Mild chronic anemia following heart transplantation: a syndrome with prognostic relevance?

Blood volume and hemoglobin mass in long-term heart transplant recipients with and without Anemia

BACKGROUND

In systolic chronic heart failure, a heterogeneous blood volume (BV) regulation can be found with plasma volume expansion in many cases, possibly leading to pseudoanemia. Little is known about the volume status after heart transplantation (HTX). So far, anemia of HTX recipients was solely investigated using hemoglobin-concentration that may be misleading in a clinical context. The objective of the study was whether a difference in plasma volume and red cell volume can be observed in clinically stable heart transplant recipients compared to matched control subjects. Secondary, the aim was to describe anemia in the long-term after HTX based on quantitative data.

METHODS

Blood volume and its constituents red cell volume and plasma volume were quantified using an abbreviated carbon monoxide rebreathing method (aCORM) with focus on its primary measure total hemoglobin mass (Hbmass) and coincidental anemia in 36 (7 women) heart transplant recipients. For comparison, a matched control group of 46 (5 women) healthy subjects was selected.

RESULTS

Neither Hbmass nor blood volumes were significantly different in HTX patients compared to matched healthy control group subjects. The prevalence of anemia 6.3 ± 4.3 years after transplantation was 19%. Hbmass and red cell volume were significantly lower in anemic HTX patients compared to non-anemic patients while plasma volume was not expanded. Various immunosuppressant regimens did not have an effect on Hbmass, plasma volume or red cell volume.

CONCLUSIONS

There was no difference in blood volumes and Hbmass between HTX patients and control subjects. The pathophysiologic blood volume regulation in chronic heart failure does not seem to be longer active in long-term HTX recipients. However, in the long-term after HTX, anemia occurs in a considerable number of patients as true anemia without a clear association with immunosuppression.

TRIAL REGISTRATION

German registry for clinical studies, DRKS00006078. Registered 09 May 2014, https://www.drks.de/drks_web/navigate.do?navigationId=trial . HTML&TRIAL_ID=DRKS00006078.

Sirolimus is associated with impaired hematopoiesis in heart transplant patients? A retrospective analysis

BACKGROUND

Proliferation signal inhibitors may adversely impact bone marrow function. We sought to describe the impact of sirolimus on hemoglobin and erythropoiesis in heart transplant recipients.

METHODS

We have conducted a single-center, retrospective analysis of all heart transplant patients treated with sirolimus. We measured serum hemoglobin (Hb) at baseline and at 3 months to determine the prevalence of anemia and change in Hb after sirolimus initiation. We also characterized hematologic profile of patients to gain insights into the effects of sirolimus on erythropoiesis.

RESULTS

There were 84 patients included in the study. The prevalence of anemia increased from 71% to 75% after sirolimus initiation. Anemic patients were more likely to be male (P = .026) and have worse renal function (glomerular filtration rate 49 ± 27 vs 70 ± 42 mL/min; P = .012). A ≥20 g/L drop in Hb was observed in 25% of the overall cohort. Patients investigated for anemia (n = 67) had a low Hb (111 ± 24 g/L), normal mean corpuscular volume (87 ± 47 FL), and low serum iron levels (10 ± 5 μmol/L) and transferrin saturation (0.22 ± 0.12). Serum ferritin was variable (263 ± 370 μg/L). Bone marrow evaluation in 19 patients revealed adequate marrow iron stores in all cases.

CONCLUSION

Anemia is prevalent in heart transplant patients treated with sirolimus and increases over time. Patients have a characteristic hematologic profile suggestive of anemia of chronic disease and functional iron deficiency.

Role of erythropoietin in anemia after heart transplantation

BACKGROUND

Anemia after heart transplantation is common; however, there are scant data on etiology and treatment. This study evaluates type of anemia and the effects of erythropoietin therapy.

METHODS

In 37 anemic heart transplant recipients (31 male/59.1+/-10.3 years/hemoglobin <12.0 g/dl), complete anemia work-up was performed including erythropoietin determination. For three months, 12 anemic patients with renal failure (9 male/64.1+/-13.6 years) were treated with 1-3x4000 IU of epoietin beta/week; treatment endpoints were hemoglobin levels and quality of life as determined by questionnaire.

RESULTS

In 31 patients no other cause of anemia than renal insufficiency (mean creatinine 1.9+/-0.9 mg/dl, mean calculated GFR 50.8+/-21.5 ml/min, no hemodialysis) was found; in 93.5% of these patients with renal insufficiency, measured erythropoietin levels were markedly lower than predicted [Beguin Y, Clemons GK, Pootrakul P, Fillet G. Quantitative assessment of erythropoiesis and functional classification of anemia based on measurements of serum transferrin receptor and erythropoietin. Blood 1993; 81(4):1067-1076.]. There was an inverse correlation of hemoglobin levels with serum creatinine/creatinine clearance and a strong trend for inverse correlation of erythropoietin levels. All 12 patients treated with erythropoietin showed a significant increase in hemoglobin levels after three months returning to pre-treatment values within 3 months of cessation of therapy (before study 10.8+/-1.1 g/dl, end of study 14.1+/-1.7 g/dl, three months after end of study 11.6+/-2.1 g/dl; p<0.005). Quality of life was significantly improved in eight patients (75%).

CONCLUSIONS

Anemia after heart transplantation is associated with moderate renal failure and low erythropoietin levels in most patients. Erythropoietin therapy resulted in increased hemoglobin levels in all and improved quality of life in 75% of patients. Erythropoietin may be a superior marker of functional renal impairment after heart transplantation; its therapeutic substitution allows effective anemia management and improves quality of life.

Unexpectedly high prevalence of posttransplant anemia in pediatric and young adult renal transplant recipients

BACKGROUND

Although posttransplant anemia (PTA) is recognized as a common problem in adult renal transplant recipients, few pediatric studies have been published.

METHODS

In this retrospective cohort study of 162 pediatric renal transplant recipients treated at Stanford University, the authors sought to determine the prevalence, severity, and the predictive factors of PTA. Anemia was defined as a hematocrit (HCT) level greater than 2 SD below published means for age or as erythropoietin dependency to maintain a normal HCT.

RESULTS

Sixty-seven percent of pediatric renal transplant recipients were anemic at the time of transplantation. The prevalence of anemia increased to 84.3% in the first month posttransplant. From 6 months to 60 months posttransplant, the prevalence of anemia remained high at 64.2% to 82.2%. Only 4 patients (2.5%) were never anemic. Iron depletion was detected in 19 of 26 and 23 of 23 anemic patients 12 and 60 months posttransplant, respectively. Serum erythropoietin levels were low relative to hematocrit levels in 38 of 56 anemic patients. Logistic regression at 3 months posttransplant showed that discharge hematocrit level (P < 0.0001), calcium (P = 0.0004), and cyclosporine dose (P = 0.0002) correlated with anemia. Creatinine clearance (P = 0.002) and white blood cell count (P = 0.004) correlated with anemia at 12 months posttransplant, but only creatinine clearance (P = 0.011) correlated with anemia 60 months posttransplant.

CONCLUSION

Nearly all pediatric renal transplant recipients experience PTA. However, few children less than 2 years of age were anemic during the first year posttransplant. Antirejection therapy, bone disease, iron depletion, and creatinine clearance appear to play pivotal roles in the development of PTA in children.

Characteristics and clinical relevance of chronic anemia in adult heart transplant recipients

BACKGROUND

Mild chronic anemia following heart transplantation (HTX), with hemoglobin (Hb) values of 10-14 g/dL in men and 10-12 g/dL in women, is frequent. It has continued to be of uncertain etiology yet clinical relevance. Nonetheless, therapeutic immunosuppression has been regarded as a major cause of chronic anemia in HTX patients.

METHODS

Sixty outpatients were observed over a period of 5 yr after HTX. Laboratory values related to anemia such as Hb, erythropoietin (EPO), ferritin, transferrin, iron, and vitamin levels were obtained and analyzed monthly. Patients were divided into two groups retrospectively. Patients with persistent anemia for more than 1 yr were compared with non-anemic patients.

RESULTS

Forty-three (72%) of the 60 patients were anemic. Anemia was normochromic, normocytic, and slightly anisocytic. Anemic and non-anemic patients showed EPO levels within the expected range as defined by Erslev (Erythropoietin. N Engl J Med 1991: 324: 1339). Reticulocyte counts were found to be normal in all patients. Iron deficiency and deficiency of vitamin B12 or folic acid were not observed. Patients with persistent anemia showed a significantly shorter survival period than non-anemic patients (p<0.02).

CONCLUSIONS

Mild anemia following HTX shows the same characteristics as anemia in chronic diseases. Persisting mild anemia used to be associated with a shorter life expectancy. There is no evidence that standard immunosuppression causes anemia.