Evaluation of acute cardiac transplant rejection with targeted myocardial contrast echocardiography / 中华器官移植杂志

ABSTRACT

Objective To discuss the value of leukocyte-targeted myocardial contrast echocardiography (MCE) as a tool in observing the degree of acute rejection after heart transplantation. Methods Abdominal heterotopic cardiac transplantation was performed on 32 rats successfully, among which 8 isografts served as group A, and groups B, C and D involved 8 allografts respectively. The rats in groups B and C were treated with cyclosporine A (CsA) at a high dose (10mg· kg-1 · day-1 ), a low dose (3 mg · kg-1 · day-1 ) from 3rd day before transplantation respectively.The rats in groups A and D were untreated with CsA. MCE was performed during continuous intravenous SonoVue injection postoperatively on the third day after operation. We performed 2 types of MCE perfusion imaging and leukocyte-targeted imaging. The images were obtained at 20 s and 5 min after injection of contrast agent. The value of the contrast image grayscale (GS) was measured by image analyzer (GS20s, GS5 min). GStarget was calculated as the GS5min minus the GS20s in the same rat.Postmortem histology was performed after observation. The degree of myocardial rejection was determined by HE-stained graft myocardium. Immunohistochemistry was performed to quantify the CD3-positive cells, and correlation analysis was performed between CD3-positive cell count and GS20s,GS5min, GStarget. Results Perfusion imaging showed no significant difference in myocardial GS20s of each group. Leukocyte-Targeted imaging exhibited a clear gradient in these groups (P＜0. 05). There was significant difference in GStarget of each group (P＜0. 001). Postmortem histology showed 0- Ⅰ grade rejection in group A, Ⅰ -Ⅱ grade rejection in group B, Ⅱ-Ⅲ grade rejection in group C, Ⅲ-Ⅳ grade rejection in group D. Immunohistochemistry revealed the CD3-positive cell infiltration was increased in turn from the group A to the group D. There was a significantly positive correlation between the CD3-positive cell count and GStarget ( r = 0. 86, P ＜ 0. 001 ). Conclusion Leukocyte-targeted contrast echocardiography may thus offer a noninvasive and effective ultrasound imaging technique for detecting the degree of acute cardiac transplant rejection.