Diminished impact of cytomegalovirus infection on graft vasculopathy development in the antiviral prophylaxis era – a retrospective study

Evidence concerning an association between cytomegalovirus (CMV) infection and accelerated cardiac allograft vasculopathy (CAV) is inconclusive. Data were analyzed retrospectively from 297 consecutive heart transplants between 1.1.2002 and 31.12.2012. Patients ≤18 years of age, survival, and follow‐up ≤1‐year post‐transplant and patients with early CAV were excluded. CMV‐infection was diagnosed and monitored closely in the first year. CAV was diagnosed by coronary angiography via left heart catheterization, and results were categorized according to the International Society of Heart and Lung Transplantation (ISHLT) scoring system. Risk factors for CAV were tested in a multivariable model. Median follow‐up was 7.5 years (IQR: 5.6–10.3). CMV infection in the first year after transplantation occurred in 26% of patients (n = 78), CMV disease in 5% (n = 15). CAV ≥1 ISHLT was detected in 36% (n = 108). Incidence of CAV >1 ISHLT and severity of CAV increased over time. No statistically significant association between CMV infection and disease within the first year and risk of CAV after 1‐year post‐HTx was detected in the univariate (P = 0.16) and multivariable [hazard ratio (HR), 1.36; confidence interval (CI), 0.89–2.07; P = 0.16] Cox regression. In the multivariable Cox regression, donor age (HR, 1.04; 95% CI, 1.02–1.06; P < 0.01) and acute cellular rejection (ACR) ≥2R in the first year after HTx (HR, 1.77; 95% CI, 1.06–2.95; P = 0.03) were independent risk factors for CAV development. In our cohort, CMV infection and disease in the first year after transplantation did not significantly influence the risk of CAV in the long‐term follow‐up.     

沙利度胺对大鼠慢性移植物血管病的保护作用

目的探讨沙利度胺对大鼠慢性移植物血管病的保护作用。方法实验分为4组：同种移植对照组,供、受者均为Lewis大鼠,无特殊处理;异种移植对照组,Lewis大鼠接受Brown-Norway（BN）大鼠腹主动脉移植（BN-Lewis）;沙利度胺小剂量组（50mg·kg-1·d-1,BN-Lewis）;沙利度胺大剂量组（100mg·kg-1·d-1,BN-Lewis）。于移植后60d取移植动脉,分别进行组织病理学观察、测量内膜厚度,免疫组织化学法和蛋白质印迹法检测TNF-α及上皮细胞增殖细胞核抗原（PCNA）在移植动脉中的表达。结果同种移植对照组移植动脉形态正常;异种移植对照组移植动脉呈移植物血管病表现,血管内膜增厚;沙利度胺小剂量及大剂量组移植动脉呈内膜炎改变,内膜厚度比异种移植对照组减小（P〈0．05）。与异种移植对照组相比,沙利度胺小剂量组和大剂量组移植动脉TNF-α及PCNA蛋白表达量降低（均P〈0．05）。结论沙利度胺能降低移植动脉TNF-α及PCNA蛋白的表达,缓解移植动脉的纤维化进程以及内膜增生,对慢性排斥反应所致的移植物血管病具有抑制作用。     

Current views on chronic rejection after lung transplantation

Chronic lung allograft dysfunction (CLAD) was recently introduced as an overarching term mainly to classify patients with chronic rejection after lung transplantation, although other conditions may also qualify for CLAD. Initially, only the development of a persistent and obstructive pulmonary function defect, clinically identified as bronchiolitis obliterans syndrome (BOS), was considered as chronic rejection, if no other cause could be identified. It became clear in recent years that some patients do not qualify for this definition, although they developed a chronic and persistent decrease in FEV₁, without another identifiable cause. As the pulmonary function decline in these patients was rather restrictive, this was called restrictive allograft syndrome (RAS). In the present review, we will further elaborate on these two CLAD phenotypes, with specific attention to the diagnostic criteria, the role of pathology and imaging, the risk factors, outcome, and the possible treatment options.     

Clinical outcome and quality of life of patients surviving 20 years or longer after heart transplantation

To evaluate outcome and quality of life (QoL) in ≥20 years survivors after heart transplantation. Patients surviving ≥20 years with a single graft were retrospectively reviewed. Heterotopic, multiorgan and retransplantations were excluded. QoL was evaluated using the SF‐36 survey. Eight hundred and twenty‐seven heart transplants were performed from 1981 to 1993, and among these, 131 (16%) patients survived ≥20 years; 98 (75%) were male and mean age at transplant was 43 ± 13 years. Conditional survival in these 20 years survivors was 74.1 ± 4.3% at 23 years and 60.9 ± 5.3% at 25 years (45 deaths, 34%). Forty‐four (34%) patients suffered rejection ≥2R. Conditional survival free from rejection ≥2R was 68 ± 4.1% at 5 years and 66.4 ± 4.2% at 10 years. Thirty‐five (27%) patients had cardiac allograft vasculopathy (CAV) grade 2–3. Conditional CAV‐free survival was 76 ± 3.8% at 20 years and 72.1 ± 4% at 25. Sixty‐nine (53%) patients developed malignancy, mostly skin cancers. Conditional malignancy‐free survival was 53.5 ± 4.4% at 20 years and 45.2 ± 4.6% at 25 years. At latest follow‐up, 24.0 ± 3.0 years after transplantation, mean left ventricular ejection fraction was 62 ± 11% and mean physical and mental scores were 57 ± 23 and 58 ± 21, respectively. Sixteen per cent of heart recipients survived ≥20 years with good ventricular performance and QoL. CAV and malignancies account for late morbidity and mortality.     

Infection and rejection risk after cardiac transplantation with induction vs. no induction: a multi‐institutional study

Data from Cardiac Transplant Research Database (CTRD) were analyzed from 1999 to 2006 to examine the effects of different induction strategies at the time of cardiac transplantation. A total of 2090 primary heart transplants were categorized by induction with interleukin‐2 receptor blocker (IL‐2RB), antithymocyte globulin (ATG), or no induction (NI). Probabilities for rejection and infection were estimated with parametric time‐related models. Using these models, hazard was calculated for two theoretical patient profiles, one at lower risk for rejection and higher risk of infection (Profile 1) and higher risk for rejection and lower risk of infection (Profile 2). Of the 2090 transplants, 49.8% (1095) did not receive induction, 27.3% (599) received IL‐2RB, and 18.0% (396) received ATG. Profile 1 patients had lower hazard for rejection with IL‐2RB compared to ATG and NI (p < 0.01), but at the cost of increased risk of infection (5.0 vs. 1.8 vs. 1.6, respectively, at four wk, p < 0.01). Profile 2 patients experienced a fivefold decreased hazard for rejection when treated with IL‐2RB compared with ATG and NI (p < 0.01). In patients at high risk of infection, IL‐2RB reduced risk of rejection but at the expense of increased hazard for infection.     

LF 08‐0299 In the prophylaxis and treatment of chronic rejection in a rat aortic allograft model

Abstract Chronic rejection is the major cause of late kidney allograft failure. We evaluated the efficacy of LF 08‐299 (LF), an analogue of 15‐deoxyspergualin, in a rat aortic allograft model of chronic rejection. BN aortic allografts were transplanted to Lew recipients. LF was administered at a dose of 6 mg/kg and 2.5 mg/kg on days 0‐20 and 6 mg/kg on days 60‐90. CyA was used at a dose of 5 mg/kg on days 0‐20. Untreated isografts and allografts were used as controls. Histological changes and immunohistochemistry were monitored sequentially at 8, 12, 16 and 20 weeks. There were no differences in intimal proliferation between LF‐treated allografts and untreated or CyA‐treated controls. Only a tendency in adventitial infiltration reduction was seen in LF‐treated animals. We found a significantly less pronounced reduction in media diameter in LF‐treated animals. We concluded that LF 08‐0299 is only able to reverse reduction in media thickness in aortic allografts, but not intimal proliferation in this model of chronic rejection.     

Coronary artery disease in heart transplantation: new concepts for an old disease

Cardiac allograft vasculopathy (CAV) remains one of the main long‐term complications after heart transplantation. We performed a systematic review focused on articles published in the previous 6 years to reappraise the novel evidences supporting risk factors, pathology, prevention, and treatment of CAV. We identified a search string for a literature search on PubMed. We excluded articles specifically focused on diagnosis/biomarkers/imaging only or complications of other diseases. We included 98 studies out of our search. Forty‐eight articles describe risk factors for CAV, 13 pathology, 24 prevention, and 13 treatment for CAV. While confirming known concepts, we found supportive evidence that CAV pathophysiology may vary according to the time post‐transplant and the prevalence of metabolic versus immune‐mediated risk factors. Selective revascularization of focal lesions in patients with CAV may result in some clinical benefit, but CAV prevention, rather than treatment, by controlling risk factors and by using targeted immunosuppressive therapies is the most evidence‐based approach to reduce disease progression.     

大鼠全胰十二指肠移植术实验研究观察

目的: 建立大鼠全胰十二指肠移植(PTA)模型 。方法: 根据SunLee等的方法建立大鼠PTA模型,并进行部分改进。行大鼠PTA70例,术后观察大鼠血、尿糖变化,移植物组织病理学改变,血运情况等 。结果: 术后一周存活65例,手术成功率达92.9%。术后第一日大鼠血、尿糖即恢复正常。术后能长期存活者,移植物血管通畅,功能正常 。结论: 大鼠PTA治疗实验性糖尿病切实可行。手术方法简便、易行,手术成功率高,胰腺外分泌液引流入肠腔符合生理特点。     

Correlation between circulating endothelial progenitor cell function and allograft rejection in heart transplant patients

Endothelial progenitor cells (EPCs) may contribute to rejection and cardiac allograft vasculopathy (CAV) by being intrinsically involved in the rejection process and causing neointimal hyperplasia. The mammalian target of rapamycin inhibitors (mTORi), sirolimus and everolimus, have been demonstrated to attenuate the progression of CAV and are cytotoxic to EPC. Thus, one mechanism by which mTORi may protect against CAV is by altering EPC function. Our study measured circulating EPC function and correlated this assessment with rejection episodes in heart transplant (HT) recipients. In addition, we examined the effect of mTORi on EPCs. Patients who received HT at our institution between 1995 and 2007 were included and stratified by International Society for Heart and Lung Transplantation (ISHLT) rejection grade. Group A (n = 13) consisted of patients with at least one moderate/severe rejection episode (grade ≥ 2). Group B (n = 28) patients had no moderate/severe episodes (grade < 2). Patients were also independently stratified based on exposure as mTORi (n = 21) vs. non mTORi (n = 20). To assess EPC functional capacity, we counted the number of colony‐forming units (CFU) of EPCs in peripheral blood samples from HT recipients. There were no significant differences in baseline characteristics between groups. The mean EPC‐CFU counts/plate for group A (rejecting) were 30 ± 6 vs.16 ± 3 for group B (nonrejecting) (P = 0.03). The EPC‐CFU counts/plate in the mTORi group (15 ± 3) were lower compared to the non mTORi (27 ± 5) group (P = 0.04). We found that EPC colony‐forming capacity was higher in HT patients who experienced moderate/severe rejection episodes. Patients on mTORi showed a reduced EPC colony count consistent with our previous findings of EPC cytotoxicity. Detection of circulating EPC function post‐transplant may reliably identify patient risk level for subsequent allograft rejection and allow for appropriate adjustments to immunosuppression. Converting to mTORi therapy may reduce EPC function and provide a novel mechanism to prevent rejection and possibly attenuate the development of CAV.     

Living-related partial bladder transplantation for bladder augmentation in rats: an experimental study

Purpose

To assess the feasibility of transplanting adult bladder tissue to its offspring as a source of neobladder tissue for bladder augmentation.

Methods

The dome of the bladder of an adult Lewis rat was excised and transplanted into the omentum of a 6-week-old offspring (living-related partial bladder transplant: n = 15). The bladder remnant of the donor rat was closed. Two weeks after transplantation, a laparotomy was performed to mobilize the bladder graft with its omental pedicle into the pelvis. Bladder augmentation (BA) was performed by anastomosing the graft to the recipient’s bladder. Thirty days after BA, the entire neobladder was excised and histopathologically examined.

Results

At laparotomy, each bladder graft appeared macroscopically as a thin-walled cyst in the recipient’s omentum. Each graft could be mobilized into the pelvis and anastomosed to the recipient’s bladder. BA was successful in all 15 recipients, and histopathologic studies showed that the mucosa was normal throughout each neobladder. Postoperatively, donors and recipients were clinically well without any sign of urinary incontinence or obstruction.

Conclusions

This is the first report of adult tissue being transplanted successfully into a recipient without vascular reconstruction in a rat. Living-related partial bladder transplantation for the purpose of BA is feasible using our technique and could have application as an alternative technique for BA in a rat.