Related Experiment Videos
Transforming growth factor beta and diastolic left ventricular dysfunction after heart transplantation:
Tarek M Aziz1, Malcolm I Burgess, Philip S Haselton
1Cardiothoracic Transplant Unit, Wythenshawe Hospital, Manchester, United Kingdom. tarekaziz55@hotmail.com
Insights
Transforming growth factor beta (TGF-beta) is linked to diastolic dysfunction in heart transplant patients. This suggests TGF-beta may play a role in the abnormal repair process after transplantation.
Area of Science:
- Cardiology
- Transplantation Immunology
- Pathology
Background:
- Chronic left ventricular diastolic dysfunction is a known complication in cardiac allograft recipients.
- The underlying mechanisms, particularly in non-rejecting grafts, require further elucidation.
Purpose of the Study:
- To determine the prevalence and clinical significance of left ventricular diastolic dysfunction post-heart transplantation.
- To investigate the role of fibrotic cytokines, specifically transforming growth factor beta (TGF-beta), in the development of echocardiographic and clinical changes in these patients.
Main Methods:
- A cohort of 152 heart transplant recipients surviving >24 months was analyzed.
- Histopathology of endomyocardial biopsies (assessing TGF-beta expression), Doppler echocardiography (evaluating mitral deceleration time - MDT), and clinical status (NYHA classification) were compared between groups with restrictive (MDT <140 ms) and non-restrictive filling patterns.
Main Results:
- Patients with restrictive filling (Group 1) exhibited significantly lower MDT (122 ms vs. 177 ms) and higher TGF-beta scores (9.1 vs. 3.6) compared to Group 2.
- TGF-beta expression showed a strong inverse correlation with MDT and isovolumic relaxation time.
- Group 1 patients also presented with a higher mean NYHA functional class (2.2 vs. 1.37).
Conclusions:
- Elevated TGF-beta expression in cardiac allografts is significantly associated with impaired left ventricular diastolic function.
- These findings suggest that TGF-beta-mediated aberrant repair processes may contribute to the pathogenesis of diastolic dysfunction following heart transplantation.
Background:
The mechanism for chronic left ventricular diastolic dysfunction in the non-rejecting cardiac allograft has not been fully studied.
Objectives:
The purposes of this study were to analyze the significance and frequency of left ventricular diastolic dysfunction after heart transplantation and to examine the involvement of fibrotic cytokines (transforming growth factor beta [TGF-beta]) in development of clinical and echocardiographic changes in cardiac allograft recipients.
Methods:
We studied 152 heart transplant recipients who had survived for at least 24 months. We compared histopathologic findings (staining of endomyocardial biopsy specimens using hematoxylin and eosin, and polyclonal antibodies expressed as TGF-beta score), left ventricular function (Doppler echocardiography), and clinical course (New York Heart Association [NYHA] status). We classified patients into Group 1 (n = 41 recipients) with a restrictive filling pattern, mitral deceleration time (MDT) <140 milliseconds, and Group 2 (n = 111 recipients), MDT >or=140 milliseconds.
Results:
The MDT was 122 +/- 7 milliseconds in Group 1 compared with an MDT of 177 +/- 17 milliseconds in Group 2 (p = 0.0003). Group 1 showed significant immunohistochemical staining in endomyocardial biopsy specimens (a mean TGF-beta score of 9.1 +/- 1.2 for Group 1 compared with a mean TGF-beta score of 3.6 +/- 0.8 for Group 2 p = 0.001). The TGF-beta expression correlated inversely with both MDT and isovolumic relaxation time (r = -0.77, p = 0.0004, and r = -0.69, p = 0.004, respectively). Mean NYHA status in Group 1 recipients was 2.2 +/- 1.1 compared with 1.37 +/- 0.6 for Group 2 (p = 0.006).
Conclusions:
Transforming growth factor beta expression in cardiac allografts is associated with impaired left ventricular diastolic function. The pathogenesis of diastolic dysfunction may be an aberrant repair process after rejection-caused TGF-beta expression in the allograft.