Long-term follow-up of renal function in recipients and donors following pediatric kidney transplantation

Of 125 children undergoing kidney transplantation (tx), 87 received their grafts from living donors. Renal function of recipients (R) and donors (D) was assessed by glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) determined by clearances of inulin and para-aminohippuric acid. Rs were investigated yearly and Ds on alternate years. Within 5 months of tx, absolute GFR and ERPF (ml/min) were significantly lower in R than in D, and the differences in absolute GFR and ERPF between D and R were directly related to the difference in body surface area (BSA) between the two subjects. R and D pairs were repeatedly followed for 4, 6, and 8 years and the absolute GFR of R did not change during follow-up, while relative GFR decreased. Relative GFR decreased most in R, with the greatest difference in BSA between D and R at tx. In the donors, however, both absolute and relative GFR increased significantly up to 8 years. In conclusion, renal function of the two kidneys from the donor, i.e., the grafted kidney in the R and the single native kidney of the D, differed. The native kidney showed a capacity to increase its absolute and relative function with time. The grafted kidney, however, did not show an increase in absolute GFR, resulting in decrease in relative GFR, and the greater difference in BSA between D and R at tx, the greater fall in relative GFR of the R. Received: 7 June 2001 / Revised: 30 July 2001 / Accepted: 30 July 2001     

Donor Kidney Adapts to Body Dimensions of Recipient: No Influence of Donor Gender on Renal Function After Transplantation

Female kidneys and kidneys from small donors have been suggested to perform worse after kidney transplantation. Here, we evaluate the impact of gender and body dimensions on posttransplantation GFR in living donor transplantation. Two hundred and ninety‐three donor–recipient pairs, who were transplanted at our center were evaluated. All pairs had detailed renal function measurement (¹²⁵I‐iothalamate and ¹³¹I‐hippuran) 4 months predonation in the donor and 2.5 months posttransplantation in donor and recipient. For 88 pairs, 5 years of recipient follow‐up was available. Delta GFR was calculated as (recipient GFR–donor single kidney GFR). Recipients of both male and female kidneys had similar renal function at early and long term after transplantation. Male recipients had higher ERPF, ΔGFR and ΔERPF at both time points. Kidneys of donors smaller than their recipient had higher ΔGFR and ΔERPF than kidneys of larger donors at both time points (p < 0.05). In multivariate analysis, ΔGFR was predicted by donor/recipient BSA‐ratio together with transplantation related factors (R² 0.19), irrespective of donor and recipient gender. In conclusion, in living donor transplantation, female kidneys perform as well as male donor kidneys. Kidneys adapt to the recipient's body size and demands, independent of gender, without detrimental effects in renal function and outcome up to mid‐long term.     

Renal functional reserve in transplanted and native single kidneys of children and adults

Renal functional reserve (RFR) after an oral protein load was evaluated in 36 cyclosporine-treated children following kidney transplantation (Tx), in 15 kidney donors (Don), and in 15 children with single kidneys (Nx/Ag). Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined by clearances of inulin (and creatinine) and para-aminohippurate during water diuresis. Baseline and stimulated GFR and ERPF were determined and RFR was calculated as the difference between stimulated and baseline values. Baseline GFR and ERPF in Tx were lower than in Don and Nx/Ag. Both GFR and ERPF increased significantly in all groups from baseline to stimulated values. RFR GFR was 23%±3%, 20%±3% and 15%±3% in Tx, Don, and Nx/Ag and RFR ERPF 35%±4% in Tx, which was significantly higher than 20%±4% and 15%±3% in the two other groups respectively. Stimulated GFR and ERPF in Tx correlated with kidney length. No differences were seen in recipient-donor pairs, except for higher fractional increases of ERPF in recipients. There was no correlation between RFR measured by clearance of creatinine and clearance of inulin. In conclusion, cyclosporine-treated children following renal Tx were found to have a renal reserve capacity. Received September 19, 1995; received in revised form September 16, 1996; accepted October 1, 1996     

Renal function and kidney size in glycogen storage disease type I

Renal failure has been reported recently as a late complication of glycogen storage disease type I (GSD I). We studied the renal function of 23 patients, mean age 10.9 years (range 2.2–21.6 years). The mean glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were 188±50 and 927±292 ml/min per 1.73 m², respectively (normal values for adult controls 90–145 and 327–697, respectively). Hyperfiltration (GFR >145 ml/min per 1.73 m²) was found in 19 of 23 patients. There was no difference in GFR and ERPF between age groups 2–10 and 11–22 years. After a mean follow-up of 2.5 years (range 1–7.5 years) GFR and ERPF did not significantly change. At follow-up 3 patients (all older than 15 years) developed persistent glomerular proteinuria (0.1, 0.5 and 0.9 g/day). Besides a slight increase in fractional excretion of ₂-microglobulin (FE-₂m) in 6 patients, proximal tubular function tests (FE-₂m, tubular reabsorption of phosphate and glucosuria) were normal. In patients with increased kidney length related to body height, GFR and ERPF were significantly higher than in patients with normal kidney length. We conclude that GSD I is characterised by hyperfiltration and hyperperfusion. The relative increment in kidney length is related to the degree of hyperfiltration.     

Growth after conversion to alternate-day corticosteroids in children with renal transplants: a single-center study

During the 1980s all children with growth potential and stable/adequate renal function at 6–9 months after kidney transplantation underwent conversion to alternate-day corticosteroids in an attempt to maximize growth. Conversion was attempted in 79 of 160 children who received allografts during this decade and was considered successful if they remained on alternate-day prednisone for more than 1 year, with a calculated creatinine clearance of at least 75% of the pre-conversion baseline value. Conversion succeeded in 55 children but failed in 24. Growth was markedly improved among those successfully converted when compared with the failure group, as measured by standard deviation score for growth velocity based on chronological age (+0.94±1.58 vs. –0.86±1.53,P<0.001) and bone age (+0.49±0.61 vs. –1.24±1.47,P<0.001). The improved growth among the successfully converted patients is believed to have been related to the combined effects of lower corticosteroid dose (0.36±0.16 vs. 0.48±0.21 mg/kg per day,P<0.02) and better renal function (calculated creatinine clearance 87±32 vs. 47±21 ml/min per 1.73 m²,P<0.001) at 1 year post conversion. Two factors appeared to improve the likelihood of successful conversion: the use of cyclosporine and receiving a live-related rather than cadaver transplant. Cyclosporine was associated with improvement in the overall rate for successful conversion in all recipients, from 59% to 83% (P<0.05). Recipients of allografts from live-related donors underwent successful conversion in 90% of cases compared with 58% receiving cadaver allografts (P<0.05). Successful conversion to alternate-day corticosteroid therapy is of significant benefit for linear growth, but may be associated with a risk of rejection and loss of renal function. The risk is small in live-related recipients and has been made safer for cadaver recipients with the introduction of cyclosporine.     

Long-term renal function in heart transplant children on cyclosporine treatment

Renal function deterioration is a reason of concern in heart transplantation. Our aim was to evaluate long-term renal function in heart transplant children on cyclosporine (CsA) treatment and to investigate the effect of several variables possibly involved in renal function deterioration. Creatinine clearances were retrospectively reviewed in 50 children (median follow 99.7 months after heart transplant). Gender, age, and body weight at transplant, rejection episodes, CsA cumulative dose, and trough levels were analyzed. After an initial increase of the glomerular filtration rate (GFR), renal function worsened in most patients; 28% of the children developed renal insufficiency (defined as GFR <80 ml/min per 1.73 m²), which was already evident in the first 3 years. Neither CsA dose, trough levels, nor other patient characteristics were found to be associated with renal function deterioration. In this study renal failure occurred in one-third of the patients. The lack of association of CsA with renal insufficiency may be explained by several reasons, including the limitations of the retrospective design of the study. However, it is possible that the nephrotoxic effect of CsA is more likely to occur in a set of predisposed patients. These must be soon identified to evaluate early a calcineurin inhibitor-sparing strategy.     

Cadaveric renal transplantation in children under 5 years of age

From March 1987 to August 1990 23 cadaveric renal transplants were performed in 19 children under the age of 5 years at the time of transplantation. The mean age of the recipients was 3.3 years (range 1.3–4.7) and the mean weight 13.0 kg (range 9.3–19.2). The mean donor age was 7.8 years (range 1.5–25). All children received triple immunosuppression with prednisolone, cyclosporin A and azathioprine, and 4 who had 2 grafts during this period also received antithymocyte globulin at the time of the second transplant. Patient survival is 100%. Actuarial first cadaveric graft survival was 57% at 1 year and remains unchanged at 3 years. There were 10 graft losses, 4 were associated with renal venous thrombosis without apparent rejection. Two were lost due to acute vascular rejection with associated renal venous thrombosis, and the remaining 4 losses followed cellular or chronic vascular rejection. The mean glomerular filtration rate ±SD was 51.4±23.6 ml/min per 1.73 m² (n=11) at 1 year and 43.5±25.3 at 2 years (n=6). The mean height standard deviation score improved from –2.2±1.1 at the time of transplantation to –1.3±1.0 1 year post transplant (n=11). The immunosuppression was well tolerated with a low incidence of side effects. Cadaveric renal transplantation remains a difficult but rewarding undertaking in children under 5 years of age.     

Factors related to renal haemodynamics in young type-1 diabetes mellitus patients

The influence of metabolic control (HbA_1c), noradrenaline (NA) and insulin-like growth factors (IGF-I and IGF-II) on renal function and size was investigated in 11 insulin-dependent diabetes mellitus patients aged 11–17 years. Renal function was evaluated in terms of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal size was determined as renal parenchymal volume (RPV) by ultrasonography. The patients' HbA_1c values ranged from 8.2% to 12.9% (normal range 5.5–8.5%) and their GFR and ERPF were higher than normal. Their IGF-II values were higher, and NA and IGF-I levels were lower than those of healthy controls. Inverse correlations between NA and GFR (r=–0.66) and NA and ERPF (r=–0.63) were found. No correlation was found between serum IGF-I and renal functional parameters. The IGF-II values correlated with GFR and HbA_1c (r=0.63,r=0.70 respectively). There were linear correlations between RPV and GFR, RPV and ERPF, HbA_1c and GFR, and ERPF and RPV. Decreased NA concentrations and increased IGF-II values appear to be factors contributing to renal hyperfunction in these patients.     

Renal functional adaptation of the adult kidney following transplantation to the child

Nineteen child renal transplant recipients, aged 1.3 to 19.2 years at transplantation, and their adult living-related kidney donors, 27 to 60 years of age at nephrectomy, were investigated simultaneously with regard to renal function. At a median time of three months after transplantation clearances of inulin (GFR) and paraaminohippuric acid (ERPF) were measured, and serum urea and creatinine concentrations were determined. The absolute values for GFR (72 +/- 13 ml/min) and ERPF (369 +/- 76 ml/min) in the donors were significantly higher than those of the recipients (37 +/- 22 and 196 +/- 72 ml/min, respectively). The absolute values of GFR and ERPF were significantly correlated with the body surface areas of the recipients. Thus, in relation to body surface area, the GFR, 68 +/- 11 ml/min/1.73 m2, and ERPF, 348 +/- 65 ml/min/1.73 m2, of the donors did not differ from those of the recipients, 68 +/- 20 and 375 +/- 90 ml/min/1.73 m2, respectively. Because of the greater body mass, the serum creatinine concentrations of the donors were significantly higher than those of the recipients, whereas the serum urea concentrations were significantly higher in the recipients. The results suggest that transplantation of an adult kidney to a child results in a functional adaptation to the smaller body size of the recipient, and that this adaptation occurs within three months after transplantation.     

Renal allograft function in matched pediatric and adult recipient pairs of the same donor

BACKGROUND: To study the effect of donor age on kidney function, the authors investigated matched pairs from the same kidney donor given to a pediatric or an adult recipient. METHODS: Fifteen matched pairs of an adult and a pediatric patient, selected from the Eurotransplant registry, receiving the renal graft from the same cadaveric donor were selected for analysis of graft function over 7 years. Nine matched pairs were from adult donors (mean age, 40 years; range, 23-60 years) and six from pediatric donors (mean age, 11 years; range, 4-15 years). All recipients had comparable immunosuppression with cyclosporine A, prednisolone, and azathioprine and comparable numbers of acute rejection, cytomegalovirus reactivation, and antihypertensive therapy. Mean age of pediatric and adult recipients at transplantation was 5 years (range, 1-9 years) and 38 years (range, 25-60 years), respectively. RESULTS: The calculated glomerular filtration rate (GFR) corrected to body surface area was not different in adult and pediatric recipients. Initial absolute GFR was significantly lower in pediatric recipients (27 mL/ min; range, 17-38 mL/min) than in adult recipients (54 mL/min; range, 25-74 mL/min) (P <0.05) and remained lower in the following years. Initially, pediatric donor kidneys transplanted into pediatric recipients showed a lower absolute GFR than those transplanted into adults, however, approaching the GFR in adult recipients later. Adult donor kidneys transplanted into pediatric recipients showed a persistently lower absolute GFR in children compared with those transplanted into adult recipients. CONCLUSIONS: The authors conclude that adult donor kidneys in pediatric recipients decrease GFR in the early stages and lack an increase in GFR with growth of the child.     

Urinary protein excretion and renal function in children with IgA nephropathy

Renal haemodynamics and the pattern of urinary protein excretion were studied in 38 children (21 boys, 17 girls) with biopsy-proven IgA nephropathy (IgAN), 0.4–16.8 (median 5.3) years after onset of the disease. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were evaluated by clearances of inulin and para-aminohippuric acid. Serum and urinary albumin, IgG and beta₂-microglobulin (2) were determined and the excretion rates, clearances, and fractional clearances were calculated. The patients were grouped according to the type and the amount of proteinuria. Mean GFR and ERPF were significantly decreased (107±3 and 580±17 ml/min per 1.73 m², respectively) versus controls (119±2 and 627±14 ml/min per 1.73 m², respectively). Grouped according to albumin excretion rates, non-albuminuric patients had normal GFR, while mean GFR was reduced in patients with micro-albuminuria (106±3 ml/min per 1.73 m²) and albuminuric patients (92±7 ml/min per 1.73 m²). IgG excretion increased with increasing albuminuria, but the selectivity index was lower in albuminuric patients than in patients with micro-albuminuria. Albuminuric patients had also higher blood pressure than those with micro-albuminuria. 2 excretion did not discriminate between patients with impaired renal function. The results suggest that childhood IgAN is not a benign kidney disease. After a median duration of 5 years of the disease a number of children had impaired renal function. Mean GFR was reduced most in the albuminuric patients but was also decreased in micro-albuminuric patients, indicating that micro-albuminuria may be a predictor of more severe disease.     

Arterial hypertension following renal transplantation in children—a short-term study

Systemic arterial hypertension is a common complication among transplanted patients. The objective of this study was to investigate the risk factors for arterial hypertension after kidney transplantation in children. A retrospective study was carried out of 70 kidney transplants performed on patients under 18 years of age at the Hospital do Rim and Hipertensão, from January 1998 to June 2001. At the end of 6 months post transplant, the patients were classified into either normotensive (n=31) or hypertensive (n=39) groups. The following potential risk factors for arterial hypertension were studied: (1) hypertension before transplantation; (2) the glomerular filtration rate (GFR) at 1, 3, and 6 months post transplant; (3) acute rejection episodes; (4) cumulative dose of corticosteroids; (5) the presence of native kidneys; (6) symptomatic renal artery stenosis; (7) cold ischemia time greater than 24 h; (8) age and sex of the donor; (9) age of the recipient; (10) transplant type (living related or cadaveric donor); (11) the body mass index of recipients at the end of the follow-up period; and (12) delayed graft function. The two groups were comparable in terms of the etiology of renal insufficiency, age, gender, and immunosuppressive drugs. Among the risk factors studied, the sole factor showing a statistically significant association with arterial hypertension was the GFR at 3 and 6 months after transplantation. In the group of normotensive patients, GFRs were 92±29 and 83±20 ml/min per 1.73 m² at 3 and 6 months, respectively, whereas in the hypertensive patients, GFRs were 74±23 and 70±21 ml/min per 1.73 m² respectively. Hence, only the lower GFR can be considered a risk factor for hypertension in children within our sample. However, arterial hypertension might be a risk factor for the early onset of chronic allograft nephropathy; in this case, hypertension should be considered the cause of lower glomerular filtration. Our data do not permit us to distinguish between these two hypotheses. The known risk factors for hypertension following renal transplantation in adults were not confirmed in the present study. It remains unclear to us as to whether this means the etiology of hypertension differs in children, or if this is the result of a bias in patient selection.     

Clinical Implications of Initial Renal Function After Deceased Donor Transplant

The aim of this study was to investigate whether slow graft function (SGF) after transplantation of deceased-donor kidneys affected the prevalence of anemia or the glomerular filtration rate (GFR). We retrospectively evaluated the records of 534 kidney transplant patients who were classified based on their initial renal function, namely, immediate graft function (IGF), slow graft function (SGF), or delayed graft function (DGF). Among the 534 kidney transplant patients studied, the occurrences of each condition were IGF 104, SGF 133, and DGF 297. Six months after transplantation, a greater percentage of DGF patients were anemic compared with the others (P = .028). However, at 12 months after transplantation, SGF patients showed more anemia than the IGF group. DGF and SGF patients displayed similar GFR values at 18 and 24 months after transplantation. However, IGF patients displayed higher GFRs, even when subjects who experienced acute rejection episodes were censored (P = .004). The incidence of acute rejection episodes was similar among SGF and DGF patients. Patients displaying SGF after deceased-donor transplantation showed a greater tendency to be anemic than those displaying IGF. This study also suggested that SGF patients were at risk for acute rejection episodes and/or significantly reduced kidney function as measured by GFR.     

Donor age and graft function

We evaluated survival and renal function of cadaveric donor grafts according to donor age. The median age of the pediatric donors was 7.0 (0.7 – 16) years in 46 patients [median age 11.8 years (range) 3 – 16.8 years]. The median age of the adult donors was 34.4 (19 – 54) years in 59 patients [median age 12.1 years (range) 7 – 17.3 years]. Thirty patients were treated with azathioprine and prednisolone and 75 with cyclosporine A and prednisolone. The glomerular filtration rate (GFR) and the effective renal plasma flow (ERPF) were determined by the clearances of ⁵¹chromium-EDTA and ¹²⁵iodine-hippurate 1 – 48 months after kidney transplantation. There was no difference in graft survival between pediatric and adult grafts. There were also no differences in GFR in patients receiving grafts from pediatric or adult donors; 2 – 3 months after transplantation the GFR in recipients of pediatric grafts was 62±20 ml/min per 1.73 m² compared with 61±21 in those receiving adult grafts. The ERPF in recipients of adult grafts was significantly higher in the 1st month after transplantation: 486±239 versus 362±158 ml/min per 1.73 m². From the 4th to the 6th month after transplantation this difference disappeared: the ERPF of grafts from pediatric donors was 279±131 ml/min per 1.73 m² compared with 273±123 ml/min per 1.73 m² in grafts from adult donors. Using the single-kidney GFR and ERPF on an age-matched group of probands with minor diseases as references, 2 – 3 months after transplant the mean GFR of grafts from pediatric donors increased to 118%±51%, whereas the GFR of adult donor grafts fell to 60%±22% over the same period. After 4 – 6 months the ERPF in pediatric grafts was 96%±55% compared with 50%±22% in adult grafts. We conclude that graft survival and function in children with either a pediatric or an adult graft may not differ because graft function adapts to the requirement of the recipient. Received December 6 1995; received in revised form March 19 1996; accepted March 22 1996     

Influence of preoperative allograft function (effective renal plasma flow) on the short-term outcome following living donor kidney transplantation

OBJECTIVES: Predonation kidney function is supposed to be an important factor affecting graft outcome. Controversial evidence suggests that higher predonation glomerular filtration rate (GFR) positively correlated with posttransplant graft outcome. The purpose of this study was to examine the relationship between living donor graft kidney function as measured by effective renal plasma flow (ERPF) and short-term graft function. METHODS: We performed a retrospective analysis of 45 patients who underwent living donor renal transplantation at our institution from 2001 to 2007. The comprehensive nuclear medicine evaluation of donors' ERPF was performed before laparoscopic nephrectomy. The preoperative absolute ERPF-recipient body surface area (F/BSA) ratio and absolute ERPF-recipient body weight (F/Wt) ratio were determined for each donor-recipient pair. Posttransplant graft function was estimated by the four-variable Modification of Diet in Renal Disease (Chinese MDRD) equation. RESULTS: Estimated GFR correlated with F/BSA ratio at 3 months and 6 months (Pearson r = .495, P = .001 and r = .441, P = .012). Estimated GFR correlated with F/Wt ratio at 3 months and 6 months (r = .567, P < .001 and r = .453, P = .009). The correlations between the estimated GFR at 3 months and other variables were investigated. However, in the final multivariate model, F/BSA ratio and F/Wt ratio were the independent predictors of graft function. CONCLUSION: Preoperative ERPF can be used to calculate F/BSA and F/Wt ratios before living donor kidney transplantation. Our study provided evidence that F/BSA and F/Wt ratios may be considered predictive indices for short-term outcomes. An extreme discrepancy should be avoided between preoperative allograft function (absolute ERPF) and recipient body surface area or body weight.     

Role of Resistive Index Measurement in Diagnosis of Acute Rejection Episodes Following Successful Kidney Transplantation

Objective

This study was performed to evaluate the role of resistive index (RI) in the diagnosis of rejection episodes following successful kidney transplantation.

Materials and Methods

One hundred and one unrelated living first kidney allograft adult recipients (75 males and 26 females) of overall mean age of 39 years were enrolled and prospectively followed for 6 months. The measurement of RI by Doppler ultrasonography was performed in all patients on days 3 and 7 as well as at months 1, 3, and 6 in addition to when there was graft dysfunction. We determined serum creatinine and cyclosporine levels.

Results

Twenty-seven patients (26.7%) experienced 33 acute rejection episodes during the follow-up. There were significant differences between mean RI among patients with normal function vs rejection: 0.606 ± 0.065 vs 0.866 ± 0.083 (P < .05), respectively. Overall, elevated levels of cyclosporine, ischemic acute tubular necrosis (ATN), and renal artery thrombosis were observed in 8, 5, and 3 patients, respectively. No association was observed between these factors and RI.

Conclusions

RI was significantly higher in patients with acute rejection episodes. It had no association with ATN or cyclosporine toxicity. Hence, RI may be useful to diagnose acute renal allograft rejection following renal transplantation.     

A prospective study on size and function of paediatric kidneys (<10 years) transplanted to adults

BACKGROUND: There is increasing evidence that paediatric kidneys transplanted to adults have good graft function and satisfactory graft survival. The relationship between size increment and functional potential of paediatric kidneys following transplantation is not defined in detail. We therefore initiated a prospective single centre study, comprising detailed and repeated measurements of size and function of paediatric kidneys transplanted to adults. METHODS: Nineteen adults receiving a first kidney transplant from a paediatric donor (<10 years of age) were included in the study. All patients were followed for 12 months post-transplant. Increment in size and function of the transplanted kidneys were assessed by ultrasound, glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). All tests were performed during the first week, post-transplant and subsequently repeated at 1, 3, 6 and 12 months. RESULTS: Kidney volume increased 2.6-fold at 12 months (P < 0.001). GFR and ERPF showed a slightly more moderate increase, 1.8-fold and 1.6-fold, respectively. Patient and graft survival at 1 year were 100% and serum creatinine was 91 micromol/l (66-169). CONCLUSION: The study indicates that paediatric kidneys for transplantation may be considered as excellent rather than being referred to as suboptimal for adult recipients, at least the first year after transplantation.     

Advantages of cyclosporin A using 2-h levels in pediatric kidney transplantation

Clinical trials in adult liver and heart recipients have shown that management of cyclosporine (CsA) dose with 2-h levels (C2) leads to lower rejection rates and serum creatinine levels compared with C0 monitoring. Therefore, we investigated whether C2 monitoring might also improve late graft survival after kidney transplantation in children. To date, no results in adult renal transplantation and in pediatric transplantation have been published. Forty-nine stable pediatric kidney recipients with a minimum time of 1 year after transplantation (mean=7±5 years) entered the study. None of the patients had experienced an acute rejection up to 6 months before entering the study. CsA dosing was based on C0 monitoring for the first 6 months and then based on C2 monitoring for the following 6 months. C0 and C2 levels were measured at 4-weekly intervals. Percentage decline in glomerular filtration rate (GFR) and mean coefficients of variation of CsA levels (C_var) were calculated and compared during the 6-months periods. At the beginning of the study, the mean calculated GFR was 53±15 ml/min per 1.73 m². During the 6 months of C0 monitoring, the mean GFR decreased to 49±12 m/min per 1.73 m² (P=0.001, paired t-test). Six months after switching to C2 monitoring, the mean GFR remained stable, at 49±15 ml/min per 1.73 m² (P=0.3 paired t-test). The largest increase in GFR (3.9±7.9%) was found in patients with a decrease of their CsA dose of more than 5% under C2 monitoring. C_var was significantly lower under C2 than under C0 monitoring (0.24±0.10 vs. 0.30±0.15, P=0.02, unpaired t-test). We conclude that the switch to C2 monitoring helped to identify patients with CsA overdosing as well as to reduce variation in CsA level, which resulted in a halt in GFR decline.     

Association between preoperative allograft function (effective renal plasma flow) and the change in glomerular filtration rate among living-donor kidney transplant recipients

Background

Predonation kidney function may be an important factor affecting graft outcome. Increased baseline allograft function may be more effective than strategies to slow the decline in glomerular filtration rate (GFR). However, the role of donor effective renal plasma flow (ERPF) on long-term outcome is less well understood. The purpose of this study was to examine the relationship between preoperative allograft function as measured by ERPF and the decline of allograft function as defined by the annualized change in GFR among living-donor kidney transplant recipients.

Methods

We performed a retrospective analysis of 83 patients who underwent living donor renal transplantation at our institution from March 2001 to October 2010. A time series analysis of autoregressive integrated moving average (ARIMA) model was applied to determine the annualized change in GFR after transplantation. Univariate and stepwise multivariate analyses were performed using linear regression between preoperative ERPF and annualized change in GFR after transplantation. We also investigated the influence on annualized change in GFR of other donor or recipient variables.

Results

The ARIMA model revealed that the annualized change in GFR was −1.344 ± 12.476 mL/min/1.73 m² per year. Pearson correlation coefficient for the association between predonation ERPF of the transplanted kidney and the annualized change in GFR was 0.033 (P = .777).

Conclusions

Poor predonation kidney function was not associated with an increased rate of decline of allograft function. Neither donor age nor renal function (preoperative ERPF value) was a valid predictor of change in GFR among living-donor kidney transplant recipients.     

Differential effects of recombinant human growth hormone on glomerular filtration rate and renal plasma flow in chronic renal failure

In normal subjects recombinant human growth hormone (rhGH) increases glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) through the action of insulin-like growth factor-I (IGF-I). We have measured clearance of inulin and para-aminohippuric acid in 18 children with chronic renal failure (CRF) during their 1st year of rhGH treatment to look at the immediate (first 3 h), short-term (1 week) and long-term (1 year) effects of treatment. On day 1 mean (range) age was 9.1 (4.9–13.9) years, GFR 19 (9–58) and ERPF 77 (34–271) ml/min per 1.73 m². During treatment height velocity increased from 4.5 (1.7–6.5) to 9.5 (4.8–12.7) cm/year (P<0.0001). Two children required dialysis after 0.75 years and 1 child was electively transplanted after 0.5 years. There were no other serious adverse events. GFR and ERPF were unchanged in the 3 h following rhGH. GFR remained constant on day 8, 22 (6–56) and after 1 year, 20 (9–59) ml/min per 1.73 m². ERPF increased to 96 (33–276) ml/min per 1.73 m² on day 8P=0.005), and remained elevated, but not significantly so, at 99 (24–428) ml/min per 1.73 m² at 1 year. Fasting IGF-I increased from 147 (46–315) ng/ml to 291 (61–673) by day 8P<0.003), and to 341 (101–786) ng/ml at 1 year. There was no correlation between the change in IGF-I and renal function. Blood pressure, albumin excretion and dietary protein intake were unchanged by treatment. The significance of increased ERPF after 1 week of rhGH in CRF is unclear, but long-term follow-up of renal function is indicated.