Computerized scoring of histopathology for predicting coronary vasculopathy, validated by intravascular ultrasound.

BACKGROUND: Allograft coronary vasculopathy results from a complex interplay between immunologic and non-immunologic factors. We devised a computerized biopsy scoring method based on histopathology to predict the development of coronary vasculopathy. METHODS: One hundred forty heart transplant recipients underwent serial intravascular ultrasound analysis at baseline (within 1 month) and at 1 year after transplantation and were evaluated for development of coronary vasculopathy (change in coronary maximal intimal thickness, CMIT). We evaluated serial endomyocardial biopsy specimens for cellular rejection, vascular rejection, ischemia, and fibrosis. In a mathematical model, we computed a biopsy score in each patient based on the duration and severity of histopathology. RESULTS: We found a significant correlation between biopsy score (RY) and progression of coronary vasculopathy (r = 0.54, p = 0.001). Using a sensitivity analysis method, an RY value of > or =560 predicted development of coronary vasculopathy with a sensitivity of 86%, specificity of 62%, and diagnostic accuracy of 80%. Compared with patients with low-risk biopsy scores (RY < 560, n = 37), patients with high-risk biopsy scores (RY > or = 560, n = 103) had increased progression of coronary vasculopathy (CMIT, 0.59 +/- 0.29 vs 0.19 +/- 0.10 mm, p < 0.001) and worse 7-year event-free survival (60% vs 91%, p = 0.01). CONCLUSION: The biopsy score is an effective method for predicting the development of coronary vasculopathy and for predicting outcome in cardiac transplant recipients.     

The influence of donor gender on allograft vasculopathy: evidence from intravascular ultrasound

BACKGROUND: Allograft vasculopathy is a major risk factor for mortality following cardiac transplantation. Several immune and nonimmune factors have been evaluated as risk factors for the development of coronary vasculopathy. OBJECTIVE: We evaluated the influence of donor gender on the progression of coronary vasculopathy in heart transplant recipients. METHODS: Eighty-nine heart transplant recipients (67 men, 22 women of mean age: 56 +/- 12 years) underwent serial volumetric intravascular ultrasound analysis (IVUS) at baseline (within 1 month) and at 1 year after transplantation. Patients were divided into four groups in relation to the donor-recipient gender status: female-female, n=17; female-male, n=28; male-female, n=5; male-male, n=39. Ultrasound images were recorded during an automated pullback and with an equal number of slices (average=22 per coronary vessel). The measured IVUS indices for the left anterior descending artery were: change in maximal intimal thickness, average intimal area, total plaque volume, and intimal index. RESULTS: Patients were similar in baseline characteristics. At 1 year after transplantation, IVUS indices of coronary vasculopathy were significantly increased among recipients of female allografts (P <.05). CONCLUSION: Heart transplant recipients of female allografts display increased coronary vasculopathy progression.     

Angiotensin-converting enzyme inhibition and angiotensin II antagonism in nondiabetic chronic nephropathies

Angiotensin II (A II), the main effector of the renin angiotensin system (RAS), plays a central role in the hemodynamic and nonhemodynamic mechanisms of chronic renal disease and is currently the main target of interventions aimed to prevent the onset and progression of chronic nephropathies to end-stage renal disease (ESRD). In addition, to ameliorate glomerular hyperfiltration and size selectivity, reduce protein traffic and prevent glomerular and tubulointerstitial toxicity of ultrafiltered proteins, RAS inhibitors also limit the direct nephrotoxic effects of A II. Thus, both angiotension-converting enzyme (ACE) inhibitors (ACEi) and A II antagonists (ATA) exert a specific nephroprotective effect in both experimental and human chronic renal disease. This effect is time-dependent and is observed across degrees of renal insufficiency. Forced ACEi or ATA uptitration above doses recommended to control arterial hypertension and combined treatment with both agents allow optimization of A II inhibition and maximization of renoprotection. Multifactorial interventions combining RAS inhibition to treatments targeted also to non-RAS mechanisms could even achieve regression of glomerulosclerosis and chronic tubulointerstitial injury. Studies are needed to assess whether renal damage can be reverted to such a point that renal function could be fully prevented from worsening, and possibly improvement. The economic impact of even a partial improvement would be enormous. Moreover, chronic renal insufficiency is an independent risk factor for cardiovascular disease, and effective nephroprotection could also decrease the excess cardiovascular morbidity and mortality associated with chronic nephropathies. In patients with renal insufficiency, ACEi are even more cardioprotective than in those without and are well tolerated. Thus, RAS inhibitor therapy should be offered to all renal patients without specific contraindications, including those closer to renal replacement therapy.     

Cardiac allograft vasculopathy compared by intravascular ultrasound sonography: everolimus to mycophenolate mofetil--one single-center experience

Cardiac allograft vasculopathy (CAV) remains one of the leading causes of late graft failure and death. Cyclosporine microemulsion Neoral (CsA) had been used in heart transplantation (HTx) recipients. Meanwhile, Everolimus (EVL; Certican, Norvatis Pharmaceuticals; Basel, Switzerland) or mycophenolate mofetil (MMF) have been combined with CsA for maintenance treatment. We compared atherosclerosis in HTx patients showing CAV by intravascular ultrasound (IVUS) in two groups: the CE who received CsA, EVL, and steroid versus the CM group, who received CsA, MMF, and steroid.

Materials and Methods

We explored IVUS parameters such as plaque thickness (PT), lumen circumference (LC), media adventitial circumference, lumen diameter (LD), and media adventitial diameter to characterize the atherosclerosis among CE versus CM groups.

Results

In this study, both the CE and CM groups showed increased plaque thickening in the first year posttransplantation (P < .05). However, MMF significantly reduced LC and LD (P < .05) Upon multivariate linear regression analysis, the CE group seemed to show less effect on the maximal difference in PT between 2 and 12 months after adjusting for age at transplantation and gender (P < .05). There was no acute clinical adverse event of CAV reported in either both group during the follow-up. The atherosclerosis of CAV revealed by LC, LDmax, and LDmin was significantly less among patients treated with CE than CM.

Conclusion

These results suggested that everolimus-treated patients showed benefits compared with MMF-treated subjects as extrapolated from these IVUS data.     

Prevalence of cardiac allograft vasculopathy assessed with coronary angiography versus coronary vascular ultrasound and virtual histology

Background

Cardiac allograft vasculopathy (CAV) is a major factor limiting long-term survival after heart transplantation (HT). The purpose of this study was to characterize the coronary artery structure and to determine the prevalence of vasculopathy after HT, comparing the sensitivity of coronary angiography with that of intravascular ultrasound (IVUS) and virtual histology (VH).

Methods

A prospective recruitment cross-sectional study was performed in 31 adult HT recipients including 22 men and, 9 women of overall mean age of 45.2 ± 12.6 years at an average of 3.7 ± 3.7 years after transplantation. They underwent simultaneously coronary angiography and IVUS assessment of the left anterior descending coronary artery. We investigated histological composition of the intima. Final data were analyzed using parametric and nonparametric tests.

Results

IVUS discovered the presence of CAV among 17/31 (54.8%) patients versus coronary angiography in 10 (32.3%; P = .009). The histological composition of the intima as assessed with IVUS VH was 26.1% fiber, 8.7% necrotic core, 5.7% calcium, and 4.3% lipid. There was no significant association between preexistent risk factors and the presence of CAV. There was a correlation between time elapsed since HT and CAV development.

Conclusion

Time elapsed since HT is the most important risk factor for the development of CAV. Its prevalence almost doubled when measured with IVUS in contrast with angiography. IVUS was thus shown to be a more sensitive diagnostic tool compared with coronary angiography.     

Usefulness of stanford scale of intimal hyperplasia assessed by intravascular ultrasound to predict time of onset and severity of cardiac allograft vasculopathy

BACKGROUND: The purpose of this study was to assess the prognostic value of a single IVUS result described by the Stanford scale to predict CAV development. METHODS: Inclusion criteria were heart transplantation (OHT) before 1997 and at least one IVUS performed before 1998. IVUS studies were performed in 37 patients at 37 +/- 26 months after OHT. Based on the Stanford scale, were divided patients into Four groups: group I (grade 0 or 1): n = 4, 42 +/- 19 years, 2 men/2 women; group II (grade 2): n = 10, 44 +/- 15 years, 9 men/1 woman; group III (grade 3): n = 11, 48 +/- 11 years, 11 men; and group IV (grade 4): n = 12, 46 +/- 8 years, 12 men. We compared the incidence and time of onset of clinically significant CAV, namely significant coronary lesions, myocardial infarction and death caused by CAV. RESULTS: There was no CAV diagnosed in group I. The rates of CAV in coronary angiograms in groups II, III and IV were: 80%, 36%, and 75%, respectively. Significant CAV was found in 30%, 9%, and 50% of patients, respectively. Average times of onset of any CAV in groups II, III and IV were 4.9, 5.6, and 3.3 years, and for significant CAV were 4.1, 3.6, and 5.5 years, respectively. Deaths in groups I to IV were 1, 4, 2, and 5, respectively. CAV was the reason for death in 1 patient from group III, and 3 patients from group IV. CONCLUSIONS: Extreme grades on the Stanford scale (0, 1, and 4) describing a single IVUS study in OHT recipients appear useful to stratify patients with the lowest versus the highest risk of CAV development.     

Prevention and inhibition but not reversion of chronic allograft vasculopathy by FK778

BACKGROUND: This study aimed at investigating the efficacy of the novel immunosuppressant FK778 to prevent the development and progression of chronic allograft vasculopathy (CAV). METHODS: Orthotopic aortic transplantations were performed in the PVG-to-ACI rat model and followed over the course of 120 days. Immunosuppression with FK778 (20 mg/kg) or sirolimus (2 mg/kg) was either started early or delayed when CAV was already present. Trough levels were monitored. Aortic luminal obliteration was quantified using computer morphometry and intragraft cytokine profiles were analyzed with Western Blotting. Donor-reactive antibodies were quantified by flow cytometry. RESULTS: Untreated animals developed CAV with luminal obliteration of 25.2+/-13.6% and 41.4+/-23.3% after 80 and 120 days, respectively. Continuous immunosuppression with FK778 or sirolimus effectively prevented the development of vasculopathy. When the start of the immunosuppressive regimen was delayed until postoperative day 80, FK778 and sirolimus inhibited a progression of established CAV but did not reverse the luminal obliteration. Intragraft tumor growth factor-beta activity increased over the course of time in untreated recipients but was significantly suppressed after continuous immunosuppression with either agent. Expression of platelet-derived growth factor, intercellular adhesion molecule-1, and vascular adhesion molecule-1 also was moderately suppressed. A stable elevation of donor-reactive IgG-antibody levels was found over 120 days in the absence of treatment. With FK778 or sirolimus, antibody levels were effectively decreased. FK778 was very well tolerated and only sirolimus showed side effects with elevation of BUN, cholesterol, triglycerides, and ALT after 120 days. CONCLUSIONS: FK778 prevents the development of CAV and inhibits a progression of established disease. It shows a similar efficacy but a safer drug profile when compared to sirolimus.     

The predictive value of coronary artery calcium detected by computed tomography in a prospective study on cardiac allograft vasculopathy in heart transplant patients

The predictive value of coronary artery calcium (CAC) in heart transplant (HTX) patients is not established. We explored if the absence of CAC on computed tomography (CT) could exclude moderate and severe cardiac allograft vasculopathy [CAV_2–3; the International Society for Heart and Lung Transplantation (ISHLT) recommended nomenclature] and significant coronary artery stenosis (diameter reduction ≥50%) and predict long‐term clinical outcomes. HTX recipients (n = 133) were prospectively included and underwent CT for CAC scoring and invasive coronary angiography (ICA) 7.8 ± 5.0 years after HTX. CAC was detected in 73 (55%) patients. The absence of CAC on CT had a negative predictive value of 97% for ISHLT CAV_2–3 and 88% for significant stenosis on ICA. During 7.5 ± 2.6 years of follow‐up after CAC CT (n = 127), there were 57 (45%) nonfatal major adverse cardiac events and 23 (18%) deaths or graft losses registered as first events. Patients with CAC had significantly more events (P = 0.011). In an adjusted Cox regression analysis, the presence of CAC was significantly associated with a negative outcome (HR 1.8, 95% CI 1.1–3.0; P = 0.023). The absence of CAC predicted low prevalences of ISHLT CAV_2–3 and significant coronary artery stenosis in HTX patients. The presence of CACS was significantly associated with a worse long‐term outcome.     

冬虫夏草提取物抑制大鼠移植物血管病的实验研究

目的 探讨冬虫夏草提取物抑制大鼠移植动脉硬化的效果及其机制.方法 制备大鼠腹主动脉移植模型,分为4组进行实验:同系对照组供、受者均为Lewis大鼠,生理盐水灌胃60d;同种对照组,以Brown-Norway大鼠(BN大鼠)为供者,Lewis大鼠为受者,生理盐水灌胃60d;低剂量实验组,以BN大鼠为供者,Lewis大鼠为受者,以冬虫夏草提取物(1.5 g·kg-1·d-1)灌胃60 d;高剂量实验组,以BN大鼠为供者,Lewis大鼠为受者,以冬虫夏草提取物(3.0g·kg-1·d-1)灌胃60d.于移植后60 d取移植动脉,HE染色,进行病理学观察;免疫组织化学和蛋白质印迹法检测血管内皮生长因子(VEGF)和血小板衍生生长因子BB(PDGF-BB)在移植动脉中的表达.酶联免疫吸附试验检测受鼠血清中VEGF和PDGF- BB含量.结果 同系对照组移植动脉形态正常;同种对照组移植动脉呈移植物血管病表现,血管内膜显著增厚;2个实验组移植动脉呈内膜炎症改变,内膜厚度与同种对照组相比,差异有统计学意义(P＜0.05).同种对照组移植动脉中VEGF和PDGF-BB的表达高于同系对照组(P＜0.05);2个实验组移植动脉中VEGF和PDGF-BB的表达低于同种对照组(P＜0.05).同系对照组受鼠血清中几乎无VEGF和PDGF-BB;同种对照组血清中VEGF和PDGF-BB浓度高于同系对照组(P＜0.05);和同种对照组相比较,2个实验组血清VEGF和PDGF-BB浓度较低(P＜0.05).结论 冬虫夏草提取物能明显抑制动脉内膜的增生,可缓解慢性排斥反应所致的移植动脉硬化,这种保护作用可能与下调VEGF和PDGF-BB表达有关.     

低分子肝素对大鼠心脏移植物血管病的抑制作用

目的 观察低分子肝素对大鼠心脏移植物血管病(CAV)的作用及其机制.方法 以SD大鼠为供者,Wistar大鼠为受者,进行异位(腹部)心脏移植.将受者分为3组,每组30只.CsA组自手术当天至术后第9天腹腔注射环孢素A(CsA);实验组腹腔注射CsA(用法同CsA组),并从手术当天开始皮下注射低分子肝素,2 mg·kg-1·d-1,直至处死;L-NAME组在给予低分子肝素的同时皮下注射左旋精氨酸甲酯(L-NAME),10 mg·kg-1·d-1,其他用药同实验组.每组分别于术后30、60和90 d各选取10只大鼠,测定血中NO及内皮素-1(ET-1)的浓度,切取移植心脏,镜下观察并进行CAV评分.结果 随着时间的延长,各组的CAV评分逐渐升高,血NO浓度和ET-1浓度逐渐降低.实验组术后30、60和90 d时的CAV评分分别为1.1±0.6、1.6±0.7和2.1±0.6,血ET-1浓度分别为(133±26)pg/ml、(106±16)pg/ml和(79±16)pg/ml,均明显低于CsA组和L-NAME组(P<0.05);实验组术后30、60和90 d时的血NO浓度分别为(171±22)μmol/L、(122±27)μmol/L和(92±17)μmol/L,均明显高于CsA组和L-NAME组(P<0.05).结论 低分子肝素可以延缓心脏CAV的进展,其作用可能是通过增加NO的浓度和抑制ET-1的合成来实现的.     

落新妇甙对小鼠心脏移植后移植物血管病的抑制作用

目的探讨落新妇甙对小鼠心脏移植后移植物血管病的抑制作用。方法建立小鼠颈部心脏移植模型,将受鼠随机分为环孢素A(CsA)组(术后每天用CsA5mg/kg灌胃)和落新妇甙组(术后每天用落新妇甙5mg/kg灌胃)。术后第60d切取移植心,观察移植心脏组织学变化,以HPIAS-1000图像分析仪测量冠状动脉管壁厚度与动脉直径的比值,根据平均内膜厚度和管腔狭窄程度对CAV病变进行评分。结果CsA组移植心脏可见明显的纤维化,大量单核细胞浸润,动脉硬化明显,冠状动脉管壁厚度与血管直径的比值为0.63±0.20,明显高于落新妇甙组的0.22±0.04(P<0.01);CsA组心脏移植物血管病变评分为(2.3±0.6)分,高于落新妇甙组的(1.1±0.3)分(P<0.05)。落新妇甙组心脏移植物的冠状动脉内膜病变轻微,内皮和内弹力层基本保持完整,平滑肌细胞增殖不明显。结论落新妇甙能减缓移植心冠状动脉硬化,对小鼠心脏移植后移植物血管病有明显的抑制作用。     

Angiotensin-converting enzyme inhibition attenuates hypercholesterolemia and glomerular injury in hyperlipidemic Imai rats.

Hyperlipidemic Imai rats spontaneously develop hypercholesterolemia, proteinuria and glomerulosclerosis. We investigated the effect of enalapril, an angiotensin-converting enzyme (ACE) inhibitor, on spontaneous hypercholesterolemia and the progressive renal injury in this rat strain. Male Imai rats (n = 7) were treated with enalapril at a dose of 50 mg/l in drinking water starting at 6 weeks of age. Body weight, blood pressure, urinary protein excretion and serum constituents were checked and compared with untreated controls (n = 5) up to 38 weeks of age. Enalapril treatment significantly reduced hypercholesterolemia (247 +/- 41 vs. 102 +/- 13 mg/dl, p < 0.01, at 38 weeks) and proteinuria (766 +/- 290 vs. 206 +/- 119 mg/kg/day, p < 0.01, at 38 weeks). The glomerulosclerosis index (SI) was significantly higher in untreated control rats than in the enalapril-treated group (227 +/- 57 vs. 27 +/- 9, p < 0.01). Although we could not clarify whether hypercholesterolemia is a primary event or secondary to the nephrotic syndrome, these results indicate that the ACE inhibitor has the property to protect remnant glomeruli from glomerulosclerosis in male Imai rats as well as in other animal models in which focal and segmental glomerulosclerosis is believed to represent a common pathologic pattern. This rat strain represents a unique model of a spontaneous proteinuria which can provide an important information on the pathogenesis of human focal and segmental glomerulosclerosis.     

左旋精氨酸对大鼠心脏移植物血管病变的抑制作用

目的　研究左旋精氨酸对大鼠心脏移植物血管病变的抑制作用及其机理。方法　采用大鼠异位心脏移植模型。对照组 :移植后不用左旋精氨酸 ;实验组 :移植后按 80 0mg·kg-1·d-1将左旋精氨酸加入饮水中。于移植后 2个月和 3个月检测各组的心脏移植物 ,血管病变评分和血浆一氧化氮含量。结果　移植后 2个月 ,实验组的移植物存活率为 90 .5 % ,显著高于对照组的 6 1.5 % (P <0 .0 5 )。移植后 2个月和 3个月 ,实验组血浆一氧化氮含量均显著高于对照组 ,分别为 ( 10 5 .37± 10 .6 6 ) μmol/Lvs( 6 8.5 4± 6 .83) μmol/L(P <0 .0 5 ) ,和 ( 10 4.5 3± 12 .31) μmol/Lvs ( 6 6 .32± 10 .5 4) μmol/L(P <0 .0 5 ) ;而对照组心脏移植物血管病变评分显著高于实验组 ,分别为 2 .4± 0 .7vs 1.1± 0 .6 (P <0 .0 5 ) ,和 3.0±0 .8vs 1.6± 0 .9(P <0 .0 5 )。实验组心脏移植物的冠状动脉内膜病变轻微 ,内皮和内弹力层基本保持完整 ,平滑肌细胞增殖不明显。结论　补充左旋精氨酸可改善心脏移植物血管病变 ,其机理与一氧化氮合成增加有关。一氧化氮具有保持内皮功能 ,抑制平滑肌细胞增殖的作用。     

Suppression of cardiac allograft vasculopathy in mice by inhibition of CC-motif chemokine receptor 5

Cardiac allograft vasculopathy (CAV) is the leading cause of late morbidity and mortality in heart-transplant patients. Increasing evidences support the important role of chemokines and their receptors in transplant immunology. Chemokine-chemokine receptor interaction and subsequent recruitment of T-lymphocytes to the graft are early events in the development of chronic rejection of transplanted hearts. In this study, we first inhibited CC-motif chemokine receptor 5 (CCR5) expression by using lentiviral-mediated gene transfer of an anti-CCR5 siRNA, which introduced through CD34(+) hematopoietic stem/progenitor cell transplantation. Stably marked lymphocytes expressing siRNA and consistent downregulation of CCR5 expression were detected. Our results showed that survival was significantly prolonged in CCR5 knock-down mice and donor hearts from siRNA-treated mice developed markedly less CAV. Infiltration of CD4(+) and CD8(+) T-lymphocytes into transplanted hearts was also markedly decreased. These findings suggest that CCR5 plays an important role in CAV development and inhibition of this chemokine could improve long-term survival after cardiac transplantation.