The renin angiotensin system blockade in kidney transplantation: pros and cons

Cardiorenal Protection: Potential of SGLT2 Inhibitors and GLP-1 Receptor Agonists in the Treatment of Type 2 Diabetes

Recent large clinical trials on sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists, with the aim of verifying cardiovascular safety, have revealed that these medications have a preventative advantage on adverse cardiovascular outcomes, including worsening of heart failure and deterioration of nephropathy, in patients with type 2 diabetes (T2D). These observed benefits do not seem to correlate with the glucose-lowering effect, and the underlying mechanism is being intensively investigated. Given the results from recent studies, the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) recommend that patients with T2D and clinical cardiovascular disease (CVD) with inadequate glucose control despite treatment with metformin should receive an SGLT2 inhibitor or GLP-1 receptor agonist. In this review we summarize the results of recent cardiovascular outcome trials and discuss the potential clinical advantage of SGLT2 inhibitors and GLP-1 receptor agonists. We also present practical implications of these glucose-lowering agents for reducing the risk of adverse cardiovascular events and progressive renal comorbidity in patients with T2D and CVD.

Possible beneficial association between renin-angiotensin-aldosterone-system blockade usage and graft prognosis in allograft IgA nephropathy: a retrospective cohort study

BACKGROUND

Although immunoglobulin A nephropathy (IgAN) is associated with an increased risk of renal allograft failure, evidences for its treatment, including renin-angiotensin-aldosterone system blockade (RAASB) usage, remain limited.

METHODS

In this bi-center retrospective cohort study, we included patients who were recently diagnosed with IgAN through allograft biopsies. We identified their 6-month antihypertensive medication prescriptions and investigated the association between the medication types, albuminuria changes, and risk of 5-year death-censored-graft-failure (DCGF). The mixed effect model and cox regression analysis were used.

RESULTS

A total of 464 allograft IgAN patients were included: 272, 38, 33, and 121 patients in the no antihypertensive medication, single agent RAASB, single agent beta blocker (BB)/calcium channel blocker (CCB), and combination therapy groups, respectively. High-degree albuminuria after 6 months of allograft IgAN diagnosis was an important prognostic parameter and a partial mediator for the association between the subgroups and 5-year DCGF. The usage of single RAASB was associated with decrement of albuminuria from allograft IgAN diagnosis (P for interaction = 0.03). The single BB/CCB group demonstrated significantly worse prognosis than the single RAASB group (adjusted hazard ratio, 2.76 [1.09-6.98]; P = 0.03).

CONCLUSIONS

In conclusion, RAASB may be beneficial for graft prognosis in early allograft IgAN patients who require single antihypertensive medication therapy, by means of reducing albuminuria. Further investigation of treatment strategy in allograft IgAN is warranted.

Influence of Renin-Angiotensin System Blockers on Graft Function in Retrospective Analysis of Pairs of Renal Transplant Recipients From the Same Donor

BACKGROUND

Renin-angiotensin system (RAS) blocking agents efficiently control hypertension in renal transplant recipients (RTRs), and reduce proteinuria and post-transplant erythrocytosis. A beneficial effect on the retardation of the long-term decline in renal function has not yet been demonstrated. The aim of the study was to evaluate the effects of RAS blockade on allograft function.

METHODS

In order to minimize donor variability and bias, 33 pairs of RTRs receiving grafts from the same donor were included into the retrospective analysis. A total of 66 RTRs were enrolled in which 1 patient from the pair used an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker for a minimum period of 60 months (RAS[+]) and the second one did not use it at all (RAS[-]).

RESULTS

There were no differences between RAS(+) and RAS(-) subjects in terms of age, body mass index, mismatches number, duration of total ischemia, episodes of cytomegalovirus infections, acute rejections, or immunosuppressive treatment. Significantly, more RAS(+) patients presented with diabetes and cardiovascular complications. Among RAS(+) patients, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers were used in 28 (84.84%) and 5 (15.15%) patients in a mean dose of 23.03 ± 16.83% and 30 ± 11.18% of their maximum doses, respectively. There were no significant differences in estimated glomerular filtration rate changes (-0.37 ± 12.68 vs 2.54 ± 20.76 mL/min) and serum creatinine changes (0.05 ± 0.39 vs 0.14 ± 0.79 mg/dL) between RAS(+) and RAS(-) patients during the 60 months follow-up.

CONCLUSION

Agents inhibiting the RAS did not significantly affect graft function in RTRs during 60 months of observation.

Renal Doppler Resistance Indices in Kidney Transplant Recipients With Proteinuria

BACKGROUND

The onset of proteinuria in renal transplant recipients may be associated with an increased risk of allograft failure. Little is known about the relationships between factors influencing proteinuria and the Doppler ultrasound (DU) intrarenal resistive index (RI) and pulsatility index (PI) among donor recipients with proteinuria <1000 mg/24 h.

METHODS

We assessed correlations between the DU RI and PI and protein content in 93 selected renal transplant recipients: 62 patients with proteinuria 100 to 299 mg/24 h, 16 patients with proteinuria 300 to 499 mg/24 h, and 15 patients with proteinuria 500 to 999 mg/24 h. All patients underwent transplantation in a single center and were monitored by DU for at least 28 months post-transplantation.

RESULTS

The DU RI values of the proteinuria 100 to 299 mg/24 h, 300 to 499 mg/24 h, and 500 to 999 mg/24 h groups were 0.67 ± 0.05; 0.65 ± 0.04, and 0.64 ± 0.07, respectively, and the PI values were 1.21 ± 0.20, 1.10 ± 0.14, and 1.15 ± 0.22, respectively. Multivariate logistic regression analysis revealed a correlation between group 100 to 299 mg/24 h and RI values, serum creatinine, living donor (R² = 19.6%, P = .05); group 300 to 499 mg/24 h and the RI, PI values, cadaver donor (R² = 17.5%, P = .001); and group 500 to 999 mg/24 h and the RI, PI values, serum creatinine, graft survival (R² = 15.4%, P = .005).

CONCLUSIONS

Among donor recipients with proteinuria <1000 mg/24 h, DU RI values were <0.72 and PI values were <1.41 and correlations were revealed between the incidence of proteinuria and factors such as the RI, PI, and serum creatinine level.

Current evidence on the use of anti-RAAS agents in congenital or acquired solitary kidney

RATIONAL

The inhibition of renin-angiotensin-aldosterone system (RAAS) is a major strategy for slowing the progression of chronic kidney disease (CKD). The utility of anti-RAAS agents in patients with congenital or acquired solitary kidney is still controversial.

OBJECTIVE

A systematic literature review was conducted.

MAIN FINDINGS

The conclusions of the few available studies on the topic are homogeneously in agreement with a long-term reno-protective activity of anti-RAAS drugs in patients with solitary kidney, especially if patients are hypertensive or proteinuric. However, angiotensin 2 (ANG2) levels permit a functional adaptation to a reduced renal mass in adults and is crucial for sustaining complete kidney development and maturation in children. A hormonal interference on ANG2 levels has been supposed in women. Consequently, at least in children and women, the use of ARBs appears more appropriate. Principle conclusions: Available data on this topic are limited; however, by their overall assessment, it would appear that anti-RAAS drugs might also be reno-protective in patients with solitary kidney. The use of ARBs, especially in children and in women, seems to be more appropriate. However, more experimental data would be strictly necessary to confirm this hypothesis.

A spotlight on the management of complications associated with myeloproliferative neoplasms: a clinician's perspective

INTRODUCTION

Myeloproliferative neoplasms (MPNs) are associated with a variety of symptoms and signs which cause major morbidity for the patients. The disorders are associated with increased incidence of thromboembolic and hemorrhagic events which can lead to complications and shortened life expectancy. Areas covered: Using systematic literature review and expert clinical and research experience the authors discuss strategies for the management of symptoms and signs including pruritus, fatigue, splenomegaly, and cytopenia. Cytoreduction including treatments to inhibit the JAK/STAT pathway are considered. Pathogenesis and prevention and treatment of thrombotic and hemorrhagic events and their management is addressed and the suggested management of the special situations such as surgery and pregnancy are discussed. Expert commentary: Management of disease has traditionally focused on symptom treatment and complication prevention but the discovery of driver mutations has led to treatments aiming to eliminate the clone, which should be the ultimate goal of therapy. A future challenge is to develop safe and effective MPN therapy and to personalize therapy.

Blood disorders typically associated with renal transplantation

Renal transplantation has become one of the most common surgical procedures performed to replace a diseased kidney with a healthy kidney from a donor. It can help patients with kidney failure live decades longer. However, renal transplantation also faces a risk of developing various blood disorders. The blood disorders typically associated with renal transplantation can be divided into two main categories: (1) Common disorders including post-transplant anemia (PTA), post-transplant lymphoproliferative disorder (PTLD), post-transplant erythrocytosis (PTE), and post-transplant cytopenias (PTC, leukopenia/neutropenia, thrombocytopenia, and pancytopenia); and (2) Uncommon but serious disorders including hemophagocytic syndrome (HPS), thrombotic microangiopathy (TMA), therapy-related myelodysplasia (t-MDS), and therapy-related acute myeloid leukemia (t-AML). Although many etiological factors involve the development of post-transplant blood disorders, immunosuppressive agents, and viral infections could be the two major contributors to most blood disorders and cause hematological abnormalities and immunodeficiency by suppressing hematopoietic function of bone marrow. Hematological abnormalities and immunodeficiency will result in severe clinical outcomes in renal transplant recipients. Understanding how blood disorders develop will help cure these life-threatening complications. A potential therapeutic strategy against post-transplant blood disorders should focus on tapering immunosuppression or replacing myelotoxic immunosuppressive drugs with lower toxic alternatives, recognizing and treating promptly the etiological virus, bacteria, or protozoan, restoring both hematopoietic function of bone marrow and normal blood counts, and improving kidney graft survival.

Cardiovascular death in kidney recipients treated with renin-angiotensin system blockers

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) are widely prescribed after kidney transplantation, but evidence for an improvement in outcomes is mixed. A recent trial demonstrated a significantly lower incidence of major cardiovascular events in ACEI-treated recipients.

METHODS

Collaborative Transplant Study data on cardiovascular death during years 2 to 10 after kidney transplantation in patients with a functioning graft were analyzed according to whether ACEI/ARB or other antihypertensive therapy (excluding diuretics) was administered at year 1.

RESULTS

Of 39,251 transplants analyzed, 15,250 (38.9%) received ACEI/ARB and 24,001 (61.1%) received other antihypertensive therapy at year 1 after transplantation. The mean duration of follow-up was 5.8 years. During years 2 to 10 after transplantation, cardiovascular death occurred in 918 patients (cumulative incidence=4.7%) with a functioning graft. The rate of cardiovascular death was similar in patients who received ACEI/ARB therapy or other antihypertensive treatment overall and in subpopulations of patients who were considered by the transplant center to be at an increased cardiovascular risk, had no pretransplant risk factors, were aged 60 years and older, were treated for diabetes at year 1, or had serum creatinine of 130 μmol/L or higher at year 1. Multivariable Cox regression analysis confirmed that treatment with ACEI/ARB did not confer a beneficial effect beyond that conferred by other antihypertensive treatments on the cumulative incidence of cardiovascular death during years 2 to 10 (hazard ratio=1.1, P=0.24).

CONCLUSIONS

This large-scale retrospective analysis of prospectively collected data shows that the rate of cardiovascular death in kidney transplant recipients receiving ACEI/ARB or other antihypertensive medications is virtually identical.

Sterile leukocyturia is associated with interstitial fibrosis and tubular atrophy in kidney allograft protocol biopsies

Kidney allograft interstitial fibrosis and tubular atrophy (IF/TA) is associated with a poorer renal function and outcome. In the current clinical practice, an early diagnosis can only be provided by invasive tests. We aimed to investigate the association of sterile leukocyturia with Banff criteria histological findings in kidney allograft protocol biopsies. We studied 348 allograft biopsies from two different European countries performed at 8.5 + 3.5 months after transplantation. In these cases, the presence of sterile leukocyturia (Leuc+, n = 70) or no leukocyturia (Leuc-, n = 278) was analyzed and related to Banff elementary lesions. Only IF/TA was significantly different between Leuc+ and Leuc- groups. IF/TA was present in 85.7% of Leuc+ and 27.7% of Leuc- patients (p < 0.001). IF/TA patients had higher serum creatinine and presence of proteinuria (p < 0.05). Independent predictors of IF/TA were donor age, donor male sex, serum creatinine and Leuc+ (hazard ratio 18.2; 95% confidence interval, 8.1-40.7). The positive predictive value of leukocyturia for predicting IF/TA was 85.7% whereas the negative predictive value was 72.3%. These studies suggest that leukocyturia is a noninvasive and low-cost test to identify IF/TA. An early diagnosis may allow timely interventional measures directed to minimize its impact and improve graft outcome.

Antihypertensive pharmacotherapy and long-term outcomes in pediatric kidney transplantation

Hypertension (HTN) is common in pediatric recipients following kidney transplantation (KT). We retrospectively assessed the impact of HTN on long-term (>10-yr) outcomes in pediatric KT recipients (aged < 18 yr) at our center. Two hundred and ninety-three pediatric KT recipients (83% living donor [LD]) with graft survival (GS) for ≥5 yr were studied. HTN was defined by antihypertensive medication use at five yr post-KT. One hundred and sixty (55%) recipients did not have HTN, and 133 (45%) had HTN at five yr post-KT. There were no differences in actuarial patient survival between cohorts. Actuarial GS at 15 and 20 yr was 68% and 53% for recipients without HTN, and 53% and 33% for recipients with HTN (p = 0.006). Among LD recipients using one antihypertensive, GS at 15 yr was 100% for those using an angiotensin-converting enzyme inhibitor (ACEI) and 44% for those not using an ACEI (p = 0.04). Among these recipients, HTN treated with no ACEI was a significant risk factor for graft failure at >5 yr (hazard ratio [HR] = 2.5, p = 0.02), but HTN treated with an ACEI was not (HR = 0.6, p = 0.7). HTN at five yr post-KT is associated with poorer long-term GS in pediatric recipients, but ACEI therapy may enable better outcomes and should be studied further.

Early association of low-grade albuminuria and allograft dysfunction predicts renal transplant outcomes

BACKGROUND

Data on the combined associations of albuminuria and estimated glomerular filtration rate (eGFR) with renal transplant outcomes are limited. Our objective was to explore how renal transplant outcomes could be predicted by a combined variable of early low-grade albuminuria and allograft dysfunction.

METHODS

We studied a cohort of adult deceased-donor kidney transplant recipients who were subdivided into four groups according to median albuminuria (100 mg/day, interquartile range, 0-470 mg/day) and median eGFR (60 mL/min/1.73 m(2); interquartile range, 30-73 mL/min/1.73 m(2)) at third month posttransplantation as follows: group I (albuminuria <100 and eGFR >60, n=238); group II (albuminuria ≥100 and eGFR >60, n=151); group III (albuminuria <100 and eGFR ≤60; n=167); and group IV (albuminuria ≥100 and eGFR ≤60, n=228).

RESULTS

Death-censored graft survival was significantly lower in group IV compared with the rest (P<0.0001). Multivariate Cox regression analysis using fixed and time-dependent covariates showed that the combination of low-grade albuminuria and lower eGFR was associated with graft failure (hazard ratio, 2.2, 95% confidence interval, 1.3-3.7; P=0.003). Likewise, but to a lesser extent, the risk of mortality was increased for group IV (hazard ratio, 1.7, 95% confidence interval, 1.01-2.8; P=0.042).

CONCLUSIONS

Early association of low-grade albuminuria and allograft dysfunction represents an important risk factor of graft failure and mortality. This additive effect should be considered to identify individuals at risk for adverse kidney transplantation outcomes.

Anemia in children with chronic kidney disease

Anemia is a common comorbidity in children with chronic kidney disease (CKD). This condition is associated with multiple adverse clinical consequences and its management is a core component of nephrology care. Increased morbidity and mortality, increased risk of cardiovascular disease and decreased quality of life have been associated with anemia of CKD in children. Although numerous complex factors interact in the development of this anemia, erythropoietin deficiency and iron dysregulation (including iron deficiency and iron-restricted erythropoiesis) are the primary causes. In addition to iron supplementation, erythropoietin-stimulating agents (ESAs) can effectively treat this anemia, but there are important differences in ESA dose requirements between children and adults. Also, hyporesponsiveness to ESA therapy is a common problem in children with CKD. Although escalating ESA doses to target increased hemoglobin values in adults has been associated with adverse outcomes, no studies have demonstrated this association in children. The question of appropriate target hemoglobin levels in children, and the approach by which to achieve these levels, remains under debate. Randomized, controlled studies are needed to evaluate whether normalization of hemoglobin concentrations is beneficial to children, and whether this practice is associated with increased risks.

Renin-angiotensin system dual blockade using angiotensin receptor plus aliskiren decreases severe proteinuria in kidney transplant recipients

BACKGROUND

Renin-angiotensin system (RAS) blockade has cardioprotective and renoprotective effects in the general population; however, whether dual blockade using angiotensin-receptor blockade (ARB) plus a renin inhibitor, aliskiren, can minimize severe proteinuria in kidney transplant recipients remains undetermined.

OBJECTIVE

To analyze the efficacy and safety of dual blockade of the RAS with an ARB and aliskiren in kidney transplant recipients with severe proteinuria and creatinine concentration 2.5 mg/dL or less.

PATIENTS AND METHODS

This prospective study included 16 patients (mean age 56 years; 10 men [62%] who had undergone cadaveric renal transplantation between 1992 and 2004. Immunosuppression therapy included a calcineurin inhibitor in 9 patients (56%) or mammalian target of rapamycin inhibitor in 7 (44%), and mycophenolate mofetil in 15 (94%). All received high-dose ARB II (1.0-3.5 g/24 h) because of marked proteinuria, with poor response. Accordingly, 11 patients also received aliskiren, and in 5 who were receiving an angiotensin-converting enzyme inhibitor, therapy was changed to aliskiren. Mean (range) follow-up was 11 (3-18) months.

RESULTS

At 3 months, proteinuria decreased by 40%, and at 6 months by 60%. In addition, mean blood pressure was decreased significantly. Renal function remained stable, as did the serum potassium concentration. A slight but significant decrease in hemoglobin concentration was observed, with no clinical repercussions.

CONCLUSIONS

Dual blockade of the RAS with ARB II plus aliskiren therapy demonstrated an additive effect to decrease severe proteinuria and blood pressure in kidney transplant recipients. Neither relevant adverse effects in renal function nor anemia or hyperkalemia were observed. These findings might contribute to prolonging long-term kidney graft survival.

Hypertension in kidney transplant recipients

Arterial hypertension is frequently observed in renal transplant recipients. Its pathogenesis is multifactorial in most cases. Calcineurin inhibitors (CNI) can increase peripheral vascular resistance by inducing arteriolar vasoconstriction and can cause extracellular fluid expansion by reducing the glomerular filtration rate (GFR), activating the renin-angiotensin system (RAS), and by inactivating the atrial natriuretic peptide. Glucocorticoids can impair urinary water and salt excretion. Poor graft function can lead to increased extracellular volume and inappropriate production of renin. Native kidneys, older age of the donor and transplant renal artery stenosis (TRAS) may also contribute to the development of hypertension. Arterial hypertension not only can increases the risk for cardiovascular events but can also deteriorate renal allograft function. A number of studies have shown that the higher the levels of blood pressure are, the higher is the risk of graft failure. On the other hand, a good control of blood pressure may prevent many cardiovascular and renal complications. Appropriate lifestyle modification is the first step for treating hypertension. Calcium channel blockers (CCB) and renin-angiotensin system (RAS) inhibitors are the most frequently used antihypertensive agents, but in many cases, a combination of these and other drugs is required to obtain good control of hypertension.

Factors related to the absence of anemia in hemodialysis patients

BACKGROUND

A small number of hemodialysis (HD) patients have normal hemoglobin (Hb) levels without the need for erythropoiesis-stimulating agents (ESAs). The factors associated with this condition have been little studied. The objective of this prospective study was to determine these factors in a prevalent population of HD patients.

MATERIALS AND METHODS

All patients who had normal Hb levels and who had not received ESAs in the last 6 months (non-ESA group) were included. Epidemiological and laboratory data were collected and we performed an abdominal ultrasound to assess hepatic and renal cysts. This group was compared to a control group of 205 prevalent HD patients on ESA therapy (control group).

RESULTS

We included 45 patients (16% from the whole group) in the non-ESA group. In this group, there was a higher proportion of men (76.5 vs. 61%), patients were younger (61.1 ± 14.7 vs. 67.5 ± 15.2 years), had a longer duration of renal replacement therapy (RRT) (9.4 ± 8.3 vs. 5.3 ± 5.8 years) and had a higher prevalence of adult polycystic kidney disease (APKD) and hepatitis C virus (HCV) liver disease (42.2 vs. 10.2%), p < 0.01. In the non-ESA group, HCV+ patients had a lower prevalence of APKD (2.2 vs. 38.4%) and hepatic cysts (2.2 vs. 19.2%), but significantly higher endogenous erythropoietin levels (55.8 ± 37.1 vs. 30.9 ± 38.4 mU/ml). No significant differences in anemia, iron metabolism, insulin, IGF-1 and renin were found between non-ESA and control groups. Non-ESA patients had a significantly higher number of renal (90.6 vs. 36.5%) and hepatic cysts (12.5 vs. 3.4%), and these were also larger in size (3.3 ± 2.4 vs. 1.5 ± 0.8 cm). In the multivariate Cox analysis, independent predictor factors for absence of anemia in HD patients were number of renal cysts >10 cysts (95% CI 1.058-1.405; p = 0.00), HCV+ liver disease (95% CI 1.147-1.511; p = 0.05) and time on RRT (95% CI 1.002-1.121; p = 0.05).

CONCLUSIONS

The absence of anemia in HD patients is not infrequent. Its frequency is higher in men and younger patients with long-term RRT, in patients with HCV+ liver disease and in APKD. It is associated with increased endogenous erythropoietin production and the presence of renal and hepatic cysts.

Early risk factors for persistent anemia after kidney transplantation

STUDY OBJECTIVE

To identify predictors of persistent posttransplant anemia that appear within the first week after kidney transplantation in order to determine the high-risk patients who might receive the most benefit from erythropoiesis-stimulating agents.

STUDY DESIGN

Retrospective cohort study.

SETTING

University-affiliated hospital and outpatient clinic.

PATIENTS

One hundred sixty-four adult kidney transplant recipients (January 1, 2002-June 30, 2007) with anemia on posttransplant day 7 who were followed at the clinic for at least 2 months after transplantation.

MEASUREMENTS AND MAIN RESULTS

Data from deidentified electronic medical records of the kidney transplant recipients were collected and included demographic characteristics, primary cause of renal failure, pertinent laboratory data, and donor information. To detect early predictors of persistent anemia, patients with persistent posttransplant anemia, defined as a hemoglobin level below 11 g/dl for 2 months (day 60) after transplantation, were compared with those who had nonpersistent posttransplant anemia, defined as a hemoglobin level below 11 g/dl on day 7 but 11 g/dl or greater on day 60. Of the 164 patients classified as having anemia on posttransplant day 7, 39 (23.8%) had persistent posttransplant anemia on day 60. In univariate analyses, hemoglobin level of 9 g/dl or below on day 7, donor age younger than 10 years, and female sex were variables associated with increased risk of persistent posttransplant anemia. In a multivariate analysis, donor age younger than 10 years was the most significant predictor of persistent posttransplant anemia, followed by hemoglobin level of 9 g/dl or below.

CONCLUSION

Patients receiving transplants from donors younger than 10 years and those with hemoglobin levels of 9 g/dl or below on postoperative day 7 were found to be at highest risk for persistent posttransplant anemia and may receive the most benefit from early initiation of erythropoiesis-stimulating agent therapy. In most of the kidney transplant recipients, posttransplant anemia resolved without the use of these agents.

Risk for anemia in pediatric chronic kidney disease patients: a report of NAPRTCS

Previous studies in children with chronic kidney disease (CKD) have identified low hemoglobin as a risk factor for poor outcomes. A retrospective review of the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS) CKD registry was performed to identify the prevalence of and risk factors for anemia among children with stage 3 CKD, including both patients with low hemoglobin and those whose hemoglobin normalized with an erythropoiesis-stimulating agent (ESA). At enrollment, 2,792 patients had stage 3 CKD. Mean age was 9.5 (+/-0.11) years, 62.1% were male, 61.3% were white, and 43.7% had structural/urologic disease. Among 1,640 of those patients with 12 month follow-up data available for multivariate analysis, 73% met the criteria for anemia. Multivariate logistic regression analysis identifying risk factors for anemia at the 12-month follow-up revealed that, after controlling for estimated glomerular filtration rate, age >2 years, male sex, earlier era of study entry, and prescription of anti-hypertensive medications are associated with an increased risk for anemia at 12 months. In addition, multivariate Cox proportional hazards regression analysis revealed that when patients with ESA-corrected hemoglobin are included in the definition, anemia is not associated with increased risk of progression to end stage renal disease (dialysis initiation or transplantation).

Management of Hypertension in Renal Transplant Patients: A Comprehensive Review of Nonpharmacologic and Pharmacologic Treatment Strategies

Objective:

To review the guidelines and literature for the treatment of hypertension in renal transplant patients and to provide guidance to practitioners in the selection of appropriate nonpharmacologic and pharmacologic treatment options.

Data Sources:

A PubMed search (January 1948–March 2010) was performed using the search terms hypertension, antihypertensive agents, blood pressure, and cardiovascular disease, in combination with renal transplant and kidney transplant. The search was limited to articles published in English. All relevant peer-reviewed original studies, meta-analyses, guidelines, consensus statements, and review articles were examined. In addition, reference citations from publications identified were reviewed.

Study Selection and Data Extraction:

All literature found was evaluated for inclusion. Review articles as well as prospective and retrospective original research articles were reviewed.

Data Synthesis:

Hypertension after solid organ transplantation is a problem commonly encountered in patients during their posttransplantation clinic visits. Effective management of these patients' hypertension is crucial, as hypertension left untreated may lead to increased morbidity and mortality as well as graft loss. The unique, multifactorial etiology of hypertension in this population makes treatment choices more challenging compared to treatment of a nontransplant patient. Therefore, to guide practitioners in this process, we developed a hypertension management protocol, taking into account the unique considerations faced in the adult renal transplant population. The review guides practitioners from the initial assessment of patients' hypertension through the evaluation and selection of nonpharmacologic and pharmacologic treatment options and provides information about the discontinuation of certain antihypertensive medications. It also provides a concise, but comprehensive review of the major antihypertensive drug classes and economic considerations.

Conclusions:

The management of hypertension in posttransplantation patients is challenging and complicated, yet necessary to prevent morbidity, mortality, and graft loss for these patients. Therapy should be individualized based on patient assessment, response to previous therapy, and economic considerations.

The renin-angiotensin system: an old, newly discovered player in immunoregulation

Clinical and experimental studies that discuss the different immune functions of the renin-angiotensin system (RAS) in kidney diseases were reviewed, with emphasis on studies of kidney transplantation. The RAS has been shown to affect both the innate and adaptive immune responses and has a well-established role in fibrinogenesis. Of special clinical interest is the ability of the RAS to activate the transforming growth factor beta(1) and the Smad pathways leading to fibrinogenesis. In addition to the RAS enhancing effect on the activity of T cells, several components of the RAS have also been shown to be chemotactic to macrophages, T cells, and natural killer cells. Experimental studies have found that RAS blockade decreases the histologic lesions of chronic allograft nephropathy but can enhance acute graft vasculopathy. Although the blockade of RAS has been commonly practiced to reduce posttransplantation hypertension, proteinuria, and erythrocytosis, however, its role in prolonging graft survival is not well established.

Antihypertensives for kidney transplant recipients: systematic review and meta-analysis of randomized controlled trials

In nontransplant populations, effects of different antihypertensive drug classes vary. Relative effects in kidney transplant recipients are uncertain. We performed a systematic review including random effects meta-analysis of randomized controlled trials, using Cochrane Collaboration methodology. We identified 60 trials, enrolling 3802 recipients. Twenty-nine trials (2262 patients) compared calcium channel blockers (CCB) with placebo or no treatment, 10 trials (445 patients) compared angiotensin-converting enzyme inhibitors (ACEi) with placebo or no treatment, and seven studies (405 patients) compared CCB with ACEi. CCB compared with placebo or no treatment (plus additional agents in either arm as required) reduced graft loss (risk ratio [RR] 0.75, 95% confidence intervals [CI] 0.57-0.99) and improved glomerular filtration rate (GFR; mean difference [MD] 4.5 mL/min, 95% CI 2.2-6.7). Data on ACEi versus placebo or no treatment were inconclusive for GFR (MD -8.1 mL/min, 95% CI -18.6-2.4) and inconsistent for graft loss, precluding meta-analysis. In direct comparison with CCB, ACEi decreased GFR (MD 11.5 mL/min, 95% CI 7.2-15.8), proteinuria (MD 0.28 g/day, 95% CI 0.10-0.47), hemoglobin (MD 11.5 g/L, 95% CI 7.2-15.8), and increased hyperkalemia (RR 3.7, 95% CI 1.9-7.7). Graft loss data were inconclusive (RR 7.4, 95% CI 0.4-140). These data suggest that CCB may be preferred as first-line agents for hypertensive kidney transplant recipients.

Antihypertensive treatment for kidney transplant recipients

BACKGROUND

In some nontransplant populations, effects of different antihypertensive drug classes vary. Relative effects in kidney transplant recipients are uncertain.

OBJECTIVES

To assess comparative effects of different classes of antihypertensive agents in kidney transplant recipients.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, conference proceedings and reference lists of identified studies were searched.

SELECTION CRITERIA

Randomised controlled trials of any antihypertensive agent applied to kidney transplant recipients for at least two weeks were included.

DATA COLLECTION AND ANALYSIS

Data was extracted by two investigators independently. Study quality, transplant outcomes and other patient centred outcomes were assessed using random effects meta-analysis. Risk ratios (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, both with 95% confidence intervals (CI) were calculated. Stratified analyses and meta-regression were used to investigate heterogeneity.

MAIN RESULTS

We identified 60 studies, enrolling 3802 recipients. Twenty-nine studies (2262 participants) compared calcium channel blockers (CCB) to placebo/no treatment, 10 studies (445 participants) compared angiotensin converting enzyme inhibitors (ACEi) to placebo/no treatment and seven studies (405 participants) compared CCB to ACEi. CCB compared to placebo/no treatment (plus additional agents in either arm as required) reduced graft loss (RR 0.75, 95% CI 0.57 to 0.99) and improved glomerular filtration rate (GFR), (MD, 4.45 mL/min, 95% CI 2.22 to 6.68). Data on ACEi versus placebo/no treatment were inconclusive for GFR (MD -8.07 mL/min, 95% CI -18.57 to 2.43), and variable for graft loss, precluding meta-analysis. In direct comparison with CCB, ACEi decreased GFR (MD -11.48 mL/min, 95% CI -5.75 to -7.21), proteinuria (MD -0.28 g/24 h, 95% CI -0.47 to -0.10), haemoglobin (MD -12.96 g/L, 95% CI -5.72 to -10.21) and increased hyperkalaemia (RR 3.74, 95% CI 1.89 to 7.43). Graft loss data were inconclusive (RR 7.37, 95% CI 0.39 to 140.35). Other drug comparisons were compared in small numbers of participants and studies.

AUTHORS' CONCLUSIONS

These data suggest that CCB may be preferred as first line agents for hypertensive kidney transplant recipients. ACEi have some detrimental effects in kidney transplant recipients. More high quality studies reporting patient centred outcomes are required.

Tacrolimus and angiotensin receptor blockers associated with changes in serum adiponectin level in new-onset diabetes after renal transplantation: single-center cross-sectional analysis

We analysed whether pre- and post-transplant serum adiponectin levels in renal transplant patients were associated with new-onset diabetes after transplantation (NODAT). The mean post-transplant follow-up duration was 47.9 months. Of 98 previously non-diabetic renal transplant patients, 12 were diagnosed with NODAT and 86 without (non-NODAT). There was a significant inverse correlation between mean post-transplant serum adiponectin level and homeostasis model assessment for insulin resistance (HOMA-IR) (r = -0.22, P = 0.03), and a positive correlation between follow-up duration after transplantation and HOMA-IR (r = 0.28, P = 0.005). The mean pre- and post-transplant serum adiponectin levels in NODAT patients were significantly lower than those in non-NODAT patients (13.3 vs. 21.0 microg/ml and 13.0 vs. 16.4 microg/ml, P = 0.01 and 0.03 respectively). In addition, the post-transplant serum adiponectin level in patients treated with tacrolimus (TAC) was significantly lower than that in patients with cyclosporine (14.3 vs. 18.7 microg/ml, P = 0.01), while, that level in patients treated with angiotensin receptor blockers (ARB) was significantly higher than that in patients without treatment of ARB (17.9 vs. 14.7 microg/ml, P = 0.01). Our results indicate that post-transplant serum adiponectin levels are decreased after transplantation in association with insulin resistance in the development of NODAT, and that TAC and ARB influence the level of adiponectin in serum.