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The morphologic spectrum of dilated cardiomyopathy and its relation to immune-response genes
E Arbustini1, A Gavazzi, R Pozzi
1Department of Pathologic Anatomy, AVIS, Pavia, Italy.
Insights
Dilated cardiomyopathy (DC) patients show distinct nuclear and cellular changes in endomyocardial biopsies. These morphological differences correlate with specific Human Leukocyte Antigen (HLA) types, suggesting genetic predispositions in DC.
Area of Science:
- Cardiovascular Pathology
- Immunogenetics
- Molecular Biology
Background:
- Dilated cardiomyopathy (DC) is a significant cause of heart failure.
- Endomyocardial biopsies are crucial for diagnosing and understanding cardiomyopathies.
- Morphological heterogeneity exists among DC patients.
Purpose of the Study:
- To investigate morphological variations in endomyocardial biopsies from DC patients.
- To correlate these morphological features with Human Leukocyte Antigen (HLA) profiles.
- To identify potential genetic markers associated with specific DC phenotypes.
Main Methods:
- Analysis of endomyocardial biopsies from 174 DC patients (excluding myocarditis).
- Categorization into groups based on nuclear morphology (oversized/bizarre nuclei).
- Histomorphometric analysis (myocyte width, nuclear diameter, etc.) and HLA typing (DR antigens).
Main Results:
- Group A (abnormal nuclei) showed significantly increased myocyte width, nuclear diameter, and endocardial thickness compared to Group B.
- Interstitial fibrosis was present in both groups.
- DC patients exhibited higher frequencies of DR4 and DR5, and lower frequency of DR3 compared to controls.
- Group A had a stronger association with DR5 and weaker association with DR4 than Group B.
Conclusions:
- Endomyocardial biopsies reveal significant patient-to-patient morphological variability in DC.
- Specific HLA antigen associations (DR5, DR4) suggest a genetic component influencing DC morphology.
- Further research into the genetic basis of DC morphology is warranted.
Abstract:
Endomyocardial biopsies from 174 patients with dilated cardiomyopathy (DC) were examined. Eight patients with histologically proven myocarditis were excluded from the study. A peculiar pattern of oversized and bizarre nuclei was observed in only some of the remaining patients. Two groups were identified: those with and without this feature (groups A and B, respectively). Myocyte width, nuclear diameter and nuclear/sarcoplasmic ratio were significantly higher in group A. The mean respective values were 36 +/- 5 mu, 14 +/- 3 mu and 0.41 +/- 0.08 for group A versus 20 +/- 8 mu, 7 +/- 2 mu and 0.37 +/- 0.08 for group B. Interstitial fibrosis was similarly present in groups A and B. Endocardial thickness was significantly increased in all patients, with group A showing the highest mean value. The morphologic features showed no correlation with the clinical condition of the patients at time of presentation. HLA typing was performed in 50 consecutive patients, 38 from group A and 12 from group B. DR4 and DR5 antigens were significantly more frequent in DC patients than in a normal population control (400 blood donors), while DR3 was less frequent. Group A was more strongly associated with the DR5 antigen than group B (55.3 vs 25.0%, respectively). It was less strongly associated with the DR4 antigen compared with group B (21.5 vs 41.7%, respectively). No difference was observed between the 2 groups concerning negative association with the DR3 antigen. Endomyocardial biopsies from DC patients reveal marked morphologic changes from patient to patient.(ABSTRACT TRUNCATED AT 250 WORDS)