Volume changes in polycystic kidneys during chronic dialysis and after renal transplantation

Changes in Kidney and Liver Volumes in Patients With Autosomal Dominant Polycystic Kidney Disease Before and After Dialysis Initiation

Objective

To examine the changes in total kidney volume (TKV) and total liver volume (TLV) before and after dialysis initiation in patients with autosomal dominant polycystic kidney disease.

Patients and Methods

This was a retrospective, single-center cohort study to investigate the changes in TKV and TLV before and after dialysis initiation, along with influencing factors, using linear mixed models. We enrolled 95 patients with autosomal dominant polycystic kidney disease (85 receiving hemodialysis [HD] and 10 receiving peritoneal dialysis [PD]) who began receiving dialysis at Toranomon Hospital from January 1, 2008, to December 31, 2020.

Results

The least squares mean TKV ratio (TKV at each time point/TKV at dialysis initiation) was 63.8% (95% confidence interval [CI], 54.7%-72.9%) at 6 years before dialysis initiation and 95.5% (95% CI, 82.9%-108.2%) at 6 years after dialysis initiation (P<.001). A multivariate linear mixed model analysis revealed that dialysis style (HD or PD) had the strongest effect on changes in TKV (P=.002). The least squares mean TLV ratio was 98.2% (95% CI, 88.4%-108.0%) at 6 years before dialysis initiation and 95.7% (95% CI, 85.2%-106.2%) at 6 years after dialysis initiation (P=.01). Although PD did not have significant effects on changes in TLV (P=.27), the changes in TLV were greater in patients on PD than in those on HD.

Conclusion

The TKV increased until dialysis initiation and generally decreased after dialysis initiation. The TLV continued to increase even after dialysis initiation, however, changes in the TLV significantly decreased after dialysis initiation. The increases in TKV and TLV were greater in patients on PD than in those on HD.

The Natural Course of Total Kidney Volume in Patients with Autosomal Dominant Polycystic Kidney Disease undergoing Hemodialysis

Objectives: The natural course of native kidneys after hemodialysis initiation in patients with autosomal dominant polycystic kidney disease (ADPKD) remains poorly understood.Methods: We measured the total volumes of native kidneys in 12 patients who had at least one enhanced computed tomography (CT) image both before and after initiation of hemodialysis (group 1) and in 18 patients who had no image before dialysis but more than two images after dialysis (group 2). In patients with images, the last image was used for analysis only after dialysis.Results: The mean total kidney volume (TKV) (± SD) before hemodialysis initiation was 3132 ± 1413 mL and the mean TKV of the last image was 3047 ± 1323 mL in group 1. The mean TKV change rate (%) was - 5.2 ± 27.4% (P > 0.05) during follow-up of 3.9 ± 1.9 years in group 1. The mean TKV change rate was 2.8 ± 34.4% (P > 0.05) in group 2. The follow-up period after dialysis initiation ranged from 4.2 ± 4.7 to 8.0 ± 5.2 years.Conclusions: The results suggest that the TKV of native polycystic kidneys decreases substantially after hemodialysis initiation. This reduction occurs mainly during the early post-hemodialysis period and followed by a slow enlargement of TKV.

Kidney transplant patient with immunoglobulin A nephropathy subsequently diagnosed as concurrent autosomal dominant polycystic kidney disease during 17-year follow-up

A 14-year-old Japanese boy was diagnosed with immunoglobulin A nephropathy resulting in end-stage kidney disease (ESKD). He underwent ABO-compatible living kidney transplantation from his father at the age of 27. In the process of selecting a donor before the transplantation, it turned out that his mother had polycystic kidneys and that her family had a history of hypertension and cerebrovascular diseases. The patient himself also had bilateral multiple kidney cysts, with a normal-sized kidney, confusing us to make the diagnosis of acquired cystic kidney disease (ACKD) or ADPKD difficult at that point. Seventeen years later, his native kidneys showed bilateral swelling with multiple cysts. This, along with the histories of his mother and her relatives and with the existence of multiple liver cysts, led us to confirm the diagnosis of autosomal dominant polycystic kidney disease, not of ACKD. Contrary to previous studies that have suggested the size of cysts both in ADPKD and ACKD reduced with time, the present case showed an increase of 3.0% per year in total kidney volume (TKV) by computed tomography. It suggested the possibility that TKV, after decreasing in the relatively early stage after transplantation, may later increase in the long term after ESKD due to another kidney injury.

Effect of Sirolimus on Native Total Kidney Volume After Transplantation in Patients with Autosomal Dominant Polycystic Kidney Disease: A Randomized Controlled Pilot Study

BACKGROUND

The mammalian target of rapamycin (mTOR) pathway has been shown to be central to cyst formation and growth in patients with autosomal dominant polycystic kidney disease (ADPKD). Drugs that suppress mTOR signaling are frequently used as antiproliferative agents for maintenance immunosuppression in patients who have undergone kidney transplantation. The aim of this study was to determine the effect of sirolimus, an mTOR inhibitor, on cyst volume regression in patients with ADPKD who have undergone renal transplantation.

METHODS

In this single-center, prospective, open-label, parallel-group, randomized trial, 23 adult patients with ADPKD who successfully underwent renal transplantation from 2008 to 2012 were subsequently randomized (on a 1:1 basis) to a maintenance immunosuppression regimen with either sirolimus (sirolimus, tacrolimus, prednisone) or mycophenolate (mycophenolate, tacrolimus, prednisone). Total kidney volumes were measured by means of high-resolution magnetic resonance imaging within 2 weeks after transplantation and at 1 year. The primary end point was change in total kidney volume at 1 year.

RESULTS

Sixteen patients completed the 1-year study (8 patients in each group). There was a decrease in kidney volume in both the sirolimus group (percentage change from baseline, 20.5%; P < .001) and mycophenolate group (percentage change from baseline, 17%; P = .048), but there was no significant difference in percentage change of total kidney volume between the groups (P = .665).

CONCLUSIONS

In ADPKD patients at 1 year after kidney transplantation, there was a similar decrease in polycystic kidney volume in patients receiving an immunosuppression regimen containing sirolimus compared with patients receiving mycophenolate.

Volume regression of native polycystic kidneys after renal transplantation

BACKGROUND

The natural course of native kidneys after renal transplantation (RT) or dialysis in patients with autosomal dominant polycystic kidney disease (ADPKD) remains poorly understood.

METHODS

We measured the total volumes of native kidneys and liver in 78 and 68 ADPKD patients, respectively, who had pre-transplant (within 2 years) and at least one post-transplant computed tomography (CT)/magnetic resonance imaging (MRI); in 40 patients with at least two post-transplant but no pre-transplant CT/MRIs; in 9 patients on chronic hemodialysis with at least one CT/MRI before and after beginning dialysis; and in 5 patients who had no image before and more than one image after dialysis. The last imaging was used in patients with multiple studies.

RESULTS

Mean total kidney volume (TKV) ( ± SD) prior to transplantation was 3187 ± 1779 mL in the 78 patients who had imaging before and after transplantation and decreased by 20.2, 28.6, 38.3 and 45.8% after 0.5-1 (mean 0.7), 1-3 (1.8), 3-10 (5.7) and >10 (12.6) years, respectively. In the multivariable analysis, time on dialysis prior to RT and time from baseline to transplantation were negatively associated with reduction in TKV, whereas estimated glomerular filtration rate (eGFR) after transplantation and time from transplantation were positively associated with percent reduction in TKV. In the 40 patients with imaging only after transplantation, TKV decreased by 3.2 ± 16.3% between 7.2 ± 6.0 and 11.2 ± 6.8 years after transplantation (P < 0.001). TKV was 11.2 ± 35.6% higher (P = NS) after a follow-up of 3.4 ± 2.0 years in the 9 patients with imaging before and after initiation of hemodialysis and 3.4 ± 40.2% lower (P = NS) in the 5 patients with imaging between 2.0 ± 2.1 and 3.5 ± 3.6 years after initiation of hemodialysis. In the 68 patients with liver measurements, volume increased by 5.8 ± 17.9% between baseline and follow-up at 3.7 ± 3.8 years after transplantation (P = 0.009).

CONCLUSIONS

TKV of native polycystic kidneys decreases substantially after RT. The reduction occurs mainly during the early post-transplantation period and more slowly thereafter.

Renal transplantation in autosomal dominant polycystic kidney disease

In patients with autosomal dominant polycystic kidney disease (ADPKD) evaluated for kidney transplantation, issues related to native nephrectomy, cystic liver involvement, screening for intracranial aneurysms and living-related kidney donation deserve special consideration. Prophylactic native nephrectomy is restricted to patients with a history of cyst infection or recurrent haemorrhage or to those in whom space must be made to implant the graft. Patients with liver involvement require pretransplant imaging. Selection of patients for pretransplant screening of intracranial aneurysms should follow the general recommendations for patients with ADPKD. In living related-donor candidates aged <30 years and at-risk of ADPKD, molecular genetic testing should be carried out when ultrasonography and MRI findings are normal or equivocal. After kidney transplantation, patient and graft survival rates are excellent and the volume of native kidneys decreases. However, liver cysts continue to grow and treatment with a somatostatin analogue should be considered in patients with massive cyst involvement. Cerebrovascular events have a marginal effect on post-transplant morbidity and mortality. An increased risk of new-onset diabetes mellitus and nonmelanoma skin cancers has been reported, but several studies have challenged these findings. Finally, no data currently support the preferential use of mammalian target of rapamycin inhibitors as immunosuppressive agents in transplant recipients with ADPKD.

Kidney volume changes in patients with autosomal dominant polycystic kidney disease after renal transplantation

BACKGROUND

Few studies have investigated whether the volume of native kidney and liver (when combined with polycystic disease) in patients with autosomal dominant polycystic kidney disease (ADPKD) decreases after renal transplantation.

METHODS

Changes in the volume of native kidney (bilateral: n=28; unilateral: n=5) and liver (concomitant polycystic disease: n=18) were analyzed in 33 patients with ADPKD, who underwent renal transplantation. Volumetry was retrospectively conducted using simple computed tomography scan data 6 months before transplantation, at the time of transplantation, and 1, 3, and 5 years after transplantation. Volume change was calculated on the basis of the value at the time of transplantation.

RESULTS

Mean±standard deviation values of bilateral native kidney volume were 3100±1417 (range: 756 to 6525; median: 2499) cm at the time of transplantation. Kidney volumes were significantly reduced in all but one patient after renal transplantation, decreasing by 37.7% and 40.6% at 1 and 3 years, respectively. The major proportion of the decrease was observed within the first year posttransplantation. In contrast, 16 of 18 patients showed significant increase of liver volumes after renal transplantation. The mean rates of increase were 8.6% and 21.4% at 1 and 3 years, respectively.

CONCLUSIONS

As the volume of native polycystic kidneys could be reduced after renal transplantation, resection would be unnecessary if the space for kidney graft is available in the absence of infection, bleeding, or malignancy. When ADPKD is combined with polycystic liver disease, the possibility of intolerable symptoms caused by growing liver cysts should also be taken into account.

Frequency of hepatic cysts in adult polycystic kidney disease

The frequency of hepatic cysts in patients with adult polycystic kidney disease (APKD) is usually considered to average about 33%, but with great, and hitherto largely unexplained, variations between different studies. Sixty-six consecutive patients with APKD were all subjected to CT scanning of the liver and of the kidneys. In confirmation of one previous study, a clearcut correlation was found between age (= duration of disease) and the frequency of hepatic cysts. It was furthermore found that cysts in the liver, as opposed to cysts in the kidneys, continue to grow and appear de novo even after institution of renal replacement therapy.

Pretransplant Nephrectomy in Patients With Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease and a frequent cause of end-stage renal failure. Transplantation in patients with ADPKD is associated with specific cyst-related problems, especially urinary tract infections (UTI). Although pretransplant nephrectomy has been applied in this group of patients, evidence of the benefits of this strategy is lacking. Therefore, we compared the outcomes and posttransplant complications among patients with or without pretransplant nephrectomy.

PATIENTS AND METHODS

ADPKD patients (73) transplanted from cadaveric donors were reviewed retrospectively with regard to posttransplant complications and outcomes. The groups either underwent pretransplant unilateral nephrectomy (n = 30) or were transplanted with native kidneys intact (n = 43).

RESULTS

Two patients underwent simultaneous bilateral nephrectomy due to a large size of the polycystic kidneys interfering with the transplant operation. Overall postransplant complications were more frequent in the group without nephrectomy (34% vs 20%); however, the difference was not statistically significant. Most complications were related to cyst infections with 3 deaths (12%) due to lethal septicemia in the group without nephrectomy. No infection-related deaths were noted in the group with pretransplant nephrectomy.

CONCLUSIONS

Graft and patient outcomes as well postransplant complications were similar in both groups, independent of previous nephrectomy. It seems that pretransplant unilateral nephrectomy should not be routine and has no advantage over transplantation with both native kidneys intact, although this conclusion is limited by the small number of patients. An Individualized approach should be applied especially when there has been a history of cyst-related infection.

Simultaneous liver-renal grafting for polycystic disease

Our purpose was to describe the first in our country and fourth worldwide simultaneous liver and renal grafting for polycystic disease.

Renal ammonia in autosomal dominant polycystic kidney disease

Recent studies have suggested that defective medullary trapping of ammonia underlies the acidosis associated with renal failure and sets in motion maladaptive compensatory mechanisms that contribute to the progression of renal disease. Since a renal concentrating defect is an early functional abnormality in autosomal dominant polycystic kidney disease (ADPKD), defective medullary trapping and urinary excretion of ammonia may also occur early and have important pathophysiological consequences. The urinary pH and excretions of ammonia, titratable acid, and bicarbonate, were measured during a 24-hour baseline period and following the administration of ammonium chloride (100 mg/kg body wt) in ADPKD patients with normal glomerular filtration rate and in age- and gender-matched healthy control subjects. The distal nephron hydrogen ion secretory capacity was assessed during a bicarbonate infusion. Ammonia, sodium, pH, C3dg, and C5b-9 were measured in cyst fluid samples. The excretion rates of ammonia during the 24-hour baseline period and following the administration of ammonium chloride were significantly lower, and the relationship of ammonia excretion to urinary pH was significantly shifted downward in ADPKD. No difference in the increment of urinary pCO2 (delta pCO2) or the peripheral blood-urine pCO2 gradient (U-B pCO2) between ADPKD patients and control subjects was detected during a sodium bicarbonate infusion. Calculated concentrations of free-base ammonia in cyst fluid samples exceeded those calculated from reported concentrations of ammonia in renal venous blood of normal subjects. C3dg and C5b-9 were detected in some cyst fluids. The urinary excretion of ammonia is reduced in ADPKD patients with normal glomerular filtration rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Massive growth of kidneys in patients with autosomal dominant polycystic kidney disease treated with chronic hemodialysis

Three patients with autosomal dominant polycystic kidney disease in whom kidneys enlarged enormously during treatment with chronic hemodialysis for terminal uremia are reported. In all cases, nephrectomies were performed for the relief of symptoms caused by the large kidneys.