Anemia and erythrocytosis after kidney transplantation: a 5-year graft function and survival analysis

A systematic review and meta-analysis of factors contributing to post-kidney transplant anemia and the effect of erythropoietin-stimulating agents

BACKGROUND

The effects of various risk and associated factors on post-kidney transplant anemia (PTA) have not been fully compared and estimated. This meta-analysis aims to elucidate factors contributing to PTA and determine the influence of erythropoietin-stimulating agents (ESAs) on renal outcomes, thus offering potential pathways for enhanced management strategies post-transplant.

METHODS

A systematic review was conducted in electronical database. Studies reporting on risk factors (with cause-effect relationships) and associated factors (without definite cause-effect relationships) of PTA, and the effects of ESAs on post-kidney transplant outcomes, were included. Pooled odds ratios (ORs) and weighted mean differences (WMDs) were analyzed using random-effects models.

RESULTS

This systematic review encompassed 38,233 patients from 85 studies. Factors increased PTA risk included African American, older donor age, human antigen leukocyte mismatches, and low pre-transplant hemoglobin levels. Poor allograft function, high interleukine-6, Cytomegalovirus, delayed graft function, allograft rejections, immunosuppressive medications, and renin-angiotensin system blockades were associated with PTA. Native autosomal dominant polycystic kidney disease was a protective factor against PTA. Administration of ESAs with the aim of normalizing hemoglobin levels in patients with chronic allograft dysfunction slowed the decline in eGFR and reduce the risk of death, with a pooled OR of 0.36 (95% CI: 0.14 to 0.89; p = 0.040).

CONCLUSIONS

The risks and associated factors for PTA have been elucidated, underscoring the need for individualized treatment approaches. Late ESA therapy, aimed at hemoglobin normalization, suggests a renal-protective effect and reduced mortality, which should be considered in the management of PTA.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42024545330.

Risk factors and current state of therapy for anemia after kidney transplantation

Post-transplant anemia is one of the most common complications in kidney transplant recipients, severely affecting patient prognosis and quality of life, and is an independent predictor of graft kidney loss and patient mortality. However, our clinical understanding and the attention given to post-transplant anemia are currently insufficient. This paper reviews the current status, risk factors, and therapeutic progress in anemia after transplantation in kidney transplant recipients. We recommend that clinical staff pay attention to anemia and its complications in kidney transplant recipients and intervene early for anemia.

Eye Lesions in Patients After One Year of Kidney Transplantation

Purpose

Determine the incidence of some eye lesions in kidney transplant patients after one year at Military Hospital 103 and comment on related factors.

Patients and Methods

A cross-sectional study description of 111 kidney transplant patients (222 eyes) at Military Hospital 103. We assessed several eye lesions, including dry eyes, corneal conjunctival calcification, cataracts, and retinopathy.

Results

The rate of retinopathy was 84.7%, dry eye was 59.5%, cataract was 29.7%, and corneal conjunctival calcification was 24.8%, atrophy optic nerve was 9.9%, epiretinal membrane was 1.8%. Post-transplant influence factors associated with cataracts include the dose of prednisolone (OR= 1.6, p < 0.05) and post-transplant diabetes (OR=1.4, p < 0.05). The influence factor related to the atrophy of the optic nerve is systemic infection after transplantation (OR=2.4, p < 0.05).

Conclusion

Retinopathy accounted for the highest rate, followed by dry eye disease; cataracts ranked third; and finally, calcified corneal conjunctiva. Factors that affect cataracts are diabetes mellitus and prednisolone dose. Factors affecting optic nerve atrophy are infections after kidney transplantation.

Postrenal transplant anemia and its effects on patients and graft outcomes: Seven years follow-up

Introduction

Post-transplant anemia (PTA) is a common serious complication following kidney transplantation. It affects graft and patient survival. Anemia that presents within six months post-transplantation is defined as an early PTA. Late PTA is when anemia occurs more than six months following transplantation. Despite this, there are limited studies on the long-term impact of anemia on patient survival and graft function in kidney transplants. We conducted a retrospective study with long-term follow-up to investigate the effect of early and late PTA on patient and graft function within seven years and to estimate the prevalence of PTA at six months, two, four, and seven years postrenal transplantation along with the associated risk factors.

Method

A retrospective chart review of 145 adult patients who had kidney transplants from January 1 to December 31, 2015, and were followed up until December 31, 2022. Anemia was defined according to the World Health Organization (WHO) criteria of hemoglobin<12 gm/dl in females and<13 mg/dl in males. Pretransplant, six months, two, four, and seven years postrenal transplantation medications and laboratory data were obtained. Patients were excluded if they were pediatrics or had missing data.

Result

180 patients were screened, and 145 patients met the inclusion criteria. The prevalence of early PTA was 8.3%. Trimethoprim-sulfamethoxazole was significantly associated with anemia within six months. The prevalence of anemia increased at two, four-, and seven-years post-transplant (24.8%, 24.8%, and 27.6%, respectively). Graft failure was significantly associated with late PTA at four and seven years (p-value < 0.001). P < 0.005, respectively). Death was reported for 3 patients, and it was significantly associated with late transplant anemia (p-value < 0.005), Cytomegalovirus was associated with anemia at 6 months and 2 years post-transplant and significantly associated with graft failure (p-value < 0.037).

Conclusion

The results of this study indicate that post-transplant anemia is associated with graft failure and patient mortality. Therefore, managing anemia post-transplant should be addressed more carefully.

A Systematic Review and Meta-Analysis of Posttransplant Anemia With Overall Mortality and Cardiovascular Outcomes Among Kidney Transplant Recipients

Introduction: Posttransplant anemia is a common finding after kidney transplantation. A previous meta-analysis reported an association between anemia and graft loss. However, data on cardiovascular outcomes have not yet been reported. Objective: We conducted an updated meta-analysis to examine the association between posttransplant anemia and outcomes after transplantation including cardiovascular mortality in adult kidney transplant recipients. Methods: We comprehensively searched the databases of MEDLINE and EMBASE from inception to November 2021. Data from each study were combined using the random-effects model. Generic inverse variance method of DerSimonian and Laird was employed to calculate the risk ratios and 95% CIs. Results: Seventeen studies from August 2006 to April 2019 were included (16 463 kidney transplantation recipients). Posttransplant anemia was associated with overall mortality (pooled risk ratio = 1.72 [1.39, 2.13], I² = 56%), graft loss (pooled risk ratio = 2.28 [1.77, 2.93], I² = 94%), cardiovascular death (pooled risk ratio = 2.06 [1.35, 3.16], I² = 0%), and cardiovascular events (pooled risk ratio = 1.33 [1.10, 1.61], I² = 0%). Early anemia (≤6 months), compared with late anemia (>6 months), has higher risk of overall mortality and graft loss with a pooled risk ratio of 2.63 (95% CI 1.79-3.86; I² = 0%) and 2.96 (95% CI 2.29-3.82; I² = 0%), respectively. Discussion: In addition to increased risk of graft loss, our updated meta-analysis demonstrated that posttransplant anemia was significantly associated with poor outcomes after kidney transplantation including overall mortality, graft loss, cardiovascular death, and cardiovascular events. Future studies are required to assess the effects of treatment strategies for posttransplant anemia on posttransplant outcomes including cardiovascular mortality.

Management of drug-induced neutropenia, thrombocytopenia, and anaemia after solid organ transplantation: A comprehensive review

WHAT IS KNOWN AND OBJECTIVE

Advances in the development of more effective immunosuppressive drugs have increased graft survival and drug induced adverse effects. Haematological complications including neutropenia, thrombocytopenia, and anaemia are common side effects that affect the grafts' and patients' outcomes. Several studies have stated the important role of various medications in haematological complications after transplantation. They have reported the incidence and different mechanisms of drug induced cytopenia, as well as an overview of possible treatment modalities. However, there is no comprehensive protocol for the management of these complications following transplantation. This narrative review was performed to develop a comprehensive practical approach for management of drug induced haematological complications following solid organ transplantation.

METHOD

PubMed, Embase, Cochrane library, Web of Science, and Google scholar databases were searched without time limitations until March, 2021. In addition, some valid drug information data bases (Uptodate and Micromedex) were searched for detailed information until October, 2021.

RESULTS AND DISCUSSION

Several immunosuppressive and antimicrobial medications may induce neutropenia, thrombocytopenia or anaemia following transplantation. Most of these agents cause dose-related cytopenia, which resolves with dose reduction or drug withdrawal. However, any change in medications may result in negative consequences such as severe infections, bleeding, cardiovascular complications, acute allograft rejection, and graft or patient loss. Thus, cautious evaluation of the patient's condition and the pharmacological properties of the culprit medication are required.

WHAT IS NEW AND CONCLUSION

Three algorithms are presented to guide healthcare providers in the stepwise management of drug-induced neutropenia, thrombocytopenia, and anaemia after solid organ transplantation.

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-transplantation erythrocytosis in kidney transplant recipients-A retrospective cohort study

OBJECTIVES

To characterize risk factors for the development of post-transplant erythrocytosis (PTE), and its long-term effect on mortality, graft failure, and thrombosis.

METHODS

Retrospective study including all kidney transplant recipients in Rabin Medical Center (RMC) during the years 2005-2014. The primary outcome was a composite outcome of all-cause mortality or graft failure at the end of follow-up. Secondary outcomes included death censored graft loss, venous thromboembolism, major adverse cardiovascular events, and mortality. A matched control group was also evaluated. Univariate and multivariate time-varying Cox model analyses were conducted for outcome evaluation.

RESULTS

A total of 1304 patients were included, 169 of whom were diagnosed with PTE (12.9%). PTE was associated with male gender, higher glomerular filtration rate (GFR), and polycystic kidney disease. PTE was found to be associated with a reduced risk of the primary outcome (HR 0.355, CI 95% 0.151-0.89, P = .027) in a univariate time-varying Cox analysis, but was not associated with the composite outcome in a multivariate analysis. There was no difference in the primary outcome when the PTE group was compared with the matched control.

CONCLUSION

PTE was not found to be associated with long-term outcomes of graft failure and poor survival.

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.

Relative decrease in hemoglobin and outcomes in patients undergoing kidney transplantation surgery: A retrospective cohort study

BACKGROUND

Recent surgical literature suggests that a relative decrease in hemoglobin (ΔHb) is predictive of adverse outcomes regardless of the absolute level. We aimed to examine the association between perioperative ΔHb and kidney transplantation (KT) outcomes.

METHODS

This was a retrospective cohort study of transplant recipients, where ΔHb = [Hb0- Hb1Hb0]x 100 (Hb₀ = hemoglobin pre-KT and Hb₁ = lowest hemoglobin 24-h post-KT). The main outcome of interest was immediate graft function (IGF).

RESULTS

Of the 899 eligible patients, 38% experienced IGF, and ΔHb was associated with 36% lower odds of IGF. Also, ΔHb was associated with higher all-cause graft failure and longer length of stay but not death-censored graft failure or mortality. ΔHb ≥30% was the threshold beyond which the odds of IGF were significantly lower even if Hb₁ was ≥7 g/dL.

CONCLUSION

ΔHb is associated with inferior outcomes independent of Hb_1; whether it can be used to guide transfusion practices should be explored.

Incidence, risk factors, and outcomes of post-transplant erythrocytosis after kidney transplantation

The incidence, risk factors, and outcomes of kidney transplant recipients (KTRs) with post-transplant erythrocytosis (PTE) in the modern era of strong, protocolized immunosuppressive management are unknown. In this study, we aim to identify the incidence and risk factors of PTE and outcomes associated with PTE. This study examined adult KTRs transplanted at our hospital between 01/2001 and 12/2016. Controls were KTRs without PTE and selected in a 1:5 ratio using incident density sampling. Patient survival, graft survival, and vascular thromboembolism (VTE) incidence were outcomes of interest. Of 4,317 kidney transplants during the study period, 214 (5%) had PTE and were compared with controls. In the multivariate analysis, recipients with older age (HR: 0.97, 95% CI 0.96-0.99, p = .001) were less likely to develop PTE, while male gender (HR: 3.2; 95% CI: 1.92-5.3, p < .001) and non-preemptive transplant (HR: 3.86, 95% CI 1.56-9.56, p = .003) were associated with increased risk of PTE. After adjustment for confounding factors, PTE was not associated with patient mortality (HR: 0.99, 95% CI 0.69-1.42, p = .97), graft failure (HR: 1.11, 95% CI 0.68-1.80, p = .69), or VTE (HR: 1.07, 95% CI 0.59-1.96, p = .81). The incidence of PTE is still substantial in this era, but with proper management PTE does not impact patient or graft survival.

Haematological disorders following kidney transplantation

Transplantation offers cure for some haematological cancers, end-stage organ failure, but at the cost of long-term complications. Renal transplantation is the best-known kidney replacement therapy and it can prolong end-stage renal disease patient lives for decades. However, patients after renal transplantation are at a higher risk of developing different complications connected not only with surgical procedure but also with immunosuppressive treatment, chronic kidney disease progression and rejection processes. Various blood disorders can develop in post-transplant patients ranging from relatively benign anaemia through cytopenias to therapy-related myelodysplasia and acute myeloid leukaemia (AML) and post-transplant lymphoproliferative disorders followed by a rare and fatal condition of thrombotic microangiopathy and haemophagocytic syndrome. So far literature mainly focused on the post-transplant lymphoproliferative disease. In this review, a variety of haematological problems after transplantation ranging from rare disorders such as myelodysplasia and AML to relatively common conditions such as anaemia and iron deficiency are presented with up-to-date diagnosis and management.

Guillain-Barre syndrome: a typical paraneoplastic syndrome in a kidney transplant recipient with allograft renal cell carcinoma: a case report and review of the literature

BACKGROUND

Guillain-Barré syndrome (GBS) is an autoimmune polyneuropathy affecting the peripheral nervous system. This neurological disorder has been previously reported in bone marrow transplant recipients but is uncommon after kidney transplantation. Viral infections and calcineurin inhibitors are the main triggers of GBS in renal transplant recipients.

CASE PRESENTATION

In this report, we present a case of a 47-year-old male patient 12 years after his second kidney transplantation who developed GBS due to papillary renal cell carcinoma. Infectious and drug-related origins of GBS were excluded. Despite intensive treatment, graftectomy was performed, after which neurological symptoms resolved.

CONCLUSIONS

In kidney transplant recipients, paraneoplastic aetiology should be considered in the differential diagnosis of GBS.

Is There a Temporal Relationship Between Trough Whole Blood Tacrolimus Concentration and Acute Rejection in the First 14 Days After Kidney Transplantation?

BACKGROUND

There are inconsistent findings regarding the relationship between trough whole blood tacrolimus concentration (TAC C0) and acute kidney rejection in recipients undergoing TAC therapeutic drug monitoring (TDM). However, studies have not always assessed TAC C0 at the time of rejection or accounted for variability in hematocrit. Therefore, this study aimed to investigate the temporal relationship between TAC C0 and acute rejection, including when accounting for variation in hematocrit.

METHODS

For 38 recipients who developed biopsy-proven acute rejection (BPAR) in the first 14 days after kidney transplantation, daily TAC C0 from TDM and hematocrit was collected from case notes. Differences in log10-transformed TAC C0 between the day of BPAR (log Cr), 1 day before BPAR (log Cr-1), and 2 days before BPAR (log Cr-2) and the combined median concentrations for the days preceding these (log Cprior) were examined by repeated-measures analysis of variance with Dunnett post hoc testing. Generalized linear mixed-effects regression (glmer) examined the ability of TAC C0 to predict acute rejection episodes with and without controlling for hematocrit.

RESULTS

Log Cr-1 [mean difference (95% confidence interval) = -0.13 (-0.21 to -0.048), post hoc P = 0.002] and log Cr [-0.13 (-0.24 to -0.025), post hoc P = 0.013] were significantly lower than log Cprior. TAC C0 was a significant (P = 0.0078) predictor of rejection episodes (area under the receiver operating characteristic curve = 0.79) only in glmer models accounting for variability in hematocrit.

CONCLUSIONS

In recipients who developed BPAR, there was a significant temporal relationship between TAC C0 and BPAR incidence under TAC TDM that may not be detected in cross-sectional studies, especially if variability in hematocrit is not addressed. This supports a TAC C0-rejection relationship, which differs between recipients, and may explain why some recipients do or do not experience rejection within or below the TDM range, respectively. However, studies with larger sample sizes are needed to confirm this finding.

Anemia control in kidney transplant recipients using once-monthly continuous erythropoietin receptor activator: a prospective, observational study

In a multicenter, prospective, observational study of 279 kidney transplant recipients with anemia, the efficacy and safety of once-monthly continuous erythropoietin receptor activator (C.E.R.A.) were assessed to a maximum of 15 months. The main efficacy variable was the proportion of patients achieving a hemoglobin level of 11-12 g/dL at each of visits between months 7 and 9. At study entry, 224 patients (80.3%) were receiving erythropoiesis stimulating agent (ESA) therapy including darbepoetin alfa (98), epoetin beta (61), and C.E.R.A. (45). The mean (SD) time between C.E.R.A. applications was 34.0 (11.9) days. Among 193 patients for whom efficacy data were available, mean (SD) hemoglobin was 11.1 (0.99) g/dL at study entry, 11.5 (1.1) g/dL at month 7, 11.6 (1.3) g/dL at month 9, and 11.4 (1.1) g/dL at month 15. During months 7–9, 20.7% of patients had all hemoglobin values within the range 11-12 g/dL and 64.8% were within 10–13 g/dL. Seven patients (2.5%) discontinued C.E.R.A. due to adverse events or serious adverse events. In this observational trial under real-life conditions, once-monthly C.E.R.A. therapy achieved stable hemoglobin levels in stable kidney transplant recipients with good tolerability, and with no requirement for any dose change in 43% of patients.

Blood disorders after kidney transplantation

Post transplant anemia (PTA) is a common issue in kidney transplant recipients. Most importantly it is associated with an impaired allograft function. Other important factors associated with PTA are immunosuppressive drugs (MPA, AZA and SRL), iron deficiency, infections (Parvo B19), older donor age, rejection episodes, an increased inflammatory state, and erythropoietin hyporesponsiveness. As there are no adequately powered RCTs in the kidney transplant population on anemia treatment with ESA, we have to rely on what we know from the large RCTs in the CKD population. The recently published KDIGO guidelines do not recommend treatment with ESA if Hb is >10 g/dl. Repletion of iron stores is emphasized. Post transplant leukopenia (PTL) and thrombocytopenia (PTT) are frequent complications especially in the first six months after kidney transplantation. Myelosuppression caused by immunosuppressive agents (MPA, AZA, SRL, rATG), antimicrobial drugs (VGCV), and CMV infection is the predominant cause. There are no widely accepted guidelines on treatment strategies, but most often dose reduction or discontinuation of causative medication is done. Most clinicians tend to decrease MPA dose, but this is eventually associated with an increase in acute rejection episodes. VGCV dose reduction (preemptive treatment instead of CMV prophylaxis) may be a successful strategy. In severe cases G-CSF treatment is an important management option and seems to be safe.

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.

Increasing levels of hemoglobin improve renal transplantation outcomes

INTRODUCTION

Several studies have reported various data on prevalence of posttransplant anemia (PTA). We have little information about its impact on long-term graft outcomes and few studies of the optimal hemoglobin (Hb) target in kidney transplantation.

METHODS

We examined retrospectively 144 kidney transplant recipients of mean age 44.4 ± 12.3 years and follow-up of 40.5 ± 4.6 months. Exclusion criteria were age below 18 years, multiorgan transplantation, and graft failure in the first year. Using simple and multiple linear regression models, we evaluated the potential prediction of a serum concentration of Hb at 1 year after renal transplantation on allograft outcome as measured by Δ% estimated glomerular filtration rate (eGFR), the difference between eGFR, measured with the Modification of Diet in Renal Disease (MDRD) formula, at the end of follow-up, and at 1 year. Multiple models were adjusted for recipient sex, recipient age, donor age, ESA therapy, acute rejection episodes (ARE), days of delayed graft function, human leukocyte antigen mismatches and cold ischemia time.

RESULTS

At 1 year after transplantation, the mean Hb level was 13.77 ± 1.87 g/dL in males and 12.52 ± 1.53 g/dL in females. The average eGFR at 1 year was 63.07 ± 25.88 mL/min. At the end of follow-up, the mean Δ% eGFR was -5.73% ± 27.30%. Blood concentration of Hb correlated with donor, recipient sex, ARE, and eGFR at 1 year. There was a close correlation between the Δ% Hb and eGFR upon univariate analysis and the multiple linear regression model. Hb was the only predictor of transplant outcome.

CONCLUSIONS

Many factors are involved in kidney allograft function. Among these, Hb is important. In this work we demonstrated that increasing levels of Hb at 1 year after transplantation seemed to predict better preservation of graft function, representing a marker of a good quality graft.