Characterization of the inflammatory cells in ascending thoracic aortic aneurysms in patients with Marfan syndrome, familial thoracic aortic aneurysms, and sporadic aneurysms

doi:10.1016/j.jtcvs.2007.12.063

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Characterization of the inflammatory cells in ascending thoracic aortic aneurysms in patients with Marfan syndrome, familial thoracic aortic aneurysms, and sporadic aneurysms

Rumin He, MD^a^,_*, Dong-Chuan Guo, PhD^a^,_*, Wei Sun, PhD^d, Christina L. Papke, BS^a, Senthil Duraisamy, PhD^a, Anthony L. Estrera, MD^b, Hazim J. Safi, MD^b, Chul Ahn, PhD^a, L. Maximilian Buja, MD^c, Frank C. Arnett, MD^a, Jingwu Zhang, MD^d, Yong-Jian Geng, MD, PhD^a, Dianna M. Milewicz, MD, PhD^a^,_*

^a Department of Internal Medicine, The University of Texas Medical School at Houston, Houston, Texas
^b Department of Cardiovascular Surgery, The University of Texas Medical School at Houston, Houston, Texas
^c Department of Pathology, The University of Texas Medical School at Houston, Houston, Texas
^d Department of Immunology, Baylor College of Medicine, Houston, Texas

Received for publication June 30, 2007; revisions received November 28, 2007; accepted for publication December 18, 2007.

^_* Address for reprints: Dianna M. Milewicz, MD, PhD, The University of Texas Medical School at Houston, 6431 Fanin St, MSB 6.100, Houston, TX 77030. (Email: Dianna.M.Milewicz{at}uth.tmc.edu).

Objective: This study sought to characterize the inflammatory infiltratein ascending thoracic aortic aneurysm in patients with Marfansyndrome, familial thoracic aortic aneurysm, or nonfamilialthoracic aortic aneurysm.

Background: Thoracic aortic aneurysms are associated with a pathologic lesiontermed "medial degeneration," which is described as a noninflammatorylesion. Thoracic aortic aneurysms are a complication of Marfansyndrome and can be inherited in an autosomal dominant mannerof familial thoracic aortic aneurysm.

Methods: Full aortic segments were collected from patients undergoingelective repair with Marfan syndrome (n = 5), familial thoracicaortic aneurysm (n = 6), and thoracic aortic aneurysms (n =9), along with control aortas (n = 5). Immunohistochemistrystaining was performed using antibodies directed against markersof lymphocytes and macrophages. Real-time polymerase chain reactionanalysis was performed to quantify the expression level of theT-cell receptor β-chain variable region gene.

Results: Immunohistochemistry of thoracic aortic aneurysm aortas demonstratedthat the media and adventitia from Marfan syndrome, familialthoracic aortic aneurysm, and sporadic cases had increased numbersof T lymphocytes and macrophages when compared with controlaortas. The number of T cells and macrophages in the aorticmedia of the aneurysm correlated inversely with the patient'sage at the time of prophylactic surgical repair of the aorta.T-cell receptor profiling indicated a similar clonal natureof the T cells in the aortic wall in a majority of aneurysms,whether the patient had Marfan syndrome, familial thoracic aorticaneurysm, or sporadic disease.

Conclusion: These results indicate that the infiltration of inflammatorycells contributes to the pathogenesis of thoracic aortic aneurysms.Superantigen-driven stimulation of T lymphocytes in the aortictissues of patients with thoracic aortic aneurysms may contributeto the initial immune response.

Abbreviations and Acronyms AAA = abdominal aortic aneurysm;FTAA = familial thoracic aortic aneurysm; ICAM = intercellularadhesion molecule; MD = medial degeneration; MFS = Marfan syndrome;PCR = polymerase chain reaction; TAA = thoracic aortic aneurysm;TCR BV = T-cell receptor β-chain variable region; TGFBR2 = transforming growth factor β receptor type II; Th = T-helper;VCAM = vascular cell adhesion molecule

Surgery for Acquired Cardiovascular Disease

Characterization of the inflammatory cells in ascending thoracic aortic aneurysms in patients with Marfan syndrome, familial thoracic aortic aneurysms, and sporadic aneurysms