Characteristics of Patients with End-Stage Kidney Disease in ADPKD.

INTRODUCTION: Cystic expansion damaging the parenchyma is thought to lead to end-stage kidney disease (ESKD) in autosomal dominant polycystic kidney disease (ADPKD). Here we characterized genotypic and phenotypic attributes of ADPKD at time of ESKD. METHODS: This is a retrospective cross-sectional study of patients with ADPKD with ESKD evaluated at Mayo Clinic with available abdominal computed tomography (CT) or magnetic resonance imaging (MRI). Kidney volumes were measured (total kidney volume adjusted for height [HtTKV]), Mayo Image Class (MIC) calculated, ADPKD genotype determined, and clinical and laboratory features obtained from medical records. RESULTS: Differences in HtTKV at ESKD were associated with patient age and sex; older patients and women had smaller HtTKV at ESKD. HtTKV at ESKD was observed to be 12.3% smaller with each decade of age (P < 0.01); but significant only in women (17.8%, P < 0.01; men 6.9%, P = 0.06). Patients with onset of ESKD at <47, 47-61, or >61 years had different characteristics, with a shift from youngest to oldest in male to female enrichment, MIC from 1D/1E to 1B/1C, likely fully penetrant PKD1 mutations from 95% to 42%, and presence of macrovascular disease from 8% to 40%. Macrovascular disease was associated with smaller kidneys in female patients. CONCLUSION: HtTKV at ESKD was smaller with advancing age in patients with ADPKD, particularly in women. These novel findings provide insight into possible underlying mechanisms leading to ESKD, which differ between younger and older individuals. Cystic growth is the predominant mechanism in younger patients with ESKD, whereas aging-related factors, including vascular disease, becomes potentially important as patients age.

Epidemiology of Autosomal Dominant Polycystic Kidney Disease in Olmsted County.

BACKGROUND AND OBJECTIVES: The prevalence of autosomal dominant polycystic kidney disease (ADPKD) remains controversial. Incidence rates in Olmsted County, Minnesota, during 1935-1980 were previously reported. The current work extends this study to 2016. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Rochester Epidemiology Project and radiology databases of Mayo Clinic and Olmsted Medical Center (healthcare providers for Olmsted County) were searched to identify all subjects meeting diagnostic criteria for definite, likely, and possible ADPKD. Annual incidence rates were calculated using incident cases during 1980-2016 as numerator and age- and sex-specific estimates of the population of Olmsted County as denominator. Point prevalence was calculated using prevalence cases as numerator and age- and sex-specific estimates of the population of Olmsted County on January 1, 2010 as denominator. Survival curves from the time of diagnosis were compared with expected survival of the Minnesota population. RESULTS: The age- and sex-adjusted annual incidence of definite and likely ADPKD diagnosis during 1980-2016 was 3.06 (95% CI, 2.52 to 3.60) per 100,000 person-years, which is 2.2 times higher than that previously reported for 1935-1980 (1.38 per 100,000 person-years). The point prevalence of definite or likely ADPKD on January 1, 2010 was 68 (95% CI, 53.90 to 82.13) per 100,000 population. Much higher incidence rates and point prevalence were obtained when possible ADPKD cases were included. Contrary to the previous Olmsted County study, patient survival in this study was not different from that in the general population. CONCLUSIONS: The point prevalence of definite and likely ADPKD observed in this study is higher than those reported in the literature, but lower than genetic prevalence based on estimates of disease expectancy or on analysis of large population-sequencing databases.

Presymptomatic Screening for Intracranial Aneurysms in Patients with Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND AND OBJECTIVES: Intracranial aneurysm rupture is the most devastating complication of autosomal dominant polycystic kidney disease. Whether selective or widespread intracranial aneurysm screening is indicated remains controversial. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS: Records of 3010 patients with autosomal dominant polycystic kidney disease evaluated at the Mayo Clinic between 1989 and 2017 were reviewed. Those who had presymptomatic magnetic resonance angiography screening were included. RESULTS: Ninety-four intracranial aneurysms were diagnosed in 75 of 812 (9%) patients who underwent magnetic resonance angiography screening. Sex, age, race, and genotype were similar in the groups with and without aneurysms; hypertension and history of smoking were more frequent in the aneurysm group. Twenty-nine percent of patients with aneurysms compared with 11% of those without aneurysms had a family history of subarachnoid hemorrhage (P<0.001). Most aneurysms were small (median diameter =4 mm; range, 2-12 mm); 85% were in the anterior circulation. During a total imaging follow-up of 469 patient-years, de novo intracranial aneurysms were detected in five patients; eight intracranial aneurysms grew (median =2 mm; range, 1-3 mm). During a total clinical follow-up of 668 patient-years, seven patients had preemptive clipping or coil embolization; no intracranial aneurysms ruptured. During a total clinical follow-up of 4783 patient-years in 737 patients with no intracranial aneurysm detected on the first magnetic resonance angiography screening, two patients had an intracranial aneurysm rupture (0.04 per 100 person-years; 95% confidence interval, 0 to 0.10). The rate of intracranial aneurysm rupture in large clinical trials of autosomal dominant polycystic kidney disease was 0.04 per 100 patient-years (95% confidence interval, 0.01 to 0.06). CONCLUSIONS: Intracranial aneurysms were detected by presymptomatic screening in 9% of patients with autosomal dominant polycystic kidney disease, more frequently in those with familial history of subarachnoid hemorrhage, hypertension, or smoking. None of the patients with and two of the patients without aneurysm detection on screening suffered aneurysmal ruptures. The overall rupture rate in our autosomal dominant polycystic kidney disease cohort was approximately five times higher than that in the general population.