Pretransplantation levels of C-reactive protein predict all-cause and cardiovascular mortality, but not graft outcome, in kidney transplant recipients

Feeling gutted in chronic kidney disease (CKD): Gastrointestinal disorders and therapies to improve gastrointestinal health in individuals CKD, including those undergoing dialysis

Chronic kidney disease (CKD) affects 9.1% of the population worldwide. CKD may lead to structural and functional gastrointestinal alterations, including impairment in the intestinal barrier, digestion and absorption of nutrients, motility, and changes to the gut microbiome. These changes can lead to increased gastrointestinal symptoms in people with CKD, even in early grades of kidney dysfunction. Gastrointestinal symptoms have been associated with lower quality of life and reduced nutritional status. Therefore, there has been considerable interest in improving gastrointestinal health in this clinical population. Gastrointestinal health can be influenced by lifestyle and medications, particularly in advanced grades of kidney dysfunction. Therapies focused on gastrointestinal health have been studied, including the use of probiotics, prebiotics, and synbiotics, yielding limited and conflicting results. This review summarizes the alterations in the gastrointestinal tract structure and function and provides an overview of potential nutritional interventions that kidney disease professionals can provide to improve gastrointestinal health in individuals with CKD.

Novel options for failing allograft in kidney transplanted patients to avoid or defer dialysis therapy

PURPOSE OF REVIEW

Despite improvement in short-term renal allograft survival in recent years, renal transplant recipients (RTR) have poorer long-term allograft outcomes. Allograft function slowly declines with periods of stable function similar to natural progression of chronic kidney disease in nontransplant population. Nearly all RTR transitions to failing renal allograft (FRG) period and require transition to dialysis. Conservative chronic kidney disease management before transition to end-stage renal disease is an increasingly important topic; however, there is limited data in RTR regarding how to delay dialysis initiation with conservative management.

RECENT FINDINGS

Since immunological and nonimmunological factors unique to RTR contribute to decline in allograft function, therapies to slow progression of FRG should take both sets of factors into account. Renal replacement therapy either incremental dialysis or rekidney transplantation should be explored. This required taking benefits and risks of continuing immunosuppressive medications into account when allograft nephrectomy may be necessary.

SUMMARY

FRG may benefit from various interventions to slow progression of worsening allograft function. Until there are stronger evidence to guide interventions to preserve renal function, extrapolating evidence from nontransplant patients and clinical judgment are necessary. The goal is to provide individualized care for conservative management of RTR with FRG.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

Pretransplant Levels of C-Reactive Protein, Soluble TNF Receptor-1, and CD38+HLADR+ CD8 T Cells Predict Risk of Allograft Rejection in HIV+ Kidney Transplant Recipients

INTRODUCTION

HIV-positive (HIV+) kidney transplant recipients exhibit a 2- to 3-fold increased risk of allograft rejection. Dysregulated immune activation in HIV infection persists despite successful antiretroviral therapy and is associated with non-AIDS morbidity, including renal disease. We hypothesized that the pathological levels of inflammation and immune activation associated with chronic HIV infection could have clinical utility in the prediction of rejection in HIV+ kidney recipients.

METHODS

Prospective cohort study of 22 HIV-negative (HIV-; donor) to HIV+ (recipient) kidney transplant recipients who underwent biomarker assessment pretransplant and were subsequently followed for development of acute rejection. Plasma levels of markers of inflammation (soluble tumor necrosis factor receptor 1 [sTNF-R1] and C-reactive protein [CRP]) and microbial translocation (soluble CD14 and lipopolysaccharide) were measured by enzyme-linked immunosorbent assay or chromogenic endpoint assay. Levels of activated (CD38+HLADR+) CD4+ and CD8+ T cells, and T regulatory cells (CD4+CD25highFoxP3+) were measured by flow cytometry.

RESULTS

Among the biomarkers evaluated, only the pretransplant levels of sTNF-R1, CRP, and frequencies of CD38+HLADR+ CD8 T cells, were found to be at significantly higher levels among patients who experienced biopsy-proven acute rejection. Confirming our hypothesis, patients with high pretransplant levels of sTNF-R1 or activated CD8+ T cells had a significantly increased 200-day cumulative incidence of biopsy-proven acute rejection (0 vs. 38% for both; P = 0.01). Similarly, pretransplant CRP levels higher than 5 μg/ml were associated with increased risk of acute rejection within the first 6 months post-transplant (0 vs. 43%; P = 0.01).

CONCLUSION

Biomarker-based identification of HIV+ recipients at increased risk for rejection might facilitate individualized induction immunosuppression regimens in this vulnerable patient population.

IL-10-specific autoantibodies predict major adverse cardiovascular events in kidney transplanted patients - a retrospective cohort study

End-stage renal failure is associated with persistent systemic inflammation. The aim of this study was to investigate if systemic inflammation at the time of kidney transplantation is linked to poor graft survival, major adverse cardiovascular events (MACE), and increased mortality, and if these processes are modulated by naturally occurring cytokine-specific autoantibodies (c-aAbs), which have been shown to regulate cytokine activity in vitro. Serum levels of cytokines, high-sensitivity C-reactive protein (hsCRP) and c-aAbs specific for interleukin (IL)-1α, tumor necrosis factor (TNF)-α, IL-6, and IL-10 were measured at the time of transplantation in a retrospective cohort study of 619 kidney transplanted patients with a median follow-up of 4.9 years (range 1.2-8.2 years). Systemic inflammation was associated with all-cause mortality in simple and multiple Cox regression analyses. IL-10-specific c-aAbs were associated with MACE after transplantation, suggesting that IL-10 may be a protective factor. Similarly, patients with a history of MACE before transplantation had lower levels of TNF-α-specific c-aAbs, hence we hypothesized that TNF may be a risk factor of MACE. These findings support that pro-inflammatory activity before transplantation is a pathological driver of MACE and all-cause mortality after transplantation. This information adds to pretransplantation risk estimation in renal transplant candidates.

Effects of Exercise and Sport in Solid Organ Transplant Recipients: A Review

Solid organ transplantation is the criterion standard treatment for many with end-organ failure and can offer a new independence from the burden of disease. However solid organ transplant recipients (SOTRs) remain at high risk of cardiovascular (CV) disease, and poor quality of life and physical functioning. Increasing physical activity and exercise can improve the health of the general population; however, the effects on those with a transplant remain unclear. Intensive exercise and sporting activity has the potential to be beneficial, although there remain concerns particularly around the effects on immune function and the CV system. This review summarizes what is known about the effects of exercise on determinants of health in SOTRs and then collates the available literature investigating the consequences of intensive exercise and sport on the health of SOTR. There is a paucity of high-quality research, with most evidence being case studies or anecdotal; this is understandable given the relatively few numbers of SOTRs who are performing sport and exercise at a high level. However, if suitable evidence-based guidelines are to be formed and SOTRs are to be given reassurances that their activity levels are not detrimental to their transplanted organ and overall health, then more high-quality studies are required.

Pretransplant Immune- and Apoptosis-Related Gene Expression Is Associated with Kidney Allograft Function

Renal transplant candidates present immune dysregulation, caused by chronic uremia. The aim of the study was to investigate whether pretransplant peripheral blood gene expression of immune factors affects clinical outcome of renal allograft recipients. Methods. In a prospective study, we analyzed pretransplant peripheral blood gene expression in87 renal transplant candidates with real-time PCR on custom-designed low density arrays (TaqMan). Results. Immediate posttransplant graft function (14-day GFR) was influenced negatively by TGFB1 (P = 0.039) and positively by IL-2 gene expression (P = 0.040). Pretransplant blood mRNA expression of apoptosis-related genes (CASP3, FAS, and IL-18) and Th1-derived cytokine gene IFNG correlated positively with short- (6-month GFR CASP3: P = 0.027, FAS: P = 0.021, and IFNG: P = 0.029) and long-term graft function (24-month GFR CASP3: P = 0.003, FAS: P = 0.033, IL-18: P = 0.044, and IFNG: P = 0.04). Conclusion. Lowered pretransplant Th1-derived cytokine and apoptosis-related gene expressions were a hallmark of subsequent worse kidney function but not of acute rejection rate. The pretransplant IFNG and CASP3 and FAS and IL-18 genes' expression in the recipients' peripheral blood is the possible candidate for novel biomarker of short- and long-term allograft function.

Managing Cardiovascular Risk in the Post Solid Organ Transplant Recipient

Solid organ transplantation is an effective treatment for patients with end-stage organ disease. The prevalence of cardiovascular diseases (CVD) has increased in recipients. CVD remains a leading cause of mortality among recipients with functioning grafts. The pathophysiology of CVD recipients is a complex interplay between preexisting risk factors, metabolic sequelae of immunosuppressive agents, infection, and rejection. Risk modification must be weighed against the risk of mortality owing to rejection or infection. Aggressive risk stratification and modification before and after transplantation and tailoring immunosuppressive regimens are essential to prevent complications and improve short-term and long-term mortality and graft survival.

Post-transplant C-reactive protein predicts arterial stiffness and graft function in renal transplant recipients

BACKGROUND

The aim of this study was to evaluate the renal and cardiovascular outcomes of post-transplant c-reactive protein (CRP) levels.

METHODS

One hundred fifty renal transplant recipients (113 men; median age, 38.9 ± 10.8 years) were cross-sectionally analyzed. Mean pre-transplant and post-transplant CRP levels were analyzed by the 1(st), 3(rd), 6(th), 12(th), and 24(th) months of transplantation. Patients were divided into 3 groups according to mean post-transplantation CRP levels: group 1 (CRP >20 mg/L and fluctuating levels; n = 34), group 2 (CRP, 6-20 mg/L; n = 40), and group 3 (CRP <6 mg/L; n = 76). Arterial stiffness was measured by means of carotid femoral pulse-wave velocity (PWv) by use of the SphygmoCor system.

RESULTS

Patients in group 1 had significantly lower estimated glomerular filtration rate (eGFR) (P = .000) and left ventricular systolic function and higher duration of dialysis before transplantation, pulse-wave velocity (PWv), proteinuria, and left ventricular mass index when compared with the other two groups. In regression analysis, eGFR and PWv were detected as the predictors of post-transplantation CRP levels.

CONCLUSIONS

Fluctuating and high stable (>20 mg/L) post-transplant CRP levels predict eGFR, proteinuria, left ventricular mass index, and PWv after transplantation. Thus, CRP levels may be a useful marker to anticipate graft survival and cardiovascular morbidity in renal transplant recipients.

Pretransplant malnutrition, inflammation, and atherosclerosis affect cardiovascular outcomes after kidney transplantation

Background

Malnutrition, inflammation, and atherosclerosis (MIA) syndrome is associated with a high mortality rate in patients with end-stage renal disease. However, the clinical relevance of MIA syndrome in kidney transplantation (KT) recipients remains unknown.

Methods

We enrolled 1348 adult KT recipients. Recipients were assessed based on serum albumin, cholesterol, or body mass index for the malnutrition factor and C-reactive protein level for the inflammation factor. Any history of cardiovascular (CV), cerebrovascular, or peripheral vascular disease satisfied the atherosclerosis factor. Each MIA factors were assessed by univariate analysis and we calculated an overall risk score by summing up scores for each independent variable. The enrolled patients were divided into 4 groups depending on the MIA score (0, 2–4, 6, 8–10).

Results

The patients with higher MIA score showed worse outcome of fatal/non-fatal acute coronary syndrome (ACS) (p < 0.001) and composite outcomes of ACS and all-cause mortality (p < 0.001) than with the lower MIA score. In multivariate analysis, ACS showed significantly higher incidence in the MIA score 8-10 group than in the MIA score 0 group (Hazard ratio 6.12 95 % Confidence interval 1.84–20.32 p = 0.003).

Conclusions

The presence of MIA factors before KT is an independent predictor of post-transplant CV outcomes.

Serum adipokine and inflammatory markers before and after liver transplantation in recipients with major cardiovascular events

In the nontransplant setting, aberrant serum adipokine levels are associated with cardiovascular (CV) disease. The effects of liver transplantation (LT) on serum adipokine levels and their association with post-LT CV disease have not been studied. A nested case-control study of 77 patients with major CV events more than 4 months after LT analyzed serum adiponectin, resistin, leptin, C-reactive protein, and apolipoprotein levels measured before transplantation and 4, 12, and 24 months after LT. Adiponectin and resistin levels decreased dramatically after LT in all patients. Recipients with CV disease had lower levels of adiponectin and higher levels of resistin, leptin, C-reactive protein, and apolipoprotein B100 than controls. The pre-LT adiponectin level was associated with a 16% increased risk for CV events for every 1 μg/mL decrease in adiponectin [hazard ratio (HR) = 0.84, P = 0.046]. Pre-LT C-reactive protein levels (HR = 1.03, P = 0.047) and 12-month C-reactive protein levels (HR = 1.03, P = 0.03) were associated with CV events after LT. Pre-LT Diabetes (HR = 2.14, P = 0.09), and post-LT resistin (HR = 1.07, P = 0.07), and apolipoprotein B (HR = 1.08, P = 0.08) were associated with a nonsignificantly increased risk of CV events in this small sample size. In conclusion, pre- and post-LT changes in serum adipokine and inflammatory markers may be signals of an increased risk of CV events after LT, but further study is needed.

The impact of pretransplantation serum albumin levels on long-term renal graft outcomes

BACKGROUND

The association between pretransplantation serum albumin concentrations and renal graft outcomes is unclear. Hypoalbuminemia is a strong predictor of cardiovascular and all-cause mortality in chronic renal disease. Protein-energy wasting in dialysis patients is associated with irreversible damage and an increased risk of adverse outcomes. In this retrospective study, we investigated the association between preoperative albumin levels and short-term as well as long-term renal graft outcomes.

MATERIALS AND METHODS

We included 375 renal transplant recipients in our center between 1991 to 2011, who were grouped according to their preoperative serum albumin levels: group I (<3.5 g/dL), group II (3.5-3.9 g/dL), group III (4.0-4.4 g/dL), and group IV (≥ 4.5 g/dL). We measured the frequencies of delayed graft function (DGF), acute rejection episodes, and viral infections as well as the long-term graft outcomes.

RESULT

DGF affected 12.8%, 6.8%, 7.7%, and 9.3% of patients in groups I-IV, respectively. Acute rejection occurred in 27.7%, 27.2%, 31.6%, and 24.1%, while cytomegalovirus (CMV) and fungal infection occurred in 12.8% (6.4%), 23.3% (5.8%), 16.2% (2.6%), and 11.1% (5.6%) of patients, respectively. Serum creatinine levels at 12 months were not significantly different among the groups. Long-term graft survival was poorest in group I and best in group IV (P = .039). A Cox proportional hazards model showed group IV compared with group displayed the lowest relative risk of graft failure (hazard ratio [HR] = .536; P = .029).

CONCLUSIONS

Low pretransplantation serum albumin levels were associated with poor long-term graft outcomes and with more post-transplantation complications. It may be necessary to focus on improving patients' nutritional status prior to transplantation to ensure long-term renal graft survival.

Assessment of endothelial dysfunction: the role of symmetrical dimethylarginine and proinflammatory markers in chronic kidney disease and renal transplant recipients

OBJECTIVES

The study was designed to evaluate associations between symmetric dimethylarginine (SDMA), inflammation, and superoxide anion (O2∙-) with endothelial function and to determine their potential for screening of endothelial dysfunction in patients with chronic kidney disease (CKD) and renal transplant (RT) recipients.

MATERIALS AND METHODS

We included 64 CKD and 52 RT patients. Patients were stratified according to brachial artery flow-mediated dilation (FMD).

RESULTS

Logistic regression analysis showed that high SDMA and high sensitive C-reactive protein (hs-CRP) were associated with impaired FMD in CKD and RT patients, after adjustment for glomerular filtration rate. The ability of inflammation, SDMA, and O2∙- to detect impaired FMD was investigated by receiving operative characteristic analysis. Hs-CRP (area under the curves (AUC) = 0.754, P < 0.001), IL-6 (AUC = 0.699, P = 0.002), and SDMA (AUC = 0.689, P = 0.007) had the highest ability to detect impaired FMD. SDMA in combination with inflammatory parameters and/or O2∙- had better screening performance than SDMA alone.

CONCLUSIONS

Our results indicate a strong predictable association between hs-CRP, SDMA, and endothelial dysfunction in CKD patients and RT recipients. The individual marker that showed the strongest discriminative ability for endothelial dysfunction is hs-CRP, but its usefulness as a discriminatory marker for efficient diagnosis of endothelial dysfunction should be examined in prospective studies.

Haemoglobin variability in the early post-transplant period: association with graft survival and mortality

AIM

Haemoglobin (Hb) variability is associated with poor survival in patients with chronic kidney disease. Association of Hb variability after kidney transplantation with patients' and graft survival has not been adequetly studied.

METHODS

This retrospective study used registry data to examine the association between Hb variability in the early post-transplant period (first 6 months) and graft survival after kidney transplantatin. Kaplan-Meier and Cox regression analyses were used for univariate and multivariate associations between mortality, death censored graft survival and the composite outcome of both, in 752 patients after kidney transplantation. Hb values were collected each month during the first 6 months after transplantation, and Hb variavility was calculated using the residual standard deviation method.

RESULTS

The highest quartile of Hb variability was associated with inferior graft and patients' survival in univariate (hazard ratio (HR) 2.18; 95% confidence interval (CI) 1.51 to 3.13; P < 0.001) and multivariate models (HR 1.5; 95% CI 1.029 to 2.18; P = 0.035). This association was mainly due to increased death censored graft failure in the high variability group (HR 2.75; 95% CI 1.73 to 4.38; P < 0.001) and (HR 1.67; 95% CI 1.023 to 2.74; P = 0.04) in the univariate and multivariate models, respectively. There was no association between Hb variability and the risk of death (HR 1.51; 95% CI 0.88 to 2.57; P = 0.132).

CONCLUSION

High Hb variability is independently associated with inferior graft survival in patients after kidney transplantation.

Predictive biomarkers of renal allograft failure

BACKGROUND

Survival of renal allografts is limited by chronic allograft deterioration resulting from processes that are difficult to detect in their early stages, when therapeutic interventions would be most effective. Predictive biomarkers from easily accessible specimens, such as blood or urine, might improve early diagnosis of smoldering graft-damaging processes and help with the identification of patients at particularly high risk of sustained injury, thereby helping to tailor therapy and appropriate follow-up screening.

OBJECTIVE

This article reviews recently investigated biomarkers for the prediction of renal allograft failure, outlines the new '-omic' technologies as a potential source for the identification of new predictive biomarkers and judges the practical value of predictive biomarkers at the present timepoint.

METHODS

A literature search was performed using the medical database PubMed. No general restrictions (e.g., year of publication) were applied, but the focus was set on more recently published articles.

CONCLUSION

Despite a large number of interesting studies, none of the investigated candidate biomarkers is robustly established for widespread clinical use or able to replace biopsies for graft assessment.

Aortic stiffness and central wave reflections predict outcome in renal transplant recipients

Although renal transplantation improves survival, cardiovascular morbidity and mortality remain significantly elevated compared with nonrenal populations. The negative impact of traditional, uremia-related, and transplantation-related risk factors in this process remains, however, largely unexplored. Surrogate markers such as aortic stiffness and central wave reflections may lead to more accurate cardiovascular risk stratification, but outcome data in renal transplant recipients are scarce. We aimed to establish the prognostic significance of these markers for fatal and nonfatal cardiovascular events in renal transplant recipients. Carotid-femoral pulse wave velocity, central augmentation pressure, and central augmentation index were measured in a cohort of 512 renal transplant recipients using the SphygmoCor system. After a mean follow-up of 5 years, 20 fatal and 75 nonfatal cardiovascular events were recorded. Using receiver operating characteristic curves, the area under the curve for predicting cardiovascular events was 0.718 (95% CI 0.659-0.776) for pulse wave velocity, 0.670 (95% CI 0.604-0.736) for central augmentation pressure, and 0.595 (95% CI 0.529-0.660) for central augmentation index. When we accounted for age, gender, and C-reactive protein in Cox-regression analysis, pulse wave velocity (hazard ratio: 1.349 per 1 SD increase; 95% CI 1.104-1.649; P=0.003) and central augmentation pressure (hazard ratio: 1.487 per 1 SD increase; 95% CI 1.219-1.814; P<0.001) remained independent predictors of outcome. Aortic stiffness and increased wave reflections are independent predictors of cardiovascular events in renal transplant recipients. As single parameter of wave reflection, central augmentation pressure was better than central augmentation index. Combined measurement of pulse wave velocity and central augmentation pressure may contribute to an accurate cardiovascular risk estimation in this heterogeneous population.

Associations of pretransplant serum albumin with post-transplant outcomes in kidney transplant recipients

The association between pretransplant serum albumin concentration and post-transplant outcomes in kidney transplant recipients is unclear. We hypothesized that in transplant-waitlisted hemodialysis patients, lower serum albumin concentrations are associated with worse post-transplant outcomes. Linking the 5-year patient data of a large dialysis organization (DaVita) to the Scientific Registry of Transplant Recipients, we identified 8961 hemodialysis patients who underwent first kidney transplantation. Mortality or graft failure and delayed graft function (DGF) risks were estimated by Cox regression (hazard ratio [HR]) and logistic regression (Odds ratio [OR]), respectively. Patients were 48 ± 13 years old and included 37% women and 27% diabetics. The higher pretransplant serum albumin was associated with lower mortality, graft failure and DGF risk even after multivariate adjustment for case-mix, malnutrition-inflammation complex and transplant related variable. Every 0.2 g/dL higher pretransplant serum albumin concentration was associated with 13% lower all-cause mortality (HR = 0.87 [95% confidence interval: 0.82-0.93]), 17% lower cardiovascular mortality (HR = 0.83[0.74-0.93]), 7% lower combined risk of death or graft failure (HR = 0.93[0.89-0.97]) and 4% lower DGF risk (OR = 0.96[0.93-0.99]). Hence, lower pretransplant serum albumin level is associated with worse post-transplant outcomes. Clinical trials to examine interventions to improve nutritional status in transplant-waitlisted hemodialysis patients and their impacts on post-transplant outcomes are indicated.

Incidence of cardiovascular events after kidney transplantation and cardiovascular risk scores: study protocol

Background

Cardiovascular disease (CVD) is the major cause of death after renal transplantation. Not only conventional CVD risk factors, but also transplant-specific risk factors can influence the development of CVD in kidney transplant recipients.

The main objective of this study will be to determine the incidence of post-transplant CVD after renal transplantation and related factors. A secondary objective will be to examine the ability of standard cardiovascular risk scores (Framingham, Regicor, SCORE, and DORICA) to predict post-transplantation cardiovascular events in renal transplant recipients, and to develop a new score for predicting the risk of CVD after kidney transplantation.

Methods/Design

Observational prospective cohort study of all kidney transplant recipients in the A Coruña Hospital (Spain) in the period 1981-2008 (2059 transplants corresponding to 1794 patients).

The variables included will be: donor and recipient characteristics, chronic kidney disease-related risk factors, pre-transplant and post-transplant cardiovascular risk factors, routine biochemistry, and immunosuppressive, antihypertensive and lipid-lowering treatment. The events studied in the follow-up will be: patient and graft survival, acute rejection episodes and cardiovascular events (myocardial infarction, invasive coronary artery therapy, cerebral vascular events, new-onset angina, congestive heart failure, rhythm disturbances and peripheral vascular disease).

Four cardiovascular risk scores were calculated at the time of transplantation: the Framingham score, the European Systematic Coronary Risk Evaluation (SCORE) equation, and the REGICOR (Registre Gironí del COR (Gerona Heart Registry)), and DORICA (Dyslipidemia, Obesity, and Cardiovascular Risk) functions.

The cumulative incidence of cardiovascular events will be analyzed by competing risk survival methods. The clinical relevance of different variables will be calculated using the ARR (Absolute Risk Reduction), RRR (Relative Risk Reduction) and NNT (Number Needed to Treat).

The ability of different cardiovascular risk scores to predict cardiovascular events will be analyzed by using the c index and the area under ROC curves. Based on the competing risks analysis, a nomogram to predict the probability of cardiovascular events after kidney transplantation will be developed.

Discussion

This study will make it possible to determine the post-transplant incidence of cardiovascular events in a large cohort of renal transplant recipients in Spain, to confirm the relationship between traditional and transplant-specific cardiovascular risk factors and CVD, and to develop a score to predict the risk of CVD in these patients.

Macrophage activation is associated with poorer long-term outcomes in renal transplant patients

Long-term graft and patient survival after renal transplantation are largely determined by progression of chronic allograft dysfunction and cardiovascular disease. Inflammation plays a crucial role in both disease processes. We prospectively analyzed the association of early peri-transplant inflammatory burden on long-term outcomes in 144 consecutive deceased donor renal allograft recipients. Single time point and cumulative levels of markers of acute phase response (serum amyloid A [SAA] and C-reactive protein [SCRP]) and macrophage activation (serum and urine neopterin) were measured daily during the immediate post-operative period. Mean patient follow-up was 16 yr. Graft and patient survival rates at one-, five-, and 10-yr were 90%, 70%, and 51%, and 97%, 77%, and 59%, respectively. Graft loss occurred in 90 patients, of whom 71 died with a functioning graft and 19 returned to dialysis. CRP, SAA and neopterin (NEOP) levels were all elevated post-operatively. High levels of NEOP, in contrast to SAA or SCRP, were associated with poorer graft and patient survival (p < 0.05), specifically with death from cardiovascular events and cytomegalovirus IgG positivity. These findings strongly suggest that early post-transplant macrophage activation, as reflected by NEOP levels, is associated with poorer long-term graft and patient survival.

Primary care of the renal transplant patient

There has been a remarkable rise in the number of kidney transplant recipients (KTR) in the US over the last decade. Increasing use of potent immunosuppressants, which are also potentially diabetogenic and atherogenic, can result in worsening of pre-existing medical conditions as well as development of post-transplant disease. This, coupled with improving long-term survival, is putting tremendous pressure on transplant centers that were not designed to deliver primary care to KTR. Thus, increasing numbers of KTR will present to their primary care physicians (PCP) post-transplant for routine medical care. Similar to native chronic kidney disease patients, KTRs are vulnerable to cardiovascular disease as well as a host of other problems including bone disease, infections and malignancies. Deaths related to complications of cardiovascular disease and malignancies account for 60-65% of long-term mortality among KTRs. Guidelines from the National Kidney Foundation and the European Best Practice Guidelines Expert Group on the management of hypertension, dyslipidemia, smoking, diabetes and bone disease should be incorporated into the long-term care plan of the KTR to improve outcomes. A number of transplant centers do not supply PCPs with protocols and guidelines, making the task of the PCP more difficult. Despite this, PCPs are expected to continue to provide general preventive medicine, vaccinations and management of chronic medical problems. In this narrative review, we examine the common medical problems seen in KTR from the PCP's perspective. Medical management issues related to immunosuppressive medications are also briefly discussed.

Inflammation, coronary artery calcification and cardiovascular events in incident renal transplant recipients

OBJECTIVE

Coronary artery calcification (CAC) predicts cardiovascular events in the general population. We conducted a prospective study to determine if inflammatory markers were predictive of CAC and if CAC predicted cardiovascular events and mortality in incident renal transplant recipients.

METHODS

A prospective cohort of 112 asymptomatic incident renal transplant recipients who had no prior history of coronary artery revascularization or myocardial infarction had coronary calcifications measured early post-transplant and at least 18 months later by Agatston score and volume method.

RESULTS

The mean CAC score was 367.7 (682.3). Inflammatory markers such as WBC and CRP were predictive of CAC severity. Recipients with cardiovascular events (n=11) or death (n=12) during the follow-up period had higher mean [675.1 (669.3) vs. 296.8 (669.0), p=0.02] and median [434.8 vs. 28.9, p=0.01] CAC score compared to those without them. Recipients with CAC score less than 100 had a better cumulative survival rate compared to the recipients with CAC score greater than 100 [95.1% vs. 82.3%, p=0.03]. We found a significant unadjusted and adjusted association between CAC score and cardiovascular events and mortality. A quarter (25.9%) of recipients had CAC progression. Coronary calcification progression also predicted cardiovascular events and mortality after adjustment for diabetes and dialysis vintage.

CONCLUSION

CAC is prevalent in renal recipients and is predictive of cardiovascular events and mortality. Coronary calcification progression is common and predict clinical outcomes. Inflammatory markers are predictive of CAC severity at time of transplant, but are not predictive of future cardiovascular event or mortality.

Inflammation in renal transplantation

BACKGROUND AND OBJECTIVES

Renal transplant recipients experience premature cardiovascular disease and death. The association of inflammation, all-cause mortality, and cardiovascular events in renal transplant recipients has not been examined in a large prospective controlled trial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

ALERT was a randomized, double-blind, placebo-controlled study of the effect of fluvastatin on cardiovascular and renal outcomes in 2102 renal transplant recipients. Patients initially randomized to fluvastatin or placebo in the 5- to 6-yr trial were offered open-label fluvastatin in a 2-yr extension to the original study. The association between inflammation markers, high-sensitivity C-reactive protein (hsCRP), and IL-6 on cardiovascular events and all-cause mortality was investigated.

RESULTS

The baseline IL-6 value was 2.9 +/- 1.9 pg/ml (n = 1751) and that of hsCRP was 3.8 +/- 6.7 mg/L (n = 1910). After adjustment for baseline values for established risk factors, the hazard ratios for a major cardiac event and all-cause mortality for IL-6 were 1.08 [95% confidence interval (CI), 1.01 to 1.15, P = 0.018] and 1.11 (95% CI, 1.05 to 1.18, P < 0.001), respectively. The adjusted hazard ratio for hsCRP for a cardiovascular event was 1.10 (95% CI, 1.01 to 1.20, P = 0.027) and for all-cause mortality was 1.15 (95% CI, 1.06 to 1.1.25, P = 0.049).

CONCLUSIONS

The inflammation markers IL-6 and hsCRP are independently associated with major cardiovascular events and all-cause mortality in renal transplant recipients.

Predictive role of pretransplant serum CXCL10 for cardiac acute rejection

BACKGROUND

The detection of acute rejection in heart transplantation remains an important feature of transplant management, especially in the early phase. Frequent surveillance with endomyocardial biopsy is necessary, even though it is an invasive procedure and carries a certain risk. Hence, noninvasive biomarkers able to predict acute rejection could be a further helpful tool in patient management. The interferon-gamma-inducible chemokine CXCL10 is required for initiation and development of graft failure caused by acute or chronic rejection. It has been reported that CXCL10 serum level is predictive of graft loss in kidney graft recipients. In the present study, we investigated whether pretransplant CXCL10 serum level may be a predictive noninvasive biomarker in heart transplant (HTx) recipients, as well.

METHODS

Sera from 143 patients undergoing orthotopic heart transplantation were collected before surgery and tested for CXCL10 and CCL22 and compared with serum samples from healthy subjects.

RESULTS

We found that basal CXCL10 serum levels in HTx recipients were significantly higher than in healthy subjects, whereas no difference was seen in CCL22 levels. Among HTx recipients, CXCL10 serum levels of rejectors were significantly higher than in nonrejectors. Our results showed that CXCL10 was a significant independent risk factor of several variables and had the highest predictive value for early acute heart rejection, with 160 pg/mL cutoff value.

CONCLUSIONS

In HTx recipients, measurement of pretransplant CXCL10 serum levels could be a clinically useful tool for predicting cardiac acute rejection, especially in the early posttransplant period.

Serum C-reactive protein surge in renal transplant recipients: link with allograft survival

The restoration of kidney function by transplantation improves the common finding of chronic inflammation in patients with end-stage renal disease (ESRD). The C-reactive protein (CRP) level is a reliable marker of inflammation in renal transplant recipients. We analyzed the predictive value of posttransplant CRP surges on renal allograft survival among 141 ESRD patients who underwent renal transplantation between May 1999 and September 2001 at our institution. Twenty-seven cadaveric and 114 living donors were also studied. The subjects' demographic, clinical, and laboratory data were recorded. The renal transplant recipients were divided into three groups defined by the type of serum CRP surge: a normal, intermittently high, or consistently high serum CRP concentration. Renal allograft survival rates were 90.0% among recipients with normal serum CRP concentrations, 72.6% among those with intermittently high concentrations, and 11.1% in those with consistently high concentrations. A Cox regression analysis of factors that affect allograft survival showed that acute rejection, advanced recipient age, and consistently high serum CRP concentrations were associated with a high risk of renal allograft loss. Intermittent elevations in the serum CRP level were not associated with an increased risk of allograft loss, according to the Cox regression model. We concluded that consistently high serum CRP concentrations in renal allograft recipients showed a high negative predictive value for renal allograft survival. In recipients who exhibited ongoing inflammatory process in the 5-year posttransplant period, additional efforts are necessary to manage inflammation and therefore prolong renal allograft survival.

A J-shaped association between high-sensitivity C-reactive protein and mortality in kidney transplant recipients

In kidney transplant recipients (KTR), C-reactive protein (CRP) has been shown to be associated with increased mortality, but data on this association within the high-sensitivity (hs) range of CRP (<5 mg/l) are lacking. We prospectively studied 710 prevalent and stable KTR over >6 years. We thawed frozen plasma and measured baseline hs-CRP using an ultrasensitive assay. Detailed clinical and demographic baseline characteristics were available for study. We stratified patients by quartile of hs-CRP within the hs range (<5 mg/l), and also included KTRs whose hs-CRP was above the hs range (>5-10 and >10 mg/l). We used multivariate proportional hazards models to test for independent associations. After careful multivariate adjustment, we found a J-shaped association between hs-CRP and mortality. Compared with KTR whose hs-CRP was in the second lowest quartile of hs-CRP (0.06-1.26 mg/l), patients in the lowest quartile (<0.06 mg/l) had more than twice their mortality risk (HR = 2.07; 95% CI: 1.05-4.07), as did patients whose hs-CRP was > or =2.44 mg/l (all HRs >2.27). No association was found between hs-CRP and death-censored allograft loss. In contrast to the general population, the association between hs-CRP and mortality in KTRs is not linear, but J-shaped, suggesting that KTRs with very low hs-CRP may also be at increased risk of death.

How to Decrease Cardiovascular Mortality in Renal Transplant Recipients

Cardiovascular disease is the leading cause of death following renal transplantation, accounting for 40% to 55% of all deaths. An analysis in our center showed a 15% mortality in a cohort of renal transplant recipients followed for an average of 10 years. Various contributing risk factors of cardiovascular diseases in transplant recipients such as tobacco use, hypertension, hyperlipidemia, hereditary risk, diabetes, physical inactivity, obesity, dialysis duration, hyperuricemia, proteinuria, hyperhomocysteinemia, hyperparathyroidism, anemia; C-reactive protein level, and immunosuppressive regimen as well as some rare risk factors, such as cytomegalovirus infection, were evaluated in a population of 1200 kidney transplant recipients. Also we introduced methods for early detection, monitoring, and follow-up of proven risk factors of cardiovascular disease.

Cardiovascular complications after renal transplantation and their prevention

By the time of renal transplantation, end-stage renal disease patients have a huge burden of cardiovascular disease (CVD) and are heavily saturated with atherosclerotic risk factors. Worsening of preexisting risk factors or new CVD risk factors may develop in the posttransplant period consequent in part to the diabetogenic and atherogenic potential of immunosuppressive drugs. The annual risk of a fatal or non-fatal CVD event of 3.5 to 5% in kidney transplant recipients is 50-fold higher than the general population. Renal allograft dysfunction, proteinuria, anemia, moderate hyperhomocysteinemia and elevated serum C-reactive protein concentrations, each dependently confer greater risk of CVD morbidity and mortality in the posttransplant period. Long-term care of renal transplant recipients should programmatically incorporate the recommendations of the National Kidney Foundation Working Groups and European Best Practice Guidelines Expert Group on Renal Transplantations into the management of hypertension, dyslipidemia, smoking, and posttransplant diabetes mellitus. Timely utilization of coronary revascularization procedures should be undertaken as these treatments are equally effective in the kidney transplant population.

Cardiovascular Biomarkers in CKD: Pathophysiology and Implications for Clinical Management of Cardiac Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with all forms of chronic kidney disease (CKD). The underlying pathological state is caused by a complex interplay of traditional and nontraditional risk factors that results in atherosclerosis, arteriosclerosis, and altered cardiac morphological characteristics. This multifactorial disease introduces new challenges in predicting and treating patients with CVD sufficiently early in the course of CKD to positively alter patient outcome. Asymptomatic individuals with progressive CVD are a group of patients that deserve focused attention because early detection and intervention may provide the best opportunity for improved outcome. However, identifying CVD in asymptomatic patients with CKD or end-stage renal disease remains a significant hurdle in the management of these patients. Recently, a number of cardiovascular biomarkers were identified as predictors of patient outcome in individuals with CVD and, with additional research, may be used to guide the early diagnosis of and therapy for CVD in patients with CKD. This review examines the pathophysiological characteristics and potential clinical role of these novel cardiovascular biomarkers in risk stratification, risk monitoring, and selection of preventive therapies for patients with CKD.

Early posttransplant serum osteoprotegerin levels predict long-term (8-year) patient survival and cardiovascular death in renal transplant patients

The primary objectives of this analysis were to examine the effects of early posttransplantation (10 wk) serum levels of osteoprotegerin (OPG), mannose-binding lectin (MBL), and MBL-associated serine proteases (MASP; MASP-2 and MASP-3) on long-term (8-yr) patient survival, graft survival, and cardiovascular (CV) death. During a period of 16 mo (1995 to 1996), a total of 173 consecutive renal transplant recipients without diabetes before transplantation were included in a prospective study that was designed to address the impact of metabolic CV risk factors on survival and CV end points. Baseline sera from 172 patients were available for analysis. Follow-up data until January 1, 2004, were obtained from a national renal registry. Patients with high (fourth quartile) serum levels of OPG had significantly higher all-cause mortality (hazard ratio [HR] 6.3; 95% confidence interval [CI] 3.3 to 11.8; P<0.001) and CV death (HR 10.8; 95% CI 3.8 to 30.4; P<0.001) than patients with lower OPG concentrations. After multiple Cox regression analysis, high serum levels of OPG remained an independent predictor of all-cause mortality (HR 6.0; 95% CI 3.1 to 11.6, P<0.001) and CV death (HR 8.2; 95% CI 2.5 to 26.4; P<0.001). Multiple linear regression analysis revealed that age, creatinine clearance, and high-sensitivity C-reactive protein all were independently associated with OPG (R2=0.42). No significant association between OPG and death-censored graft loss was revealed. Serum levels of MBL, MASP-2, and MASP-3 were not significantly associated with patient survival, CV death, or graft loss. Early measured posttransplantation serum OPG is a highly significant independent predictor of death from any cause or CV death in white renal transplant recipients.

What does minor elevation of C-reactive protein signify?

Reports of the predictive value of minor elevation of serum C-reactive protein (CRP) levels (between 3 and 10 mg/L) for atherosclerotic events have generated considerable interest, as well as a degree of controversy and confusion. CRP concentrations in this range are found in about one third of the American population. To better understand the mechanisms underlying minor elevation of CRP, we have surveyed its reported associations with a variety of states and conditions. It has become clear that even minimal environmental irritants and inflammatory stimuli elicit a minor CRP response. Minor CRP elevation has been found associated with a number of genetic polymorphisms, with membership in different demographic and socioeconomic groups, with a variety of dietary patterns and with many medical conditions that are not apparently inflammatory. Finally, minor CRP elevation bears negative prognostic implications for many conditions, particularly age-related diseases, and predicts mortality in both diseased and apparently healthy individuals. In sum, minor CRP elevation is associated with a great many diverse conditions, some of which are, or may prove to be, causal. Many of these reported associations imply a mild degree of tissue stress or injury, suggesting the hypothesis that the presence of distressed cells, rather than a resulting inflammatory response, is commonly the stimulus for CRP production.

Pretransplant Pregnancy-Associated Plasma Protein-A as a Predictor of Chronic Allograft Nephropathy and Posttransplant Cardiovascular Events

BACKGROUND

Cardiovascular disease and chronic allograft nephropathy (CAN) are two of the main complications observed in patients after renal transplantation. Both appear to be manifestations of the same process, in which inflammation plays a determinate role. Pregnancy-associated plasma protein A (PAPP-A) has been shown to be a marker of acute coronary syndrome and cardiovascular pathology. The objective of this study was to demonstrate whether or not serum concentration of pretransplant PAPP-A is a marker of CAN and a predictor of posttransplant cardiovascular events.

METHODS

In all, 178 renal transplants (65% males; 53+/-12 years of age) followed up over the course of 49.3+/-33.6 months were used in this study. During the follow-up period, 19 patients developed CAN (diagnosed by renal biopsy) and 27 patients had a cardiovascular event. Previous to transplantation, the following were determined: ultrasensitive C-reactive protein (CRP) (nephelometry); interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) (immunofluorimetric automatized method), and ultrasensitive PAPP-A (ELISA).

RESULTS

A positive correlation was found between PAPP-A and the inflammatory markers (PAPP-A vs. CRP, r=0.218; P=0.004; PAPP-A vs. IL-6, r=0.235; P<0.001; PAPP-A vs. TNF-alpha, r=0.372; P<0.001). The multiple regression analysis showed PAPP-A (relative risk [RR]: 6.4; 95% confidence interval [CI]:1.24-33.11; P=0.027) and CRP (RR: 6.05; 95% CI:1.21-29.74; P=0.028) to be predictors of posttransplant cardiovascular events and PAPP-A (RR: 4.27; 95% CI: 1.03-17.60; P=0.044) and TNF-alpha (RR: 5.6; 95% CI: 1.43-21.83; P=0.013) to be predictors of CAN.

CONCLUSIONS

PAPP-A correlated with the inflammatory markers studied (CRP, IL-6 and TNF-alpha). Pretransplant serum concentration of PAPP-A is a predictor of posttransplant cardiovascular events and CAN.

C-reactive protein and albumin as predictors of all-cause and cardiovascular mortality in chronic kidney disease

BACKGROUND

High C-reactive protein (CRP) and hypoalbuminemia are associated with increased risk of mortality in patients with kidney failure. There are limited data evaluating the relationships between CRP, albumin, and outcomes in chronic kidney disease (CKD) stages 3 and 4.

METHODS

The Modification of Diet in Renal Disease (MDRD) Study was a randomized controlled trial conducted between 1989 and 1993. CRP was measured in frozen samples taken at baseline. Survival status and cause of death, up to December 31, 2000, were obtained from the National Death Index. Multivariable Cox models were used to examine the relationship of CRP [stratified into high CRP > or =3.0 mg/L (N= 414) versus low CRP<3.0 mg/L (N= 283)], and serum albumin, with all-cause and cardiovascular mortality.

RESULTS

Median follow-up time was 125 months, all-cause mortality was 20% (N= 138) and cardiovascular mortality was 10% (N= 71). In multivariable analyses adjusting for demographic, cardiovascular and kidney disease factors, both high CRP (HR, 95% CI = 1.56, 1.07-2.29) and serum albumin (HR = 0.94 per 0.1 g/dL increase, 95% CI = 0.89-0.99) were independent predictors of all-cause mortality. High CRP (HR 1.94, 95% CI 1.13-3.31), but not serum albumin (HR 0.94, 95% CI 0.87-1.02), was an independent predictor of cardiovascular mortality.

CONCLUSION

Both high CRP and low albumin, measured in CKD stages 3 and 4, are independent risk factors for all-cause mortality. High CRP, but not serum albumin, is a risk factor for cardiovascular mortality. These results suggest that high CRP and hypoalbuminemia provide prognostic information independent of each other in CKD.

Predictive value of pretransplant inflammatory markers in renal allograft survival and rejection in children

Pretransplant (pre-Tx) inflammation has been associated with acute rejection (AR) in adult Tx recipients. Our study was performed to determine whether a single pre-Tx serum C-reactive protein (CRP), Neopterin (Neo), and IL-12 determination could predict outcome in pediatric renal Tx recipients. Pre-Tx sera from 51 children transplanted between 1985 and 2000 were analyzed for serum CRP, Neo, and IL-12 for correlation with Tx-related variables. Endpoints were graft loss and AR. Kaplan-Meier and log-rank statistics were used to compare rejection-free and overall graft survival at different quartiles for each marker. Cox regression analysis was performed to determine the independent effects of various pre-Tx variables on the endpoints. The mean age of the children at Tx was 11 years. The mean CRP, Neo, and IL-12 were 1.3 mg/L, 1.78 ng/mL and 123 pg/mL, respectively. At last-follow-up (mean 4.9 years after Tx), 50% of the children had experienced AR and 29% had lost their grafts. The mean CRP, Neo, and IL-12 were not different between the patients with versus without AR or graft loss (P > .4 for all). Neither rejection-free survival nor graft survival was affected by CRP, Neo, or IL-12 quartiles (log-rank test). Cox regression analysis demonstrated no predictive value of any marker on the outcomes. Unlike adults, a single pre-Tx determination of inflammatory markers was not predictive of AR or graft loss in children. The pathogenesis of AR may be different in children with a lesser contribution of alloantigen-independent factors such as chronic infections.

Assessment of pretransplant inflammation in pediatric renal allograft recipients

Pretransplant (Tx) inflammation is linked to adverse outcomes in adult Tx recipients but no such data exist for children. Our study evaluated the predictive value of three pre-Tx inflammatory markers: serum C-reactive protein (CRP), Neopterin (Neo) and interleukin (IL) 12, in determining outcome. Pre-Tx serum on 51 children (mean age 11 years) transplanted between 1985 and 2000 was analyzed. Data on other variables were abstracted from patient records. Primary end-points were graft survival and acute rejection (AR). Kaplan-Meier and log-rank statistics compared endpoints in patients at different quartiles for each marker. Cox regression analysis was used to determine the independent effect of the markers on the end-points. The mean CRP, Neo, and IL-12 were 1.3 mg/l, 1.78 ng/ml, and 123 pg/ml, respectively. The mean CRP, Neo, and IL-12 were not different between the patients with and without AR or graft loss (P > 0.4 for all). Neither rejection-free survival nor graft survival was affected by CRP, Neo, or IL-12 quartiles. Cox-regression analysis demonstrated no predictive value of any marker on outcome. Unlike adults, a single pre-Tx determination of inflammatory markers was not predictive of AR or graft loss in children, indicating that the pathogenesis of AR may be different in children.

Hypertension in Kidney Transplantation

Arterial hypertension in renal transplant patients plays a major role in the progression to chronic allograft failure, and in morbidity and mortality associated with cardiovascular disease. Its cause is diverse, with contributions not only from donor and/or recipient factors, but it also is influenced strongly by the type of immunosuppressive regimen. Despite increased awareness of the adverse effects of hypertension in both graft and patient survival, long-term studies have shown that arterial hypertension in the transplant population has not been controlled adequately. Ambulatory blood pressure measurements provide the advantage of a better assessment of the diurnal blood pressure variation, a predictor of target organ damage and cardiovascular morbidity and mortality events. Although the available data do not support the recommendation of any class of antihypertensive medication as preferred agents for blood pressure management in the transplant population, angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers have shown beneficial effects beyond their antihypertensive effects. Clinical data in transplant recipients are emerging that suggest that applying interventions proven to be effective in reducing cardiovascular morbidity and mortality in the general population may be effective for the transplant population.

Incidence and predictors of myocardial infarction after kidney transplantation

The risk and predictors of post-kidney transplantation myocardial infarction (PTMI) are not well described. Registry data collected by the United States Renal Data System were used to investigate retrospectively PTMI among adult first renal allograft recipients who received a transplant in 1995 to 2000 and had Medicare as the primary payer. PTMI events were ascertained from billing and death records, and participants were followed for up to 3 yr after transplant or until the end of observation (December 31, 2000). Extended Cox's hazards analysis was used to identify independent clinical correlates of PTMI (hazard ratio [HR]) and to examine PTMI as an outcomes predictor. Among 35,847 eligible participants, the cumulative incidence of PTMI was 4.3% (95% confidence interval [CI], 4.1 to 4.5%), 5.6% (95% CI, 5.3 to 5.8%), and 11.1% (95% CI, 10.7 to 11.5%) at 6, 12, and 36 mo, respectively. Risk factors for PTMI included older recipient age, pretransplantation comorbidities (diabetes, angina, peripheral vascular disease, and MI), transplantation from older donors and deceased donors, and delayed graft function. Women, blacks, Hispanics, and employed recipients experienced reduced risk. The hazard of PTMI rose after a diagnosis of posttransplantation diabetes (HR, 1.60; 95% CI, 1.35 to 1.88) and markedly increased after graft failure (HR, 2.78; 95% CI, 2.41 to 3.19). In separate analyses, PTMI predicted death-censored graft failure (HR, 1.89; 95% CI, 1.63 to 2.20) and strongly predicted death in a manner that declined with time after PTMI. Risk factors for PTMI include potentially modifiable posttransplantation complications. Because PTMI in turn predicts graft failure and death, reducing the risk for PTMI may improve outcomes after kidney transplantation.

High pretransplant serum levels of CXCL10/IP-10 are related to increased risk of renal allograft failure

In experimental models, the chemokine CXCL10/IP-10 is required for graft failure owing to both acute and chronic rejection. In the present study, pretransplantation sera from 316 cadaver kidney graft recipients were tested for serum CXCL10 and CCL22/MDC levels by an ELISA assay. Kidney graft recipients with normally functioning grafts showed significantly lower serum CXCL10 levels than patients who experienced graft failure, whereas no differences for serum CCL22 levels were observed. After the assignment of all patients to four groups according to serum CXCL10 levels, the death-censored survival rates of grafts were 97.5%, 93.6%, 89.7%, 78.7% (p = 0.0006) at 5 years, while no influence was observed on patient survival. Accordingly, patients with the highest CXCL10 levels showed an increased frequency and severity of rejection episodes. Serum C-reactive protein (CRP) level was also assayed in the same samples. Increase of serum CRP levels represented a predictive parameter for death, but not for graft failure. Multivariate analysis demonstrated that among the analyzed variables, CXCL10 had the highest predictive power of graft loss (RR 2.787). Thus, measurement of pretransplant serum CXCL10 levels might represent a clinically useful parameter to identify subjects who are at high risk of severe rejection and graft failure.