Mast cells in calcific aortic stenosis

Area of Science:

• Cardiovascular Pathology
• Immunohistochemistry
• Valvular Heart Disease

Background:

• Calcific aortic stenosis (CAS) is the leading acquired valvular disease in developed nations.
• CAS shares inflammatory origins with atherosclerosis, featuring vascular, lymphatic, and immune cell infiltration.
• Metaplastic bone tissue can also be present in affected aortic valves.

Purpose of the Study:

• To investigate the presence and distribution of CD117-positive mast cells in calcific aortic stenosis.
• To compare mast cell numbers in CAS valves with normal aortic valves.
• To explore potential correlations between mast cell presence and specific valve morphologies or pathological features.

Main Methods:

• Histopathological examination of 56 calcified aortic valves from cardiac surgery.
• Immunohistochemical staining to identify CD117-positive mast cells.
• Comparison of mast cell counts between different valve types (bicuspid vs. tricuspid) and presence/absence of metaplastic bone.

Main Results:

• Mast cells were consistently detected in all 56 examined CAS valves.
• Significantly higher mast cell numbers were observed in congenitally malformed/bicuspid valves compared to tricuspid valves.
• Valves with metaplastic bone showed significantly greater mast cell infiltration than those without bone formation.

Conclusions:

• Mast cells are a constant component of the cellular infiltrate in calcific aortic stenosis.
• Increased mast cell presence correlates with specific pathological features of CAS, including bicuspid morphology and metaplastic bone formation.
• These findings suggest a potential role for mast cells in the inflammatory pathogenesis of calcific aortic stenosis.