Project description:Apolipoprotein L-1 (APOL1) gene variants are associated with end-stage renal disease in African Americans (AAs). Here we investigate the impact of recipient APOL1 gene distributions on kidney allograft outcomes. We conducted a retrospective analysis of 119 AA kidney transplant recipients, and found that 58 (48.7%) carried two APOL1 kidney disease risk variants. Contrary to the association seen in native kidney disease, there is no difference in allograft survival at 5-year posttransplant for recipients with high-risk APOL1 genotypes. Thus, we were able to conclude that APOL1 genotypes do not increase risk of allograft loss after kidney transplantations, and carrying 2 APOL1 risk alleles should not be an impediment to transplantation.
Project description:BackgroundIn chronic kidney disease, intensive systolic blood pressure (SBP) control reduces mortality at a cost of greater acute kidney injury risk. Kidney transplantation involves implantation of denervated kidneys and immunosuppressive medications that increase acute kidney injury risk. The optimal blood pressure (BP) target in kidney transplant recipients (KTRs) is uncertain. Prior observational studies from the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial demonstrate associations of lower SBP levels and reduced mortality risk, but the relationship of BP with kidney allograft function remains unknown. Thus, in FAVORIT, we investigated the relationship of SBP and diastolic blood pressure (DBP) with risk of kidney allograft failure and estimated glomerular filtration rate (eGFR) slope among stable KTRs.MethodsCox proportional hazards and multivariable linear regression models adjusted for demographics, transplant characteristics, comorbidities, baseline eGFR, and urine albumin-to-creatinine ratio were used to determine associations of SBP and DBP with time to a composite kidney outcome of ≥50% eGFR decline or dialysis dependence, and with annualized eGFR change, respectively. Multivariable restricted cubic spline plots were developed to evaluate the functional form of the relationships.ResultsAmong 3,598 KTRs, mean age was 52 ± 9 years, SBP was 136 ± 20 mm Hg, DBP was 79 ± 12 mm Hg, and eGFR was 49 ± 18 ml/minute/1.73 m2. There were 369 events of ≥50% eGFR decline or dialysis dependence during a mean follow-up of 4.0 ± 1.5 years. There was no association of either SBP (compared with SBP 120 to <130 mm Hg, hazard ratio (HR) for the SBP < 110 was 1.01 (95% confidence interval (CI) 0.60 to 1.70) and 130 to <140 was 0.89 (0.64 to 1.24)) or DBP (compared with DBP 70 to <80 mm Hg, HR for the DBP 60 to <70 was 1.00 (95% CI 0.74 to 1.34) and 80 to <90 was 0.90 (0.68 to 1.18)) with the kidney failure outcome or annualized eGFR slope, and, when examined using restricted cubic splines, there was no evidence of "J"- or "U"-shaped relationships.ConclusionsIn a large sample of stable KTRs, we found no evidence of thresholds at which lower BPs were related to higher risk of allograft failure or eGFR decline. In light of prior findings of mortality benefit at low SBP, these observational findings suggest lower BP may be beneficial in KTRs. This important question requires confirmation in future randomized trials in KTRs.
Project description:BackgroundThe effect of donor hypertension on the blood pressure of renal transplant recipients and the allograft outcomes are unclear. The aim of this study was to summarize the evidence about the effects of donor hypertension on renal transplant recipients' blood pressure, renal allograft outcomes and mortality.MethodsStudies published from January 1960 to 31 January 2019 in English were identified through a systematic search of six databases; PubMed, Embase, SCOPUS, Web of Science, Cochrane Database of Systematic Reviews, and CINAHL. Eligible observational studies with at least 1 year of follow-up were selected. Pooled estimates were obtained using random effects model.ResultsWe identified 15 papers from eight countries containing data on donor hypertension and renal transplantation carried out between 1963 and 2014. The median (range) follow-up period of the studies was 3.8 (1-11.9) years. The prevalence of post-transplant hypertension among recipients of a renal allograft from a normotensive donor range from 8 to 17.6%, while the prevalence of post-transplant hypertension among recipients of a renal allograft from a hypertensive donor range from 2.9 to 25%. Overall, pooled risk ratios (RR) indicated that donor hypertension was a risk factor for allograft failure or loss among renal transplant recipients (RR 1.31; 95% CI 1.06-1.63: P = 0.014). However, donor hypertension was not a risk factor for mortality among renal transplant recipients (RR 0.996; 95% CI 0.652-1.519: P = 0.984).ConclusionsDonor hypertension increases the risk of post-transplant hypertension among renal transplant recipients and increases the risk of allograft failure, However, donor hypertension was not a risk factor for mortality among renal transplant recipients, Closer monitoring should be given to renal allograft recipients from hypertensive donors, and further well-designed studies are needed to expand our knowledge of the impact of donor hypertension on the survival of renal allograft recipients.
Project description:BackgroundPulse wave velocity (PWV) is a measure of arterial stiffness. We investigated PWV and blood pressure (BP) to determine to what extent BP changes contribute to arterial stiffness, and secondly, to identify influencing factors on BP in children after kidney transplantation.MethodsSeventy children ≥ 2.5 years post-transplantation with at least two PWV measurements were included. Changes of systolic (Δ SBP) and diastolic BP (Δ DBP) were classified into "stable/decreasing," "1-10 mmHg increase," and " > 10 mmHg increase." Linear mixed modeling for PWV z-score (PWVz) adjusted either for Δ SBP or Δ DBP was performed. An extended dataset with monthly entries of BP, immunosuppression, and creatinine was obtained in 35 participants over a median of 74 months to perform linear mixed modeling for SBP and DBP.ResultsPWVz increased with a rate of 0.11/year (95% CI 0.054 to 0.16). Compared to participants with stable BP, those with 1-10-mmHg SBP and DBP increase showed a higher PWVz of 0.59 (95% CI 0.046 to 1.13) and 0.86 (95% CI 0.43 to 1.30), respectively. A > 10-mmHg BP increase was associated with an even higher PWVz (SBP β = 0.78, 95% CI 0.22 to 1.34; DBP β = 1.37, 95% CI 0.80 to 1.94). Female sex and participants with lower eGFR showed higher PWVz. In the extended analysis, DBP was positively associated with cyclosporin A and everolimus trough levels.ConclusionsA higher increase of PWV is seen in patients with greater BP increase, with higher cyclosporin A and everolimus trough levels associated with higher BP. This emphasizes the role of BP as a modifiable risk factor for the improvement of cardiovascular outcome after transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.
Project description:In kidney transplant recipients, the cytomegalovirus (CMV) is frequently causing infection/reactivation and can trigger allograft rejection. To assess the risk of reactivation, the cellular immune response against CMV is increasingly assessed by cellular in vitro methods, such as the interferon (IFN)-γ ELISpot. In the current study we compared the IFN-γ ELISpot with our newly established CMV-specific ELISpot assays determining IL-17A, IL-21, IL-22, granzyme B, and perforin and correlated the results with flow cytometric data and clinical parameters. In 77 kidney transplant recipients, the highest frequency was observed for CMV pp65-specific cells secreting IFN-γ, followed by cells secreting IL-21 (62.9 and 23.2 Δ spot forming cells/10⁵ cells). We observed a positive correlation between the percentage of CMV-specific CD3+ CD4+ CD154+ cells and results of the CMV-specific IL-21 ELISpot (p = 0.002). Results of the CMV pp65-specific IL-21 ELISpot correlated negatively with kidney function (estimated glomerular filtration rate, p = 0.006) and were significantly higher in women (p = 0.005). IL-21, a cytokine involved in aging that is secreted by activated CD4+ T cells, may also impact on allograft function. Thus, the CMV-specific IL-21 ELISpot could become a new tool to assess if CMV seropositivity represents a hazard for the graft.
Project description:BackgroundPost-transplant diabetes mellitus (PTDM) is a complex condition arising from various factors including immunosuppressive medications, insulin resistance, impaired insulin secretion and inflammatory processes. Its impact on patient and graft survival is a significant concern in kidney transplant recipients. PTDM's impact on kidney transplant recipients, including patient and graft survival and cardiovascular mortality, is a significant concern, given conflicting findings in previous studies. This meta-analysis was imperative not only to incorporate emerging evidence but also to delve into cause-specific mortality considerations. We aimed to comprehensively evaluate the association between PTDM and clinical outcomes, including all-cause and cardiovascular mortality, sepsis-related mortality, malignancy-related mortality and graft loss, in kidney transplant recipients.MethodsPubMed, Ovid/Medline, Web of Science, Scopus and Cochrane Library databases were screened and studies evaluating the effect of PTDM on all-cause mortality, cardiovascular mortality, sepsis-related mortality, malignancy-related mortality and overall graft loss in adult kidney transplant recipients were included.ResultsFifty-three studies, encompassing a total of 138 917 patients, evaluating the association between PTDM and clinical outcomes were included. Our analysis revealed a significant increase in all-cause mortality [risk ratio (RR) 1.70, 95% confidence interval (CI) 1.53 to 1.89, P < .001] and cardiovascular mortality (RR 1.86, 95% CI 1.36 to 2.54, P < .001) among individuals with PTDM. Moreover, PTDM was associated with a higher risk of sepsis-related mortality (RR 1.96, 95% CI 1.51 to 2.54, P < .001) but showed no significant association with malignancy-related mortality (RR 1.20, 95% CI 0.76 to 1.88). Additionally, PTDM was linked to an increased risk of overall graft failure (RR 1.33, 95% CI 1.16 to 1.54, P < .001).ConclusionThese findings underscore the importance of comprehensive management strategies and the need for research targeting PTDM to improve outcomes in kidney transplant recipients.
Project description:BackgroundHypertension is a major cardiovascular risk factor in both kidney transplant recipients (KTRs) and patients with chronic kidney disease (CKD). Ambulatory blood pressure monitoring (ABPM) is considered the gold-standard method for hypertension management in these subjects. This is the first study evaluating the full ambulatory blood pressure (BP) profile and short-term BP variability (BPV) in KTRs versus CKD patients without kidney replacement therapy.MethodsNinety-three KTRs were matched with 93 CKD patients for age, sex, and estimated glomerular filtration rate. All participants underwent 24-hour ABPM. Mean ambulatory BP levels, BP trajectories, and BPV indices (standard deviation [SD], weighted SD, and average real variability) were compared between the two groups.ResultsThere were no significant between-group differences in 24-hour systolic BP (SBP)/diastolic BP (DBP) (KTRs: 126.9 ± 13.1/79.1 ± 7.9 mmHg vs. CKD: 128.1 ± 11.2/77.9 ± 8.1 mmHg, p = 0.52/0.29), daytime SBP/DBP and nighttime SBP; nighttime DBP was slightly higher in KTRs (KTRs: 76.5 ± 8.8 mmHg vs. CKD: 73.8 ± 8.8 mmHg, p = 0.04). Repeated measurements analysis of variance showed a significant effect of time on both ambulatory SBP and DBP (SBP: F = [19, 3002] = 11.735, p < 0.001, partial η2 = 0.069) but not of KTR/CKD status (SBP: F = [1, 158] = 0.668, p = 0.42, partial η2 = 0.004). Ambulatory systolic/diastolic BPV indices were not different between KTRs and CKD patients, except for 24-hour DBP SD that was slightly higher in the latter group (KTRs: 10.2 ± 2.2 mmHg vs. CKD: 10.9 ± 2.6 mmHg, p = 0.04). No differences were noted in dipping pattern between the two groups.ConclusionMean ambulatory BP levels, BP trajectories, and short-term BPV indices are not significantly different between KTRs and CKD patients, suggesting that KTRs have a similar ambulatory BP profile compared to CKD patients without kidney replacement therapy.
Project description:Accurate prediction of allograft survival after kidney transplantation allows early identification of at-risk recipients for adverse outcomes and initiation of preventive interventions to optimize post-transplant care. Many prediction algorithms do not model cohort heterogeneity and may lead to inaccurate assessment of longer-term graft outcomes among minority groups. Using data from a national Australian kidney transplant cohort (2008-2017) as the derivation set, we developed P-Cube, a multi-step precision prediction pathway model for predicting overall graft survival in three ethnic subgroups: European Australians, Asian Australians and Aboriginal and Torres Strait Islander Peoples. The concordance index for the European Australians, Asian Australians, and Aboriginal and Torres Strait Islander Peoples subpopulations were 0.99 (0.98-0.99), 0.93 (0.92-0.94) and 0.92 (0.91-0.93), respectively. Similar findings were observed when validating P-cube using an external dataset [Scientific Registry of Transplant Recipient Registry (2006-2020)]. Six sub-categories of recipients with distinct risk factor profiles were identified. Some factors such as blood group compatibility were considered important across the entire transplant population. Other factors such as human leukocyte antigen (HLA)-DR mismatches were unique to older recipients. The P-cube model identifies allograft survival specific risk factors within a heterogenous population and offers personalized survival predictions in a diverse cohort.
Project description:BackgroundHypertension is the most prevalent cardiovascular risk factor in kidney transplant recipients (KTRs). Preliminary data suggest similar ambulatory blood pressure (BP) levels in KTRs and haemodialysis (HD) patients. This is the first study comparing the full ambulatory BP profile and short-term BP variability (BPV) in KTRs versus HD patients.MethodsA total of 204 KTRs were matched (2:1 ratio) with 102 HD patients for age and gender. BP levels, BP trajectories and BPV indices over a 24-h ambulatory BP monitoring (ABPM) in KTRs were compared against both the first and second 24-h periods of a standard 48-h ABPM in HD patients. To evaluate the effect of renal replacement treatment and time on ambulatory BP levels, a two-way ANOVA for repeated measurements was performed.ResultsKTRs had significantly lower systolic blood pressure (SBP) and pulse-pressure (PP) levels compared with HD patients during all periods studied (24-h SBP: KTR: 126.5 ± 12.1 mmHg; HD first 24 h: 132.0 ± 18.1 mmHg; P = 0.006; second 24 h: 134.3 ± 17.7 mmHg; P < 0.001); no significant differences were noted for diastolic blood pressure levels with the exception of the second nighttime. Repeated measurements ANOVA showed a significant effect of renal replacement therapy modality and time on ambulatory SBP levels during all periods studied, and a significant interaction between them; the greatest between-group difference in BP (KTRs-HD in mmHg) was observed at the end of the second 24 h [-13.9 mmHg (95% confidence interval -21.5 to -6.2); P < 0.001]. Ambulatory systolic and diastolic BPV indices were significantly lower in KTRs than in HD patients during all periods studied (24-h SBP average real variability: KTRs: 9.6 ± 2.3 mmHg; HD first 24 h: 10.3 ± 3.0 mmHg; P = 0.032; second 24 h: 11.5 ± 3.0 mmHg; P < 0.001). No differences were noted in dipping pattern between the two groups.ConclusionsSBP and PP levels and trajectories, and BPV were significantly lower in KTRs compared with age- and gender-matched HD patients during all periods studied. These findings suggest a more favourable ambulatory BP profile in KTRs, in contrast to previous observations.
Project description:BackgruoundPost-transplant diabetes mellitus (PTDM) is a risk factor for poor outcomes after kidney transplantation (KT). However, the outcomes of KT have improved recently. Therefore, we investigated whether PTDM is still a risk factor for mortality, major atherosclerotic cardiovascular events (MACEs), and graft failure in KT recipients.MethodsWe studied a retrospective cohort of KT recipients (between 1994 and 2017) at a single tertiary center, and compared the rates of death, MACEs, overall graft failure, and death-censored graft failure after KT between patients with and without PTDM using Kaplan-Meier analysis and a Cox proportional hazard model.ResultsOf 571 KT recipients, 153 (26.8%) were diagnosed with PTDM. The mean follow-up duration was 9.6 years. In the Kaplan- Meier analysis, the PTDM group did not have a significantly increased risk of death or four-point MACE compared with the non-diabetes mellitus group (log-rank test, P=0.957 and P=0.079, respectively). Multivariate Cox proportional hazard models showed that PTDM did not have a negative impact on death or four-point MACE (P=0.137 and P=0.181, respectively). In addition, PTDM was not significantly associated with overall or death-censored graft failure. However, patients with a long duration of PTDM had a higher incidence of four-point MACE.ConclusionPatient survival and MACEs were comparable between groups with and without PTDM. However, PTDM patients with long duration diabetes were at higher risk of cardiovascular disease.