Anemia Due to Losartan in Hypertensive Renal Transplant Recipients Without Posttransplant Erythrocytosis

Post-renal transplantation anemia at 12 months: prevalence, risk factors, and impact on clinical outcomes

PURPOSE

To investigate any association between post-transplantation anemia (PTA) and clinical outcomes following living donor kidney transplantation.

METHODS

We retrospectively evaluated 887 patients who received living donor kidney transplantations at our medical center between January 2006 and December 2012 to evaluate whether PTA, defined as serum hemoglobin (Hb) levels of <130 g/l in men and <120 g/l in women, at 12 months is associated with post-transplant outcomes, including graft function, death-censored graft survival, or patient survival.

RESULTS

The prevalence of PTA at 1, 3, 6, and 12 months was 84.3, 39.5, 26.2, and 21.6 %, respectively. Donor age [hazard ratio (HR), 1.03; 95 % confidence interval (CI) 1.01-1.05] and acute rejection (HR 2.13; 95 % CI 1.28-3.54) were found to be independent risk factors for PTA at 12 months. Recipient age (HR 0.98; 95 % CI 0.95-1.00), pre-transplantation Hb levels (HR 0.99; 95 % CI 0.98-1.00), and estimated glomerular filtration rates (eGFRs) at 12 months (HR 0.96; 95 % CI 0.94-0.97) were found to confer slight protection against PTA at 12 months. PTA at 12 months was associated with increased graft loss (HR 1.046; 95 % CI 1.045-1.046). For each increase in anemia degree, there was a 2.77-fold greater risk of graft loss (HR 2.77; 95 % CI 1.50-5.13). When stratified according to eGFR, PTA was found to be a predictor of graft loss in patients with an eGFR of <60 ml/min/1.73 m(2) (HR 4.57; 95 % CI 1.98-10.56) but not in patients with an eGFR of >60 ml/min/1.73 m(2) (HR 1.89; 95 % CI 0.13-27.78). PTA was not found to be a predictor of patient survival.

CONCLUSIONS

Anemia is common after kidney transplantation, and its prevalence declines with time after transplantation. Presence of anemia at 12 months post-transplant was an independent predictor of graft loss, with higher risk of graft loss in patients with anemia and poorer kidney functions.

Comparative effect of angiotensin II type I receptor blockers and calcium channel blockers on laboratory parameters in hypertensive patients with type 2 diabetes

BACKGROUND

Both angiotensin II type I receptor blockers (ARBs) and calcium channel blockers (CCBs) are widely used antihypertensive drugs. Many clinical studies have demonstrated and compared the organ-protection effects and adverse events of these drugs. However, few large-scale studies have focused on the effect of these drugs as monotherapy on laboratory parameters. We evaluated and compared the effects of ARB and CCB monotherapy on clinical laboratory parameters in patients with concomitant hypertension and type 2 diabetes mellitus.

METHODS

We used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between Nov 1, 2004 and July 31, 2011, to identify cohorts of new ARB users (n = 601) and propensity-score matched new CCB users (n = 601), with concomitant mild to moderate hypertension and type 2 diabetes mellitus. We used a multivariate-adjusted regression model to adjust for differences between ARB and CCB users, and compared laboratory parameters including serum levels of triglyceride (TG), total cholesterol (TC), non-fasting blood glucose, hemoglobin A1c (HbA1c), sodium, potassium, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), hemoglobin and hematocrit, and white blood cell (WBC), red blood cell (RBC) and platelet (PLT) counts up to 12 months after the start of ARB or CCB monotherapy.

RESULTS

We found a significant reduction of serum TC, HbA1c, hemoglobin and hematocrit and RBC count and a significant increase of serum potassium in ARB users, and a reduction of serum TC and hemoglobin in CCB users, from the baseline period to the exposure period. The reductions of RBC count, hemoglobin and hematocrit in ARB users were significantly greater than those in CCB users. The increase of serum potassium in ARB users was significantly greater than that in CCB users.

CONCLUSIONS

Our study suggested that hematological adverse effects and electrolyte imbalance are greater with ARB monotherapy than with CCB monotherapy.

Efficacy and safety of losartan in treatment of hyperuricemia and posttransplantation erythrocytosis: results of a prospective, open, randomized, case-control study

BACKGROUND

Hyperuricemia and posttransplantation erythrocytosis (PTE) are frequent complications after kidney transplantation and are important risk factors for cardiovascular events. Losartan decreases serum uric acid and hemoglobin (Hb) concentrations and may be a useful agent for treatment of hyperuricemia and PTE.

OBJECTIVE

To evaluate the influence of losartan on serum creatinine (SCr), serum uric acid, and hemoglobin (Hb) concentrations in patients after kidney transplantation and to evaluate the safety profile of losartan in these patients.

PATIENTS AND METHODS

Sixty-six Han Chinese patients (43 men and 23 women; mean [SD] age, 40.45 [11.50] years) were enrolled in the study. All patients had undergone a first cadaveric donor kidney transplantation at least 3 months previously and had stable graft function with SCr concentration less than 176.8 micromol/L and Hb concentration greater than 110 g/L. The patients were divided into 2 groups (losartan group, n = 34; and control group, n = 32) according to the odevity of patient identification number. Patients in the losartan group received losartan, 50 mg/d; patients in the control group did not receive losartan. Each patient was followed up for 6 months.

RESULTS

Nine patients in the losartan group and 5 patients in the control group dropped out because of acute renal insufficiency, anemia, acute rejection, or poor compliance. The serum uric acid concentration in the losartan group continuously decreased at months 1, 2, 3, and 6 (P = .12, P = .01, P = .04, and P = .005 compared with baseline, and P = .02, P = .003, P = .02, and P = .006 compared with control), especially in the patients with hyperuricemia (P = .02, P < .001, P = .003, and P < .001 compared with baseline, and P = .02, P = .002, P = .02, and P = .002 compared with control). The Hb level in the losartan group decreased significantly at months 1, 2, 3, and 6 (P = .003, P < .001, P = .004, and P = 0.02 compared with baseline, and P = .001, P < .001, P = .001, and P = .005 compared with control), especially in patients with PTE. In patients without PTE, there was no significant decline in Hb concentration in the losartan group compared with baseline. There was no significant decline in estimated glomerular filtration rate in the losartan group.

CONCLUSIONS

Losartan may be an effective agent for treatment of hyperuricemia and PTE in Han Chinese patients after kidney transplantation. However, in some patients, losartan may not be safe.

Impact of very early high doses of recombinant erythropoietin on anemia and allograft function in de novo kidney-transplant patients

After kidney transplantation, occurrence of anemia in the early post-transplant period (<1 month) is high and arises out of issues that are multifactorial. We performed a retrospective single-center study to assess whether delivery of high doses of erythropoietin-stimulating agents (ESA) within the first week of kidney transplantation, translates at 1 month post-transplant, in to causing less anemia and whether it has an impact on allograft function. Ninety-nine patients were not given ESA (group I), whereas 82 were (250 IU/kg/week; group II). All patients had similar pretransplant and baseline (day 0) variables. Similar numbers of group II patients were still receiving ESA by day 14 (97.5%) and day 30 (89%). Respective figures for group I were 27% and 27%. Independent factors for anemia at 1 month post-transplant included: being male subject, treatment for hypertension at pretransplant, anemia at transplant, a higher mean corpuscular volume at transplant, and an induction therapy using antithymocyte globulins. Independent predictive factors for lower creatinine clearance included being female subjects, having a donor aged >50 years, being a recipient aged >50 years, not treated for hypertension at pretransplant, and no post-transplant ESA therapy. High doses of ESA within the first month of kidney transplantation have no impact on anemia or renal function by 1 month post-transplant.

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.

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.

The effect of losartan on hemoglobin concentration and renal outcome in diabetic nephropathy of type 2 diabetes

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers can decrease hemoglobin, causing anemia and this may be an independent risk factor for chronic kidney disease progression. We studied the relationship between a decline in hemoglobin and outcome in 1513 patients with type 2 diabetes and kidney disease by a post hoc analysis of the RENAAL Study (Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan) with an average follow-up of 3.4 years. The relationship between baseline and year-1 hemoglobin and treatment on end-stage renal disease (ESRD) and ESRD or death was evaluated using multivariate Cox models (covariates: baseline hemoglobin, proteinuria, serum albumin, serum creatinine, and year-1 hemoglobin). Compared with placebo, losartan treatment was associated with a significant decrease of hemoglobin, with the largest between-group difference at 1 year. After adjustment, there were significant relative risk reductions for losartan compared with placebo for ESRD and for ESRD or death regardless of the baseline hemoglobin even in those patients with a baseline hemoglobin below 120 g l(-1). Hence, the renoprotective properties of losartan were maintained despite a significant lowering of the hemoglobin concentration.

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.