Inflammatory diseases of the Aorta
VASCULITIDES
1. For practical  purposes, the vasculitides can be classified on the basis of the size of the  vessel(s) involved and will be presented accordingly in the following sections
2. Specific cause can  be identified in only a minority of cases 
3. Can be divided into  infectious and noninfectious groups, with the latter much more extensive 
4. There is a  correlation between the type of antineutrophil cytoplasmic autoantibodies  (ANCA) and the specific vasculitis syndrome 
5. cANCA  (antiproteinase 3) is more often seen in active Wegener disease 
6. pANCA  (antimyeloperoxidase) is more often seen in microscopic Polyangiitis, primary  glomerular disease (idiopathic crescentic glomerulonephritis) and in Churg-Strauss  syndrome
    Takayasu  Arteritis
    - Takayasu Arteritis Clinical aspects.
      1. Onset of disease  usually before the age of 50
      2. Predominantly  affects women
      3. More prevalent in  Asia than in the US and Europe
      4. Disease  manifestation is variable and includes decreased/absent pulses in upper  extremities, renovascular hypertension 
      - Takayasu Arteritis Gross exam.
      1. Involvement of  aorta, aortic arch branches, pulmonary arteries, and occasionally coronary  arteries 
      2. May involve only a  portion (thoracic more often affected than abdominal) or the entire aorta
      3. Stenosing lesions  more common than aneurysms
      4. Aorta is thickened,  sometimes with superimposed thrombosis
      - Takayasu Arteritis Microscopic exam.
      1. Chronic  granulomatous inflammation predominantly affecting the media and adventitia
      2. Inflammatory cells  are composed of lymphocytes, plasma cells and macrophages, giant cells are  commonly present 
      3. Intima shows  reactive hyperplasia
      4. In chronic lesions,  media shows destruction and fragmentation of elastic lamellae and adventitia  often markedly fibrotic
Giant Cell Arteritis  (GCA) 
    - Giant Cell Arteritis Clinical aspects.
      1. Onset of disease  usually after the age of 50
      2. Female predominance
      3. May be but not always  associated with temporal arteritis 
      4. Clinical  manifestations include temporal headache, visual disturbances, jaw or tongue  claudication, scalp tenderness, polymyalgia rheumatica
      5. Aortic aneurysms are  late complications of the disease
      6. Temporal artery biopsy  may be performed when GCA is associated with cranial arteritis and visual loss  is a serious complication of the disease
      - Giant Cell Arteritis Gross exam.
      1. Preferentially  involves the thoracic aorta
      2. Aortic wall may be  thickened with “tree-barking” of the intima and superimposed atherosclerosis 
    - Giant Cell Arteritis Microscopic exam.
    1. Areas of medial  necrosis bordered by mononuclear cells and giant cells
      2. Proliferation of  vasa vasorum with surrounding mononuclear inflammatory cells (lymphocytes,  plasma cells, macrophages) 
      3. Reactive intimal  hyperplasia 
      4. Adventitia with mild  inflammation and mild fibrotic thickening
      5. Histopathology  sometimes indistinguishable between systemic (aortic involvement in GCA) and  isolated aortitis
      6. Temporal arteritis
      - Granulomatous  inflammation in the media consisting of macrophages and lymphocytes
      - Giant cells are  present in most cases, but not a prerequisite for the diagnosis of temporal  arteritis
      - Disruption of the  internal elastic lamina associated with the inflammation
Other rare causes of  large-vessel vasculitis          
   1. Behcet’s disease
   2. Rheumatoid arthritis
   3. Ankylosing spondylitis
   4. Cogan’s syndrome
   5. Relapsing polychondritis
   6. IgG4-related disorders 
   7. Behcet’s disease 
   8. Rheumatoid arthritis
   9. Ankylosing spondylitis
      10. Cogan’s syndrome
      11. Relapsing  polychondritis
      12. IgG4-related disorders  


