Related Experiment Videos
Chronic rheumatic heart disease in India: a reappraisal of pathologic changes
1Department of Pathology, All India Institute of Medical Sciences, New Delhi.
Insights
Rheumatic heart disease causes severe heart valve damage, especially in Indian children and young adults, leading to juvenile mitral stenosis. This condition involves significant inflammation and lung changes, highlighting the need for further research into its pathogenesis.
Area of Science:
- Cardiology
- Pathology
- Immunology
Background:
- Rheumatic heart disease (RHD) is a major cause of heart disease in India.
- It often leads to severe valvular deformities, particularly affecting the mitral valve in young individuals, termed juvenile mitral stenosis.
- Juvenile mitral stenosis presents with heart enlargement, heart failure, and high pulmonary pressures.
Purpose of the Study:
- To investigate the pathological characteristics of RHD in India.
- To analyze the extent of valvular and pulmonary involvement in RHD, especially in juvenile cases.
- To explore the cellular and molecular mechanisms underlying RHD pathogenesis.
Main Methods:
- Autopsy-based study of patients with RHD.
- Detailed examination of heart valves (mitral, aortic, tricuspid) for organic changes and calcification.
- Immunohistochemical staining to identify inflammatory cell phenotypes (T-helper/inducer lymphocytes).
- Histopathological analysis of lung tissues for vascular and parenchymal changes.
Main Results:
- The mitral valve was the most frequently and severely affected valve in RHD.
- Significant calcification was observed in 36.4% of mitral valves.
- T-helper/inducer lymphocytes were a prominent feature of inflammatory infiltrates.
- Juvenile RHD cases showed more severe pulmonary vascular and parenchymal changes, including medial hypertrophy and smooth muscle prominence in bronchoalveolar walls.
Conclusions:
- Juvenile mitral stenosis is a distinct and severe manifestation of RHD in India.
- Chronic inflammation, particularly involving T-helper/inducer lymphocytes, plays a key role in RHD.
- Pulmonary changes are significant and more pronounced in juvenile patients, suggesting an ongoing inflammatory process possibly triggered by persistent streptococcal antigens.
Abstract:
Rheumatic heart disease contributes to significant cardiac morbidity and mortality in India. The disease predominantly affects the valvular endocardium culminating in crippling valvular deformities, preferentially involving the mitral valve which may be severely affected in children and young adults. This appears to be unique to India and has been termed juvenile mitral stenosis. It is characterized by cardiomegaly, refractory congestive heart failure, and marked by elevated pulmonary vascular pressures and a progressive, fulminant clinical course. Autopsies of patients dying of rheumatic heart disease revealed that the mitral valve was most commonly afflicted either alone or in combination with the aortic and tricuspid valves in 31.6% and 52.8%, respectively. Organic involvement of the tricuspid valve was documented in 38.4% of cases. The extent and severity of the disease process was most marked in the mitral valve, followed by the aortic and tricuspid valves. Mitral valves showed various degrees of calcification, moderate or severe calcification being observed in 36.4%. Chronic inflammatory cell infiltration was observed in both calcified and non-calcified valves. The phenotypic profile of the inflammatory cells by immunohistochemical staining revealed a significant number to be T-helper/inducer lymphocytes. Lungs from cases of mitral stenosis exhibited prominent vascular and parenchymal changes. Pulmonary vessels revealed moderate to marked medial hypertrophy of the medium sized branches of the pulmonary artery. Dilatation lesions were also seen in a few cases. The most striking parenchymal change was the prominent smooth muscle in the bronchoalveolar walls. The extent and severity of the vascular and parenchymal changes were more marked in juvenile patients. The presence of inflammatory cells in cases of chronic heart disease reflects a possible ongoing insult/injury to some persistent antigenic stimulus by beta hemolytic streptococcal antigens that have primed the various target tissues. Further study of surface characteristics of various mesenchymal cells may help in understanding the nature and pathogenesis of this serious cardiac problem.