Torres, Vicente E

Key Points In an observational cohort of mostly non-Hispanic White women, pregnancy was not associated with later-life accelerated kidney function decline. Pregnancy occurring during the HALT Progression of Polycystic Kidney Disease (HALT-PKD) trial was not associated with kidney disease progression relative to women who did not become pregnant. Prior evidence indicates that adverse pregnancy outcomes may be involved in autosomal dominant polycystic kidney disease progression; pregnant women should be closely monitored. Background Data are conflicting regarding whether pregnancy influences disease progression in women with autosomal dominant polycystic kidney disease (ADPKD). This study examined whether pregnancy or number of pregnancies was associated with kidney disease progression in women with ADPKD. Methods Women with early- (study A) and late-stage (study B) ADPKD from the HALT Progression of Polycystic Kidney Disease (HALT-PKD) trial were included to examine the association between self-reported number of pregnancies (categorical predictor: no pregnancy versus 1–2 pregnancies and ≥3 pregnancies), annual slope of eGFR, annual percent change in total kidney volume (%ΔTKV), and a composite outcome (kidney failure, 50% decline in eGFR, or death) using multivariable linear regression and Cox proportional hazard models. In addition, women who became pregnant, had full-term pregnancies, and available data during study participation ( n =13) were propensity matched (1:4) to women who were not pregnant during study participation, and a mixed model was applied to determine the association of pregnancy with eGFR slope and %ΔTKV. Results Across all analyses, 455 women with a median age of 45 (interquartile range, 38–50) years and eGFR of 69±25 ml/min per 1.73 m 2 at baseline were included. One hundred ninety-nine women had 1–2 pregnancies, and 165 women had ≥3 pregnancies. There was no association of 1–2 pregnancies or ≥3 pregnancies (versus no pregnancies) with eGFR slope ( β -estimate [95% confidence interval (CI)]; 1–2 pregnancies: 0.22 [−0.44 to 0.89]; ≥3 pregnancies: −0.46 [−1.16 to 0.25]), %ΔTKV ( β -estimate [95% CI]; 1–2 pregnancies: 0.92 [−0.34 to 2.17]; ≥3 pregnancies: 0.69 [−0.67 to 2.04]), or time to composite outcome (hazard ratio [95% CI]; 1–2 pregnancies: 1.04 [0.56 to 1.93]; ≥3 pregnancies: 1.48 [0.78 to 2.77]) in adjusted models. Moreover, there was no difference in annual eGFR slope ( β -estimate: −0.14 [95% CI, −2.72 to 2.44]) and %ΔTKV ( β -estimate: 0.04 [95% CI, −3.74 to 3.82]) in women who became pregnant matched to women who did not became pregnant during their participation in the study. Conclusions Pregnancy was not associated with ADPKD progression among women with early- and late-stage ADPKD enrolled in the HALT-PKD trial.

ABSTRACT Background A decrease in renal blood flow (RBF) precedes estimated glomerular filtration rate (eGFR) decline among patients with autosomal dominant polycystic kidney disease (ADPKD) and inversely associates with disease severity and progression. However, it is unknown whether RBF independently predicts progression to kidney failure in patients with ADPKD. Methods A total of 379 participants with early-stage ADPKD (mean age 36.6 ± 8.5 years; eGFR: 92.9 ± 17.1 ml/min/1.73 m2) who participated in the Halt Progression of Polycystic Kidney Disease Study A (HALT PKD A; NCT00283686) with baseline RBF (phase contrast magnetic resonance imaging) data were included in the primary analysis. Kaplan–Meier survival analysis and multivariate Cox proportional hazard models were used to determine the association of baseline RBF as a continuous and categorical variable with kidney failure risk (during the HALT study and subsequently linked to the US Renal Data System) over a median follow-up period of 13.1 years (interquartile range 7.5–14.5) (primary outcome). All-cause mortality was also considered as a competing risk (Fine and Gray method). The associations of RBF with eGFR slope and the change in height-adjusted total kidney volume (∆htTKV) were evaluated with linear and logistic regression models. Results The kidney failure incidence rate was the highest among those with the lowest RBF tertile {1.90 [95% confidence interval (CI) 1.31–2.78] versus 0.34 [95% CI 0.14–0.83] events/100 person-years in tertile 3}. In the fully adjusted model, the lowest RBF tertile was associated with a higher risk of progression to kidney failure [hazard ratio (HR) 3.19 (95% CI 1.05–9.67] versus the highest tertile]. The association of RBF with kidney failure risk was slightly attenuated in adjusted models. All associations remained similar when considering death as a competing risk [HR 0.82 (95% CI 0.67–1.00) per 100 ml/min/1.73 m2 higher RBF]. Higher RBF was associated with a slower eGFR decline and lower odds of rapid annual ∆htTKV. Conclusions Lower baseline RBF independently associates with a greater risk of progression to kidney failure in early-stage patients with ADPKD.

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.

Significance Statement Changes in albuminuria and GFR slope are individually used as surrogate end points in clinical trials of CKD progression, and studies have demonstrated that each is associated with treatment effects on clinical end points. In this study, the authors sought to develop a conceptual framework that combines both surrogate end points to better predict treatment effects on clinical end points in Phase 2 trials. The results demonstrate that information from the combined treatment effects on albuminuria and GFR slope improves the prediction of treatment effects on the clinical end point for Phase 2 trials with sample sizes between 100 and 200 patients and duration of follow-up ranging from 1 to 2 years. These findings may help inform design of clinical trials for interventions aimed at slowing CKD progression. Background Changes in log urinary albumin-to-creatinine ratio (UACR) and GFR slope are individually used as surrogate end points in clinical trials of CKD progression. Whether combining these surrogate end points might strengthen inferences about clinical benefit is unknown. Methods Using Bayesian meta-regressions across 41 randomized trials of CKD progression, we characterized the combined relationship between the treatment effects on the clinical end point (sustained doubling of serum creatinine, GFR <15 ml/min per 1.73 m 2 , or kidney failure) and treatment effects on UACR change and chronic GFR slope after 3 months. We applied the results to the design of Phase 2 trials on the basis of UACR change and chronic GFR slope in combination. Results Treatment effects on the clinical end point were strongly associated with the combination of treatment effects on UACR change and chronic slope. The posterior median meta-regression coefficients for treatment effects were −0.41 (95% Bayesian Credible Interval, −0.64 to −0.17) per 1 ml/min per 1.73 m 2 per year for the treatment effect on GFR slope and −0.06 (95% Bayesian Credible Interval, −0.90 to 0.77) for the treatment effect on UACR change. The predicted probability of clinical benefit when considering both surrogates was determined primarily by estimated treatment effects on UACR when sample size was small (approximately 60 patients per treatment arm) and follow-up brief (approximately 1 year), with the importance of GFR slope increasing for larger sample sizes and longer follow-up. Conclusions In Phase 2 trials of CKD with sample sizes of 100–200 patients per arm and follow-up between 1 and 2 years, combining information from treatment effects on UACR change and GFR slope improved the prediction of treatment effects on clinical end points.

Background and objectives The progression of polycystic liver disease is not well understood. The purpose of the study is to evaluate the associations of polycystic liver progression with other disease progression variables and classify liver progression on the basis of patient's age, height-adjusted liver cystic volume, and height-adjusted liver volume. Design, setting, participants, & measurements Prospective longitudinal magnetic resonance images from 670 patients with early autosomal dominant polycystic kidney disease for up to 14 years of follow-up were evaluated to measure height-adjusted liver cystic volume and height-adjusted liver volume. Among them, 245 patients with liver cyst volume >50 ml at baseline were included in the longitudinal analysis. Linear mixed models on log-transformed height-adjusted liver cystic volume and height-adjusted liver volume were fitted to approximate mean annual rate of change for each outcome. The association of sex, body mass index, genotype, baseline height-adjusted total kidney volume, and Mayo imaging class was assessed. We calculated height-adjusted liver cystic volume ranges for each specific age and divided them into five classes on the basis of annual percentage increase in height-adjusted liver cystic volume. Results The mean annual growth rate of height-adjusted liver cystic volume was 12% (95% confidence interval, 11.1% to 13.1%; P <0.001), whereas that for height-adjusted liver volume was 2% (95% confidence interval, 1.9% to 2.6%; P <0.001). Women had higher baseline height-adjusted liver cystic volume than men, but men had higher height-adjusted liver cystic volume growth rate than women by 2% (95% confidence interval, 0.4% to 4.5%; P =0.02). Whereas the height-adjusted liver cystic volume growth rate decreased in women after menopause, no decrease was observed in men at any age. Body mass index, genotype, and baseline height-adjusted total kidney volume were not associated with the growth rate of height-adjusted liver cystic volume or height-adjusted liver volume. According to the height-adjusted liver cystic volume growth rate, patients were classified into five classes (number of women, men in each class): A (24, six); B (44, 13); C (43, 48); D (28, 17); and E (13, nine). Conclusions Compared with height-adjusted liver volume, the use of height-adjusted liver cystic volume showed greater separations in volumetric progression of polycystic liver disease. Similar to the Mayo imaging classification for the kidney, the progression of polycystic liver disease may be categorized on the basis of patient’s age and height-adjusted liver cystic volume.

Background Acute changes in GFR can occur after initiation of interventions targeting progression of CKD. These acute changes complicate the interpretation of long-term treatment effects. Methods To assess the magnitude and consistency of acute effects in randomized clinical trials and explore factors that might affect them, we performed a meta-analysis of 53 randomized clinical trials for CKD progression, enrolling 56,413 participants with at least one estimated GFR measurement by 6 months after randomization. We defined acute treatment effects as the mean difference in GFR slope from baseline to 3 months between randomized groups. We performed univariable and multivariable metaregression to assess the effect of intervention type, disease state, baseline GFR, and albuminuria on the magnitude of acute effects. Results The mean acute effect across all studies was −0.21 ml/min per 1.73 m 2 (95% confidence interval, −0.63 to 0.22) over 3 months, with substantial heterogeneity across interventions (95% coverage interval across studies, −2.50 to +2.08 ml/min per 1.73 m 2 ). We observed negative average acute effects in renin angiotensin system blockade, BP lowering, and sodium-glucose cotransporter 2 inhibitor trials, and positive acute effects in trials of immunosuppressive agents. Larger negative acute effects were observed in trials with a higher mean baseline GFR. Conclusion The magnitude and consistency of acute GFR effects vary across different interventions, and are larger at higher baseline GFR. Understanding the nature and magnitude of acute effects can help inform the optimal design of randomized clinical trials evaluating disease progression in CKD.

Significance Statement Patients with autosomal dominant polycystic kidney disease are treated with tolvaptan, a V2 receptor antagonist, to slow progression toward ESKD. In theory, tolvaptan could have both BP-increasing and BP-decreasing effects. To investigate the magnitude and time course of the effect of tolvaptan use on BP, the authors conducted a post hoc analysis of data from the TEMPO 3:4 trial, which randomized 1445 patients with autosomal dominant polycystic kidney disease to tolvaptan or placebo. Their analysis shows that directly after start of tolvaptan therapy, BP does not change, but in the long term, BP gradually becomes lower in patients with tolvaptan compared with placebo. This observation might be attributed to the beneficial effect of tolvaptan on disease progression, a sustained natriuretic effect, or both. Background The V2 receptor antagonist tolvaptan is prescribed to patients with autosomal dominant polycystic kidney disease to slow disease progression. Tolvaptan may alter BP via various acute and chronic effects. Methods To investigate the magnitude and time course of the effect of tolvaptan use on BP, we conducted a post hoc study of the TEMPO 3:4 trial, which included 1445 patients with autosomal dominant polycystic kidney disease randomized 2:1 to tolvaptan or placebo for 3 years. We evaluated systolic and diastolic BP, mean arterial pressure, hypertension status, and use and dosing of antihypertensive drugs over the course of the trial. Results At baseline, BP did not differ between study arms. After 3 weeks of tolvaptan use, mean body weight had decreased from 79.7 to 78.8 kg, and mean plasma sodium increased from 140.4 to 142.6 mmol/L (both P <0.001), suggesting a decrease in circulating volume. We observed none of these changes in the placebo arm. Nonetheless, BP remained similar in the study arms. After 3 years of treatment, however, mean systolic BP was significantly lower in participants receiving tolvaptan versus placebo (126 versus 129 mm Hg, respectively; P =0.002), as was mean diastolic BP (81.2 versus 82.6 mm Hg, respectively; P =0.01). These differences leveled off at follow-up 3 weeks after discontinuation of the study medication. Use of antihypertensive drugs remained similar in both study arms during the entire study. Conclusions Long-term treatment with tolvaptan gradually lowered BP compared with placebo, which may be attributed to a beneficial effect on disease progression, a continued natriuretic effect, or both. Clinical Trial registry name and registration number: TEMPO 3:4, NCT00428948

Background and objectives Tolvaptan slows kidney function decline in patients with autosomal dominant polycystic kidney disease (ADPKD) at risk of rapid progression. In the 3-year Tolvaptan Efficacy and Safety in Management of ADPKD and Its Outcomes (TEMPO) 3:4, 2-year extension to TEMPO 3:4 (TEMPO 4:4), and 1-year Replicating Evidence of Preserved Renal Function: An Investigation of Tolvaptan Safety and Efficacy in ADPKD (REPRISE) trials, aquaretic adverse events were common. Serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) elevations occurred in all three studies. Three patients met Hy Law criteria (ALT or AST more than three times and total bilirubin more than two times the upper limit of normal) for severe drug-induced liver injury (two in TEMPO 3:4 and one in TEMPO 4:4). In REPRISE, liver enzyme monitoring frequency was increased to monthly, with no Hy Law cases. A long-term, phase 3 safety study has further characterized tolvaptan safety. Design, setting, participants, & measurements Subjects who completed TEMPO 4:4, REPRISE, or other tolvaptan trials could enroll in this prospective, multinational, open-label safety study. Assessments included monthly liver enzyme testing during the first 18 months of tolvaptan exposure and every 3 months thereafter. Results Among 1803 subjects, median tolvaptan exposure during the extension was 651 days (interquartile range, 538–924), and cumulative exposure (extension and previous trials) was ≤11 years. Subjects entering from REPRISE placebo experienced more aquaretic adverse events compared with subjects from TEMPO 4:4 or REPRISE tolvaptan ( i.e ., patients with prior long-term tolvaptan exposure). Liver enzyme elevations also occurred more frequently in subjects from REPRISE placebo. Percentages experiencing ALT ≥3/≥5/ ≥10/≥20 times the upper limit of normal were 3.2%/2.1%/0.9%/0.7%, respectively, in subjects from REPRISE placebo and 0.6%–1.1%/0.0%–0.1%/0%/0%, respectively, in those from REPRISE tolvaptan and TEMPO 4:4. Percentages experiencing AST ≥3/ ≥5/≥10/≥20 times the upper limit of normal were 6.9%/3.8%/2.3%/0.8%, respectively, in subjects from REPRISE placebo and 0.9%–2.0%/0.0%–1.0%/0%/0%, respectively, in those from REPRISE tolvaptan and TEMPO 4:4. No Hy Law cases occurred. Conclusions No new safety signals emerged during this long-term extension. Monthly liver function testing for the first 18 months of treatment appeared to enable effective detection and management of transaminase elevations. Clinical Trial registry name and registration number: Open Label Extension of TEMPO 3:4, NCT02251275

Background and objectives We assessed safety and efficacy of another somatostatin receptor analog, pasireotide long-acting release, in severe polycystic liver disease and autosomal dominant polycystic kidney disease. Pasireotide long-acting release, with its broader binding profile and higher affinity to known somatostatin receptors, has potential for greater efficacy. Design, setting, participants, & measurements Individuals with severe polycystic liver disease were assigned in a 2:1 ratio in a 1-year, double-blind, randomized trial to receive pasireotide long-acting release or placebo. Primary outcome was change in total liver volume; secondary outcomes were change in total kidney volume, eGFR, and quality of life. Results Of 48 subjects randomized, 41 completed total liver volume measurements ( n =29 pasireotide long-acting release and n =12 placebo). From baseline, there were −99±189 ml/m absolute and −3%±7% change in annualized change in height-adjusted total liver volume (from 2582±1381 to 2479±1317 ml/m) in the pasireotide long-acting release group compared with 136±117 ml/m absolute and 6%±7% increase (from 2387±759 to 2533±770 ml/m) in placebo ( P <0.001 for both). Total kidney volumes decreased by −12±34 ml/m and −1%±4% in pasireotide long-acting release compared with 21±21 ml/m and 4%±5% increase in the placebo group ( P =0.05 for both). Changes in eGFR were similar between groups. Among the n =48 randomized, adverse events included hyperglycemia (26 of 33 [79%] in pasireotide long-acting release versus four of 15 [27%] in the placebo group; P <0.001), and among the 47 without diabetes at baseline, 19 of 32 (59%) in the pasireotide long-acting release group versus one of 15 (7%) in the placebo group developed diabetes ( P =0.001). Conclusions Another somatostatin analog, pasireotide long-acting release, slowed progressive increase in both total liver volume/total kidney volume growth rates without affecting GFR decline. Participants experienced higher frequency of adverse events (hyperglycemia and diabetes). Clinical Trial registry name and registration number Pasireotide LAR in Severe Polycystic Liver Disease, NCT01670110 Podcast This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_08_28_CJN13661119.mp3