Comparison of the effects of enalapril and losartan on posttransplantation erythrocytosis in renal transplant recipients: prospective randomized study

JAK2 unmutated erythrocytosis: 2023 Update on diagnosis and management

DISEASE OVERVIEW

JAK2 unmutated or non-polycythemia vera (PV) erythrocytosis encompasses a heterogenous spectrum of hereditary and acquired entities.

DIAGNOSIS

Foremost in the evaluation of erythrocytosis is the exclusion of PV through JAK2 (inclusive of exons 12-15) mutation screening. Initial assessment should also include gathering of previous records on hematocrit (Hct) and hemoglobin (Hgb) levels, in order to streamline the diagnostic process by first distinguishing longstanding from acquired erythrocytosis; subsequent subcategorization is facilitated by serum erythropoietin (Epo) measurement, germline mutation screening, and review of historical data, including comorbid conditions and medication list. Hereditary erythrocytosis constitutes the main culprit in the context of longstanding erythrocytosis, especially when associated with a positive family history. In this regard, a subnormal serum Epo level suggests EPO receptor mutation. Otherwise, considerations include those associated with decreased (high oxygen affinity Hgb variants, 2,3-bisphosphoglycerate deficiency, PIEZO1 mutations, methemoglobinemia) or normal oxygen tension at 50% Hgb saturation (P50). The latter include germline oxygen sensing pathway (HIF2A-PHD2-VHL) and other rare mutations. Acquired erythrocytosis commonly results from central (e.g., cardiopulmonary disease, high-altitude habitat) or peripheral (e.g., renal artery stenosis) hypoxia. Other noteworthy conditions associated with acquired erythrocytosis include Epo-producing tumors (e.g., renal cell carcinoma, cerebral hemangioblastoma) and drugs (e.g., testosterone, erythropoiesis stimulating agents, sodium-glucose cotransporter-2 inhibitors). Idiopathic erythrocytosis is an ill-defined terminology that presumes the existence of an increased Hgb/Hct level without an identifiable etiology. Such classification often lacks accounting for normal outliers and is marred by truncated diagnostic evaluation.

MANAGEMENT

Current consensus treatment guidelines are not supported by hard evidence and their value is further undermined by limited phenotypic characterization and unfounded concerns for thrombosis. We are of the opinion that cytoreductive therapy and indiscriminate use of phlebotomy should be avoided in the treatment of non-clonal erythrocytosis. However, it is reasonable to consider therapeutic phlebotomy if one were to demonstrate value in symptom control, with frequency determined by symptoms rather than Hct level. In addition, cardiovascular risk optimization and low dose aspirin is often advised.

FUTURE DIRECTIONS

Advances in molecular hematology might result in better characterization of "idiopathic erythrocytosis" and expansion of the repertoire for germline mutations in hereditary erythrocytosis. Prospective controlled studies are needed to clarify potential pathology from JAK2 unmutated erythrocytosis, as well as to document the therapeutic value of phlebotomy.

Risk factors and outcomes of post-transplant erythrocytosis among adult kidney transplant recipients: a systematic review and meta-analysis

Post-transplant erythrocytosis (PTE) can occur in up to 10-16% after kidney transplant (KT). However, the post-transplant outcomes of recipients with PTE in the literature were conflicting. We performed systematic review and meta-analysis of published studies to evaluate risk factors of PTE as well as outcomes of recipients who developed PTE compared with controls. A literature search was conducted evaluating all literature from existence through February 2, 2021, using MEDLINE and EMBASE. Data from each study were combined using the random-effects model. (PROSPERO: CRD42021230377). Thirty-nine studies from July 1982 to January 2021 were included (7,099 KT recipients). The following factors were associated with PTE development: male gender (pooled RR = 1.62 [1.38, 1.91], I²  = 39%), deceased-donor KT (pooled RR = 1.18 [1.03, 1.35], I²  = 32%), history of smoking (pooled RR = 1.36 [1.11, 1.67], I²  = 13%), underlying polycystic kidney disease (PKD) (pooled RR=1.56 [1.21, 2.01], I² =44%), and pretransplant dialysis (pooled RR=1.6 [1.02, 2.51], I² =46%). However, PTE was not associated with outcomes of interest, including overall mortality, death-censored graft failure, and thromboembolism. Our meta-analysis demonstrates that male gender, deceased-donor KT, history of smoking, underlying PKD, and pretransplant dialysis were significantly associated with developing PTE. However, with proper management, PTE has no impact on prognosis of KT patients.

Post-transplant erythrocytosis after kidney transplantation: A review

Post-transplant erythrocytosis (PTE) is defined as persistently elevated hemoglobin > 17 g/dL or hematocrit levels > 51% following kidney transplantation, independent of duration. It is a relatively common complication within 8 months to 24 months post-transplantation, occurring in 8%-15% of kidney transplant recipients. Established PTE risk factors include male gender, normal hemoglobin/hematocrit pre-transplant (suggestive of robust native kidney erythropoietin production), renal artery stenosis, patients with a well-functioning graft, and dialysis before transplantation. Many factors play a role in the development of PTE, however, underlying endogenous erythropoietin secretion pre-and post-transplant is significant. Other contributory factors include the renin-angiotensin- aldosterone system, insulin-like growth factors, endogenous androgens, and local renal hypoxia. Most patients with PTE experience mild symptoms like malaise, headache, fatigue, and dizziness. While prior investigations showed an increased risk of thromboembolic events, more recent evidence tells a different story-that PTE perhaps has lessened risk of thromboembolic events or negative graft outcomes than previously thought. In the evaluation of PTE, it is important to exclude other causes of erythrocytosis including malignancy before treatment. Angiotensin converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) are the mainstays of treatment. Increased ACE-I/ARB use has likely contributed to the falling incidence of erythrocytosis. In this review article, we summarize the current literature in the field of post-transplant erythrocytosis after kidney transplantation.

JAK2 unmutated erythrocytosis: current diagnostic approach and therapeutic views

JAK2 unmutated or non-polycythemia vera (PV) erythrocytosis encompasses both hereditary and acquired conditions. A systematic diagnostic approach begins with documentation of historical hematocrit (Hct)/hemoglobin (Hgb) measurements and classification of the process as life-long/unknown duration or acquired. Further investigation in both categories is facilitated by determination of serum erythropoietin level (EPO). Workup for hereditary/congenital erythrocytosis requires documentation of family history and laboratory screening for high-oxygen affinity hemoglobin variants, 2, 3 biphosphoglycerate deficiency, and germline mutations that are known to alter cellular oxygen sensing (e.g., PHD2, HIF2A, VHL) or EPO signaling (e.g., EPOR mutations); the latter is uniquely associated with subnormal EPO. Acquired erythrocytosis is often elicited by central or peripheral hypoxia resulting from cardiopulmonary disease/high-altitude dwelling or renal artery stenosis, respectively; EPO in the former instance is often normal (compensated by negative feed-back). Other conditions associated with acquired erythrocytosis include EPO-producing tumors and the use of drugs that promote erythropoiesis (e.g., testosterone, erythropoiesis stimulating agents). "Idiopathic erythrocytosis" loosely refers to an otherwise not explained situation. Historically, management of non-PV erythrocytosis has been conflicted by unfounded concerns regarding thrombosis risk, stemming from limited phenotypic characterization, save for Chuvash polycythemia, well-known for its thrombotic tendency. In general, cytoreductive therapy should be avoided and phlebotomy is seldom warranted where frequency is determined by symptom control rather than Hct threshold. Although not supported by hard evidence, cardiovascular risk optimization and low-dose aspirin use are often advised. Application of modern genetic tests and development of controlled therapeutic intervention trials are needed to advance current clinical practice.

The effect of initiation of renin-angiotensin system inhibitors on haemoglobin: A national cohort study

AIMS

To determine whether initiation of treatment with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers (ACEI/ARBs) is associated with a subsequent reduction in haemoglobin in the general population.

METHODS

We undertook a national cohort study over a 13-year period (2004-2016), using routine primary healthcare data from the UK Clinical Practice Research Datalink. We compared ACEI/ARB initiation with calcium channel blocker (CCB) initiation, to minimise confounding by indication. We included all first ACEI/ARB or CCB prescriptions in adults with at least 1 haemoglobin result in the 12 months before and 6 months after drug initiation. Our primary outcome was a ≥1 g/dL haemoglobin reduction in the 6 months after drug initiation.

RESULTS

We examined 146 610 drug initiation events in 136 655 patients. Haemoglobin fell by ≥1 g/dL after drug initiation in 19.5% (16 936/86 652) of ACEI/ARB initiators and 15.9% (9521/59 958) of CCB initiators. The adjusted odds ratio of a ≥1 g/dL haemoglobin reduction in ACEI/ARB initiators vs CCB initiators was 1.15 (95% confidence interval 1.12-1.19).

CONCLUSION

ACEI/ARBs are associated with a modest increase in the risk of a haemoglobin reduction. For every 100 patients in our study that initiated a CCB, 16 experienced a ≥1 g/dL haemoglobin decline. If the effect is causal, 3 additional patients would have experienced this outcome if they had received an ACEI/ARB. This may have implications for drug choice and monitoring for many patients in primary care. Further research could identify patients at higher risk of this outcome, who may benefit from closer monitoring.

Histone deacetylase inhibitor CG200745 ameliorates high-fat diet-induced hypertension via inhibition of angiotensin II production

Obesity is growing rapidly worldwide due to consumption of westernized diet and lack of exercise. Obesity is one of the major risk factors of hypertension. The novel histone deacetylase (HDAC) inhibitor CG200745 was originally developed to treat various cancers. Previous studies showed that CG200745 attenuated hypertension through inhibition of cardiac hypertrophy and fibrosis in deoxycorticosterone acetate-induced hypertensive rat. The purpose of this study is to investigate the role and underlying mechanism of CG200745 in high-fat diet (HFD)-induced hypertension. Nine-week old C57BL/6 mice were fed a normal diet (ND) or HFD for 17 weeks. Each group of mice was treated with vehicle or CG200745 by intraperitoneal injection for 9 days. HFD group showed higher body weight, blood pressure (BP), HDAC activities, angiotensinogen and renin expressions in kidney, angiotensin-converting enzyme (ACE) expression in the lung, serum angiotensin II (Ang II) concentration, and myosin light chain₂₀ (MLC₂₀) phosphorylation in mesenteric artery compared with ND group. CG200745 lowered BP, HDAC activity, renin and angiotensinogen in the kidney, ACE in the lung, serum Ang II level, and phosphorylation of MLC₂₀ in HFD group. In conclusion, CG200745 ameliorated HFD-induced hypertension through inhibition of HDAC/Ang II/vascular contraction axis. Our results offer CG200745 as a novel therapeutic option for HFD-induced hypertension.

Comparative effectiveness of different antihypertensive agents in kidney transplantation: a systematic review and meta-analysis

Background

We conducted a systematic review and meta-analysis to compare benefits and harms of different antihypertensive drug classes in kidney transplant recipients, as post-transplant hypertension (HTN) associates with increased cardiovascular (CV) morbidity and mortality.

Methods

The Ovid-MEDLINE, PubMed and CENTRAL databases were searched for randomized controlled trials (RCTs) comparing all main antihypertensive agents versus placebo/no treatment, routine treatment.

Results

The search identified 71 RCTs. Calcium channel blockers (CCBs) (26 trials) reduced the risk for graft loss {risk ratio [RR] 0.58 [95% confidence interval (CI) 0.38–0.89]}, increased glomerular filtration rate (GFR) [mean difference (MD) 3.08 mL/min (95% CI 0.38–5.78)] and reduced blood pressure (BP). Angiotensin-converting enzyme inhibitors (ACEIs) (13 trials) reduced the risk for graft loss [RR 0.62 (95% CI 0.40–0.96)] but decreased renal function and increased the risk for hyperkalaemia. Angiotensin receptor blockers (ARBs) (10 trials) did not modify the risk of death, graft loss and non-fatal CV events and increased the risk for hyperkalaemia. When pooling ACEI and ARB data, the risk for graft failure was lower in renin–angiotensin system (RAS) blockade as compared with control treatments. In direct comparison with ACEIs or ARBs (11 trials), CCBs increased GFR [MD 11.07 mL/min (95% CI 6.04–16.09)] and reduced potassium levels but were not more effective in reducing BP. There are few available data on mortality, graft loss and rejection. Very few studies performed comparisons with other active drugs.

Conclusions

CCBs could be the preferred first-step antihypertensive agents in kidney transplant patients, as they improve graft function and reduce graft loss. No definite patient or graft survival benefits were associated with RAS inhibitor use over conventional treatment.

Antihypertensive drugs

Successful treatment of hypertension is possible with limited side effects given the availability of multiple antihypertensive drug classes. This review describes the various pharmacological classes of antihypertensive drugs, under two major aspects: their mechanisms of action and side effects. The mechanism of action is analysed through a pharmacological approach, i.e. the molecular receptor targets, the various sites along the arterial system, and the extra-arterial sites of action, in order to better understand in which type of hypertension a given pharmacological class of antihypertensive drug is most indicated. In addition, side effects are described and explained through their pharmacological mechanisms, in order to better understand their mechanism of occurrence and in which patients drugs are contra-indicated. This review does not address the effectiveness of monotherapies in large randomized clinical trials and combination therapies, since these are the matters of other articles of the present issue. Five major pharmacological classes of antihypertensive drugs are detailed here: beta-blockers, diuretics, angiotensin converting enzyme inhibitors, angiotensin II receptor antagonists, and calcium channel blockers. Four additional pharmacological classes are described in a shorter manner: renin inhibitors, alpha-adrenergic receptor blockers, centrally acting agents, and direct acting vasodilators.

Renal association clinical practice guideline in post-operative care in the kidney transplant recipient

These guidelines cover the care of patients from the period following kidney transplantation until the transplant is no longer working or the patient dies. During the early phase prevention of acute rejection and infection are the priority. After around 3-6 months, the priorities change to preservation of transplant function and avoiding the long-term complications of immunosuppressive medication (the medication used to suppress the immune system to prevent rejection). The topics discussed include organization of outpatient follow up, immunosuppressive medication, treatment of acute and chronic rejection, and prevention of complications. The potential complications discussed include heart disease, infection, cancer, bone disease and blood disorders. There is also a section on contraception and reproductive issues.Immediately after the introduction there is a statement of all the recommendations. These recommendations are written in a language that we think should be understandable by many patients, relatives, carers and other interested people. Consequently we have not reworded or restated them in this lay summary. They are graded 1 or 2 depending on the strength of the recommendation by the authors, and AD depending on the quality of the evidence that the recommendation is based on.

Management of Hypertension in Solid-Organ Transplantation

Posttransplant hypertension is a major risk factor for cardiovascular disease and chronic renal allograft dysfunction. A significant number of transplant recipients suffer from posttransplant hypertension in part because of corticosteroid and calcineurin inhibitor use. Although the optimal blood pressure range and the antihypertensive agents of choice in the transplant population have not been determined, the guidelines for blood pressure control in the general population can be extrapolated to the transplant population. The choice of an antihypertensive regimen should be tailored on the basis of the individual patient's risk factors and comorbidities.

Anemia and erythrocytosis in patients after kidney transplantation

Anemia is a highly prevalent disorder in recipients of renal allografts. Despite its frequent occurrence, there is still uncertainty with regard to treatment targets and treatment options. This includes questions on appropriate iron management, the choice and dosage of erythropoietin stimulating agents, criteria for the timing of treatment initiation and the targeted hemoglobin values. The review summarizes available data on recent therapeutic strategies for post transplant anemia, as well as for post transplant erythrocytosis, another hematological disorder, that has decreased in recent years.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

Effect of angiotensin II type-1 receptor blockers on stable allograft kidneys: prospective randomized study

OBJECTIVE

Is assess the effects of angiotensin II type-I receptor blockers on outcomes in renal transplant recipients without proteinuria or posttransplantation erythrocytosis.

PATIENTS AND METHODS

Fifty renal transplant recipients (30 men and 20 women, with a mean [SD] age of 40 [13] years) were randomized into 2 groups of 25 patients each; 1 group was treated with losartan for 1 year, and the other was not (control group). Blood pressure and other biochemical parameters were measured at baseline and at 6 and 12 months posttransplantation.

RESULTS

After 1 year, the losartan group had significantly lower systolic blood pressure (113 [22] mm Hg vs 126 [18] mm Hg; P = .04) and hemoglobin concentration (12.8 [1.9] g/dL vs 14.5 [2.1] g/dL; P = .006) and significantly higher serum high-density lipoprotein cholesterol concentration (58 [22] mg/dL vs 47 [10] mg/dL; P = .03) compared with the control group; however the incidence of anemia did not differ (37% vs 20%; P = .20). In the losartan group, there were significant changes in hemoglobin concentration between baseline and 6 months (14.5 [1.6] g/dL vs 12.9 [1.49] g/dL; P < .001), but not between 6 and 12 months (12.9 [1.49] g/dL vs 12.8 [1.96] g/dL; P = .43). After 1 year, there were no significant between-group differences in diastolic hypertension, serum creatinine concentration, creatinine clearance, and serum potassium, low-density lipoprotein cholesterol, triglyceride, and uric acid concentrations.

CONCLUSION

Losartan significantly increased high-density lipoprotein concentration and significantly decreased systolic hypertension. Although losartan decreased the hemoglobin concentration during the first 6 months, its effect did not progress with longer use. To determine the effect of losartan on renal function, additional studies with longer follow-up are needed.

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.

Post-transplant erythrocytosis: a disappearing phenomenon?

BACKGROUND

Erythrocytosis is relatively common post-kidney transplantation and may have adverse consequences. This study examined whether the incidence of erythrocytosis has remained stable over time and explored the impact of this condition on patient outcomes.

METHODS

This was a retrospective single center review of an incidence cohort (transplanted between 1993 and 2005). Predictors of erythrocytosis and hemoglobin levels and subsequent patient and allograft survival were examined.

RESULTS

Erythrocytosis (hemoglobin >170 g/L for >1 month) was observed in 59 of 511 recipients. Erythrocytosis developed in only 8.1% of those transplanted from 1997 to 2005, compared with 18.7% in those transplanted from 1993 to 1996 (p = 0.0005). Independent predictive factors were use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs) (HR 0.176, 95% CI 0.040-0.71, p = 0.016), male gender (HR 3.72, 95% CI 1.54-9.0, p = 0.003), and mycophenolic acid agents (HR 0.49, 95% CI 0.237-0.99, p = 0.049). Patients with erythrocytosis had superior overall survival (HR for death 0.105, 95% CI 0.014-0.760, p = 0.026) but a trend for worse death censored graft loss (univariate HR 2.06, 95% CI 0.91-4.65, p = 0.084).

CONCLUSIONS

The incidence of erythrocytosis is falling and is likely related to greater ACEi/ARB use and possibly more antiproliferative immunosuppression. Patient survival is excellent in those with erythrocytosis, but long-term graft survival may be compromised.

Traditional and novel approaches to management of heart failure: successes and failures

Although considerable progress has been made in the pharmacologic and device management of chronic heart failure in recent decades, heart failure patients continue to remain symptomatic, with high hospitalization and mortality rates. A number of novel agents, including endothelin antagonists and tumor-necrosis factor blockers, have recently failed to improve the clinical outcomes of patients with heart failure. Have we reached a ceiling in preventing the progression of the disease? This article reviews successes and late-stage clinical trial disappointments in the treatment of patients with heart failure. Furthermore, the article discusses how agents that have beneficial effects in heart failure also generally attenuate or reverse ventricular remodeling, whereas the newer agents that have failed to improve clinical outcomes either had no effect on remodeling or have been associated with adverse remodeling.

Renin-angiotensin system polymorphisms and hemoglobin level in renal allografts: a comparative study between losartan and enalapril

INTRODUCTION

In this study, hemoglobin (Hb) concentrations secondary to enalapril (E) or losartan (L) therapy were evaluated with respect to renin-angiotensin system (RAS) polymorphisms in renal transplant recipients.

MATERIALS AND METHODS

After determination of RAS polymorphisms [angiotensin-converting enzyme (DD, non-DD), angiotensinogen (TT, non-TT), and angiotensin receptor type 1 (CC, non-CC)] by polymerase chain reaction, 70 renal transplant recipients were recruited to four groups randomly: first and second groups were treated with E (10 mg/d, 15 patients) and L (50 mg/d, 20 patients) alone, respectively. The third group received E+L (10 mg/d + 50 mg/d, 13 patients) and the fourth group (22 patients) received no medication. The treatment protocol was followed for 16 weeks. Complete blood counts were checked before treatment and every 2 months. P<.05 was considered to indicate statistical significance.

RESULTS

Treatment for 4 months decreased the Hb level in the E+L (14.15 +/- 0.94 to 12.06 +/- 0.66 g/dL, P=.000), E (14.00 +/- 0.86 to 13.11 +/- 0.82 g/dL, P=.02), and L (14.12 +/- 0.90 to 12.10 +/- 2.35 g/dL, P=.01) groups, but not in the control group (13.55 +/- 0.70 to 13.36 +/- 0.69 g/dL, P>.05). None of these regimens showed greater Hb reduction than the others (P>.05). None of the RAS polymorphisms predicted the intensity of the reduced Hb according to the type of treatment (P>.05). Any other sets of RAS polymorphisms (alone or together) did not impact on Hb levels pre- or post-intervention (P>.05).

CONCLUSION

Our findings suggest that low dosages of E and/or L decrease Hb levels regardless of the RAS polymorphisms.

Antihypertensive Medications and Anemia

Antihypertensive medication use can be associated with a reduction in hemoglobin concentration. The magnitude of such a change is generally small, but in certain instances it can be extreme enough to produce a clinically significant degree of anemia. The mechanistic basis for antihypertensive medication-related changes in hemoglobin concentration include hemodilution, hemolytic anemia, and suppression of red blood cell production, as this occurs most commonly with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. A reduction in hemoglobin concentration in a patient who is receiving treatment for hypertension and does not have an obvious source of blood loss should account for potential antihypertensive therapy involvement.

Congestive heart failure-related anemia and a role for erythropoietin

Congestive heart failure (CHF) is a common clinical problem, especially affecting the elderly. Current strategies of neurohormonal blockade with medications like angiotensin converting enzyme inhibitors have improved morbidity and mortality, but further improvement in outcomes requires new strategies. Both anemia and chronic renal disease commonly accompany congestive heart failure; their close relationship, in which one disease exacerbates the other, has been termed the cardio-renal-anemia syndrome. Correction of anemia in CHF patients using recombinant erythropoietin is feasible; small studies suggest that anemic congestive heart failure patients may have improved morbidity with this therapy. Recent animal and human studies of erythropoietin have shown that its benefit may be derived from both hematological and newly discovered non-hematological properties. Anemia might soon be considered a modifiable risk factor for optimal CHF management.

Levels of Hematopoiesis InhibitorN-Acetyl-Seryl-Aspartyl-Lysyl-Proline Partially Explain the Occurrence of Anemia in Heart Failure

BACKGROUND

Anemia is common in patients with chronic heart failure (CHF) and is associated with a poor prognosis. However, only a minority of patients with CHF have impaired renal function or underlying hematinic deficiencies. It has been shown that inhibition of the renin-angiotensin system is associated with the development of anemia. The aim of the present study was to determine possible mechanisms linking anemia to renin-angiotensin system activity in CHF patients.

METHODS AND RESULTS

We initially evaluated 98 patients with advanced stable CHF who were treated with ACE inhibitors (left ventricular ejection fraction, 28+/-1%; age, 69+/-1 years; 80% male), 10 of whom had an unexplained anemia (normal hematinics and no renal failure). These 10 anemic patients were matched with 10 nonanemic patients in terms of age and left ventricular ejection fraction. Serum ACE activity was 73% lower in anemic CHF patients compared with nonanemic CHF patients (P=0.018). Moreover, serum of these patients inhibited in vitro the proliferation of bone marrow-derived erythropoietic progenitor cells of healthy donors by 17% (P=0.003). Levels of the hematopoiesis inhibitor N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), which is almost exclusively degraded by ACE, were significantly higher in anemic CHF patients and were clearly correlated to erythroid progenitor cell proliferation (r=-0.64, P=0.001).

CONCLUSIONS

Serum ACE activity is markedly lower in anemic CHF patients, and serum of these patients inhibits hematopoiesis. The clear correlation between Ac-SDKP and proliferation of erythroid progenitor cells suggests an inhibitory role of Ac-SDKP on hematopoiesis in CHF patients, which may explain the observed anemia in patients treated with ACE inhibitors.

Anemia and Change in Hemoglobin Over Time Related to Mortality and Morbidity in Patients With Chronic Heart Failure

Background— Anemia is known to be a prognostic marker for patients with heart failure. However, little is known about the prognostic value of changes in hemoglobin (Hgb) over time or about the causes of anemia.

Methods and Results— Retrospective analysis of Valsartan Heart Failure Trial data indicated that the quartile of patients with the biggest average decrease in Hgb over 12 months (from 14.2 to 12.6 g/dL) had significantly ( P ≤0.01) increased risk of subsequent hospitalization (hazard ratio [HR], 1.47), morbid events (HR, 1.41), and death (HR, 1.6) compared with the quartile that exhibited little change in Hgb over 12 months (from 13.7 to 13.8 g/dL). Increasing Hgb was significantly associated with lower mortality in patients with (HR, 0.78) and without (HR, 0.79) anemia at baseline. Anemia at baseline and the changes in Hgb were independently associated with serum albumin, blood pressure, glomerular filtration rate, B-type natriuretic peptide, and C-reactive protein. Lack of anemia at baseline and increases in Hgb over 12 months were not associated with smaller left ventricular diameters or higher ejection fractions.

Conclusions— Changes in Hgb over 12 months were inversely associated with subsequent risk of mortality and morbidity, independently of the effects of baseline anemia and other important predictors. Several factors were independently related to anemia at baseline and changes in Hgb, suggesting multiple causes of anemia in patients with heart failure. These findings raise important questions about the optimal level of Hgb in patients with moderate to severe heart failure and how to achieve them.

Angiotensin-converting enzyme inhibitor as a risk factor for the development of anemia, and the impact of incident anemia on mortality in patients with left ventricular dysfunction

OBJECTIVES

We aimed to investigate the impact of angiotensin-converting enzyme inhibitors (ACEIs) on hematocrit values in those with heart failure, and the relationship between incident anemia and mortality.

BACKGROUND

Prevalent anemia is an independent risk factor for morbidity and mortality in those with heart failure. Studies in patients with polycythemia have demonstrated that ACEIs are effective in lowering hematocrit values.

METHODS

We used the Studies Of Left Ventricular Dysfunction (SOLVD) database to compare the odds of developing new anemia at one year in patients who were not anemic at entry and who were randomized to enalapril or placebo. Cox proportional hazards models were utilized to determine the impact of incident and prevalent anemia on subsequent mortality.

RESULTS

Enalapril increased the odds of incident anemia (hematocrit < or =39% in men or < or =36% in women) at one year by 48% (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.20 to 1.82) in unadjusted and 56% (OR 1.56, 95% CI 1.26 to 1.93) in adjusted models. With multivariate analysis, prevalent anemia at randomization was associated with a 44% (hazard ratio [HR] 1.44, 95% CI 1.31 to 1.66) increase in all-cause mortality, whereas incident anemia after randomization was associated with a 108% increase (HR 2.08, 95% CI 1.82 to 2.38). After adjusting for incident and prevalent anemia, use of enalapril was associated with a survival benefit.

CONCLUSIONS

Enalapril was associated with increased odds of developing anemia at one year. Those with periods of time with incident anemia had the poorest survival, followed by those with prevalent anemia, then those without anemia. Enalapril was protective of overall mortality after adjusting for incident anemia and in those with prevalent anemia.

Angiotensin-converting enzyme inhibitors side effects--physiologic and non-physiologic considerations

Angiotensin-converting enzyme (ACE) inhibitors are increasingly recognized as having an important role in the treatment of hypertension and/or end-organ disease. The sheer number of ACE inhibitors in the United States--now numbering 10 different chemical entities--has created a sense of comfort with these compounds, which is particularly evident when these compounds are used in the patient with essential hypertension; conversely, when comorbid conditions are present in the ACE inhibitor-treated patient, circumstances change and physician vigilance becomes more of a necessity. ACE inhibitor therapy in patients with either cardiac and/or renal disease is as much an art as it is a science, and even in the most skilled hands can prove a challenging undertaking. This review discusses the physiologic and non-physiologic basis for side effects with ACE inhibition.

Impact of kidney transplantation on the progression of cardiovascular disease

Kidney transplantation, of all the treatment modalities for end-stage renal disease, affords the greatest potential for prolonged survival and improved quality of life. Great strides in immunosuppressant therapy have improved graft survival and forced clinicians to consider other health-care needs of kidney transplant recipients. Chief among these needs is the prevention and treatment of cardiovascular disease. Cardiovascular disease is the most common cause of death among patients with a working renal allograft. Because therapies for primary and secondary prevention are successful in the general population, transplant clinicians are increasingly focused on preventing or limiting the progression of cardiovascular disease. Initiation of aggressive management of conventional atherosclerotic risk factors and uremia-related risk factors, ideally during the early stages of chronic kidney disease (CKD) or after kidney transplantation, and efforts to delay the progression of kidney disease will hopefully reduce the cardiovascular burden in transplant recipients.

Angiotensin-Converting enzyme gene polymorphism significantly affects renal posttransplantation erythrocytosis

Posttransplantation erythrocytosis (PE) is a frequent problem in renal transplant patients. The pathogenesis and mechanisms of both the problem and therapy strategy are unknown. Since ACE and angiotensin 2 receptor inhibitors have been used to successfully manage PE, we speculated a relation between gene polymorphisms and this complication. Ninety-six ( 30 women, 66 men, age 34.4 +/- 11.0 years) renal transplant patients evaluated retrospectively, for gene polymorphisms of ACE, angiotensinogen, angiotensin 1 and 2 receptors (ATR1 and ATR2), as well as endothelial nitric oxide synthase (ecNOS). They were divided into two groups; patients with versus without PE, which was defined as >15 g/dL hemoglobin levels during the first year after renal transplantation. PE was found to be significantly more prevalent among D/D than I/I gene polymorphism of ACE genes (P <.04). The distribution of D/D, I/D, and I/I polymorphisms were 39.1%, 45.9%, and 7.6%, respectively. There was no difference between D/D and I/D polymorphisms. Comparing the I/D and I/I polymorphisms showed PE to be statistically more prevalent in the I/D polymorphism (P <.01). Logistic regression analysis revealed that D/D and I/D polymorphisms were significant risk factors for PE (P <.05, RR = 7.714 and P <.03, RR = 10.199, respectively). While previous studies revealed a relation between angiotensin II and PE, our study discovered the contribution of ACE gene polymorphism.

Polycythemia vera: a comprehensive review and clinical recommendations

More than a century has elapsed since the appearance of the modern descriptions of polycythemia vera (PV). During this time, much has been learned regarding disease pathogenesis and PV-associated molecular aberrations. New information has allowed amendments to traditional diagnostic criteria. Phlebotomy remains the cornerstone treatment of PV, whereas myelosuppressive agents may augment the benefit of using phlebotomy for thrombosis prevention in high-risk patients. Excessive aspirin use is contraindicated in PV, although the use of lower-dose aspirin has been shown to be safe and effective in alleviating microvascular symptoms including erythromelalgia and headaches. Recent studies have shown the utility of selective serotonin receptor antagonists for treating PV-associated pruritus. Nevertheless, many questions remain unanswered. What is the specific genetic mutation or altered molecular pathway that is causally related to the disease? In the absence of a specific molecular marker, how is a working diagnosis of PV made? What evidence supports current practice in the management of PV? This article summarizes both old and new information on PV; proposes a modern diagnostic algorithm to formulate a working diagnosis; and provides recommendations for patient management, relying whenever possible on an evidence-based approach.