Do Exercise, Physical Activity, Dietetic, or Combined Interventions Improve Body Weight in New Kidney Transplant Recipients? A Narrative Systematic Review and Meta-Analysis

Weight gain within the first year of kidney transplantation is associated with adverse outcomes. This narrative systematic review and meta-analysis examines the effect of exercise, physical activity, dietary, and/or combined interventions on body weight and body mass index (BMI) within the first year of kidney transplantation. Seven databases were searched from January 1985 to April 2021 (Prospero ID: CRD42019140865), using a ‘Population, Intervention, Controls, Outcome’ (PICO) framework. The risk-of-bias was assessed by two reviewers. A random-effects meta-analysis was conducted on randomized controlled trials (RCTs) that included post-intervention body weight or BMI values. Of the 1197 articles screened, sixteen met the search criteria. Ten were RCTs, and six were quasi-experimental studies, including a total of 1821 new kidney transplant recipients. The sample sizes ranged from 8 to 452. Interventions (duration and type) were variable. Random-effects meta-analysis revealed no significant difference in post-intervention body weight (−2.5 kg, 95% CI −5.22 to 0.22) or BMI (−0.4 kg/m2, 95% CI −1.33 to 0.54). Despite methodological variance, statistical heterogeneity was not significant. Sensitivity analysis suggests combined interventions warrant further investigation. Five RCTs were classified as ‘high-risk’, one as ‘some-concerns’, and four as ‘low-risk’ for bias. We did not find evidence that dietary, exercise, or combined interventions led to significant changes in body weight or BMI post kidney transplantation. The number and quality of intervention studies are low. Higher quality RCTs are needed to evaluate the immediate and longer-term effects of combined interventions on body weight in new kidney transplant recipients.

Download Full-text

Prognostic value of myocardial perfusion imaging in kidney transplant recipients: a systematic review and meta-analysis

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeab111.032 ◽

2021 ◽

Vol 22 (Supplement_3) ◽

Author(s):

FEJ Jolink ◽

JR Kelderman ◽

AG Monroy Gonzalez ◽

S Benjamens ◽

RHJA Slart ◽

...

Keyword(s):

Kidney Transplantation ◽

Myocardial Perfusion Imaging ◽

Myocardial Perfusion ◽

Kidney Transplant ◽

Cardiovascular Mortality ◽

Prognostic Value ◽

Meta Analysis ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Increased Risk

Abstract Funding Acknowledgements Type of funding sources: None. Background Kidney transplant recipients are at risk for major adverse cardiac events (MACE) and cardiovascular mortality. We aimed to assess the prognostic value of myocardial perfusion imaging (MPI) single-photon emission computed tomography (SPECT), in patients evaluated for transplantation, for MACE and cardiovascular mortality after kidney transplantation. Methods We performed a systematic literature search in PubMed, EMBASE, Web of Science, OvidSP, The Cochrane Library and Google Scholar. We retrieved studies investigating the prognostic value of MPI for MACE and mortality in kidney transplant recipients. After risk of bias assessment using QUIPS, a meta-analysis was conducted. Results Out of 1379 records, 14 studies (7 prospective and 7 retrospective) using MPI SPECT were included in the meta-analysis with a total of 4643 MPI procedures. No studies were excluded after QUIPS assessment. Median follow-up duration of patients ranged from 1 to 8 years. Kidney transplant recipients with perfusion defects on MPI showed an increased risk for MACE (RR 2.76, 95%-CI 1.73-4.42), cardiovascular mortality (RR 3.15, 95%-CI 1.94-5.13) and all-cause mortality (RR 2.12, 95%-CI 1.76-2.54) compared to recipients with normal MPI findings. Significant heterogeneity existed across the included studies investigating MACE. Conclusions Our results showed that MPI SPECT may identify patients at increased risk for MACE and mortality after kidney transplantation.

Download Full-text

Analysis of Extracellular Fluid Volume in Peritoneal Dialysis Patients before and after Kidney Transplantation

Blood Purification ◽

10.1159/000496639 ◽

2019 ◽

Vol 47 (Suppl. 2) ◽

pp. 56-62

Author(s):

Ken Sakai ◽

Youji Hyoudou ◽

Hiroshi Nihei ◽

Takeshii Kawamura

Keyword(s):

Body Weight ◽

Kidney Transplantation ◽

Kidney Transplant ◽

Urine Volume ◽

Extracellular Fluid ◽

Body Weight Loss ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Dialysis Duration ◽

Transplant Patients

Background/Aims: To examine the relationship of extracellular fluid (ECF) volume and osmotic excess with treatment modality, we retrospectively analyzed spontaneous body weight loss and osmotic excretion versus true body weight after kidney transplantation in peritoneal dialysis (PD) patients and preemptive transplant recipients compared with hemodialysis (HD) patients. We also examined maximum bladder volume in other transplant recipients on PD. Methods: From 2005 to 2011, 42 PD patients underwent kidney transplantation at our institution. Patients aged <12 years and cadaveric transplantations were excluded; we enrolled 27 PD patients (PD group; age 35.7 ± 14.4 years at transplantation; dialysis duration 36.5 ± 31.2 months) and 14 adult preemptive kidney transplant patients (preemptive group; age 31.7 ± 15.7 years; estimated glomerular filtration rate 8.26 ± 1.8 mL/min/1.73 m2 at transplantation). From 2005 to 2006, 29 adult living-related donor kidney transplant recipients on HD support (HD group) were enrolled as controls (age 36.4 ± 11.3 years; dialysis duration 37.5 ± 55.2 months). Results: Percentage body weight loss at 1 month after transplantation was 5% from ideal body weight for the PD group (51.2 ± 14.3 to 48.6 ± 13.0 kg, p = 0.002), 5.1% for the preemptive group (56.7 ± 17.4 to 53.8 ± 16.5 kg, p = 0.0005), and 1% for the HD group (52.9 ± 12.4 to 52.1 ± 12.5 kg, p = 0.079); post-transplantation 24-h osmotic excretion was greater in the PD and preemptive groups (387.3 ± 175.7 mOsm) groups than in HD (250 ± 124 mOsm; p = 0.006. Another 69 adult living-related donor kidney transplant recipients (PD and HD support) with dialysis duration ≤5 years were examined. Mean dialysis duration differed in the HD (17.5 ± 13.1 months) and PD (29.6 ± 20.4 months, p = 0.015) groups; mean urine volume and maximum desire to void (MDV) were similar. Conclusion: ECF volume and osmotic excess occurred in the PD and preemptive groups compared with the HD group pre-transplantation. Although PD maintains MDV and residual and total urine volume, ECF volume and osmotic excess should be monitored before transplant; pre-transplant HD support should always be considered in PD and preemptive transplant patients.

Download Full-text

Epidemiology and Prognostic Importance of Atrial Fibrillation in Kidney Transplant Recipients: A Meta-Analysis

Journal of Clinical Medicine ◽

10.3390/jcm7100370 ◽

2018 ◽

Vol 7 (10) ◽

pp. 370 ◽

Cited By ~ 4

Author(s):

Charat Thongprayoon ◽

Ronpichai Chokesuwattanaskul ◽

Tarun Bathini ◽

Nadeen Khoury ◽

Konika Sharma ◽

...

Keyword(s):

Atrial Fibrillation ◽

Kidney Transplantation ◽

Kidney Transplant ◽

Meta Analysis ◽

Random Effect ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

The Individual ◽

Allograft Loss ◽

Over Time

This meta-analysis was conducted with the aims to summarize all available evidence on (1) prevalence of pre-existing atrial fibrillation (AF) and/or incidence of AF following kidney transplantation; (2) the outcomes of kidney transplant recipients with AF; and (3) the trends of estimated incidence of AF following kidney transplantation over time. A literature search was conducted utilizing MEDLINE, EMBASE, and the Cochrane Database from inception through March 2018. We included studies that reported (1) prevalence of pre-existing AF or incidence of AF following kidney transplantation or (2) outcomes of kidney transplant recipients with AF. Effect estimates from the individual study were extracted and combined utilizing random-effect, generic inverse variance method of DerSimonian and Laird. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42018086192). Eight cohort studies with 137,709 kidney transplant recipients were enrolled. Overall, the pooled estimated prevalence of pre-existing AF in patients undergoing kidney transplantation was 7.0% (95% CI: 5.6–8.8%) and pooled estimated incidence of AF following kidney transplantation was 4.9% (95% CI: 1.7–13.0%). Meta-regression analyses were performed and showed no significant correlations between year of study and either prevalence of pre-existing AF (p = 0.93) or post-operative AF after kidney transplantation (p = 0.16). The pooled odds ratios (OR) of mortality among kidney transplant recipients with AF was 1.86 (3 studies; 95% CI: 1.03–3.35). In addition, AF is also associated with death-censored allograft loss (2 studies; OR: 1.55, 95% CI: 1.02–2.35) and stroke (3 studies; OR: 2.54, 95% CI: 1.11–5.78) among kidney transplant recipients. Despite advances in medicine, incidence of AF following kidney transplant does not seem to decrease over time. In addition, there is a significant association of AF with increased mortality, allograft loss, and stroke after kidney transplantation.

Download Full-text

P1623MAJOR ADVERSE CARDIOVASCULAR EVENTS (MACE) AFTER KIDNEY TRANSPLANTATION: A POPULATION-COHORT ANALYSIS OF ENGLISH TRANSPLANT CENTRES

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa143.p1623 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Benjamin Anderson ◽

Felicity Evison ◽

Suzy Gallier ◽

Charles Ferro ◽

Adnan Sharif

Keyword(s):

Kidney Transplantation ◽

Kidney Transplant ◽

Kidney Failure ◽

Patient Survival ◽

Cohort Analysis ◽

Index Admission ◽

First Year ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Cardiac Screening

Abstract Background and Aims Due to a high burden of cardiovascular disease in end-stage kidney failure, candidates for kidney transplantation must undergo cardiac screening to determine their ‘cardiac fitness’ to proceed with surgery even when asymptomatic and in the absence of robust evidence. MACE rates within the first year after kidney transplantation in North American centres are reported at between 7.0% and 8.7% but data from an European cohort is lacking. Therefore, the aim of this population-cohort analysis was to determine the MACE rate within the first year after kidney transplantation for all kidney transplant recipients in England. Method We obtained data from every kidney transplant procedure performed in England between 1st April 2002 and 31st March 2018. Data was extracted from Hospital Episode Statistics using administrative ICD-10 and OPCS-4 codes, with linkage to the national death registry for mortality data (including causality). We excluded age ≤18, repeat transplant in same period, multi-organ transplant and residence outside England. MACE was defined as any hospital admissions with myocardial infarction, stroke, unstable angina, heart failure, any coronary revascularisation procedure and/or any cardiovascular-related death. Univariable and multivariable logistical regression analyses were conducted to investigate the odds for MACE after kidney transplantation. Results After exclusions, we had a cohort of 30,325 kidney transplant recipients for analysis. MACE events occurred in 781 kidney transplant recipients within the first-year post-transplantation (2.6% of all kidney transplant procedures). Of these 781 MACE events, 201 occurred during the index admission for kidney transplantation surgery (representing 25.7% of all first-year MACE events and 0.7% of all kidney transplant procedures). Predictors of long-term mortality on Cox regression include; age, non-White ethnicity, socio-economic deprivation, deceased donor, pre-existing diabetes, increased Charlson score, previous cardiac history and MACE within the first year (HR 2.59; 95% CI 2.34-2.88, p<0.001). Kidney transplant recipients who suffered a non-fatal MACE within the first year had 1-, 3-, 5- and 10-year patient survival of 80.5%, 70.2%, 54.5% and 38.6%, compared to 97.4%, 94.4%, 90.7% and 78.4% for kidney transplant recipients not developing MACE within the first year post-transplant (p<0.001). Kidney transplant recipients having MACE events during the index admission compared to subsequent admissions were differentiated by age, sex and previous cardiac history but had similar patient survival (p=0.283). Conclusion MACE events within the first year after kidney transplantation are associated with increased mortality risk in England but MACE rates are significantly lower at 2.6% than those reported in North America. This is despite similar cardiac screening strategies, which may reflect different patient demographics and kidney failure care. In the context of the increased debate concerning the utility of cardiac screening asymptomatic kidney transplant candidates, understanding baseline MACE rates can shape the design of clinical trials exploring non-inferiority of cardiac screening versus non-screening before joining the waiting list (which differs methodologically from the CARSK study). However, renal physicians and surgeons will need to determine the upper boundary of the 95% confidence interval for the hazard ratio of MACE risk in any future clinical trial.

Download Full-text

#77: Impact of Targeted Tacrolimus Levels on BK Polyomavirus DNAemia Among Pediatric Kidney Transplant Recipients

Journal of the Pediatric Infectious Diseases Society ◽

10.1093/jpids/piaa170.011 ◽

2021 ◽

Vol 10 (Supplement_1) ◽

pp. S4-S4

Author(s):

I Yildirim ◽

R Liverman ◽

S Serluco ◽

R George ◽

R Garro ◽

...

Keyword(s):

Kidney Transplant ◽

Early Onset ◽

Bk Virus ◽

First Year ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Post Intervention ◽

Post Transplant ◽

Bk Polyomavirus ◽

The Impact

Abstract Background Uncontrolled BK Polyomavirus (BK) DNAemia in kidney transplant recipients is a significant cause of allograft dysfunction that can lead to BK Polyomavirus-associated nephropathy with permanent damage and graft loss. BK virus DNAemia can occur early (within the first year) or late (after the first year) following a kidney transplant in children. Prospective monitoring for BK viremia with pre-emptive lowering of immunosuppression has been suggested as an effective approach to prevent BK nephropathy. We evaluated the impact of changes in targeted tacrolimus levels on the incidence of BK DNAemia early post-transplant. Methods In response to a cluster of early-onset BK virus DNAemia cases in the first quarter of 2015, we pursued a quality improvement study to determine whether changes to tacrolimus trough targets for the first 100 days post-transplant would reduce the incidence and severity of BK DNAemia. Targeted tacrolimus levels were decreased by approximately 25% (see Table) and patients receiving transplant from March 20, 2015, and December 31, 2018, were prospectively monitored. The incidence rates of BK DNAemia detected on monthly surveillance testing in the first-year post-transplant were compared for patients transplanted between January 1, 2013, and March 14, 2015 (pre-intervention) and March 15, 2015, to December 31, 2018 (post-intervention). Results Of 148 children who received kidney transplants during the study period, 52 (35%) were transplanted in the pre-intervention era and 96(65%) were transplanted during the post-intervention era. The median age at transplant was 13.9 years [interquartile range (IQR) 8.0–16.7 years]. Age at transplant, gender (overall 55% male), and race (overall 54% White, 35% Black) was not significantly different between the cohorts. The risk of early-onset BK DNAemia within the first 100 days post-transplant was 19 per 100 patients in the pre-intervention cohort and 13 per 100 patients in the post-intervention cohort, corresponding to a 35% reduction after lowering targeted tacrolimus levels. The median time to first detected BK DNAemia increased from 77 days (IQR 45–90 days) in pre-intervention to 104 days (IQR 47–174 days) in the post-intervention cohort. Conclusions BK DNAemia heralds a serious complication of kidney transplantation and may represent over immunosuppression and increased risk for other infectious complications. We were able to reduce the rate of early-onset BK DNAemia by reducing tacrolimus target levels in the first 12 weeks post-transplant. Preventing early uncontrolled viremia may decrease the need for immunosuppression reduction which increases the risk for rejection.

Download Full-text

Current Pharmacological Intervention and Medical Management for Diabetic Kidney Transplant Recipients

Pharmaceutics ◽

10.3390/pharmaceutics13030413 ◽

2021 ◽

Vol 13 (3) ◽

pp. 413

Author(s):

Theerawut Klangjareonchai ◽

Natsuki Eguchi ◽

Ekamol Tantisattamo ◽

Antoney J. Ferrey ◽

Uttam Reddy ◽

...

Keyword(s):

Diabetes Mellitus ◽

Kidney Transplantation ◽

Kidney Transplant ◽

Pharmacological Intervention ◽

Diabetic Patients ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Kidney Allograft ◽

Post Transplant ◽

Glucose Management

Hyperglycemia after kidney transplantation is common in both diabetic and non-diabetic patients. Both pretransplant and post-transplant diabetes mellitus are associated with increased kidney allograft failure and mortality. Glucose management may be challenging for kidney transplant recipients. The pathophysiology and pattern of hyperglycemia in patients following kidney transplantation is different from those with type 2 diabetes mellitus. In patients with pre-existing and post-transplant diabetes mellitus, there is limited data on the management of hyperglycemia after kidney transplantation. The following article discusses the nomenclature and diagnosis of pre- and post-transplant diabetes mellitus, the impact of transplant-related hyperglycemia on patient and kidney allograft outcomes, risk factors and potential pathogenic mechanisms of hyperglycemia after kidney transplantation, glucose management before and after transplantation, and modalities for prevention of post-transplant diabetes mellitus.

Download Full-text

BK Polyomavirus Micro-RNAs: Time Course and Clinical Relevance in Kidney Transplant Recipients

Viruses ◽

10.3390/v13020351 ◽

2021 ◽

Vol 13 (2) ◽

pp. 351

Author(s):

Baptiste Demey ◽

Véronique Descamps ◽

Claire Presne ◽

Francois Helle ◽

Catherine Francois ◽

...

Keyword(s):

Viral Replication ◽

Kidney Transplant ◽

Clinical Relevance ◽

Graft Loss ◽

First Year ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Post Transplantation ◽

Bk Polyomavirus ◽

Micro Rnas

Background: Kidney transplant recipients (KTRs) are exposed to a high risk of BK polyomavirus (BKPyV) replication, which in turn may lead to graft loss. Although the microRNAs (miRNAs) bkv-miR-B1-3p and bkv-miR-B1-5p are produced during the viral cycle, their putative value as markers of viral replication has yet to be established. In KTRs, the clinical relevance of the changes over time in BKPyV miRNA levels has not been determined. Methods: In a retrospective study, we analyzed 186 urine samples and 120 plasma samples collected from 67 KTRs during the first year post-transplantation. Using a reproducible, standardized, quantitative RT-PCR assay, we measured the levels of bkv-miR-B1-3p and bkv-miR-B1-5p (relative to the BKPyV DNA load). Results: Detection of the two miRNAs had low diagnostic value for identifying patients with DNAemia or for predicting DNAuria during follow-up. Seven of the 14 KTRs with a sustained BKPyV infection within the first year post-transplantation showed a progressive reduction in the DNA load and then a rapid disappearance of the miRNAs. DNA and miRNA loads were stable in the other seven KTRs. Conclusions: After the DNA-based diagnosis of BKPyV infection in KTRs, bkv-miR-B1-3p and bkv-miR-B1-5p levels in the urine might be valuable markers for viral replication monitoring and thus might help physicians to avoid an excessive reduction in the immunosuppressive regimen.

Download Full-text

Standard induction with basiliximab versus no induction in low immunological risk kidney transplant recipients: study protocol for a randomized controlled trial

Trials ◽

10.1186/s13063-021-05253-1 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Aziza Ajlan ◽

Hassan Aleid ◽

Tariq Zulfiquar Ali ◽

Hala Joharji ◽

Khalid Almeshari ◽

...

Keyword(s):

Kidney Transplant ◽

De Novo ◽

Controlled Trial ◽

Controlled Clinical Trial ◽

First Year ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Double Blind ◽

Donor Specific Antibodies

Abstract Background Induction therapy with IL-2 receptor antagonist (IL2-RA) is recommended as a first-line agent in low immunological risk kidney transplant recipients. However, the role of IL2-RA in the setting of tacrolimus-based immunosuppression has not been fully investigated. Aims To compare different induction therapeutic strategies with 2 doses of basiliximab vs. no induction in low immunologic risk kidney transplant recipients as per KFSHRC protocol. Methods Prospective, randomized, double blind, non-inferiority, controlled clinical trial Expected outcomes 1. Primary outcomes: Biopsy-proven acute rejection within first year following transplant 2. Secondary outcomes: a. Patient and graft survival at 1 year b. eGFR at 6 months and at 12 months c. Emergence of de novo donor-specific antibodies (DSAs) Trial registration The study has been prospectively registered at clinicaltrials.gov (NTC: 04404127). Registered on 27 May 2020.

Download Full-text

Outcomes of Kidney Transplantation in Fabry Disease: A Meta-Analysis

Diseases ◽

10.3390/diseases9010002 ◽

2020 ◽

Vol 9 (1) ◽

pp. 2

Author(s):

Maria L. Gonzalez Suarez ◽

Charat Thongprayoon ◽

Panupong Hansrivijit ◽

Juan Medaura ◽

Pradeep Vaitla ◽

...

Keyword(s):

Kidney Transplantation ◽

Fabry Disease ◽

Kidney Transplant ◽

Allograft Rejection ◽

Graft Failure ◽

Current Therapy ◽

Transplant Recipients ◽

Lysosomal Storage ◽

Kidney Transplant Recipients ◽

Enzyme Replacement

Background: Fabry disease (FD) is a rare X-linked lysosomal storage disorder with progressive systemic deposition of globotriaosylceramide, leading to life-threatening cardiac, central nervous system, and kidney disease. Current therapy involves symptomatic medical management, enzyme replacement therapy (ERT), dialysis, kidney transplantation, and, more recently, gene therapy. The aim of this systematic review was to assess outcomes of kidney transplantation among patients with FD. Methods: A comprehensive literature review was conducted utilizing MEDLINE, EMBASE, and Cochrane Database, from inception through to 28 February 2020, to identify studies that evaluate outcomes of kidney transplantation including patient and allograft survival among kidney transplant patients with FD. Effect estimates from each study were extracted and combined using the random-effects generic inverse variance method of DerSimonian and Laird. Results: In total, 11 studies, including 424 kidney transplant recipients with FD, were enrolled. The post-transplant median follow-up time ranged from 3 to 11.5 years. Overall, the pooled estimated rates of all-cause graft failure, graft failure before death, and allograft rejection were 32.5% (95%CI: 23.9%–42.5%), 14.5% (95%CI: 8.4%–23.7%), and 20.2% (95%CI: 15.4%–25.9%), respectively. In the sensitivity analysis, limited only to the recent studies (year 2001 or newer when ERT became available), the pooled estimated rates of all-cause graft failure, graft failure before death, and allograft rejection were 28.1% (95%CI: 20.5%–37.3%), 11.7% (95%CI: 8.4%–16.0%), and 20.2% (95%CI: 15.5%–26.0%), respectively. The pooled estimated rate of biopsy proven FD recurrence was 11.1% (95%CI: 3.6%–29.4%), respectively. There are no significant differences in the risks of all-cause graft failure (p = 0.10) or mortality (0.48) among recipients with vs. without FD. Conclusions: Despite possible FD recurrence after transplantation of 11.1%, allograft and patient survival are comparable among kidney transplant recipients with vs. without FD.

Download Full-text

FC 124PATTERNS OF RENAL OSTEODYSTROPHY ONE YEAR AFTER KIDNEY TRANSPLANTATION

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfab147.003 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

Hanne Skou Jørgensen ◽

Geert Behets ◽

Patrick D'Haese ◽

Pieter Evenepoel

Keyword(s):

Kidney Transplantation ◽

Bone Turnover ◽

Kidney Transplant ◽

Renal Osteodystrophy ◽

Bone Disease ◽

Transplant Recipients ◽

Kidney Transplant Recipients ◽

Post Transplant ◽

Steroid Dose ◽

Bone Biopsies

Abstract Background and Aims Bone disease after kidney transplantation is an issue of growing concern, as prolonged graft survival and older age of recipients necessitate focus on long-term health burdens such as osteoporosis and fractures. Pre-existing type of renal osteodystrophy, post-transplant immunosuppressive treatment, and de novo disturbances of mineral metabolism all contribute to bone disease in kidney transplant recipients. The current pattern of renal osteodystrophy after kidney transplantation is not well characterized. This study reports histomorphometric findings of protocolled bone biopsies in a large cohort of kidney transplant recipients 1 year post-transplant. Method Histomorphometric analysis of transiliac bone biopsies with prior tetracycline labelling was performed in 141 kidney transplant recipients. Biochemical measurements included bioactive parathyroid hormone (PTH), total calcium, phosphate, calcidiol, bicarbonate, and sclerostin. Kruskal-Wallis and Wilcoxon signed rank tests were used to evaluate differences across categories and between groups, respectively. Stepwise multivariate linear regression was performed to identify key demographic and biochemical determinants of bone turnover (bone formation rate, BFR), mineralization (mineralization lag time, Mlt), and volume (Bone area, BAr). Results Mean age was 57±11 years, 71% were men, and all were Caucasian. Mean eGFR was 49±16 (range 19 to 106) ml/min/1.73 m². Hyperparathyroidism (PTH > 1.5xUNL) was seen in 48%, hypercalcemia (>10.3 mg/dL) in 18%, hypophosphatemia (<2.3 mg/dl) in 12%, and vitamin D deficiency (<15 ng/mL) in 4% of patients. Categorization of bone turnover, mineralization, and volume is shown in Figure 1. Bone turnover was normal in the vast majority (71%). Patients with low turnover (26%) had received a higher cumulative steroid dose (2.78 vs 2.34g in low vs non-low turnover; p=0.02). Patients with delayed mineralization (16%) were younger (52 vs 58 yrs, p=0.02) and had received a higher cumulative steroid dose (2.85 vs 2.36g, p=0.003). They had higher levels of PTH (124 vs 53 ng/L, p<0.001), and lower levels of phosphate (2.68 vs 3.18 mg/dL, p<0.001), calcidiol (29 vs 37ug/L, p=0.02), bicarbonate (21.3 vs 23.3 mmol/L, p=0.004), and sclerostin (493 vs 594 pg/mL, p=0.03) compared to patients with normal mineralization. Patients with low bone volume tended to be older (61 vs 56 years, p=0.07). Independent determinants of BFR were PTH (β=0.68, p<0.001) and cumulative steroid dose (β = -0.22, p=0.02). Determinants of Mlt were phosphate (β=-0.48, p=0.001) and cumulative steroid dose (β=0.18, p=0.004), and determinants of BAr were age (β=-0.15, p=0.002), and BMI (β=0.33, p=0.002). Conclusion Bone turnover is normal in the majority of kidney transplant recipients at 1 year post-transplant, despite a high prevalence of hyperparathyroidism. Low levels of bicarbonate, phosphate, and calcidiol may contribute to delayed bone mineralization in kidney transplant recipients.

Download Full-text