Can a living kidney donor become a kidney recipient?

The living kidney donor represents a good resource for kidney transplantation. These grafts display better function and long-term graft survival at 5 and 10 years of follow-up. Furthermore, living donors prefer the possibility to increase kidney donation for a large waiting list of patients with end-stage renal disease (ESRD). However, kidney donation is a major surgical procedure associated with benefits and risks. The risks of donation have been studied in large series of living donors to focus on morbidity and mortality rates associated with the surgical procedure. New surgical laparoscopic techniques promote living kidney donation. While the benefits to the recipient are obvious, those for the donor are subjective and not quantifiable. However, donors describe donation as a great experience in life. The risk of kidney donation may be divided into the perioperative and the long-term risks. The evaluate the long-term risks for kidney donors requires a long follow-up. The main source of kidney donors in our transplant center has been living-related and -unrelated donors, with a minor percentage of cadaveric donors. In this report we present four kidney donors who developed ESRD thereafter, three becoming kidney recipients.     

Atrial natriuretic peptide attenuates kidney–lung crosstalk in kidney injury

Background

Renal ischemia–reperfusion injury (IRI) is a common cause of acute kidney injury after cardiovascular surgery, which in turn deteriorates oxygenation. Atrial natriuretic peptide (ANP) has natriuretic, diuretic, and anti-inflammatory effects. To elucidate whether renal IRI induces inflammation in the kidney and lung and ANP attenuates kidney–lung crosstalk.

Materials and methods

The rats were anesthetized, tracheostomized, mechanically ventilated, and randomized to four groups: saline + IRI (n = 12), ANP + IRI (n = 12), ANP + sham (n = 6), and saline + sham (n = 6). Saline (6 mL/kg/h) or ANP (0.2 μg/kg/min) at the rate of 6 mL/kg/h was started 5 min before clamping, respectively. Renal IRI was induced by clamping the left renal pedicle for 30 min. The hemodynamics, arterial blood gases, and plasma concentrations of creatinine and lactate were measured at baseline and 1, 2, and 3 h after declamping. Lung wet-to-dry ratio was measured. The mRNA expression of tumor necrosis factor (TNF)-α, interleukin (IL) 1β, and IL-6 and histologic localization of TNF-α in the kidney and lung were measured.

Results

Renal IRI induced metabolic acidosis, pulmonary edema, increases in plasma concentrations of creatinine and lactate, and augmentation of the cytokine mRNA expression and histologic localization of TNF-α in the kidney and Renal IRI induced lung. ANP prevented IRI-induced metabolic acidosis, pulmonary edema, increases in creatinine, lactate, and the cytokine mRNA expression, attenuated histologic localization of TNF-α in the kidney and lung, and increased oxygenation.

Conclusions

ANP has renoprotective and anti-inflammatory effects on the kidney and lung in a rat model of renal IRI, suggesting that ANP attenuates kidney–lung crosstalk.     

Lung injury following acute kidney injury: kidney–lung crosstalk

The mortality of acute kidney injury (AKI) remains unacceptably high, especially associated with acute respiratory failure. Lung injury complicated with AKI was previously considered as “uremic lung”, which is characterized by volume overload and increased vascular permeability. New experimental data using rodent models of renal ischemia–reperfusion and bilateral nephrectomy have emerged recently focusing on kidney–lung crosstalk in AKI, and have highlighted the pathophysiological significance of increased cytokine concentration, enhanced inflammatory responses, and neutrophil activation. In this review, we outline the history of uremic lung and acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), the epidemiological data on the synergistic effect of AKI and lung injury on mortality, and recent basic research which has identified possible pathways in AKI-induced lung injury. These findings will enable us to develop new therapeutic strategies against lung injury associated with AKI and improve the outcomes of critically ill patients in intensive care units.     

Do multiple renal arteries in the remnant kidney have a negative influence on kidney donors after kidney donation?

Aim: To investigate whether the presence of multiple renal arteries in the remnant kidney has implications for lower renal function or increased incidence of hypertension. Methods: We reviewed the intraoperative and follow‐up data of 101 live kidney donors who underwent nephrectomies at our institution. Sixty‐nine donors (68.3%) had single artery in the remnant kidney (Group A), while 32 donors (31.7%) had multiple renal arteries in the remnant kidney (Group B). We compared the demographic and intraoperative data between the two groups. The follow‐up data of donors in each group were divided into three subgroups based on the length of the follow‐up period (12–24 months, 24–48 months and ≥48 months). Subgroups were created based on blood pressure and serum creatinine level. The δblood pressure (follow‐up blood pressure minus preoperative blood pressure) and δserum creatinine (follow‐up serum creatinine minus preoperative serum creatinine) in each subgroup in Group A were compared with the counterparts in Group B. Results: Renal arterial stenosis and calcification of renal arterial wall were not observed in all donors. There were no significant differences in the intraoperative characteristics (e.g. age, body mass index, operative duration and estimated blood loss) between the two groups. In addition, the blood pressure and serum creatinine level among subgroups within each group were similar. Furthermore, significant differences in δblood pressure and δserum creatinine were not observed between subgroups within the same follow‐up period. Recipient survival rate and serum creatinine level were similar and acceptable in both groups. Conclusions: The presence of multiple renal arteries in the remnant kidney does not have additional negative influence on kidney donors after kidney donation.     

Obesity and the kidney: Why is the kidney at risk?

Two recent studies may help to account for the increase in risk of renal injury associated with obesity. One study pointed to a role for renin-system activation. In the other study, the pattern of renal hemodynamics was compatible with a renin mechanism.     

Preoperative evaluation of living related kidney donor: which kidney to donate?

OBJECTIVES: As the number of cadaveric donor is far beyond the demand of the waiting list, living related kidney transplantation is important for the worldwide organ shortage. Besides, living related transplantation has advantages compared with cadaveric transplantation in terms of graft function and survival. However, the remaining kidney function of the living donor needs to be evaluated. METHODS: We collected 28 paired living kidney donations from March 2003 to March 2005. All patients underwent laparoscopic donor nephrectomy. The preoperative kidney evaluation included renal echography, renal nuclear scan, computed tomography angiography (CTA), and creatinine clearance (CCr). The renal function of the donor kidney was expressed as (donor kidney/both kidneys)%. The percentage renal function from renal echography, renal nuclear scan, and CTA were correlated with CCr. RESULTS: The mean percentage of donor kidney function according to renal echo, nuclear scan, and CTA were 49.77%, 51.83%, and 50.70%, respectively. The correlation coefficients for renal echography, nuclear scan, and CTA to CCr were -0.316, -0.201, and 0.123, respectively. The correlation coefficients for renal echography, nuclear scan, and CTA to postoperative serum creatinine of donor were 0.426, 0.036, and -0.119, respectively. CONCLUSION: From the viewpoint of donor postoperative residual renal function, preoperative renal sonography offered a better predictive value than nuclear scan or CTA.     

Time to differentiate ‘decreased kidney function’ from ‘kidney disease’: towards improving the definition of chronic kidney disease

Chronic kidney disease (CKD) has become an ‘epidemic’ worldwide, since the publication of K/DOQI guidelines in 2002. This classification indeed has raised the profile of CKD worldwide. However, despite limitations of the glomerular filtration rate (GFR) estimating equations, the majority of this epidemic is caused by the large number of persons with stage 3 CKD, with many elderly individuals with ‘low-normal GFR’ being diagnosed with CKD, when, in fact, the majority of those may not have the disease, and a handful of resources being utilized in investigating these relatively ‘low-risk patients’ with ‘decreased eGFR’ without CKD. Recently, concerns have been raised by nephrologists about this classification system, and I strongly feel that it is important to differentiate ‘decreased kidney function’ from ‘kidney disease’, as the GFR estimating equations predict renal function only and nothing else; therefore, I propose some modifications to improve the current classification, so that limited resources and efforts are effectively focused on managing high-risk patients.     

Do kidney histology lesions predict long‐term kidney function after liver transplantation?

Histological renal lesions observed after liver transplantation are complex, multifactorial, and interrelated. The aims of this study were to determine whether kidney lesions observed at five yr after liver transplantation can predict long‐term kidney function. Ninety‐nine liver transplant patients receiving calcineurin inhibitor (CNI)‐based immunosuppression, who had undergone a kidney biopsy at 60 ± 48 months post‐transplant, were included in this follow‐up study. Kidney biopsies were scored according to the Banff classification. Estimated glomerular filtration rate (eGFR) was assessed at last follow‐up, that is, 109 ± 48 months after liver transplantation. eGFR decreased from 92 ± 33 mL/min at transplantation to 63 ± 19 mL/min after six months, to 57 ± 17 mL/min at the kidney biopsy, to 54 ± 24 mL/min at last follow‐up (p < 0.0001). At last follow‐up, only three patients required renal replacement therapy. After the kidney biopsy, 13 patients were converted from CNIs to mammalian target of rapamycin inhibitors, but no significant improvement in eGFR was observed after conversion. Elevated eGFR at six months post‐transplant and a lower fibrous intimal thickening score (cv) observed at five yr post‐transplant were the two independent predictive factors for eGFR ≥60 mL/min at nine yr post‐transplant. Long‐term kidney function seems to be predicted by the kidney vascular lesions.     

Native nephrectomy for autosomal dominant polycystic kidney disease: before or after kidney transplantation?

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? The indications and timing of native nephrectomy in patients with autosomal dominant polycystic kidney disease (ADPKD) is controversial, especially for those undergoing renal transplantation. Post‐transplant unilateral native nephrectomy appears to be the preferred intervention compared to pre‐transplant native nephrectomy. There seems to be substantial additive risk to bilateral over unilateral nephrectomy, especially prior to transplantation. Pre‐transplant native nephrectomy should only be carried out when there are clear indications such as massive size preventing allograft placement, severe pain, early satiety, recurrent bleeding and infections, or suspected malignancy.

OBJECTIVE

To analyse indications, timing and outcomes of native nephrectomy in autosomal dominant polycystic kidney disease (ADPKD) patients listed for kidney transplantation.

PATIENTS AND METHODS

A retrospective analysis of all ADPKD patients who had a native nephrectomy prior to or following transplantation between January 2003 and December 2009 at a single centre, including those undergoing the sandwich technique (removal of the most severely affected native kidney prior to transplantation, and the other afterwards), was undertaken.

RESULTS

There were 35 individuals in our cohort (M : F = 16 : 19), with a median age of 51.5 years (range 43–65). Twenty patients were in the pre‐transplant nephrectomy group, 12 in the post‐transplant group, and three underwent the sandwich technique. Indications for nephrectomy varied but were most commonly pain/discomfort, space for transplantation, ongoing haematuria, recurrent infections, and gastrointestinal pressure symptoms (early satiety). Seven individuals in the pre‐transplant group and three in the post‐transplant group required critical care admission after nephrectomy. Transient renal graft dysfunction occurred in two post‐transplant bilateral nephrectomy patients. Two patients in the bilateral nephrectomy pre‐transplant group and one in the bilateral nephrectomy post‐transplant group died in the immediate post‐operative period. No complications were noted in the sandwich technique group.

CONCLUSION

Native nephrectomy in ADPKD is a major undertaking associated with significant morbidity especially in the pre‐transplant group. Post‐transplant unilateral nephrectomy appears to be the safest approach with fewest complications.     

PPAR�� and chronic kidney disease

Peroxisome proliferator-activated receptor-γ (PPARγ) agonists, exemplified by the thiazolidinediones (TZDs), have been used extensively for their beneficial effects to improve insulin sensitivity and lipid metabolism in type 2 diabetic patients. PPARγ receptors are part of the steroid hormone nuclear receptor family and, when activated by agonist binding, can affect numerous target genes expressing PPAR response elements. Results from experimental studies and a limited number of studies in humans suggest that PPARγ agonists have manifold effects beyond those on dysmetabolic syndrome. These potentially beneficial actions are mediated via renal parenchymal and infiltrating cells and modulate fibrotic, inflammatory, immune, proliferative, reactive oxygen and mitochondrial injury pathways. Thus, the potential benefits of TZDs in chronic kidney disease impact numerous pathogenic pathways. This review will focus on evidence of the effects of TZDs in nondiabetic chronic kidney disease in experimental and human disease settings.     

Does donor kidney to recipient body weight ratio influence long-term outcomes of living-donor kidney transplantation?

This study evaluated the effect of the donor kidney to recipient body weight (Kw/Rw) ratio on long-term graft function and survival. We investigated retrospectively whether there was any association between Kw/Rw ratio and long-term graft survival and function after a follow-up of >10 years. We studied a consecutive series of 123 adult-to-adult living kidney transplants. According to the Kw/Rw ratio, patients were divided into 3 groups: “low” (Kw/Rw <2.85; n = 29), “medium” (2.85 ≤ Kw/Rw < 4.04; n = 63), and “high” (≥4.04; n = 31). Among the 3 groups, the mean serum creatinine levels at 1 and 6 months as well as 1 year after transplantation were significantly lower among patients with a high Kw/Rw ratio than in those with a medium or low ratio, but serum creatinine levels at 3 and 5 years did not differ significantly (P = .394 and 0.620, respectively). Graft survival rates at 5 and 10 years after transplantation were significantly lower in the “low” group. We observed a significant association between Kw/Rw ratio and graft survival (P = .018). The Kw/Rw ratio is an important factor for long-term graft survival and early graft function. However, it did not significantly affect subsequent renal function.