Revisiting racial differences in ESRD due to ADPKD in the United States.

INTRODUCTION: Autosomal dominant polycystic kidney disease (ADPKD) affects all races. Whether the progression of ADPKD varies by race remains unclear. METHODS: In this retrospective cohort study from 2004 to 2013 non-Hispanic blacks and non-Hispanic whites of all ages classified in the US Renal Data System (USRDS) with incident ESRD from ADPKD (n = 23,647), hypertension/large vessel disease (n = 296,352), or diabetes mellitus (n = 451,760) were stratified into five-year age categories ranging from < 40 to > 75 (e.g., < 40, 40-44, 45-49, …, 75+). The Cochran-Mantel-Haenszel test was used to determine the association of race and incidence of ESRD from ADPKD, diabetes, or hypertension. The difference in the proportions of ESRD in non-Hispanic black and non-Hispanic white patients at each age categorical bin was compared by two-sample proportion test. The age of ESRD onset between non-Hispanic black and non-Hispanic white patients at each year was compared using two-sample t-test with unequal variance. RESULTS: 1.068% of non-Hispanic blacks and 2.778% of non-Hispanic whites had ESRD attributed to ADPKD. Non-Hispanic blacks were less likely than non-Hispanic whites to have ESRD attributed to ADPKD (odds ratio (OR) (95% CI) = 0.38 (0.36-0.39), p <  0.0001). Using US Census data as the denominator to adjust for population differences non-Hispanic blacks were still slightly under-represented (OR (95% CI) 0.94 (0.91-0.96), p = 0.004). However, non-Hispanic blacks with ADPKD had a younger age of ESRD (54.4 years ±13) than non-Hispanic whites (55.9 years ±12.8) (p <  0.0001). For those < 40 years old, more non-Hispanic blacks had incident ESRD from ADPKD than non-Hispanic whites (9.49% vs. 7.68%, difference (95% CI) = 1.81% (0.87-2.84%), p <  0.001) for the combined years examined. CONCLUSIONS: As previously shown, we find the incidence of ESRD from ADPKD in non-Hispanic blacks is lower than in non-Hispanic whites. Among the younger ADPKD population (age < 40), however, more non-Hispanic blacks initiated dialysis than non-Hispanic whites. Non-Hispanic blacks with ADPKD initiated dialysis younger than non-Hispanic whites. A potential implication of these findings may be that black race should be considered an additional risk factor for progression in ADPKD.

Preimplantation Genetic Diagnosis Counseling in Autosomal Dominant Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary forms of chronic kidney disease. Mutations within PKD1 or PKD2 lead to innumerable fluid-filled cysts in the kidneys and in some instances, end-stage renal disease (ESRD). Affected individuals have a 50% chance of passing the mutation to each of their offspring. Assisted reproductive technology using preimplantation genetic diagnosis (PGD) allows these individuals to reduce this risk to 1% to 2%. We assess the disease burden of 8 individuals with ADPKD who have undergone genetic testing in preparation for PGD. Clinical features that predict high risk for progression to ESRD in patients with ADPKD include genotype, early onset of hypertension, a urologic event before age 35 years, and a large height-adjusted total kidney volume. Patients may have a family history of intracranial aneurysms or complications involving hepatic cysts, which may further influence the decision to pursue PGD. We also explore the cost, risks, and benefits of using PGD. All patients with ADPKD of childbearing potential, regardless of risk for progression to ESRD or risk for a significant disease burden, will likely benefit from genetic counseling.