Chebib, Fouad T

Key Points This study demonstrates that peritoneal dialysis is a safe and feasible option for patients with autosomal dominant polycystic kidney disease, even with high cystic organ volumes. Larger organ volumes, including height-adjusted cumulative kidney and liver volume, were not associated with increased peritoneal dialysis–related complications. Background Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent genetic kidney disorder and the fourth leading cause of kidney failure. Peritoneal dialysis (PD), preferred for its home-based convenience and cost-effectiveness, is often underutilized in ADPKD because of concerns over enlarged kidneys and heightened risk of complications. Methods This retrospective cohort study used data from the Mayo Clinic Polycystic Kidney Disease Database to evaluate individuals with ADPKD undergoing PD. We analyzed demographics, clinical parameters, and PD-related parameters. Complications were correlated with kidney and liver volumes derived from pre-kidney failure imaging. Results A total of 155 individuals with ADPKD on PD were included, of whom 45.1% were male. The mean age at PD initiation was 54.3±12.8 years, and the mean body mass index was 28.0±7.0 kg/m 2 . The median duration of PD was 24.3 months (interquartile range [IQR], 10.7–43.1), with 21.9% transitioning to hemodialysis. The most common complications were abdominal hernias (30.3%) and peritonitis (23.9%), with a peritonitis rate of 0.11 episodes per patient-year. Imaging analyses performed on a subset of 50 patients showed a median height-adjusted total kidney liver volume of 2731.9 ml/m (IQR, 2102.5–3131.1) and a median height-adjusted total kidney volume of 1303.5 ml/m (IQR, 733.1–1829.4). Kaplan–Meier analysis demonstrated no differences in complications rates on the basis of height-adjusted total kidney liver volume or height-adjusted total kidney volume (above versus below median values) or body mass index categories. Multivariate Cox regression analysis revealed that higher height-adjusted cumulative organ volume was associated with a lower risk of PD-related complications (hazard ratio=0.56, P = 0.026). Conclusions PD is a safe and feasible treatment option for patients with ADPKD, with no increased risk of PD-related complications associated with larger height-adjusted cumulative organ volumes. Infectious complication rates in this cohort were within International Society of Peritoneal Dialysis guideline thresholds, further supporting the safety of PD in this population.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disorder. It is primarily caused by pathogenic variants in the PKD1 or PKD2 genes. This leads to the development of numerous kidney cysts, which can result in kidney enlargement and progression to kidney failure. Pain is a common symptom in ADPKD and can negatively affect quality of life (QOL). This pain is often due to the continuous growth of kidney and liver cysts or associated cystic complications. We present a case of a 29-year-old woman with ADPKD who experienced chronic, refractory right-sided flank pain that significantly affected her QOL. Her pain persisted despite taking daily multimodal analgesics and undergoing multiple invasive interventions. She had an unusual asymmetric disease with the right kidney accounting for only 24% of her kidney function. After exhausting all other pain control strategies, she underwent right nephrectomy and partial hepatectomy, which led to substantial improvement in pain and QOL. This review describes the causes, manifestations, and management strategies for abdominal and/or flank pain in ADPKD, including a practical stepwise algorithm to guide clinicians in managing pain and improve QOL of patients with ADPKD. Pain in ADPKD can either be acute or chronic and can lead to significant physical and psychologic distress. Effective pain management in ADPKD requires a multidisciplinary approach, incorporating both nonpharmacologic and pharmacologic interventions such as gabapentin or tolvaptan in select cases. Interventions considered in ADPKD pain control include cyst aspiration with sclerotherapy, celiac plexus blockade, spinal cord stimulation, renal denervation, or nephrectomy.

Key Points Loss-of-function ALG8 and ALG9 variants were enriched in polycystic kidney/liver groups and International Classification of Diseases–coded cystic individuals in population cohorts. The ALG8 and ALG9 kidney phenotypes were usually mild to moderate, and lower eGFR or kidney failure was rare. ALG8 pathogenic variants sometimes resulted in severe polycystic liver disease. Background Autosomal dominant polycystic kidney disease (ADPKD) is a common, inherited nephropathy often resulting in kidney failure. It is genetically heterogeneous; along with the major genes, PKD1 and PKD2 , at least eight others have been suggested. ALG8 pathogenic variants have been associated with autosomal dominant polycystic liver disease and implicated in ADPKD, while ALG9 has been suggested as an ADPKD gene, but details of the phenotypes and penetrance are unclear. Methods We screened >3900 families with cystic kidneys and/or livers using global approaches to detect ALG8 or ALG9 pathogenic variants. In addition, population cohorts with sequence data (Genomics England 100K Genomics Project, UK Biobank, and Mayo Clinic Biobank [MCBB]) were screened for ALG8 / ALG9 pathogenic variants. Results Multicenter screening of individuals with polycystic kidney and/or liver disease identified 51 (1.3%) ALG8 (7 multiplex) and 23 (0.6%) ALG9 (5 multiplex) families—frequencies that were approximately 10× and approximately 24× greater than nonpolycystic kidney disease controls. Analysis of individuals with polycystic kidney disease phenotypes in 100K Genomics Project, UK Biobank, and MCBB identified nine ALG8 (0.39%) and nine ALG9 (0.39%) families, an enriched frequency over controls. Two individuals had PKD1 and ALG8 pathogenic changes. Eighty-nine percent of individuals with ALG8 mutations with imaging in the entire MCBB had kidney cysts (50%, >10 cysts), with greater median kidney and liver cyst numbers than controls. For ALG9, 78% had kidney cysts (27%, >10 cysts). Individuals with ALG8 mutations typically had mild cystic kidneys with limited enlargement. Liver cysts were common (71%), with enlarged livers (>2L) found in 11 of 62 patients, although surgical intervention was rare. The ALG9 kidney phenotype was also of mild cystic kidneys, but enlarged livers were rare; for both genes, CKD or kidney failure were rare. Conclusions ALG8 and ALG9 are defined as cystic kidney/liver genes but with limited penetrance for lower eGFR.

The Autosomal Dominant Polycystic Kidney Disease (ADPKD) Centers of Excellence (COE) Program, launched by the Polycystic Kidney Disease Foundation in 2022, aims to bridge the gap in specialized care for individuals with ADPKD. This program seeks to enhance the availability of specialized clinicians and simplify the process for patients seeking expert care. It is founded on three pillars: improving care for all individuals with ADPKD, educating and empowering the community, and advancing polycystic kidney disease research. The program draws inspiration from successful models in other diseases, such as cystic fibrosis and muscular dystrophy, which have demonstrated the effectiveness of standardized care centers in improving patient outcomes. Patient and clinician stakeholder interviews have identified key areas where a national program could make a significant effect, including the need for a core care team with defined referral processes, mentorship and shared care models, patient navigation services, and education around expert consensus and care guidelines. The program introduces two designations to accommodate diverse care settings and enhance patient access to specialists: COE and Partner Clinic. The Partner Clinic designation ensures that patients in smaller community practices have access to specialized care through mentorship and guidance from experts at COE. The program also emphasizes the importance of specialized services, especially in underserved communities experiencing health disparities, to manage the complexities of ADPKD care. Patient focus groups have highlighted the need for care navigation services, centralized sources of knowledge, and access to local care. The program aims to address these needs by providing a structured framework for care coordination, enhancing patient self-advocacy, and improving overall outcomes for individuals with ADPKD. Key Points The Autosomal Dominant Polycystic Kidney Disease Centers of Excellence Program aims to improve specialized care for autosomal dominant polycystic kidney disease patients. It introduces two designations to accommodate diverse care settings and enhance patient access to specialists: Center of Excellence and Partner Clinic. The program draws inspiration from successful models in other diseases, such as cystic fibrosis and muscular dystrophy, which have demonstrated the effectiveness of standardized care centers in improving patient outcomes. Key needs and programmatic goals identified through patient and clinician stakeholder interviews include establishing a core care team with defined referral processes, implementing mentorship and shared care models, providing patient navigation services, and offering education on expert consensus and care guidelines.

Key Points PIEZO1 activation reduces cystogenesis: Yoda1 activates PIEZO1, raising calcium and lowering cAMP, reducing cyst growth in autosomal dominant polycystic kidney disease models. Context-dependent role of PIEZO1: PIEZO1 knockout in mice with or without polycystic kidneys does not affect cyst formation, suggesting redundancy in mechanosensitive pathways. Therapeutic potential: Findings support PIEZO1 activation as a part of combination therapy to slow cyst growth in autosomal dominant polycystic kidney disease, needing more in vivo studies. Background The disruption of calcium signaling associated with polycystin deficiency is a key factor in abnormal epithelial growth in autosomal dominant polycystic kidney disease. Calcium homeostasis can be influenced by mechanotransduction. The mechanosensitive cation channel PIEZO1 has been implicated in sensing intrarenal pressure and regulating urinary osmoregulation, but its role in kidney cystogenesis is unclear. Methods We hypothesized that altered mechanotransduction contributes to cystogenesis in autosomal dominant polycystic kidney disease and that activation of mechanosensitive cation channels could be a therapeutic strategy. Results We demonstrate that Yoda1, a PIEZO1 activator, increases intracellular calcium and reduces forskolin-induced cAMP levels in mouse inner medullary collecting duct (mIMCD3) cells. Notably, knockout of polycystin-2 attenuated the efficacy of Yoda1 in reducing cAMP levels in mIMCD3 cells. Yoda1 also reduced forskolin-induced mIMCD3 cyst surface area in vitro and cystic index in mouse metanephros ex vivo in a dose-dependent manner. However, collecting duct–specific PIEZO1 knockout neither induced cystogenesis in wild-type mice nor altered cystogenesis in the Pkd1 RC/RC mouse model. Conclusions These findings support the potential role of PIEZO1 agonists in mitigating cystogenesis by increasing intracellular calcium and reducing cAMP levels, but the unaltered in vivo cystic phenotype after PIEZO1 knockout in the collecting duct suggests possible redundancy in mechanotransductive pathways.

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder marked by the development of cysts in the kidneys and other organs, leading to diverse clinical manifestations, including kidney failure. The psychological burden of ADPKD is substantial, with significant contributors including pain, daily life disruptions, depression, anxiety, and the guilt associated with transmitting ADPKD to offspring. This review details the psychological impacts of ADPKD on patients, addressing how they navigate physical and emotional challenges, including pain management, genetic guilt, mood disorders, and disease acceptance. This review also underscores the need for comprehensive research into the psychological aspects of ADPKD, focusing on the prevalence and contributing factors of emotional distress and identifying effective strategies for managing anxiety and depression. Furthermore, it highlights the importance of understanding the diverse factors that influence patients' quality of life and advocates for holistic interventions to address these psychological challenges.

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.

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by kidney cyst formation and progressive kidney function loss. Dietary interventions such as caloric restriction, intermittent fasting, and ketogenic diet have recently emerged as potential strategies to induce metabolic reprogramming and slow ADPKD progression. We review the available evidence supporting the efficacy and safety of these interventions in ADPKD. Dietary interventions show promise in managing ADPKD by improving metabolic health and reducing oxidative stress. However, while preclinical studies have shown favorable outcomes, limited clinical evidence supports their effectiveness. In addition, the long-term consequences of these dietary interventions, including their effect on adverse events in patients with ADPKD, remain uncertain. To optimize ADPKD management, patients are advised to follow a dietary regimen that aims to achieve or maintain an ideal body weight and includes high fluid intake, low sodium, and limited concentrated sweets. Caloric restriction seems particularly beneficial for patients with overweight or obesity because it promotes weight loss and improves metabolic parameters. Supplementation with curcumin, ginkgolide B, saponins, vitamin E, niacinamide, or triptolide has demonstrated uncertain clinical benefit in patients with ADPKD. Notably, β -hydroxybutyrate supplements have shown promise in animal models; however, their safety and efficacy in ADPKD require further evaluation through well-designed clinical trials. Therefore, the use of these supplements is not currently recommended for patients with ADPKD. In summary, dietary interventions such as caloric restriction, intermittent fasting, and ketogenic diet hold promise in ADPKD management by enhancing metabolic health. However, extensive clinical research is necessary to establish their effectiveness and long-term effects. Adhering to personalized dietary guidelines, including weight management and specific nutritional restrictions, can contribute to optimal ADPKD management. Future research should prioritize well-designed clinical trials to determine the benefits and safety of dietary interventions and supplementation in ADPKD.