NH2 terminal of light chain, or - both. It is seen with monoclonal B-cell proliferations .

17. AA type of amyloid It is derived from precursor SAAP . SAAP is an acute phase protein synthesized by liver in response to inflammatory conditions . SAAP is normally degraded by macrophage derived enzymes. Defective proteolysis of SAAP results in AA deposition.

18. A β amyloid It is found in the core of cerebral plaques of cerebral blood vessels in cases of Alzheimer’s disease . It is derived from amyloid precursor protein (APP).

19. ATTR type of amyloid It is derived from Transthyretin (TTR) , a normal plasma protein that binds and transports thyroxine & retinol. ATTR is deposited in senile cardiac amyloidosis due to abnormally high concentration. Mutant TTR in Familial amyloidotic polyneuropathy .

20. A β 2m amyloid It is derived from β 2 microglobulin ,which is a normal plasma protein & a component of MHC class I molecule. It reaches high concentrations in patients of CRF who are on chronic hemodialysis as it is not efficiently filtered through the dialysis membrane.

21. PATHOGENESIS OF AMYLOIDOSIS

22. CLASSIFICATION OF AMYLOIDOSIS CLINICO PATHOLOGICAL CATEGORY ASSOCIATED DISEASE MAJOR PROTEIN PRECURSOR PROTEIN SYSTEMIC/ GENERALIZED PRIMARY AMYLOIDOSIS Multiple myeloma & other monoclonal B cell proliferations. AL Immuno-globulin light chains λ type SECONDARY AMYLOIDOSIS. HEMODIALYSIS ASSOCIATED. Chronic inflammatory & neoplastic conditions. Chronic renal failure. AA A β 2m SAAP Β 2 microglobulin .

23. CLINICO PATHOLOGICAL CATEGORY ASSOCIATED DISEASE MAJOR PROTEIN PRECURSOR PROTEIN HERADITARY AMYLOIDOSIS - Familial mediterranean fever. - Familial amyloidotic polyneuropathy. AR AD AA ATTR SAAP Transthyretin B. LOCALIZED AMYLOIDOSIS Senile Cardiac Senile Cerebral. Endocrine amyloid. Alzheimer’s disease Medullary carcinoma thyroid. ATTR A β Acal Transthyretin APP Procalitonin

24. CLINICO PATHOLOGICAL CATEGORY ASSOCIATED DISEASE MAJOR PROTEIN PRECURSOR PROTEIN Contd.. ENDOCRINE AMYLOID. Islet tumor of pancreas. Type II Diabetes. AIAPP Islet amyloid polypeptide. ISOLATED ATRIAL AMYLOIDOSIS. CNS – PRION DISEASE. AANF Aprion . Atrial natriuretic factor. Prion protein.

25. PRIMARY AMYLOIDOSIS Most common type of amyloidosis. Systemic in distribution. AL type. Seen with Multiple myeloma & other monoclonal B cell proliferations. MM is a malignant neoplasm of plasma cells . Abnormal amounts of a single specific Ig (monoclonal gammopathy ). M (myeloma) spike on serum protein electrophoresis. κ or λ light chains ( Bence Jones protein) in serum &urine. Defective proteolysis gives amyloidogenic potential Majority have B cell dyscrasia .

26. M – SPIKE IN MULTIPLE MYELOMA

27. SECONDARY AMYLOIDOSIS Autoimmune conditions – Rheumatoid arthritis. Ankylosing spondylitis. Inflammatory bowel ds.- Crohn’s ds.& UC. Chronic inflammatory conditions – Tuberculosis. Chronic osteomyelitis. Bronchiectasis. Ch. skin infections – skin popping of narcotics. Neoplastic conditions – Renal cell carcinoma. Hodgkin lymphoma.

28. FAMILIAL(HEREDITARY) AMYLOIDOSIS FAMILIAL MEDITERRANEAN FEVER : - Autosomal recessive disorder. Seen in individuals of Armenian,Jewish & Arabic origin. Characterized by fever & inflammation of serosal membranes like peritoneal,pleural&synovial memb . Mutant pyrin gene – functions to regulate acute inflammation by inhibiting the function of neutrophil. Autoinflammatory syndrome – excess production of IL-1. Type of amyloid deposited is AA .

29. FAMILIAL AMYLOIDOTIC POLYNEUROPATHY Autosomal dominant condition. Amyloid deposition in the peripheral & autonomic nerves mainly, in few there are cardiac deposits. Amyloid is of ATTR type derived from mutant TTR . Seen in Portugal, Japan, Sweden & US.

30. HEMODIALYSIS ASSOCIATED Patients on long-term hemodialysis for renal failure can develop amyloid deposits derived from β2-microglobulin. The classical features of this form of amyloidosis are the triad of scapulohumeral periarthritis , carpal tunnel syndrome, and flexor tenosynovitis of the hand.

31. LOCALIZED AMYLOIDOSIS Amyloid deposits are limited to a single organ or tissue without involvement of any other site in the body. The deposits may produce grossly detectable nodular masses or be evident only on microscopic examination. Nodular deposits of amyloid are most often encountered in the lung, larynx, skin, urinary bladder, tongue, and the region about the eye.

32. ENDOCRINE AMYLOID Localized amyloid may be found with – Medullary carcinoma thyroid. Islet tumors of the pancreas. Pheochromocytomas . Undifferentiated ca of stomach. Pts.of type II diabetes – in the islets of Langerhans.

33. AMYLOID OF AGING SENILE SYSTEMIC AMYLOIDOSIS. SENILE CARDIAC AMYLOIDOSIS – with restrictive cardiomyopathy and arrhythmias. ATTR is deposited which is derived from normal TTR.

34. MORPHOLOGY

35. GROSS APPEARANCE There are no consistent or distinctive patterns of organ or tissue  distribution of amyloid deposits in any of the categories cited,  but a few generalizations can be made. In primary amyloidosis – Heart, GIT, tongue, respiratory tract, peripheral nerves and skin. In secondary amyloidosis – Kidney, liver, spleen, adrenal, thyroid and lymph nodes. In familial types - ??

36. GROSS APPEARANCE May /may not be apparent on gross examination. In smaller amounts – Cut surface of the organ – painted with iodine & sulfuric acid – Mahogany brown staining of amyloid deposits. In larger amounts – The organ is enlarged,firm . Cut surface is grey,waxy .

37. MICROSCOPIC Amyloid deposition is always  extracellular  and  begins  between cells , often closely adjacent to basement membranes. In primary, perivascular and vascular deposits are common. The diagnosis of amyloidosis is based on histopathology .  Under LM with H&E stain, amyloid appears as an amorphous, eosinophilic, hyaline, extracellular substance. With Congo red, under LM - ? Polarization microscopy/ EM / IFM - ?? Subtyping of amyloid  is most reliably done by  Mass spectroscopy & Immunohistochemistry.

38. RENAL AMYLOIDOSIS Most common &most serious form of organ involvement. GROSS : Normal / Enlarged pale gray, firm, waxy. Later it is shrunken because of the ischemia   caused by vascular narrowing due to deposition of amyloid within arterial and arteriolar walls.

39. MICROSCOPIC : GLOMERULUS – Focal deposits within the mesangial matrix. - Nodular/diffuse thickening of the capillary basement membrane. - Complete replacement by broad ribbons of amyloid. INTERSTITIAL PERITUBULAR DEPOSITS –with pink casts within tubular lumen. BLOOD VESSELS – Amyloid deposition within the vessel wall with v.narrowing .

40. RENAL AMYLOIDOSIS

41. DIFFUSE THICKENING OF GLOMERULAR CAPILLARY WALL & VESSEL WALL.

42. SPLENIC AMYLOIDOSIS GROSS – Moderate to marked splenomegaly. MICROSCOPIC – 2 patterns of involvement seen a. SAGO SPLEEN – Deposits limited to splenic follicles producing tapioca like granules. b. LARDACEOUS SPLEEN – amyloid involves the  walls of the  splenic sinuses  and connective tissue framework in  the red pulp. Fusion of the early deposits gives rise to large,  maplike  areas of amyloidosis, 

43. AMYLOID SPLEEN- ENLARGED,PALE GREY,WAXY.

44. SAGO SPLEEN

45. AMYLOID DEPOSITS IN FOLLICLES

46. AMYLOID DEPOSITS IN SINUSES

47. AMYLOIDOSIS LIVER GROSS – Massive hepatomegaly. CUT SURFACE – Pale gray, firm, waxy. MICROSCOPIC –  - Amyloid appears first in the space of Disse . - It then progressively encroaches on adjacent   hepatic parenchymal cells and sinusoids. - So pressure atrophy with disappearance of  hepatocytes & sheets of amyloid deposits seen. - Vascular involvement and deposits in Kupffer  cells are frequent.

48. AMYLOIDOSIS LIVER

49. CARDIAC AMYLOIDOSIS GROSS – Minimal to moderate cardiomegaly. - Gray pink, dew drop like subendocardial elevations, particularly in the atrial chambers. MICROSCOPIC – Amyloid deposits are found inbetween the cardiac myocytes, eventually causing their pressure atrophy.

50. CARDIAC AMYLOIDOSIS- AMORPHOUS,PALE PINK AMYLOID INBETWEEN DARK PINK MYOFIBRES.

51. AMYLOID LYMPH NODE

52. AMYLOIDOSIS SKIN

53. ENDOCRINE AMYLOID Adrenals, thyroid & pituitary are commonly involved. Amyloid deposition begins in relation to stromal & endothelial cells. Causes progressive atrophy of parenchymal cells.

54. GIT Amyloid may be found at all levels . May form small deposits or tumorous masses. Nodular deposition in the tongue produces MACROGLOSSIA. ( Gingival, intestinal & rectal biopsies are commonly used for diagnosis)

55. MACROGLOSSIA

56. CLINICAL FEATURES Unsuspected anatomic finding / autopsy finding. Nonspecific , such as weakness, weight loss, lightheadedness, or syncope. Renal involvement - proteinuria- nephrotic syndrome In advanced cases ultimately leads to chronic renal failure and uremia. Cardiac amyloidosis - Congestive heart failure. Conduction disturbances and arrhythmias. Restrictive cardiomyopathy and Chronic constrictive pericarditis. GIT - asymptomatic, or - hamper speech and swallowing. - Malabsorption & diarrhea. Vascular amyloidosis - vascular fragility & bleeding , sometimes massive, that can occur spontaneously or following seemingly trivial trauma. AL amyloid binds and inactivates factor X, a critical coagulation factor, leading to a life-threatening bleeding disorder.

57. DIAGNOSIS OF AMYLOIDOSIS I. BIOPSY OF THE INVOLVED SITE Renal biopsy. Rectal or gingival biopsy ( In systemic cases) Abdominal fat aspirates. SPECIAL STAINS : 1. CONGO RED – LM – Pink to red intercellular amyloid deposits. EM – Non branching fibrils of indefinite length. X-ray Crystallography – β pleated sheet conformation. Polarization microscopy – Apple green birefringence.

58. Immunohistochemistry – To confirm the type of amyloid – AL, AA,A β ,ATTR,A β 2m,Acal,Aprion,AANF. Spectroscopy – To Confirm the type of amyloid. OTHER SPECIAL STAINS : a. METACHROMATIC STAINS – Methyl violet, Crystal violet – Rose pink colour . b. Fluorescent stains – Thioflavin T & S – yellow fluorescence. c. P.A.S.stain – positive. d. Sulfated Alcian blue – Bluish green colour .

59. ABDOMINAL FAT ASPIRATE

60. METACHROMATIC STAIN (CRYSTAL VIOLET – Rose pink)

61. THIOFLAVIN T & S – Yellow fluorescence to amyloid.

62. SULFATED ALCIAN BLUE – BLUISH GREEN COLOR TO AMYLOID

63. II. In suspected PRIMARY AMYLOIDOSIS – a. Serum and urine protein electrophoresis – M- spike. b. Urine for Bence Jones proteins. c. Bone marrow aspirate – Plasmacytosis . III. In suspected SECONDARY AMYLOIDOSIS – Serum CRP levels – raised. IV. Scintigraphy with radiolabeled SAP ( Serum amyloid P component) – rapid and specific test since SAP binds with the amyloid deposits and reveals their presence.

64. M – SPIKE IN MULTIPLE MYELOMA

65. PROGNOSIS ?

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