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.

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.

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.

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.

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.

Combined liver and kidney transplantation in children and long-term outcome

Combined liver-kidney transplantation(CLKT)is a rarely performed complex surgical procedure in children and involves transplantation of kidney and either whole or part of liver donated by the same individual(usually a cadaver)to the same recipient during a single surgical procedure.Most common indications for CLKT in children are autosomal recessive polycystic kidney disease and primary hyperoxaluria type 1.Atypical haemolytic uremic syndrome,methylmalonic academia,and conditions where liver and renal failure co-exists may be indications for CLKT.CLKT is often preferred over sequential liver-kidney transplantation due to immunoprotective effects of transplanted liver on renal allograft;however,liver survival has no significant impact.Since CLKT is a major surgical procedure which involves multiple and complex anastomosis surgeries,acute complications are not uncommon.Bleeding,thrombosis,haemodynamic instability,infections,acute cellular rejections,renal and liver dysfunction are acute complications.The long-term outlook is promising with over 80%5-year survival rates among those children who survive the initial six-month postoperative period.

Possible PKHD1 Hot-spot Mutations Related to Early Kidney Function Failure or Hepatofibrosis in Chinese Children with ARPKD:A Retrospective Single Center Cohort Study and Literature Review

PKHD1 mutations are generally considered to cause autosomal recessive polycystic kidney disease(ARPKD).ARPKD is a rare disorder and one o f the most severe conditions leading to end-stage renal disease in childhood.With the biallelic deletion mutation,patients have difficulty in surviving the perinatal period,resulting in perinatal or neonatal death.This study retrospectively analyzed patient characteristics,imaging characteristics,laboratory examinations and family surveys from 7 Chinese children with different PKHD1 gene mutations diagnosed by high-throughput sequencing from January 2014 to February 2018.O f the 7 children,there were 3 males and 4 females.Eight missense mutations,two frameshift mutations,two deletion mutations,and two intronic slicing mutations were identified.Six of the mutations have not previously been identified.In the literature search,we identified a total of 29 Chinese children with PKHD1 mutations.The missense mutation c.2507T>C in exon 24 was found in one patient in our study,and five patients with liver fibrosis but normal renal function were reported in the literature.The missense mutation c.5935G>A in exon 37 was found in two patients in our study and three cases in the literature.Four patients had renal failure at an age as young as 1 year of those five patients with the missense mutation c.5935G>A in exon 37.It was concluded that:(1)Kidney length more than 2-3 SDs above the mean and early-onset hypertension might be associated with PKHDI-associated ARPICD;(2)The more enlarged the kidney size is,the lower the renal function is likely to be;(3)c.5935G>A may be a hot spot that leads to early renal failure in Chinese children with PKHD1 mutations;(4)c.2507T>C may be a hot-spot mutation associated with hepatic lesions in Chinese children with PKHD1.

Genetic Architecture of Childhood Kidney and Urological Diseases in China

Kidney disease is manifested in a wide variety of phenotypes,many of which have an important hereditary component.To delineate the genotypic and phenotypic spectrum of pediatric nephropathy,a multicenter registration system is being imple-mented based on the Chinese Children Genetic Kidney Disease Database(CCGKDD).In this study,all the patients with kidney and urological diseases were recruited from 2014 to 2020.Genetic analysis was conducted using exome sequencing for families with multiple affected individuals with nephropathy or clinical suspicion of a genetic kidney disease owing to early-onset or extrarenal features.The genetic diagnosis was confirmed in 883 of 2256(39.1%)patients from 23 provinces in China.Phenotypic profiles showed that the primary diagnosis included steroid-resistant nephrotic syndrome(SRNS,23.5%),glomerulonephritis(GN,32.2%),congenital anomalies of the kidney and urinary tract(CAKUT,21.2%),cystic renal disease(3.9%),renal calcinosis/stone(3.6%),tubulopathy(9.7%),and chronic kidney disease of unknown etiology(CKDu,5.8%).The pathogenic variants of 105 monogenetic disorders were identified.Ten distinct genomic disorders were identified as pathogenic copy number variants(CNVs)in 11 patients.The diagnostic yield differed by subgroups,and was highest in those with cystic renal disease(66.3%),followed by tubulopathy(58.4%),GN(57.7%),CKDu(43.5%),SRNS(29.2%),renal calcinosis/stone(29.3%)and CAKUT(8.6%).Reverse phenotyping permitted correct identification in 40 cases with clinical reassessment and unexpected genetic conditions.We present the results of the largest cohort of children with kidney disease in China where diagnostic exome sequencing was performed.Our data demonstrate the utility of family-based exome sequencing,and indicate that the combined analysis of genotype and phenotype based on the national patient registry is pivotal to the genetic diagnosis of kidney disease.

Tsc2 mutation induces renal tubular cell nonautonomous disease

TSC renal cystic disease is poorly understood and has no approved treatment.In a new principal cell-targeted murine model of Tsc cystic disease,the renal cystic epithelium is mostly composed of type A intercalated cells with an intact Tsc2 gene confirmed by sequencing,although these cells exhibit a Tsc-mutant disease phenotype.We used a newly derived targeted murine model in lineage tracing and extracellular vesicle(EV)characterization experiments and a cell culture model in EV characterization and cellular induction experiments to understand TSC cystogenesis.Using lineage tracing experiments,we found principal cells undergo clonal expansion but contribute very few cells to the cyst.We determined that cystic kidneys contain more interstitial EVs than noncystic kidneys,excrete fewer EVs in urine,and contain EVs in cyst fluid.Moreover,the loss of Tsc2 gene in EV-producing cells greatly changes the effect of EVs on renal tubular epithelium,such that the epithelium develops increased secretory and proliferative pathway activity.We demonstate that the mTORC1 pathway activity is independent form the EV production,and that the EV effects for a single cell line can vary significantly.TSC cystogenesis involves significant contribution from genetically intact cells conscripted to the mutant phenotype by mutant cell derived EVs.