Related Experiment Videos
Immunohistochemical characterization of coronary thrombi in allograft vascular disease
E Arbustini1, B Dal Bello, P Morbini
1Pathology Department, IRCCS Policlinico San Matteo, University of Pavia, Italy. e.arbustini@smatteo.pv.it
Insights
Platelets are the main component of early cardiac transplant coronary artery thrombi, while fibrin dominates older, occlusive thrombi in allograft vascular disease (AVD). This study characterizes thrombus composition in AVD.
Area of Science:
- Cardiovascular Pathology
- Transplantation Immunology
- Thrombosis Research
Background:
- Coronary thrombosis is a common complication in cardiac transplant recipients with allograft vascular disease (AVD).
- Limited data exists on the specific composition of thrombi in these affected coronary arteries.
Purpose of the Study:
- To characterize the components of coronary artery thrombi in transplanted hearts with AVD.
- To investigate the relationship between thrombus composition, type, and age.
Main Methods:
- Utilized single and double immunostaining with antibodies against platelet markers (gpIIb-IIIa, CD41a, CD61), fibrin, and endothelial cells.
- Analyzed 55 cardiac allografts with AVD, examining 440 coronary vessels for mural and occlusive thrombi.
Main Results:
- Mural thrombi (17%) and occlusive thrombi (8%) were identified. Early mural thrombi were platelet-rich, with increasing fibrin content as thrombus size grew.
- Organizing mural thrombi showed persistent gpIIb-IIIa staining, while old mural thrombi consisted solely of fibrin within intimal lesions.
- Occlusive thrombi composition varied from platelet and fibrin in recent thrombi to exclusively fibrin in organized, multichannel patterns.
Conclusions:
- Thrombus composition in AVD is dependent on both thrombus type and age.
- Platelets are the primary early constituents of mural microthrombi.
- Fibrin becomes the predominant component in occlusive thrombi.
Background:
Coronary thrombosis is a frequent complication of allograft vascular disease (AVD) in cardiac transplant recipients. No data are available on thrombus composition in these hearts.
Methods:
The present study aimed at characterizing thrombus components in coronary arteries from transplanted hearts with AVD, using single and double immunostain with anti-gpIIb-IIIa, anti-fibrin, and anti-endothelial antibodies. The pathologic series consists of 55 grafts survived longer than 2 months, and obtained from 55 patients deceased (n=44) or undergone repeat transplantation (n=11).
Results:
Mural thrombi were found in multiple segments of 75 of 440 total coronary vessels (17%) (recent in 33, organizing in 28, and organized in 14), whereas occlusive thrombi were found in 19 vessels (8 recent and 11 with multichannel pattern of organization). Recent and thin mural thrombi were mostly constituted of CD41a- and CD61-positive platelets; the amount of fibrin progressively increased with the increase of thrombus size. In organizing mural thrombi, gpIIb-IIIa immunostain was still present. Fibrin was the only identifiable thrombus component in old mural thrombi embedded within the intimal lesions. Recent occlusive thrombi immunoreacted both with anti-CD41a and anti-CD61 and with anti-fibrin antibodies, whereas organized occlusive thrombi with multichannel pattern exclusively immunoreacted with anti-fibrin antibodies. Double immunostain showed that mural thrombi were stratified on de-endothelized arterial segments.
Conclusions:
Thrombus composition is related to both type and "age" of thrombus, with platelets as the early and major components of mural microthrombi at one end of the spectrum, and fibrin as the dominant component of occlusive thrombi at the other end.