Autosomal Recessive Polycystic Kidney Research Articles

Assessing the potential of DZIP1L gene in autosomal recessive polycystic kidney disease gene therapy

Assessing the potential of <i>DZIP1L</i> gene in autosomal recessive polycystic kidney disease gene therapy

CFTR Modulators Mitigate Autosomal Recessive Polycystic Kidney Disease

CFTR Modulators Mitigate Autosomal Recessive Polycystic Kidney Disease

The molecular structure and function of fibrocystin, the key gene product implicated in autosomal recessive polycystic kidney disease (ARPKD).

Autosomal recessive polycystic kidney disease is an early onset inherited hepatorenal disorder affecting around 1 in 20,000 births with no approved specific therapies. The disease is almost always caused by variations in the polycystic kidney and hepatic disease 1 gene, which encodes fibrocystin (FC), a very large, single-pass transmembrane glycoprotein found in primary cilia, urine and urinary exosomes. By comparison to proteins involved in autosomal dominant PKD, our structural and molecular understanding of FC has lagged far behind such that there are no published experimentally determined structures of any part of the protein. Bioinformatics analyses predict that the ectodomain contains a long chain of immunoglobulin-like plexin-transcription factor domains, a protective antigen 14 domain, a tandem G8-TMEM2 homology region and a sperm protein, enterokinase and agrin domain. Here we review current knowledge on the molecular function of the protein from a structural perspective.

State of the Science and Ethical Considerations for Preimplantation Genetic Testing for Monogenic Cystic Kidney Diseases and Ciliopathies.

There is a broad phenotypic spectrum of monogenic polycystic kidney diseases (PKDs). These disorders often involve cilia-related genes and lead to the development of fluid-filled cysts and eventual kidney function decline and failure. Preimplantation genetic testing for monogenic (PGT-M) disorders has moved into the clinical realm. It allows prospective parents to avoid passing on heritable diseases to their children, including monogenic PKD. The PGT-M process involves embryo generation through in vitro fertilization, with subsequent testing of embryos and selective transfer of those that do not harbor the specific disease-causing variant(s). There is a growing body of literature supporting the success of PGT-M for autosomal-dominant and autosomal-recessive PKD, although with important technical limitations in some cases. This technology can be applied to many other types of monogenic PKD and ciliopathies despite the lack of existing reports in the literature. PGT-M for monogenic PKD, like other forms of assisted reproductive technology, raises important ethical questions. When considering PGT-M for kidney diseases, as well as the potential to avoid disease in future generations, there are regulatory and ethical considerations. These include limited government regulation and unstandardized consent processes, potential technical errors, high cost and equity concerns, risks associated with pregnancy for mothers with kidney disease, and the impact on all involved in the process, including the children who were made possible with this technology.

Complications and prognosis of patients diagnosed with autosomal recessive polycystic kidney disease in neonatal period.

There are no clinical guidelines for performing nephrectomy in patients with autosomal recessive polycystic kidney disease (ARPKD). Few reports have described the clinical course of ARPKD diagnosed in the neonatal period in detail. Here, we report seven patients diagnosed with ARPKD and treated at our center during the neonatal period. Two died within 48h of life due to pulmonary hypoplasia. Of the remaining five patients, three had anuria and required for kidney replacement therapy (KRT) within one week after birth, whereas two with a milder phenotype survived without KRT. All three patients who received KRT underwent unilateral nephrectomy and peritoneal dialysis (PD) catheter placement. To prevent fluid leakage, PD was initiated 7-14days after catheter placement. However, peritoneal leakage occurred in two patients, resulting in peritonitis and discontinuation of PD; one who required long-term hemodialysis contracted a catheter-related bloodstream infection as well as developed subdural and epidural hematomas. Meanwhile, two patients underwent a second nephrectomy within 6weeks after birth; one developed severe persistent hypotension and neurological complications, while the other died of bacteremia that may have resulted from cholangitis diagnosed on day 67 of life. A severe clinical course, life-threatening adverse events, and severe neurological sequalae may occur in patients with ARPKD who receive KRT in neonatal period.

Fibrocystin/Polyductin releases a C-terminal fragment that translocates into mitochondria and suppresses cystogenesis

Fibrocystin/Polyductin (FPC), encoded by PKHD1, is associated with autosomal recessive polycystic kidney disease (ARPKD), yet its precise role in cystogenesis remains unclear. Here we show that FPC undergoes complex proteolytic processing in developing kidneys, generating three soluble C-terminal fragments (ICDs). Notably, ICD15, contains a novel mitochondrial targeting sequence at its N-terminus, facilitating its translocation into mitochondria. This enhances mitochondrial respiration in renal epithelial cells, partially restoring impaired mitochondrial function caused by FPC loss. FPC inactivation leads to abnormal ultrastructural morphology of mitochondria in kidney tubules without cyst formation. Moreover, FPC inactivation significantly exacerbates renal cystogenesis and triggers severe pancreatic cystogenesis in a Pkd1 mouse mutant Pkd1V/V in which cleavage of Pkd1-encoded Polycystin-1 at the GPCR Proteolysis Site is blocked. Deleting ICD15 enhances renal cystogenesis without inducing pancreatic cysts in Pkd1V/V mice. These findings reveal a direct link between FPC and a mitochondrial pathway through ICD15 cleavage, crucial for cystogenesis mechanisms.

Research progress on the pathogenesis autosomal recessive polycystic kidney disease

Research progress on the pathogenesis autosomal recessive polycystic kidney disease

Metformin does not slow cyst growth in the PCK rat model of polycystic kidney disease.

Metformin (MET) has the potential to activate p-AMPK and block mTORC1-induced proliferation of tubular cells in PKD kidneys. The aim of this study was to determine the effects of MET on cyst growth, kidney function, AMPK and mTOR signaling, and lactate levels in male PCK rats, a Pkhd1 gene mutation model of human autosomal recessive polycystic kidney disease (ARPKD). MET 300 mg/kg/day IP from days 28 to 84 of age resulted in a mean serum metformin level that was 10 times the upper limit of therapeutic, no effect on cyst indices, nephrotoxicity, and increased serum lactate. MET 150 mg/kg resulted in a therapeutic serum metformin level but had no effect on kidney weight, cyst indices, kidney function, or mTOR and autophagy proteins. In summary, a standard dose of MET was ineffective in reducing PKD, did not activate p-AMPK or suppress mTOR and the higher dose resulted in increased lactate levels and nephrotoxicity. In conclusion, the study dampens enthusiasm for human studies of MET in PKD. Doubling the metformin dose resulted in a 10-fold increase in mean blood levels and toxicity suggesting that the dosage range between therapeutic and toxic is narrow.

Pkhd1cyli/cyli mice have altered renal Pkhd1 mRNA processing and hormonally sensitive liver disease.

Autosomal-recessive polycystic kidney disease (ARPKD; MIM #263200) is a severe, hereditary, hepato-renal fibrocystic disorder that causes early childhood morbidity and mortality. Mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene, which encodes the protein fibrocystin/polyductin complex (FPC), cause all typical forms of ARPKD. Several mouse lines carrying diverse, genetically engineered disruptions in the orthologous Pkhd1 gene have been generated, but none expresses the classic ARPKD renal phenotype. In the current study, we characterized a spontaneous mouse Pkhd1 mutation that is transmitted as a recessive trait and causescysticliver (cyli), similar to the hepato-biliary disease in ARPKD, but which is exacerbated by age, sex, and parity. We mapped the mutation to Chromosome 1 and determined that an insertion/deletion mutation causes a frameshift within Pkhd1 exon 48, which is predicted to result in a premature termination codon (UGA). Pkhd1cyli/cyli (cyli) mice exhibit a severe liver pathology but lack renal disease. Further analysis revealed that several alternatively spliced Pkhd1 mRNA, all containing exon 48, were expressed in cyli kidneys, but in lower abundance than in wild-type kidneys, suggesting that these transcripts escaped from nonsense-mediated decay (NMD). We identified an AAAAAT motif in exon 48 upstream of the cyli mutation which could enable ribosomal frameshifting, thus potentially allowing production of sufficient amounts of FPC for renoprotection. This mechanism, expressed in a species-specific fashion, may help explain the disparities in the renal phenotype observed between Pkhd1 mutant mice and patients with PKHD1-related disease. KEY MESSAGES: The Pkhd1cyli/cylimouse expresses cystic liver disease, but no kidney phenotype. Pkhd1 mRNA expression is decreased in cyli liver and kidneys compared to wild-type. Ribosomal frameshifting may be responsible for Pkhd1 mRNA escape from NMD. Pkhd1 mRNA escape from NMD could contribute to the absent kidney phenotype.

АУТОСОМНО-ДОМИНАНТНАЯ ПОЛИКИСТОЗНАЯ БОЛЕЗНЬ ПОЧЕК С ОЧЕНЬ РАННИМ НАЧАЛОМ

Both autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease may occur at any age starting infancy and up to adulthood. Manifestations of autosomal dominant polycystic kidney disease usually occur in adult patients with a risk of development of end-stage renal failure after the fifth decade of life. However, an increase in the number of pediatric cases of a very-early onset of the disease, in utero or during the first 18 months of life, had been registered recently, that were characterized by severe clinical manifestations which in tis turn had mimic the autosomal recessive polycystic kidney disease. The three infant cases of autosomal dominant polycystic kidney disease are observed in the Article with perinatal period features, clinical manifestations of the disease, tests’ results and its interpretation given. Children with very-early onset of autosomal dominant polycystic kidney disease are in the high-risk group for nephromegaly, severe hypertension and the early end-stage renal failure.

Portal hypertension syndrome in children with autosomal recessive polycystic kidney disease with liver cysts and hepatic fibrosis

Hepatic fibrosis, liver cysts, and portal hypertension are extrarenal manifestations that determine the prognosis of autosomal recessive polycystic kidney disease in children.Purpose. To assess the features of the manifestation and course of liver cystic disease and fibrosis, the development of portal hypertension in the follow-up medical history of children with autosomal recessive polycystic kidney disease.Material and methods. We studied 27 children with autosomal recessive polycystic kidney disease, with two children with a fatal outcome in the neonatal period excluded. 25 children 1–17 years old with autosomal recessive polycystic kidney disease were divided into 2 groups depending on the presence of portal hypertension syndrome. In the long-term follow-up 10 (40%) of 25 children with autosomal recessive polycystic kidney disease had no signs of portal hypertension (group 1), 15 (60%) children had portal hypertension syndrome (group 2). The long-term follow-up, clinical, genealogical, laboratory and instrumental (US, MRI/CT of kidney and abdominal cavity, liver elastography) research methods were used in the study. The diagnosis was confirmed by autopsy for 3 children.Results. There were no cases of changes in the liver and bile ducts characteristic of autosomal recessive polycystic kidney disease by prenatal ultrasound examination. From 27 children with autosomal recessive polycystic kidney disease, in 10 (37%) were diagnosed the liver fibrosis in the long-term follow-up, 22 (81%) had cystic enlargement of intrahepatic veins, of which 15 (68%) had polycystic liver disease, 3 (14%) had Caroli disease. All children with autosomal recessive polycystic kidney disease and portal hypertension syndrome had varicose veins of the esophagus and stomach according to esophagoduodenoscopy, 53% with indications for ligation of phlebectasia, 47% were diagnosed with thrombocytopenia, 67% with anemia, 100% with splenomegaly, 13% with esophageal-gastric bleeding.Conclusion. The differences in the initial manifestations of autosomal recessive polycystic kidney disease were revealed, while no differences in the incidence of hepatic fibrosis and liver cysts were found in 2 compared groups of children.

Polycystic liver disease: an overview of clinical manifestations, diagnosis, and treatment

Polycystic liver disease (PLD) is a hereditary disease characterized by the presence of 20 or more liver cysts. It is classified into three types: isolated autosomal dominant PLD, PLD with autosomal dominant polycystic kidney disease, and PLD with autosomal recessive polycystic kidney disease. Genetic alterations, ciliary dysfunction of the biliary epithelial cells, and aberrant cell signaling pathways are the main factors contributing to the pathophysiology of PLD; however, other complicated mechanisms are also involved. The Gigot and Schnelldorfer classifications are widely used in clinical practice. Most patients with PLD are asymptomatic; however, a few patients with advanced-stage disease may develop symptoms and complications that impair their quality of life and require treatment. The known treatment options for PLD are somatostatin analogues, aspiration with sclerotherapy, fenestration, hepatic resection, and liver transplantation. Although liver transplantation remains the only curative treatment for PLD, medical therapies are gradually being developed with the increasing knowledge of the disease’s pathophysiology. This review focuses on the clinical manifestations and diagnosis of PLD, as well as treatment strategies, to support clinicians regarding the clinical management of the disease.

A novel PKHD1 splicing variant identified in a fetus with autosomal recessive polycystic kidney disease.

Objective: Variants of the polycystic kidney and hepatic disease 1 (PKHD1) gene are associated with autosomal recessive polycystic kidney disease (ARPKD). This study aimed to identify the genetic causes in a Chinese pedigree with ARPKD and design a minigene construct of the PKHD1 gene to investigate the impact of its variants on splicing. Methods: Umbilical cord samples from the proband and peripheral blood samples from his parents were collected, and genomic DNA was extracted for whole-exome sequencing (WES). Bioinformatic analysis was used to identify potential genetic causes, and Sanger sequencing confirmed the existence of variants within the pedigree. A minigene assay was performed to validate the effects of an intronic variant on mRNA splicing. Results: Two variants, c.9455del (p.N3152Tfs*10) and c.2408-13C>G, were identified in the PKHD1 gene (NM_138694.4) by WES; the latter has not been previously reported. In silico analysis predicted that this intronic variant is potentially pathogenic. Bioinformatic splice prediction tools revealed that the variant is likely to strongly impact splice site function. An in vitro minigene assay revealed that c.2408-13C>G can cause aberrant splicing, resulting in the retention of 12 bp of intron 23. Conclusion: A novel pathogenic variant of PKHD1, c.2408-13C>G, was found in a fetus with ARPKD, which enriches the variant spectrum of the PKHD1 gene and provides a basis for genetic counseling and the diagnosis of ARPKD. Minigenes are optimal to determine whether intron variants can cause aberrant splicing.

Cystin is required for maintaining fibrocystin (FPC) levels and safeguarding proteome integrity in mouse renal epithelial cells: A mechanistic connection between the kidney defects in cpk mice and human ARPKD.

Autosomal recessive polycystic kidney disease (ARPKD) is caused primarily by mutations in PKHD1, encoding fibrocystin (FPC), but Pkhd1 mutant mice failed to reproduce the human phenotype. In contrast, the renal lesion in congenital polycystic kidney (cpk) mice, with a mutation in Cys1 and cystin protein loss, closely phenocopies ARPKD. Although the nonhomologous mutation diminished the translational relevance of the cpk model, recent identification of patients with CYS1 mutations and ARPKD prompted the investigations described herein. We examined cystin and FPC expression in mouse models (cpk, rescued-cpk (r-cpk), Pkhd1 mutants) and mouse cortical collecting duct (CCD) cell lines (wild type (wt), cpk). We found that cystin deficiency caused FPC loss in both cpk kidneys and CCD cells. FPC levels increased in r-cpk kidneys and siRNA of Cys1 in wt cells reduced FPC. However, FPC deficiency in Pkhd1 mutants did not affect cystin levels. Cystin deficiency and associated FPC loss impacted the architecture of the primary cilium, but not ciliogenesis. No reduction in Pkhd1 mRNA levels in cpk kidneys and CCD cells suggested posttranslational FPC loss. Studies of cellular protein degradation systems suggested selective autophagy as a mechanism. In support of the previously described function of FPC in E3 ubiquitin ligase complexes, we demonstrated reduced polyubiquitination and elevated levels of functional epithelial sodium channel in cpk cells. Therefore, our studies expand the function of cystin in mice to include inhibition of Myc expression via interaction with necdin and maintenance of FPC as functional component of the NEDD4 E3 ligase complexes. Loss of FPC from E3 ligases may alter the cellular proteome, contributing to cystogenesis through multiple, yet to be defined, mechanisms.

Multiple Polycystic Organs in A Middle Age Female: A Rare Case of More Than Ten Years Without Surgical Intervention

Some organs are recognized to develop cysts more common than others do; these include the kidney the liver, the pancreas and the spleen. The structure and function of these organs may play a role. The frequency of polycystic kidney is variable. It is reported as 50 or less in 100000 (5 in 10000), 1 in 400 and 1 in 1000 life birth. Prevalence of autosomal dominant polycystic kidney disease (ADPKD) is thought to be overestimated by 2 to 5 folds. Multiple polycystic organs are not common, and reviewing the literature revealed some case reports, which indicates that such cases do not have regular pattern. Inherited polycystic kidney disease has two varieties; autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD).

#4413 MOLECULAR SPECTRUM OF GENETIC ANOMALIES IN PEDIATRIC PATIENTS WITH EARLY ONSET OF RENAL CYSTIC DISEASE

Abstract Background and Aims Renal cystic disease (RCD) includes a spectrum of disorders with heterogenous clinical presentation. Among RCD are autosomal dominant polycystic kidney disease (ADPKD), autosomal recessive polycystic kidney disease (ARPKD), ciliopathies, HNF1B-nephropathy, and congenital anomalies of the kidneys and of the urinary tract (CAKUT). Diagnosis is based on clinical criteria, yet, given the extreme genetic heterogeneity and phenotypic overlap among different conditions, confirmation by genetic testing is paramount for correct clinical management and recurrence risk assessment. Although genotype-phenotype correlations are scanty, recently, coexisting variants in the same gene or in multiple cystogenes have been associated with earlier and more severe renal phenotype. The aim of this study is to describe the clinical and molecular characteristics of pediatric patients with early onset of RCD and provide genotype-phenotype correlations. Method A retrospective study was conducted collecting patients with a prenatal or early-childhood ultrasound finding of renal hyper-echogenicity or cysts. All patients were followed at the Pediatric Nephrology Unit of the Città della Salute e della Scienza University Hospital of Torino, Italy. Genetic analyses were mostly performed at the Immunogenetic and Transplant Biology Unit and included clinical exome sequencing (CES), array-CGH, MLPA and single gene testing. Results 65 patients we recruited, 42 males (64.6%) and 23 females (35.4%), mean age 8 ± 5.9 years (range 0-18). The most frequent clinical suspicion was ADPKD (n = 40, 61.5%), followed by CAKUT (n = 9, 13.8%), ARPKD (n = 8, 12.3%), ciliopathy and tuberous sclerosis complex (TSC) (n = 3, 4.6% for each condition), and medullary cystic disease (n = 2, 3.1%). Overall, causative variants (C4/C5) were identified in 39 patients (60.0%), 18 (27.7%) were carriers of variants of uncertain significance (C3) and 8 (12.3%) were inconclusive. Among the 40 patients with a clinical suspicion of ADPKD, 23 received a conclusive genetic diagnosis with 20 (87%) variants in PKD1, 2 (8.7%) in PKD2, one in HNF1B and 14 carried C3 variants. All patients with a clinical suspicion of ARPKD received molecular confirmation and, notably, in one case we observed biallelic variants in PKD1. Among the 21 patients with PKD1 variants, 6 (28.6%) had multiple PKD1 variants and 2 (9.5%) carried an additional PKHD1 variant. TSC diagnosis was confirmed in all 3 cases and two of them (66.7%) carried a contiguous gene TSC2-PKD1 deletion. Two out of 3 (66.7%) patients with a clinical suspicion of ciliopathy carried biallelic variants in BBS10, in one case associated with an additional variant in PKD2. Four (44.4%) CAKUT cases were solved with 3 causative variants in HNF1B (75%) and one in PAX2 (25%), 2 cases (22.2%) carried C3 variants and 3 (33.3%) were inconclusive. Causative variants were de novo in 10 cases (25.6%). Conclusion Our data confirms that genetic evaluation is a powerful tool for the diagnosis of RCD, as witnessed by a detection rate of 60%. Although the clinical suspicion was confirmed in the majority of cases, one suspected ARPKD case carried two PKD1 variants and one suspected ADPKD case carried a whole HNF1B gene deletion, highlighting the need for extensive genetic analysis. Moreover, nine patients had multiple variants potentially contributing with additive effect to a more severe renal phenotype: 6 patients had two variants in PKD1, 2 patients with a PKD1 variant had an additional variant in PKHD1 and one patient had biallelic BBS10 variants plus a nonsense PKD2 variant. In this context, genetic analysis by CES permits simultaneous evaluation of all RCD associated genes, uncovering both multiple variants and clinical phenocopies. In conclusion, the CES driven genetic characterization of pediatric patients with renal cysts allows to avoid misdiagnosis, minimize diagnostic invasive investigations, set up correct follow-up, and define recurrence risk, with a time- and cost- efficient approach.

#5114 THE GENOTYPE DISTRIBUTION IN A SINGLE-CENTRE COHORT OF PATIENTS WITH POLYCYSTIC KIDNEY DISEASE

Abstract Background and Aims Polycystic kidney disease (PKD) is one of the most common causes of chronic kidney disease (CKD) and could lead to the end-stage kidney disease (ESKD) both in adulthood and in childhood. In the last few years many genes were discovered to be associated with PKD beyond the classical genes PKD1 and PKD2, that account for the majority of patients with ADPKD (Autosomal Dominant Polycystic Kidney Disease), and PKHD1 and DZIPIL that are responsible of ARPKD (Autosomal Recessive Polycystic Kidney Disease). The new genes are associated with different type of extra-renal involvement and with variable chance to develop CKD or ESKD. Thus, it is important for clinicians to define what mutation is involved in each patient to improve care in a context of precision medicine. We here describe a cohort of 65 consecutive patients followed at our PKD outpatient clinic who underwent the genetic analysis. Method We conducted a retrospective study of patients followed at our PKD outpatient clinic who underwent a genetic test for clinical reasons. We recorded why test was performed, with which modality and what was the result. If the analysis was positive we analyzed if only one or more genes were found mutated and if they belong to new genes described as being involved in PKD or if they are usually described in association with different diseases. Then, we collected demographic and clinical information (age, sex, renal function/presence of absence of ESKD) and the radiological description of kidneys in order to distinguish between typical and atypical PKDs. Results Among the 65 patients of our cohort 28 (43%) were males and 37 (57%) were females, the mean age was 56±18.6 years old; 20% had ESKD. They underwent genetic analysis for different reasons: 31 because of atypical PKD forms, 6 to define a suspected de novo mutation, 14 as a familiar screening and 14 for a better prognosis definition or when they approached the kidney transplant. The genetic analysis was conducted in two main ways: sequencing of PKD1 and PKD2 genes according to modern standards or exome sequencing. The first type of analysis was used for typical ADPKD forms whereas the second type was used when patients displayed an atypical presentation for both cysts distribution and kidney diameter (usually not enlarged kidneys with multiple bilateral cysts) and in two patients in which PKD1 and PKD2 sequencing was negative despite the PKD phenotype. We found that 25% of patients were negative, and the others are almost equally distributed between typical gene mutations and mutations in other genes (40% and 35% respectively) (Figure 1A). Of those with typical mutation, 81% was PKD1 positive and 19% PKD2 positive, a distribution that reflects that of literature (Figure 1B). Of those with other genes positivity: 52% had a DNAJB11 mutation, 17% a mutations in other PKD genes (ALG8, LRP5, PKHD1, COL4A1, IFT140), 32% had a mutation in genes usually associated with CAKUT (congenital anomalies of kidney and urinary tract) or with syndromic or extra-renal diseases (Figure 1C). 18 patients presented with multiple mutations, usually 2, in one case three and in another 4. Of them, the 22% had a double PKD1 mutation, while the others showed mutations in different genes associated with syndromic or extra-renal diseases (Figure 1D). Conclusion Our cohort revealed a wide variety of genetic mutations and also an almost equal distribution between typical genes and atypical/other genes. This could be the result of the small number of patients involved and of the monocentric design of the study (we have a cluster of patients with DNAJB11 belonging to the same small geographical area), but also of the larger inclusion of patients presenting with atypical PKDs. Unfortunately a 25% of patients remained genetically unresolved despite the use of exome sequencing.

INDIAMAN-20 (INstant DIAgnosis of 20 Major ANomalies) protocol: application of IOTA diagnostic strategy to fetal anomalies.

To compile a list of instant diagnoses of major fetal anomalies, and to present their sonographic descriptors and test them in a retrospective series of fetuses with congenital anomalies managed at our center. The first step was to identify major anomalies that meet the following criteria: (1) can be diagnosed directly and unequivocally on the basis of a set of descriptors evident on a single sonographic view; (2) are among those more commonly diagnosed in utero; (3) represent major lethal or life-threatening malformations or anomalies for which no or only palliative surgery can be performed. For each of these anomalies, a sonographic descriptor was produced. The second step was to test the descriptors of the instant diagnoses in all cases with these anomalies evaluated since January 2000 in our Fetal Medicine Unit, retrieved from our electronic database. For each congenital anomaly-sonographic descriptor pair we then evaluated the presence vs absence of an unequivocal relationship between anomaly and descriptor, assessing: whether a particular descriptor in a set reference plane identified unequivocally the anomaly, i.e. the same descriptor could not be found in any other malformation; and whether a particular anomaly presented the corresponding descriptor in all cases. Finally, we evaluated whether the sonographic descriptors could be applied in all trimesters or only selectively, considering the natural history of the 20 instant diagnoses. Of the 20 instant diagnoses, five involved the central/peripheral nervous system (exencephaly/anencephaly, alobar/semilobar holoprosencephaly, cephalocele, open spinal dysraphism, complete agenesis of corpus callosum), five involved the heart (hypoplastic left heart syndrome, complete atrioventricular septal defect, severe Ebstein's anomaly, critical aortic stenosis, transposition of the great arteries), five involved the abdominal wall (left-sided congenital diaphragmatic hernia, exomphalos, gastroschisis, body-stalk anomaly) or gastrointestinal tract (duodenal atresia), and five involved the remaining systems (three urinary (autosomal recessive polycystic kidney disease, multicystic dysplastic kidney, lower urinary tract obstruction), two skeletal (transverse limb defect, radial ray defect)). All of the descriptors were found to identify unequivocally the related malformations, whereas four of the malformations were not associated with their reference descriptors in every case. For example, congenital diaphragmatic hernia (left-sided) presented without the stomach in the thorax in 42/93 (45.2%) cases. Due to the natural history of the condition, not all signs were recognizable in the first trimester, some becoming evident only from the second trimester onwards. We have defined sonographic descriptors that enable an unequivocal instant diagnosis for a list of 20 major congenital anomalies: the 'INDIAMAN-20' (INstant DIAgnosis of Major ANomalies) protocol. We believe that using this approach may facilitate focused training of less experienced operators and that it may be incorporated into artificial intelligence and deep learning protocols, further boosting the instant prenatal recognition of these lethal or life-threatening malformations. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

SUPPORTING EXAMINATION OF CT-SCAN ON POLYCYSTIC KIDNEY DISEASE PATIENT AT DUSTIRA HOSPITAL CIMAHI INDONESIA

Polycystic Kidney Disease (PKD) is the growth of many kidney cysts. PKD is divided into Autosomal Dominant Polycystic Kidney Disease (ADPKD) and Autosomal Recessive Polycystic Kidney Disease (ARPKD). ADPKD prevalence 1:500 and ARPKD 1:6000-40000. The patient, a 34-year-old male, came to the hospital with the main complaint of bilateral low back pain. Patients are given symptomatic treatment by diclofenac sodium 50mg 2 dd 1—supporting Examination for PKD diagnosis with CT-Scan. The author is interested in studying more about PKD because it is asymptomatic and only becomes symptomatic at the age of 30-40 years in ADPKD and has high mortality in the ARPKD type.

TRPV4 functional status in cystic cells regulates cystogenesis in autosomal recessive polycystic kidney disease (ARPKD) during variations in dietary potassium

Mechanosensitive Ca2+-permeable transient receptor potential vanilloid type 4 (TRPV4) channel plays a dominant role in maintaining intracellular Ca2+ ([Ca2+]i) homeostasis and flow-sensitive [Ca2+]i signaling in the distal segments of renal tubule and collecting duct. Polycystic kidney disease (PKD) manifests as progressive cyst growth with cystic cells exhibiting exacerbated cAMP-dependent fluid secretion along with deficient mechanosensitivity and reduced basal [Ca2+]i levels, and impaired TRPV4 activity. In this study, we tested how regulation of renal TRPV4 function by elevated dietary K+ intake modulates the rate of cystogenesis and mechanosensitive [Ca2+]i signaling in cystic cells of PCK453 rats (1 m.o.), a homologous model of human autosomal recessive PKD (ARPKD), where cyst development is restricted to the collecting duct. One month treatment with both high KCl (5% K+) and KB/C (5% K+ with bicarbonate to citrate in 4:1 ratio) diets significantly increased kidney TRPV4 levels in PCK453 rats when compared to the control group fed regular diet (0.9% K+). High KCl diet also caused an increased TRPV4-dependent Ca2+ influx, higher basal [Ca2+]i, and partial restoration of mechanosensitivity in freshly isolated monolayers of cystic cells. Unexpectedly, high KB/C diet induced an opposite effect by reducing TRPV4 activity and further worsening [Ca2+]i homeostasis. Importantly, high KCl diet decreased, whereas high KB/C diet further increased cAMP levels, as was assessed by the extent of cAMP-dependent translocation of AQP2 water channel to apical membrane in cystic cells. At the systemic level, high KCl diet fed PCK453 rats had significantly lower kidney-to-bodyweight ratio and reduced cystic area in renal sections. The beneficial effects of high KCl diet were negated by a concomitant administration of an orally active TRPV4 antagonist, GSK2193874, resulting in greater kidney weight and accelerated cystogenesis, when compared to these values in control rats. In a similar manner, high KB/C diet exacerbated renal manifestations of ARPKD, consistent with deficient TRPV4 activity in cystic cells. Moreover, KCl+GSK2193874 and high KB/C treated PCK453 rats have increased urinary levels of a renal injury marker, KIM-1.In conclusion, we demonstrate that TRPV4 channel activity negatively regulates cAMP levels in cystic cells upon variations in K+ intake thus attenuating (high activity) or accelerating (low activity) ARPKD progression in PCK453 rats. We propose that pharmacological or dietary means leading to TRPV4 stimulation might be useful to counteract PKD progression in the clinical setting. This research was supported by NIH-NIDDK DK117865, DK119170, AHA EIA35260097 (to O. Pochynyuk) and AHA-19CDA34660148 (to V. N. Tomilin). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.