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Abstract: TH-PO824

The Value of Genotypic and Imaging Information to Predict Outcomes in a Large Longitudinal ADPKD Mayo Cohort

Session Information

Category: Genetic Diseases of the Kidneys

  • 1001 Genetic Diseases of the Kidneys: Cystic

Authors

  • Lavu, Sravanthi, Mayo Clinic, Rochester, Minnesota, United States
  • Vaughan, Lisa E., Mayo Clinic, Rochester, Minnesota, United States
  • Edwards, Marie E., Mayo Clinic, Rochester, Minnesota, United States
  • Senum, Sarah R., Mayo Clinic, Rochester, Minnesota, United States
  • Chebib, Fouad T., Mayo Clinic, Rochester, Minnesota, United States
  • Torres, Vicente E., Mayo Clinic, Rochester, Minnesota, United States
  • Harris, Peter C., Mayo Clinic, Rochester, Minnesota, United States
Background

Variability in severity of ADPKD is influenced by genic and allelic factors at the causative locus, plus other genetic and environmental factors. In a mutation characterized ADPKD cohort, we analyzed the predictive ability of the germline mutation and Mayo Imaging Class (MIC) to predict renal functional and structural outcomes.

Methods

Mayo Clinic patients >15 years having a PKD1 or PKD2 pathogenic variant were included (n=1072). Longitudinal eGFR (n=870) and htTKV (n=600) data were collected until ESRD. PKD1 patients were divided into truncating (Mutation Strength Group 1; MSG1), and strongly and weakly predicted non-truncating mutations (MSG2 & 3). The associations between MSG group or MIC and time to 50% loss of eGFR or ESRD or 50% increase in TKV were evaluated using Cox regression with age as the timescale.

Results

Median time from baseline to 50% eGFR loss/ESRD was 8.1, 8.8, 15.5 and 15.6 years for PKD1 MSG1, 2, 3, and PKD2, and 6.7, 8.2, 10.7 and 17.2 years for MIC classes 1E, 1D, 1C & 1B, respectively (MIC class 1A survival was >50% throughout follow-up). This equates to PKD1 MSG2, 3, and PKD2 being associated with a lower risk of 50% eGFR loss/ESRD compared to MSG1 [HR (95% CI): 0.69 (0.51-0.93), 0.35 (0.25-0.49), and 0.28 (0.20-0.40), respectively; P<0.001]; MIC classes 1A-1D were also associated with a lower risk of ESRD compared to class 1E [HR (95% CI): 0.039 (0.018-0.087), 0.10 (0.065-0.16), 0.19 (0.13-0.28), and 0.44 (0.30-0.63), respectively; P<0.001]. A multivariable model including both MSG and MIC had strong discriminatory ability (C-statistic of 0.802). Median time to 50% increase in htTKV was 8.3, 11.1, 12.9, 13.3 & not reached, respectively, for MIC 1E, 1D, 1C, 1B & 1A; hence the other imaging classes had a lower risk of reaching this endpoint than MIC group 1E (P<0.001). However, genotypic class was not found to be associated with a 50% increase in htTKV (p=0.56).

Conclusion

Genotype (MSG) and MIC are strong predictors of functional renal outcome in ADPKD; however, genotype was not associated with htTKV increase of 50%. Utilizing both genotype and imaging class is helpful for identifying patients with severe disease, thereby aiding selection of patients for clinical trials and treatment.

Funding

  • NIDDK Support