Safety and efficacy of transcatheter arterial embolization in autosomal dominant polycystic kidney patients with gross hematuria: Six case reports

BACKGROUND To retrospectively report the safety and efficacy of renal transcatheter arterial embolization for treating autosomal dominant polycystic kidney disease(ADPKD)patients with gross hematuria.CASE SUMMARY The purpose of this study is to retrospectively report the safety and efficacy of renal transcatheter arterial embolization for treating ADPKD patients with gross hematuria.Materials and methods:During the period from January 2018 to December 2019,renal transcatheter arterial embolization was carried out on 6 patients with polycystic kidneys and gross hematuria.Renal arteriography was performed first,and then we determined the location of the hemorrhage and performed embolization under digital subtraction angiography monitoring.Improvements in routine blood test results,routine urine test results,urine color and postoperative reactions were observed and analyzed.Results:Renal transcatheter arterial embolization was successfully conducted in 6 patients.The indices of 5 patients and the color of gross hematuria improved after surgery compared with before surgery.No severe complication reactions occurred.CONCLUSION For autosomal dominant polycystic kidney syndrome patients with gross hematuria,transcatheter arterial embolization was safe and effective.

Incidental renal cell carcinoma post bilateral nephrectomy in autosomal dominant polycystic kidney disease

BACKGROUND Renal cell carcinoma(RCC)is more common in patients with autosomal dominant polycystic kidney disease(ADPKD)than in the general population.Diagnosing RCC in ADPKD is challenging due to the presence of multiple renal cysts,often leading to delays and difficulties in distinguishing RCC from cyst infection or hemorrhage.A total of 38 kidneys were excised from 19 patients,with a mean age of 56.8 years and an average hemodialysis duration of 84.2 months.Eight patients underwent open nephrectomies,and 11 underwent hand-assisted laparoscopic nephrec-tomies.RCC was detected in 15.8%of kidneys,affecting 21.1%of patients.Two patients had multifocal RCC in both kidneys.All RCC cases were pT1 stage,with the largest lesion averaging 16.5 mm in diameter.The average operative duration was 120 minutes,with intraoperative blood loss averaging 184.2 mL.Five patients required blood transfusions.Postoperative complications occurred in five patients,with a mean hospital stay of 17.1 days.The mean follow-up period was 28.1 months.CONCLUSION The prevalence of RCC is higher in patients with ADPKD with ESRD than in those with ESRD alone.Thus,clinicians should be cautious and implement surveillance programs to monitor the development of RCC in patients with ADPKD,particularly those on dialysis.

Prevalence and outcomes of polycystic kidney disease in African populations:A systematic review

BACKGROUND Polycystic kidney disease(PKD)is the most common genetic cause of kidney disease.It is a progressive and irreversible condition that can lead to end-stage renal disease and many other visceral complications.Current comprehensive data on PKD patterns in Africa is lacking.AIM To describe the prevalence and outcomes of PKD in the African population.METHODS A literature search of PubMed,African journal online,and Google Scholar databases between 2000 and 2023 was performed.The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed to design the study.Clinical presentations and outcomes of patients were extracted from the included studies.RESULTS Out of 106 articles,we included 13 studies from 7 African countries.Ten of them were retrospective descriptive studies concerning 943 PKD patients with a mean age of 47.9 years.The accurate prevalence and incidence of PKD were not known but it represented the third causal nephropathy among dialysis patients.In majority of patients,the diagnosis of the disease was often delayed.Kidney function impairment,abdominal mass,and hypertension were the leading symptoms at presentation with a pooled prevalence of 72.1%(69.1-75.1),65.8%(62.2-69.4),and 57.4%(54.2-60.6)respectively.Hematuria and infections were the most frequent complications.Genotyping was performed in few studies that revealed a high proportion of new mutations mainly in the PKD1 gene.CONCLUSION The prevalence of PKD in African populations is not clearly defined.Clinical symptoms were almost present with most patients who had kidney function impairment and abdominal mass at the diagnostic.Larger studies including genetic testing are needed to determine the burden of PKD in African populations.

Current management of autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease （ADPKD）, the most frequent cause of genetic renal disease affecting approximately 4 to 7 million individuals worldwide and accounting for 7%-15% of patients on renal replacement therapy, is a systemic disorder mainly involving the kidney but cysts can also occur in other organs such as the liver, pancreas, arachnoid membrane and seminal vesicles. Though computed tomography and magnetic resonance imaging （MRI） were similar in evaluating 81% of cystic lesions of the kidney, MRI may depict septa, wall thickening or enhancement leading to upgrade in cyst classification that can affect management. A screening strategy for intracranial aneurysms would provide 1.0 additional year of life without neurological disability to a 20-year-old patient with ADPKD and reduce the fnancial impact on society of the disease. Current treatment strategies include reducing： cyclic adenosine monophosphate levels, cell proliferation and fluid secretion. Several randomised clinical trials （RCT） including mammalian target of rapamycin inhibitors, somatostatin analoguesand a vasopressin V2 receptor antagonist have beenperformed to study the effect of diverse drugs ongrowth of renal and hepatic cysts, and on deteriorationof renal function. Prophylactic native nephrectomy isindicated in patients with a history of cyst infection orecurrent haemorrhage or to those in whom space musbe made to implant the graft. The absence of largeRCT on various aspects of the disease and its treatmen leaves considerable uncertainty and ambiguity in many aspects of ADPKD patient care as it relates to end stage renal disease （ESRD）. The outlook of patients with ADPKD is improving and is in fact much better than that for patients in ESRD due to other causes. This review highlights the need for well-structured RCTs as a frst step towards trying newer interventions so as to develop updated clinical management guidelines.

Role of calcium in polycystic kidney disease:From signaling to pathology

Autosomal dominant polycystic kidney disease （ADPKD） is the most common inherited monogenic kidney disease. Characterized by the development and growth of cysts that cause progressive kidney enlargement, it ultimately leads to end-stage renal disease. Approximately 85% of ADPKD cases are caused by mutations in the PKD1 gene, while mutations in the PKD2 gene account for the remaining 15% of cases. The PKD1 gene encodes for polycystin-1 （PC1）, a large multi-functional memb-rane receptor protein able to regulate ion channel complexes, whereas polycystin-2 （PC2）, encoded by the PKD2 gene, is an integral membrane protein that functions as a calcium-permeable cation channel, located mainly in the endoplasmic reticulum （ER）. In the primary cilia of the epithelial cells, PC1 interacts with PC2 to form a polycystin complex that acts as a mechanosensor, regulating signaling pathways involved in the differentiation of kidney tubular epithelial cells. Despite progress in understanding the function of these proteins, the molecular mechanisms associated with the pathogenesis of ADPKD remain unclear. In this review we discuss how an imbalance between functional PC1 and PC2 proteins may disrupt calcium channel activities in the cilium, plasma membrane and ER, thereby altering intracellular calcium signaling and leading to the aberrant cell proliferation and apoptosis associated with the development and growth of renal cysts. Research in this feld could lead to the discovery of new molecules able to rebalance intracellular calcium, thereby normalizing cell proliferation and reducing kidney cyst progression.

OFD1 mutation induced renal failure and polycystic kidney disease in a pair of childhood male twins in China

BACKGROUND Oral-facial-digital syndrome type 1(OFD1) is a rare ciliopathy mainly with an Xlinked dominant pattern of inheritance, which is caused by mutations in the OFD1 gene. The OFD1 protein is located within the centrosomes and basal bodies of the primary cilia. It is reported that approximately 15%–50% cases of OFD1 progress to end-stage renal disease(ESRD) following development of polycystic kidney diseases(PKD). Here we report a pair of childhood male twins who presented only renal failure and PKD caused by an OFD1 mutation in China.CASE SUMMARY A pair of 14-year male twins were hospitalized with a complaint of abnormal renal function for nine days. They both complained of ankle pain for 3 mo vs 2 wk, respectively. They denied fever, abdominal pain, daytime or nighttime enuresis, urgency, dysuria, or gross hematuria. Laboratory tests at a local hospital showed renal failure(serum creatinine 485 μmol/L vs 442 μmol/L, blood urea nitrogen 14.7 mol/L vs 14.5 mol/L) and anemia(hemoglobin 88 g/L vs 98 g/L).The twins are monozygotic. There was no abnormal birth, past medical, or family history. Clinical data were analyzed and genetic analysis on PKD was carried out in the twins by next-generation sequencing. The results showed that the twins presented low-molecular-weight proteinuria, hyposthenuria, anemia, renal failure, and renal polycystic changes. Genetic tests showed that the twins both carried a hemizygous mutation in exon 19 c.2524 G>A(p. G842 R) of the OFD1 gene. Their mother heterozygously carried the same mutation as the twins but was without any phenotypes while their father was normal.CONCLUSION We have reported a pair of childhood male twins with an OFD1 mutation who presented ESRD and PKD but without any other phenotypes of OFD1 in China.

Constitutive renal Rel/nuclear factor-κB expression in Lewis polycystic kidney disease rats

AIM： To determine the temporal expression and pattern of Rel/nuclear factor （NF）-κB proteins in renal tissue in polycystic kidney disease （PKD）. METHODS： The renal expression of Rel/NF-κB proteins was determined by immunohistochemistry, immunofuorescence and immunoblot analysis in Lewis polycystic kidney rats （LPK, a genetic ortholog of human nephronopthsis-9） from postnatal weeks 3 to 20. At each timepoint, renal disease progression and the mRNA expression of NF-κB-dependent genes （TNFa and CCL2） were determined. NF-κB was also histologically assessed in human PKD tissue.RESULTS： Progressive kidney enlargement in LPK rats was accompanied by increased renal cell proliferation and interstitial monocyte accumulation （peaking at weeks 3 and 10 respectively）, and progressive interstitial fibrosis （with a smooth muscle actin and Sirius Red deposition significantly increased compared to Lewis kidneys from weeks 3 to 6 onwards）. Rel/NF-κB proteins （phosphorylated-p105, p65, p50, c-Rel and RelB） were expressed in cystic epithelial cells （CECs） of LPK kidneys as early as postnatal week 3 and sustained until late-stage disease at week 20. From weeks 10 to 20, nuclear p65, p50, RelB and cytoplasmic IκBa protein levels, and TNFa and CCL2 expression, were upregulated in LPK compared to Lewis kidneys. NF-κB proteins were consistently expressed in CECs of human PKD. The DNA damage marker γ-H2AX was also identifed in the CECs of LPK and human polycystic kidneys. CONCLUSION： Several NF-κB proteins are consistently expressed in CECs in human and experimental PKD. These data suggest that the upregulation of both the canonical and non-canonical pathways of NF-κB signaling may be a constitutive and early pathological feature of cystic renal diseases.

Simultaneous nephrectomy during kidney transplantation for polycystic kidney disease does not detrimentally impact comorbidity and graft survival

BACKGROUND The lack of space,as an indication for a native unilateral nephrectomy for positioning a future kidney graft in the absence of other autosomal dominant polycystic kidney disease-related symptoms,remains controversial.AIM To evaluate the surgical comorbidity and the impact on graft survival of an associated ipsilateral native nephrectomy during isolated kidney transplantation in patients with autosomal dominant polycystic kidney disease.METHODS One hundred and fifty-four kidney transplantations performed between January 2007 and January 2019 of which 77 without(kidney transplant alone(KTA)group)and 77 with associated ipsilateral nephrectomy(KTIN group),were retrospectively reviewed.Demographics and surgical variables were analyzed and their respective impact on surgical comorbidity and graft survival.RESULTS Creation of space for future graft positioning was the main reason(n=74,96.1%)for associated ipsilateral nephrectomy.No significant difference in surgical comorbidity(lymphocele,wound infection,incisional hernia,wound hematoma,urinary infection,need for blood transfusion,hospitalization stay,Dindo Clavien classification and readmission rate)was observed between the two study groups.The incidence of primary nonfunction and delayed graft function was comparable in both groups[0%and 2.6%(P=0.497)and 9.1%and 16.9%(P=0.230),respectively,in the KTA and KTIN group].The 1-and 5-year graft survival were 94.8%and 90.3%,and 100%and 93.8%,respectively,in the KTA and KTIN group(P=0.774).The 1-and 5-year patient survival were 96.1%and 92.9%,and 100%and 100%,respectively,in the KTA and KTIN group(P=0.168).CONCLUSION Simultaneous ipsilateral native nephrectomy to create space for graft positioning during kidney transplantation in patients with autosomal dominant polycystic kidney disease does not negatively impact surgical comorbidity and short-and long-term graft survival.

Tesevatinib ameliorates progression of polycystic kidney disease in rodent models of autosomal recessive polycystic kidney disease

AIMTo investigate the therapeutic potential of tesevatinib （TSV）, a unique multi-kinase inhibitor currently in Phase Ⅱ clinical trials for autosomal dominant polycystic kidney disease （ADPKD）, in well-defined rodent models of autosomal recessive polycystic kidney disease （ARPKD）. METHODSWe administered TSV in daily doses of 7.5 and 15 mg/kg per day by I.P. to the well characterized bpk model of polycystic kidney disease starting at postnatal day（PN） 4 through PN21 to assess efficacy and toxicity in neonatal mice during postnatal development and still undergoing renal maturation. We administered TSV by oral gavage in the same doses to the orthologous PCK model （from PN30 to PN90） to assess effcacy and toxicity in animals where developmental processes are complete. The following parameters were assessed： Body weight, total kidney weight; kidney weight to body weight ratios; and morphometric determination of a cystic index and a measure of hepatic disease. Renal function was assessed by： Serum BUN; creatinine; and a 12 h urinary concentrating ability. Validation of reported targets including the level of angiogenesis and inhibition of angiogenesis （active VEGFR2/KDR） was assessed by Western analysis.RESULTSThis study demonstrates that： （1） in vivo pharmacological inhibition of multiple kinase cascades with TSV reduced phosphorylation of key mediators of cystogenesis： EGFR, ErbB2, c-Src and KDR; and （2） this reduction of kinase activity resulted in signifcant reduction of renal and biliary disease in both bpk and PCK models of ARPKD. The amelioration of disease by TSV was not associated with any apparent toxicity.CONCLUSIONThe data supports the hypothesis that this multi-kinase inhibitor TSV may provide an effective clinical therapy for human ARPKD.

Simultaneous kidney transplantation and ipsilateral native nephrectomy in patients with autosomal dominant polycystic kidney disease

The simultaneous kidney transplantation and ipsilateral native nephrectomy for autosomal dominant polycystic kidney disease does not seem to be associated with increased rates of comorbidity and complications.This outcome can efficiently be achieved when the indication and surgical approach of native nephrectomy are properly justified.

A Presumed Synonymous Mutation of PKD2 Caused Autosomal Dominant Polycystic Kidney Disease in a Chinese Family

Objective:Autosomal dominant polycystic kidney disease(ADPKD)is mainly caused by the pathogenic mutation of PKD1 or PKD2 gene and usually affects bilateral kidneys.Synonymous mutations are generally assumed to be neutral as they do not alter amino acids.Herein,we described an extremely rare ADPKD child caused by a heterozygous synonymous mutation of PKD2 gene accompanied by massive proteinuria and congenital solitary kidney.Methods:Clinical characteristics of the patients were summarized.Whole-exome sequencing was performed to screen the disease-causing gene mutation,and reverse transcription polymerase chain reaction(RT-PCR)and Sanger sequencing were applied to analyze the impact of the identified mutation on gene transcription and splicing.Results:Polycystic changes were found in the solitary kidney of a girl initially presented with nephrotic-range proteinuria.Thereafter her mother and 2 other family members were diagnosed to be ADPKD.Whole-exome sequencing of the proband identified a heterozygous synonymous mutation(c.1716G>A,p.Lys572=)located in the splicing site of exon 7 in PKD2 gene,which was co-segregated with the PKD phenotype in the family.RT-PCR and direct sequencing of amplified products revealed that this heterozygous synonymous mutation led to exon7 skipping in PKD2 gene.Conclusion:We reported an extremely rare child case of ADPKD2 in combination with solitary kidney and nephrotic-range proteinuria,and firstly confirmed the pathogenicity of a heterozygous synonymous mutation(c.1716G>A)in PKD2 gene.The results indicate that synonymous mutations should not be excluded from disease-causing if they are located in splicing site of an exon.

Successful endoscopic surgery for emphysematous pyelonephritis in a non-diabetic patient with autosomal dominant polycystic kidney disease: A case report

BACKGROUND Emphysema pyelonephritis(EPN)is a very dangerous type of urinary tract infection.It is a lethal disease that develops rapidly and causes the patient to deteriorate rapidly,and it can easily lead to systemic infections and even sepsis.The incidence is extremely low,and it is prevalent in patients with diabetes.We here report a case of EPN in a non-diabetic patient with autosomal dominant polycystic kidney disease(ADPKD).We share the diagnosis and treatment procedure for this extremely rare condition to make this disease easier to identify and address early.CASE SUMMARY A 47-year-old woman presented to the emergency department of our hospital with a high fever and left back pain lasting 4 d.She had a history of autosomal dominant polycystic kidney and polycystic liver.She was diagnosed with left type I EPN and her vital signs deteriorated so quickly that she underwent an emergency operation in which a D-J tube was inserted into her left ureter on the second day after admission.Two months later,she underwent a second-stage flexible ureteroscopy and lithotripsy.Despite postoperative sepsis,she finally recovered after active symptomatic support treatment and effective anti-infective treatment.CONCLUSION Although EPN is more likely to occur in diabetic patients,for non-diabetic patients with ADPKD and upper urinary tract obstruction,the disease also causes rapid deterioration.Early and accurate diagnosis and timely removal of the obstruction by invasive means may be able to save the damaged kidney and the patient’s life.

Ganoderma triterpenes slow cyst growth in polycystic kidney disease

OBJECTIVE Autosomal dominant polycystic kidney disease(ADPKD)is a common inherited disease with a high morbidity around 1/1000-1/400,characterized by progressive enlargement of fluid-fil ed cysts derived from renal tubular epithelial cells.Massive cysts gradually compress renal parenchyma destroying normal renal structures and compromising renal functions.Unfortunately,it will cause end-stage renal disease in most of the patients but without effective therapy now,who have to live on hemodialysis or kidney transplantation.Based on this present situation,it is of great significance to find early intervention to inhibit renal cyst development.The projective of this study was to investigate whether Ganoderma triterpenes(GT)can inhibit renal cyst development and study the related mechanism.METHODS and RESULTS First,we used MDCK cyst model,cultivated MDCK cells in vitro to form fluid-filled cysts surrounded by monolayer cells.GT inhibited MDCK cyst formation significantly,and inhibited cyst enlargement dose-dependently proving GT cyst inhibition in vitro.Then we used an embryonic kidney cyst model,wile-type mice kidneys were taken out on embryonic day 13.5 to form renal cysts stimulated with 8-Br-c AMP.GT inhibited embryonic kidney cyst development significantly in a dosedependent and reversible manner proving GT cyst inhibition at organ level.Furthermore,we used two ADPKD mouse models with severe cystic kidney disease phenotypes.GT dramatically inhibited renal cyst development,decreased ADPKD mouse kidney volume and the cyst index inside proving GT cyst inhibition in vivo.By Western blot,we proved GT down-regulated Ras/MAPK signal pathway without detectable effect on m TOR signal pathway both in MDCK cells and two ADPKD mouse kidneys.CONCLUSION GT retard renal cyst development both in vitro and in vivo significantly.The related mechanisms were involved in GT promoting renal tubular epithelial cell differentiation,down-regulating intracellular c AMP level and Ras/MAPK signal pathway.

Tolvaptan ameliorated kidney function for one elderly autosomal dominant polycystic kidney disease patient: A case report

BACKGROUND Polycystic kidney disease(PKD)is a genetic disorder characterized by the growth of numerous cysts within the kidneys.Disease progress of some patients often occurs at the early stage.Thus,managing and controlling disease progress is important to slow the kidney function decline especially for the patient with other disorders.CASE SUMMARY One 80-year-old male autosomal dominant polycystic kidney disease(ADPKD)patient with chronic kidney disease and other clinical disorders was treated with tolvaptan and edoxaban.Estimated glomerular filtration rate,creatinine and uric acid were monitored during the treatment.In addition,the whole exome sequencing was performed to screen ADPKD genetic variants.The kidney function decline was prevented after using tolvaptan and edoxaban treatment and in the meantime,a venous thromboembolism was removed and leg and pedal edema were alleviated.One mutation c.10102G>A/p.D3368N in the PKD1 gene was identified.CONCLUSION Tolvaptan combined with edoxaban administration could delay kidney function decline and eliminate the edema caused by the thromboembolism.

Spontaneous coronary dissection should not be ignored in patients with chest pain in autosomal dominant polycystic kidney disease:A case report

BACKGROUND When autosomal dominant polycystic kidney disease(ADPKD)presents with acute coronary syndrome(ACS),the possibility of spontaneous coronary artery dissection(SCAD)should be highly considered.In some cases,SCAD is considered an extrarenal manifestation of ADPKD depending on the pathological characteristics of the unstable arterial wall in ADPKD.CASE SUMMARY Here,we report a 46-year-old female patient with ADPKD who presented with ACS.Coronary angiography revealed no definite signs of dissection,while intravascular ultrasound revealed a proximal to distal dissection of the left circumflex.After a careful conservative medication treatment,the patient exhibited favorable prognosis.CONCLUSION In cases of ADPKD co-existing with ACS,differential diagnosis of SCAD should be considered.Moreover,when no clear dissection is found on coronary angiography,IVUS should be performed to prevent missed diagnosis.

Acute Effects of Tolvaptan on Renal Hemodynamics in Autosomal Dominant Polycystic Kidney Disease —A Randomized, Cross-Over, Double Blind, Placebo-Controlled Study of Renal Plasma Flow and Glomerular Filtration Rate

Background: Previous studies have shown that reduced renal plasma flow (RPF) may play a role in progression of renal disease in autosomal dominant polycystic kidney disease (ADPKD). Tolvaptan, a vasopressin 2 antagonist, reduces growth of total kidney volume and slows the decrease in estimated glomerular filtration rate (eGFR) in ADPKD. The purpose of this randomized, cross-over, double-blind, placebo-controlled study was to investigate if acute tolvaptan treatment increases RPF in ADPKD patients. Methods: Eighteen ADPKD patients (chronic kidney disease stages I-III) were investigated twice (min. 10 days apart) after acute treatment with either tolvaptan 60 mg or placebo. Two hours after treatment RPF and GFR were estimated by Technetium-99m diethylenetriamine penta-acetic acid (99-mTc-DTPA) renography. During the examination day, central and brachial blood pressures (BP) were measured using Mobil-O-Graph? PWA. We also measured plasma concentrations of vasopressin (p-AVP), renin (PRC), angiotensin II (p-AngII) and aldosterone (p-Aldo), urine excretion of aquaporin 2 (u-AQP2), urine output (OU), urine osmolality (u-Osm) and fractional excretion of sodium (FENa). Results: 99-mTc-DTPA renography showed a similar RPF (673 ± 262 ml/min after tolvaptan vs. 650 ± 209 ml/min after placebo, p = 0.571) and GFR (78 ± 26 ml/min after tolvaptan vs. 79 ± 21 ml/min after placebo p = 0.774) after tolvaptan and placebo treatment. P-AVP and UO increased and u-Osm decreased after tolvaptan and remained unchanged during placebo. Systolic BP tended to decrease during renography during tolvaptan. Very small or insignificant changes were seen in PRC, p-AngII and p-Aldo. Conclusions: Acute tolvaptan treatment did not change renal hemodynamics in ADPKD.

Research on autosomal dominant polycystic kidney disease in China

Objective To review the history and recent development of research on autosomal dominant polycystic kidney disease （ADPKD） in China. Data sources Both Chinese and English literatures were searched in MEDLINE/CD ROM （1979 - 2006） and the Chinese Biomedical Literature Disk （1979 - 2006）. Study selection Published articles about ADPKD from mainland of China were selected. Data were mainly extracted from 58 articles which are listed in the reference section of this review. Results Some preliminary reports on cyst decompression surgeries and mutation analysis represent the contribution to the ADPKD research from China in the history. A serial of basic research and clinical studies on ADPKD in recent years also have been summarized. A technique platform for ADPKD research was firstly established. The genomics/proteomics/bioinformatics approach was introduced, which provide a lot of valuable information for understanding the pathogenesis. By denature high performance liquid chromatography （DHPLC） technique the entire PKD1 and PKD2 gene sequence screening system for Chinese Han population has been successfully established. Based on the characteristic data of Chinese patients, an integrated therapy protocol was put forward and won an advantage over the traditional therapy. Some novel experimental studies on therapy also were encouraging. Condusions Remarkable progress of ADPKD research in China have been made recently. Still many works, including the government support, international collaboration and active participation of more Chinese nephrologists, should be enhanced to advance this process in the near future.

Exome sequencing identifies compound heterozygous PKHD1 mutations as a cause of autosomal recessive polycystic kidney disease

Background Autosomal recessive polycystic kidney disease （ARPKD） is a rare inherited disease, which is a disorder with multiple organ involvement, mainly the kidney and liver. It is caused by mutations in the PKHD1 gene. Here, we reported the clinical characteristics of a case with ARPKD and analyze the genetic features of this patient as well as of his father using targeted exome sequencing and Sanger sequencing. Methods Genomic DNA was extracted from peripheral blood leukocytes obtained from a patient with ARPKD. The mutations were identified using exome sequencing and confirmed by Sanger sequencing. Results The patient was diagnosed as ARPKD based on ultrasonography and abdominal computed tomography which showed polycystic changes, multiple calcinosis of both kidneys, and multiple dilated bile ducts of the liver. Compound heterozygous PKHD1 gene mutations A979G and G5935A, which lead to substitution of an asparagine for an aspartate at amino acid 327 （N327D） and a glycine for an arginine at amino acid 1979 （G1979R） respectively, were identified using targeted exome sequencing and confirmed by Sanger sequencing for the patient. In addition, the father of the patient was identified to be a carrier of heterozygous A979G mutation of this gene. Conclusions We identified that the compound heterozygous PKHD1 gene mutations are the molecular basis of the patient with ARPKD. Targeted exome sequencing is suitable for genetic diagnosis of single-gene inherited diseases like ARPKD in which the pathogenic gene is a large.

Clinical characteristics and mutation analysis of three Chinese children with autosomal recessive polycystic kidney disease

Background:There are few studies on the genotypes and phenotypes of autosomal recessive polycystic kidney disease in Chinese patients.Methods:PKHD1 mutations in three children were detected with PCR and direct sequencing,and their clinical data were retrospectively reviewed.Results:All of the children had bilateral enlarged polycystic kidneys,congenital hepatic fibrosis and intrahepatic bile duct dilatation.One of three children had classical multiple small cysts throughout the kidneys,and the other two children had bilateral multiple renal cysts of various sizes.Two children had abnormally shaped livers,portal hypertension and splenomegaly.Two heterozygous mutations(p.T36M,and p.P137S)were detected in Patient 1 and two were detected in Patient 2(p.L2658X and p.V836A).One heterozygous mutation(p.L1425R)was detected in Patient 3.Conclusions:The study shows that renal and liver phenotypes of the Chinese children varied.Five mutations were identifi ed in the three children,three of which were novel mutations.

Peritoneal dialysis for autosomal dominant polycystic kidney disease: a retrospective study

To describe the long-term clinical outcomes of patients with autosomal dominant polycystic kidney disease （ADPKD） who are on peritoneal dialysis （PD） therapy. We performed a retrospective matched-cohort analysis com- paring the clinical outcomes of 30 ADPKD patients with those of 30 non-diabetic patients who had bilateral small kidneys between July 1 2007 and July 31 2014. The patient groups were matched by age, gender, and time of PD initiation. There were no significant differences in the demographic or biochemical parameters, comorbid conditions, residual glomerular filtration rate, or Charison comorbidity score at the beginning of PD. The median renal volume was 1315 ml for the ADPKD group and 213 ml for the control group. Patients with ADPKD had similar 3-year patient survival （90.6% versus 86.3%, ,~=-0.807） and technique survival （89.2% versus 74.3%, P=0.506） compared with non-ADPKD patients. Also, there was no significant difference in the peritonitis-free survival between the ADPKD and control groups （P=0.22）, and rates of peritonitis were similar （0.19 versus 0.21 episodes per patient-year, P=-0.26）. No differences were observed in the incidence of PD-related complications, such as hernia and dialysate leak. ADPKD is not a con- traindication for PD, and a subgroup of ADPKD patients with relatively small kidney volume can be treated using PD.