Renal function in type 1 diabetics one year after successful pancreas transplantation

Chatzizacharias NA, Vaidya A, Sinha S, Smith R, Jones G, Sharples E, Friend PJ. Renal function in type 1 diabetics one year after successful pancreas transplantation.
Clin Transplant 2011: 25: E509–E515. © 2011 John Wiley & Sons A/S. Abstract: The effect of pancreas transplantation on renal function remains a matter of debate. The purpose of this retrospective, single‐unit study is a preliminary analysis of renal function one yr after pancreas transplant (pancreas alone [PTA] or pancreas after kidney [PAK]). Fifty‐nine patients were included. Serum creatinine and estimated glomerular filtration rate (eGFR) levels were compared three, six, and 12 months post‐transplantation for the whole sample and separately for PTA and PAK and high (>45 mL/min/1.73 m²) and low (≤45 mL/min/1.73 m²) pre‐transplant eGFR subgroups. Overall, eGFR did not change significantly (p = 0.228) at the end of the first year post‐transplant, with patients of low initial eGFR presenting a more prominent trend toward stable or improved levels. In the PAK subgroup, eGFR was significantly improved (p = 0.035). High eGFR subgroup demonstrated no significant deterioration in renal function, while patients with low initial eGFR had significantly higher levels 3 (p = 0.012) and six months (p = 0.009) post‐transplant. Our study shows that renal function did not deteriorate significantly one yr after pancreas transplant (PTA or PAK), even in patients with substantial pre‐existing renal dysfunction. Evaluation at a wider scale and identification of risk factors for potential deterioration are challenges for future research.     

Decline in native renal function early after bladder-drained pancreas transplantation alone

BACKGROUND: Pancreas transplant alone (PTA) has become accepted therapy for select nonuremic patients with type 1 diabetes mellitus. However, PTA may lead to significant complications including a decline in native renal function. This study examines trends in native renal function during the first posttransplant year in PTA recipients with a spectrum of pretransplant glomerular filtration rates (GFR). METHODS: Renal function was studied in 23 recipients of bladder-drained PTA who underwent transplantation from April 1998 through September 2001. GFR was measured by corrected iothalamate clearance at the time of transplant evaluation and 1 year posttransplant and also calculated using the Cockcroft-Gault method at the transplant evaluation; at the day of transplantation; and at 1, 6, and 12 months posttransplant. RESULTS: Iothalamate clearance decreased in the first year in 96% of patients (22 of 23). The mean measured GFR decreased from 84 +/- 33 mL/min/1.73 m2 pretransplant to 52 +/- 26 mL/min/1.73 m2 at 1 year (P <0.001). Calculated creatinine clearance declined in the majority of patients at both 1 and 12 months after PTA, but some patients, including a few with low GFR, maintained stable renal function. Calculated GFR generally correlated well with measured GFR in most patients, with a few notable exceptions. One patient (baseline GFR, 42 mL/min/1.73 m2) developed renal failure in the first year after transplant and required kidney transplantation. CONCLUSIONS: Bladder-drained PTA results in a decline in native renal function in the majority of patients regardless of the pretransplant GFR. These data suggest the need for strategies to prevent or minimize the decline in renal function after PTA.     

The natural history of renal function following orthotopic heart transplant

BACKGROUND: The outcome of solid organ transplantation has dramatically improved after the introduction of the calcineurin inhibitor cyclosporine. With the increasing longevity of heart transplant recipients, the long-term effects of cyclosporine on renal function have become more evident. The natural history of kidney function following orthotopic heart transplant is not well defined and long-term follow up studies are scant. METHODS: We conducted an observational study on patients who received a heart transplant at Saint Louis University Hospital between January 1, 1983 and December 31, 1988. Patients were followed up for 15 yr or until death whichever occurred first. In order to assess the effect of heart transplantation and cyclosporine exposure on long-term renal function we restricted the statistical analysis to patients who survived the first year post-transplantation. RESULTS: A total of 68 patients received orthotopic heart transplants at Saint Louis University Hospital between 1983 and 1988. Forty-eight (71%) patients survived for more than 1 yr. All patients were treated with cyclosporine based triple immunosuppressive regimen, with gradual cyclosporine dose reduction over time. The mean duration of follow-up was 8 yr. The estimated GFR at 5 and 10 yr post-transplant were significantly lower than estimated GFR at baseline and 1 yr post-transplant. There was no significant difference between estimated GFR at 15 yr and estimated GFR at baseline or 1 yr post-transplant. The cumulative incidence of chronic renal failure (GFR < or = 29 mL/min/1.73 m2) at 5, 10 and 15 yr was 4.2, 10.4 and 12.5%, respectively (p < 0.05). The cumulative incidence of severe chronic renal failure (GFR < or = 15 mL/min/1.73 m2) at 5, 10 and 15 yr was 2.1, 8.3 and 8.3%, respectively. The mortality rate was 8, 37, and 52% at 5, 10, and 15 yr, respectively. The 10 and 15 yr survivors had an estimated GFR at 1 yr post-transplant that was significantly higher than the non-survivors. Age, pre-transplantation estimated GFR, pre-transplantation diabetes and pre-transplantation hypertension are risk factors associated with > or = 10 mL/min/1.73 m2 decrement in estimated GFR. CONCLUSION: Heart transplant survivors beyond the first year post-transplant have a significant decrease in renal function and significant mortality observed over time. Age, pre-transplant GFR, pre-transplant diabetes and pre-transplant hypertension are important risk factors for decrement in renal function.     

Modifiable patient factors are associated with the late decline in renal function following liver transplantation

Strategies to delay or avoid the long-term decline in renal function and progression to chronic kidney disease (CKD) in liver transplant recipients remain unclear. Our aim was to examine the change in estimated GFR (eGFR) from six months after liver transplantation, and to identify modifiable factors associated with a faster rate of decline. This was a single-center retrospective study of 97 patients who underwent elective liver transplantation and survived ≥ 5 yr. eGFR was estimated using the MDRD6-variable equation, and the annualized change in eGFR was determined using simple linear regression. The baseline eGFR was 75 mL/min/1.73 m(2) . Thereafter, eGFR declined at a mean rate of 1.08 mL/min/1.73 m(2) per year. 49% had a decline in renal function greater than the rate expected with aging. Decline in eGFR was an independent predictor of CKD by five yr post-transplant (p = 0.001). Multivariate modeling found a higher baseline eGFR (p < 0.001), female gender (p = 0.006), hypertension (p = 0.019), and dyslipidemia (p = 0.034) to be associated with a faster rate of decline in renal function. In conclusion, liver transplant recipients have a clinically relevant decline in eGFR from six months post-transplant. Prospective studies are required to examine the effects of aggressive blood pressure and lipid control on the development of CKD in this setting.     

Renal function in patients with β-thalassaemia major: a long-term follow-up study

Background Little information is available about the kidney's involvement in patients with β-thalassaemia major (TM). In particular, there are no studies reporting the outcome of renal function over time. Methods In this retrospective study, we evaluated the changes in estimated glomerular filtration rate (eGFR) in 81 adult patients with TM followed for 10 years. Only patients who had an eGFR of >90 mL/min/1.73 m(2) at presentation were admitted to the study. All patients were regularly followed for at least 10 years. Results At 10 years, 66 patients showed a mild decline in eGFR that remained, however, within a normal range (from 119.9 to 113.6 mL/min/1.73 m(2), P = 0.636). In the remaining 15 patients (18.5%), eGFR decreased to <90 mL/min (from 98.1 to 78.2 mL/min/1.73 m(2); P = 0.004). The repeated-measures models showed that the decline in eGFR over time was significantly higher (P = 0.0068) in patients with baseline phosphaturia >1000 mg/24 h (P = 0.0068), while eGFR tended to decline more rapidly in patients with baseline uricuria >700 mg/24 h than in those with lower uricuria (P = 0.0783). Univariate Cox's proportional regression models showed that abnormal levels of calcaemia were associated with the risk of kidney damage [hazard ratio (HR) 0.30, 95% confidence interval 0.09-0.97 for calcaemia 8.4-10.2 mg/dL versus HR not estimable for calcaemia <8.4 or >10.2 mg/dL]. Conclusions In most adults with TM, the eGFR tends to remain within a normal range after 10 years. However, patients with elevated phosphaturia, elevated uricuria and/or abnormal levels of calcaemia show a significant decline in eGFR over time, suggesting that tubular damage acquired in childhood caused by either TM or its treatment may eventually result in abnormal eGFR. Further studies in a larger cohort of TM patients are needed to further elucidate the long-term impact of TM on renal function.     

Long-term outcome of transplant renal artery stenosis managed conservatively or by radiological intervention

The natural history and optimal treatment of transplant renal artery stenosis (TRAS) is poorly defined. Few studies reported long-term clinical outcomes. A single centre analysis of 43 patients diagnosed with TRAS 1990-2003 was performed. Twenty-seven had percutaneous intervention (including 10 patients who had >1 intervention) and 16 were managed conservatively at the discretion of the attending clinicians. Transplant function was assessed by slope of estimated glomerular filtration rate (eGFR) over five yr of follow-up. Patients in the intervention group had lower mean eGFR (36.3 mL/min/1.73 m(2) vs. 46.3 mL/min/1.73 m(2); p = 0.07) at baseline. Five transplants in the intervention group failed (including two as a direct result of intervention) and one in the conservative group failed. There was no significant difference in the rate of deterioration in renal function (mean slope of eGFR minus 0.8 mL/min/yr and minus 1.0 mL/min/yr in the intervention and conservative groups, respectively; p = 0.79). There was no significant difference in blood pressure or number of anti-hypertensive agents between the groups at any time point. Baseline Doppler ultrasound indices showed no significant correlation with slope of eGFR in either group. Our data demonstrate that selected patients with TRAS can be managed without intervention and that this approach is associated with good long-term outcome. Selection of appropriate patients for intervention remains difficult and larger randomized studies are required.     

Changes in Renal Function after Clinical Islet Transplantation: Four-Year Observational Study

Tight glycemic control can reduce progression of diabetic nephropathy (DN) while the histological changes may regress after pancreas transplantation. Clinical islet transplantation (CIT) can restore euglycemia but the effects of CIT and concomitant immunosuppression on renal function are not known. Renal function (modification of diet in renal disease estimated glomerular filtration rate [GFR]) is reported in 41 type 1 diabetes subjects followed for 29.8 (6-57) months after CIT who received sirolimus and tacrolimus. HbA(1c) improved by 3 months (6.1 +/- 0.5 vs. 8.1 +/- 1.3%, p < 0.001) and was sustained. Over 4 years estimated GFR (eGFR) declined (repeated measures ANOVA: p = 0.0011). The median rate of change in eGFR was -0.39 mL/min/1.73 m(2)/month but was highly variable (range: +1.62 to -2.79 mL/min/1.73 m(2)/month). Progression of albuminuria was observed in ten individuals while regression of microalbuminuria was observed in only one (chi square = 22.51, df = 4, p = 0.0002). Despite improved glycemia, CIT and concomitant immunosuppression, was associated with a fall in eGFR and progression of albuminuria over 4 years of observation. The rate of decline in eGFR was extremely variable and difficult to predict. The risk of progressive nephrotoxicity with decline in eGFR should be discussed with prospective CIT candidates and the risk: benefit ratio carefully considered in individuals with pre-existing renal impairment.     

The early decline in renal function in patients with type 1 diabetes and proteinuria predicts the risk of end-stage renal disease

The risk of end-stage renal disease (ESRD) remains high in patients with type 1 diabetes and proteinuria; however, little is known about the rate of decline in their renal function. To help determine this, we enrolled patients with type 1 diabetes and proteinuria whose estimated glomerular filtration rate (eGFR) was normal (equal to or above 60?ml/min per 1.73?m(2)). Using a minimum of five serial measurements of serum creatinine for 161 patients, we determined individual trajectories of eGFR change and the occurrence of ESRD during 5-18 years of follow-up. The rates were linear for 110 patients, for 24 the nonlinear rate was mild enough to satisfy a linear model, and the rates were clearly nonlinear for only 27 patients. Overall, in more than one-third of patients, the eGFR decline was less than 3.5?ml/min per 1.73?m(2) per year and the lifetime risk of ESRD could be considered negligible. In the remainder of patients, eGFR declined with widely different slopes and ESRD developed within 2 to 18 years. Based on up to 5 years observation, when renal function was within the normal range, the estimates of early eGFR slope predicted the risk of ESRD during subsequent follow-up better than the baseline clinical characteristics of glycated hemoglobin, blood pressure, or the albumin to creatinine ratio. Thus, the early slope of eGFR decline in patients with type 1 diabetes and proteinuria can be used to predict the risk of ESRD.     

Kidney Function and Risk of Cardiovascular Disease and Mortality in Kidney Transplant Recipients: The FAVORIT Trial

In kidney transplant recipients, cardiovascular disease (CVD) is the leading cause of death. The relationship of kidney function with CVD outcomes in transplant recipients remains uncertain. We performed a post hoc analysis of the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial to assess risk factors for CVD and mortality in kidney transplant recipients. Following adjustment for demographic, clinical and transplant characteristics, and traditional CVD risk factors, proportional hazards models were used to explore the association of estimated GFR with incident CVD and all‐cause mortality. In 4016 participants, mean age was 52 years and 20% had prior CVD. Mean eGFR was 49±18 mL/min/1.73 m². In 3676 participants with complete data, there were 527 CVD events over a median of 3.8 years. Following adjustment, each 5 mL/min/1.73 m² higher eGFR at levels below 45 mL/min/1.73 m² was associated with a 15% lower risk of both CVD [HR = 0.85 (0.80, 0.90)] and death [HR = 0.85 (0.79, 0.90)], while there was no association between eGFR and outcomes at levels above 45 mL/min/1.73 m². In conclusion, in stable kidney transplant recipients, lower eGFR is independently associated with adverse events, suggesting that reduced kidney function itself rather than preexisting comorbidity may lead to CVD.     

Immune checkpoint inhibitors further aggravate proteinuria in patients with metastatic renal cell carcinoma after long-term targeted therapy

BackgroundIncreasing number of patients with metastatic renal cell carcinoma (mRCC) are receiving subsequent programmed cell death protein-1 (PD-1) inhibitor combination therapy following tyrosine-kinase inhibitor (TKI) resistance. To explore whether PD-1 inhibitor would further deteriorate proteinuria and renal function, we observed their proteinuria’s and renal function’s condition since the administration of PD-1 inhibitor.MethodsTo assess the change in proteinuria and renal function, the data of 141 patients with mRCC treated with TKI were collected, 66 of whom were further prescribed PD-1 inhibitor. Proteinuria and estimated glomerular filtration rate (eGFR) were measured and analyzed. Logistic regression models were established to identify the predictors of proteinuria deterioration and significant eGFR decline (≥15%).ResultsOf the 141 patients, 74 (52%) had an increase in proteinuria level after an average of 22.98 months of TKI treatment. In multivariate analysis, longer duration of TKI (>12 months) and administration of PD-1 inhibitor were independent predictors for proteinuria deterioration. The median eGFR decreased from 81.56 mL/min/1.73 m² to 66.75 mL/min/1.73 m² after TKI treatment. Logistic regression identified older age (>60 years old) and longer duration of TKI (>12 months) as independent predictors for significant eGFR decline. Finally, of the 66 patients who received subsequent PD-1 inhibitor, 34 had sufficient proteinuria and eGFR data at follow-up. The level of proteinuria increased further after the administration of PD-1 inhibitor, although the decrease in eGFR was not statistically significant (P=0.182). Log-rank analysis identified proteinuria deterioration and eGFR decline were both significantly associated with patent’s survival (P<0.001).ConclusionsTargeted therapy was associated with an increase in proteinuria level and a decrease in eGFR in patients with mRCC. The administration of PD-1 inhibitor contributed to exacerbation in proteinuria, but no significant difference in a decrease of eGFR was observed.     

Simultaneous Intestinal and Kidney Transplantation in Adults

Aim of the study: Intestinal transplantation (IT) is a life-saving procedure for carefully selected patients with intestinal failure. We evaluated patients who had undergone simultaneous intestinal and kidney transplantation (SIKT) to determine whether UK guidelines for inclusion of a renal allograft (dialysis dependent or estimated glomerular filtration rate ((eGFR)) < 45 ml/min/1.73 m²) are justified. Methods: A single centre analysis was undertaken of adults undergoing IT at the Cambridge Transplant Centre between December 2007 and January 2016. A prospectively maintained database was used to identify SIKT recipients and determine outcomes. Results: Over this period, 63 intestinal transplants were performed. Seven (11.1%) recipients received a SIKT. Five were pre-dialysis (median eGFR 29 ml/min/1.73 m², range 16–36 ml/min/1.73 m²). One recipient was on dialysis, and one needed bilateral nephrectomy at transplant. There were no primary kidney allograft failures and at three months, the median eGFR (55 ml/min/1.73 m² range 39–124) was similar to recipients of IT alone (median eGFR 56 ml/min/1.73 m² range 17–143 ml/min/1.73 m²). Two recipients required dialysis due to sepsis related kidney injury and died from multi-organ failure (20 and 63 months). Two died with a functioning renal transplant (10 and 15 months). The remaining three patients are alive at follow up (12–96 months) with an eGFR of 20–45 ml/min/1.73 m². Conclusion: Patients with significant renal impairment (eGFR <45 ml/min/1.73 m²), and receiving dialysis may benefit from SIKT. Patient survival and renal function are broadly comparable to those undergoing IT alone. Further studies are required to justify allocation of a kidney to this complex high risk group.     

腹膜透析患者残余肾功能下降速率的相关影响因素分析

目的 探讨腹膜透析患者残余肾功能(RRF)下降速率的相关影响因素,以期为临床早期干预提供依据.方法 将纳入的95例患者按估算的肾小球滤过率(eGFR)水平分为A组[eGFR＜ 6mL·(min·1.73m2)-1]、B组[eGFR(6 ～10)mL·(min·1.73m2)-1]及C组[eGFR＞ 10mL·(min·1.73m2)-1],随访患者18个月或至终点事件发生,计算eGFR平均下降速率,并建立回归模型,分析各项指标与eGFR下降速率的关系.结果 95例患者eGFR下降速率平均为-0.156mL·(min·1.73m2)-1,其中A组为-0.091mL·(min·1.73m2)-1,B组为-0.153mL·(min·1.73m2)-1,C组为-0.251mL· (min·1.73m2)-1;共有37例(38.95％)eGFR丧失,其中A组18例(60.00％)、B组13例(40.63％),C组6例(18.18％);3组eGFR下降速率及eGFR丧失率组间比较均有显著差异(P ＜0.001).至终点时,3组死亡率、转HD治疗及行肾移植组间比较均无显著差异(P＞0.05).多因素回归分析显示,基线时eGFR、Hb、血清白蛋白、总胆固醇、NT-pro-BNP为为eGFR下降速率的独立影响因素.结论 腹膜透析患者eGFR下降速率与基线时eGFR、Hb、血浆白蛋白、总胆固醇及NT-pro-BNP水平等密切相关,临床上应识别并重视.     

Hypobilirubinemia Might be a Possible Risk Factor of End-Stage Kidney Disease Independently of Estimated Glomerular Filtration Rate

Background/Aims: The relationship between serum total bilirubin (TB) and estimated glomerular filtration rate (eGFR) is controversial and there is no report on the association between TB and end-stage kidney disease (ESKD). Methods: We examined the cross-sectional association between TB and eGFR and investigated whether TB can predict ESKD with multivariable logistic regression adjusted for age, sex, and baseline eGFR using hospital-based data. Results: The geometric mean TB of patients with eGFR ≥ 90 mL/min/1.73 m(2) (S1), 8960 mL/min/1.73 m(2) (S2), 59-30 mL/min/1.73 m(2) (S3), 29-15 mL/min/1.73 m(2) (S4), and < 15 mL/min/1.73 m(2) (S5 = ESKD) was 0.55 mg/dL, 0.59 mg/dL, 0.56 mg/dL, 0.47 mg/dL, and 0.36 mg/dL (all p<0.0001 except for S1 vs. S3 where p=0.3726), respectively excluding patients with hyperbilirubinemia (TB > 1.24 mg/dL). The odds ratio (95% confidence interval) of incident ESKD for each 0.1 mg/dL increase in TB and hypobilirubinemia defined as TB ≤ 0.34 mg/dL were 0.92 (0.80-1.07) (p=0.2804) and 3.51 (1.56-7.88) (p=0.0023), respectively in patients with baseline eGFR ≥ 15 mL/min/1.73m(2) and 0.59 (0.37-0.95) (p=0.0283) and 6.03 (1.63-22.30) (p=0.0071), respectively in patients with baseline eGFR 29-15 mL/min/1.73m(2). Conclusions: Hypobilirubinemia might be a possible risk factor of ESKD.     

Hyperlipidemia Is Associated With Accelerated Chronic Kidney Disease Progression After Lung Transplantation

Hyperlipidemia is associated with faster progression of chronic kidney disease (CKD) in the general public. We sought to investigate this association after lung transplantation. Data was retrospectively collected on 230 lung recipients transplanted between January 1997 and December 2003. Estimated glomerular filtration rates (eGFR) and lipid levels were recorded at regular intervals posttransplant. Independent associations between lipid levels early posttransplant and pertinent renal endpoints were investigated. Baseline LDL was 110 ± 35 mg/dL and remained unchanged at 6 months. A faster decline in eGFR was seen in those with 6 month LDLs > versus < the mean level of 110 mg/dL (p = 0.05). By 6 months posttransplant eGFRs were lower in the 6 month LDL > versus < 110 mg/dL group (53 ± 23 vs. 62 ± 29 mL/min/1.73 m², p = 0.01), a difference that persisted at 60 months (39 ± 24 vs. 73 ± 57 mL/min/1.73 m², p = 0.05). On univariate analysis, a 6 month LDL in the highest quartile, i.e. >140 mg/dL, predicted faster progression to CKD, defined as declining to an eGFR < 30 mL/min/1.73 m² (HR 1.5, p = 0.01). This finding persisted in the multivariate Cox-proportional model (HR 1.4, p = 0.02). Hyperlipidemia predicts faster decline in renal function after lung transplant. Prospective trials are needed to confirm this finding.     

Polyomavirus Nephropathy in Pediatric Kidney Transplant Recipients

Given the limited information regarding BK virus-associated nephropathy (BKVN) in pediatric kidney transplant recipients, we assessed the incidence, risk factors, clinical and virologic features of BKVN in pediatric renal transplant recipients at a single transplant center by means of a retrospective cohort study. Histologically confirmed BKVN developed in 6 of 173 (3.5%) kidney transplant recipients at a median of 15 months post-transplant (range: 4-47 months). At a median follow-up of 28 months (range: 5-32), all patients had functioning grafts with mean creatinine and GFR of 1.9 mg/dL and 58 mL/min/1.73 m2, respectively. At the time of diagnosis, all cases had viruria (median 6.1 x 10(6) copies/mL, range: 10(5) to 3.9 x 10(8) copies/mL) and viremia (median 21,000 copies/mL, range: 10,000-40,000 copies/mL). Recipient seronegativity for BKV was significantly associated with the development of BKVN (p = 0.01). BKVN is an important cause of late allograft dysfunction and is strongly associated with recipient seronegativity in pediatric kidney transplant recipients. Further studies to confirm this finding and to define the clinical utility of routine pre-transplant BKV serologic testing are warranted.     

Early post‐transplant conversion from tacrolimus to belatacept for prolonged delayed graft function improves renal function in kidney transplant recipients

Prolonged delayed graft function (DGF) in kidney transplant recipients imparts a risk of poor allograft function; tacrolimus may be detrimental in this setting. We conducted a retrospective single center analysis of the first 20 patients converted to belatacept for prolonged DGF as part of a clinical protocol as a novel treatment strategy to treat prolonged DGF. Prior to conversion, patients underwent an allograft biopsy to rule out rejection and confirm tubular injury. The primary outcome was the estimated glomerular filtration rate (eGFR) at 12 months post‐transplant; secondary outcome was the change in eGFR 30 days post‐belatacept conversion. At 1 year post‐transplant, the mean eGFR was 54.2 (SD 19.2) mL/min/1.73 m². The mean eGFR on the day of belatacept conversion was 16 (SD 12.7) mL/min/1.73 m² and rose to 43.1 (SD 15.8) mL/min/1.73 m² 30 days post‐conversion (P<.0001). The acute rejection rate was 20% with 100% patient survival at 12 months post‐transplant. There was one graft loss in the setting of an invasive Aspergillus infection that resulted in withdrawal of immunosuppression and transplant nephrectomy. Belatacept conversion for prolonged DGF is a novel treatment strategy that resulted in an improvement in eGFR. Additional follow‐up is warranted to confirm the long‐term benefits of this strategy.     

Renal transplant and secondary hyperparathyroidism

OBJECTIVE: To investigate the impact of mineral metabolism, renal function, months on dialysis and months since transplant for predicting intact parathyroid hormone (iPTH) levels in a cohort of patients who had undergone their first renal graft with estimated glomerular filtration rates (eGFRs) of 30-60 and >60 ml/min/1.73 m2. MATERIAL AND METHODS: One hundred and twenty-eight patients (mean age 56.0 +/- 14.6 years) with an eGFR of >30 ml/min/1.73 m2 were included. The median time since transplant was 88.6 months (range 2.8-403.2 months). Blood samples were collected for measurement of iPTH, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, calcium, albumin, phosphate and creatinine. The eGFR was calculated using the formula for the modification of diet in renal disease. RESULTS: One hundred and three patients (80%) had an elevated level of iPTH, 29 (23%) had hypercalcaemia and 42 (35%) had a 25-hydroxyvitamin D3 level of <40 nmol/L. In stepwise backward regression, eGFR and 25-hydroxyvitamin D3 were associated with iPTH, as follows: iPTH = 24.91 -(0.06 x 25-hydroxyvitamin D3) - (0.16 x eGFR) (R2 = 0.14). No associations with these two variables were, however, detected in patients with an eGFR of >60 ml/min/1.73 m2. Forty patients (31%) were transplanted pre-emptively, and the iPTH concentrations were significantly lower in these patients. CONCLUSIONS: Decreasing eGFR was the single most important variable predicting iPTH level in a cohort of renal transplant patients with an eGFR of 30-60 ml/min/1.73 m2, but not in patients with an eGFR of >60 ml/min/1.73 m2. Patients transplanted pre-emptively had a statistically significantly lower iPTH level compared with patients who had received dialysis.     

Weekly enzyme replacement therapy may slow decline of renal function in patients with Fabry disease who are on long-term biweekly dosing

This study was performed to determine whether adult male patients with Fabry disease who demonstrate a continuing decline in renal function despite 2 to 4 yr of conventionally dosed agalsidase alfa therapy (0.2 mg/kg every other week [EOW]) show an improved slope of decline with weekly administration using the same dosage. Eleven (27%) of 41 adult male patients with Fabry disease who participated in long-term agalsidase alfa clinical trials and who had demonstrated a slope of decline in estimated GFR (eGFR) of > or =5 ml/min per 1.73 m(2)/yr while receiving long-term treatment with agalsidase alfa at the currently recommended dosage of 0.2 mg/kg, infused EOW, were enrolled in this open-label, prospective study. Patients were switched from EOW to weekly infusions and followed for an additional 24 mo. Before switching to weekly dosing, eGFR was 53.7 +/- 6.3 ml/min per 1.73 m(2) (mean +/- SEM), and mean rate of change in eGFR was -8.0 +/- 0.8 ml/min per 1.73 m(2)/yr. During the 24-mo follow-up period after switching to weekly dosing, the mean rate of change in eGFR was observed to slow to -3.3 +/- 1.4 ml/min/1.73 m(2)/yr (P = 0.01 versus EOW). After switching to weekly dosing, three patients demonstrated an improvement in eGFR and six patients demonstrated a slowing in the rate of eGFR decline; only two patients failed to improve their eGFR slope. A multiple regression model confirmed that the weekly infusion regimen was the strongest explanatory variable for the change in eGFR (P = 0.0008), with a weaker contribution from the concomitant use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers (P = 0.02). These results suggest that weekly infusions of agalsidase alfa at a dosage of 0.2 mg/kg may be beneficial in the subgroup of patients who have Fabry disease and whose kidney function continues to decline after 2 to 4 yr or more of standard EOW dosing.     

Long-Term Deterioration of Kidney Allograft Function

Although long-term survival after kidney transplantation is critically dependent on maintaining stable allograft function, few studies have examined renal allograft function over time. Using pooled data from 10 278 consecutive transplants at five centers, we calculated slopes of estimated glomerular filtration rates (eGFR) measured after 1, 6 and 12 months in 9515, 8861 and 7359 patients surviving > or =1, > or =6 and > or =12 months, respectively. Slopes of eGFR progressively diminished for patients transplanted during 1984-1989, 1990-1993, 1994-1998 and 1999-2002 (analysis of variance p < 0.0001 and p = 0.1245 for slopes measured after 1 and 6 months, respectively). Slopes measured after 12 months were less in the most recent era: -2.2 +/- 7.2 mL/min/1.73 m(2)/year, -2.3 +/- 6.6 mL/min/1.73 m(2)/year, -2.4 +/- 7.4 mL/min/1.73 m(2)/year and -1.4 +/- 10.9 mL/min/1.73 m(2)/year, respectively, p = 0.0058. Slopes measured after 1, 6 and 12 months each were less for transplantations during 1999-2002, after adjusting for multiple transplantation characteristics (p < 0.0001). Similarly, in Cox proportional hazards analysis, the risk (95% CI) for a 25% reduction in eGFR was 0.92 (0.85-1.01), p = 0.0736 during 1990-1994; 0.94 (0.82-1.08), p = 0.4111 during 1995-1998 and 0.78 (0.64-0.95), p = 0.0110 during 1999-2002 (compared to 1984-1989). We conclude that the rate of decline in allograft function after kidney transplantation has improved, suggesting that stable, long-term function may be achievable.     

Corticosteroids in IgA Nephropathy: A Retrospective Analysis from the VALIGA Study

Current guidelines suggest treatment with corticosteroids (CS) in IgA nephropathy (IgAN) when proteinuria is persistently ≥1 g/d despite 3–6 months of supportive care and when eGFR is >50 ml/min per 1.73 m². Whether the benefits of this treatment extend to patients with an eGFR≤50 ml/min per 1.73 m², other levels of proteinuria, or different renal pathologic lesions remains unknown. We retrospectively studied 1147 patients with IgAN from the European Validation Study of the Oxford Classification of IgAN (VALIGA) cohort classified according to the Oxford-MEST classification and medication used, with details of duration but not dosing. Overall, 46% of patients received immunosuppression, of which 98% received CS. Treated individuals presented with greater clinical and pathologic risk factors of progression. They also received more antihypertensive medication, and a greater proportion received renin angiotensin system blockade (RASB) compared with individuals without immunosuppressive therapy. Immunosuppression was associated with a significant reduction in proteinuria, a slower rate of renal function decline, and greater renal survival. Using a propensity score, we matched 184 subjects who received CS and RASB to 184 patients with a similar risk profile of progression who received only RASB. Within this group, CS reduced proteinuria and the rate of renal function decline and increased renal survival. These benefits extended to those with an eGFR≤50 ml/min per 1.73 m², and the benefits increased proportionally with the level of proteinuria. Thus, CS reduced the risk of progression regardless of initial eGFR and in direct proportion to the extent of proteinuria in this cohort.