Amyloidosis

The term amyloid is used with the idea that it has a relationship with starch . The resemblance with starch is due to its staining property with iodine .

Structure ….

 The amyloid iss fibrilar in appearance and each fibre consists of 2 to 5 fine protofibrils .

 Chemical nature ..

i)                    Antigen-antibody complex .

ii)                  Complex of globulin and chondroitin sulphuric acid . The chondroitin sulphuric acid in a derivative of Hyaluronic acid .

 Causes ….

i)                    Chronic pyogenic infection and also in tuberculosis of lung

ii)                  Suppurative changes of bones and joints .

iii)                In case of multiple myeloma and other allergic condition .

iv)                Broken down gumma .

 Type of amyloid …………

I.                   Depending on thee staining property ..

a)      Typical amyloid – Amyloid when shows the usual staining character by using different stain .

b)      Atypical amyloid – Whn the material behaves an indifferent ways with the usual staining technique .

II .  Depending on genesis ……

   A . systemic amyloidosis with recognized predisposing disease 9 secondary amyloidosis ) –

a)      associated with chronic infection – Tuberculosis , osteomyelitis , bronchiectasis , syphilis .

b)      Associated with chronic inflammatory diseases of uncertain aetiology – Rheumatoid arthritis , ulcerative colitis , chron’s disease .

c)      Associated with neoplasms -  plasma cells myeloma , renal carcinoma , Hodgkin’s disease

B .. systemic amyloidosis not associated with known predisposing disorders ( primary amyloidosis ) – The material is deposited in the system without any predisposing factor . the systems usually involved are tongue , G.I tract , cardio vascular system , spleen etc .

C.. heredo-familial amyloidosis –

a)      Familial Mediterranean fever with systemic amyloidosis .

b)      Familial amyloid polyneuropathy .

c)      Familial cardiac amyloidosis .

d)     Familial amyloid nephropathy .

e)      Familial amyloidotic medullary thyroid carcinoma .

D.. Isolated organ amyloidosis ….

a)      Senile amyloidosis -  Heart , brain , seminal v esicle .

b)      Tumour amyloid of the tongue .

c)      Amyloidosis of the islets of langerhan in diabetes mellitus .