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Kidney Week

Abstract: TH-PO666

Correlation of Gene Mutation and Prognosis in Japanese ADPKD Patients

Session Information

Category: Genetic Diseases of the Kidney

  • 1001 Genetic Diseases of the Kidney: Cystic

Authors

  • Kawashima, Keisuke, Hokkaido University, Sapporo, Japan
  • Nishio, Saori, Hokkaido University, Sapporo, Japan
  • Watanabe, Kanako, Hokkaido University, Sapporo, Japan
  • Seki, Toyokazu, Otsuka Pharmaceutical Co.,Ltd , Tokushima, Japan
  • Shimada, Hiroki, Kitami Red-cross Hospital, Kitami, Japan
  • Nakagawa, Naoki, Asahikawa Medical University, Asahikawa, Japan
  • Nakazawa, Daigo, Hokkaido University, Sapporo, Japan
  • Ishikawa, Yasunobu, Hokkaido University, Sapporo, Japan
  • Atsumi, Tatsuya, Hokkaido University, Sapporo, Japan
Background

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most prevalent hereditary renal disorder. PKD1 mutation is one of the risk factors of worse renal prognosis. Recently, the prognostic classification(Mayo classification) ,based on height-adjusted total kidney volume and age, has been proposed to predict renal outcomes. It is still unclear, however, whether PKD 1 mutation is definitive risk factor in Japanese patients due to the lack of relevant studies. The aim of this study is to examine whether known risk factors of ESRD are valid to predict renal prognosis in Japanese ADPKD patients.

Methods

Study design: retrospective cohort study. Primary outcome : Event-free survival rate; more than 30% decline in eGFR and initiation of renal replacement therapy were defined as event. We enrolled patients who visited our hospitals during 2006-2016. Gene analysis to detect PKD1 or PKD2 mutation was performed in all participants. Patients were classified into 1A~1E according to height-adjusted TKV (HtTKV) and age according to the Mayo classification. Cox proportional hazard model was used to estimate hazard ratios for renal event.

Results

We identified 255 patients with ADPKD. Among them,191 patients (74.9%) had PKD1 mutation,50 patients (19.6%) had PKD2 mutation, and in 14 patients (5.5%), we could not detect the mutations. In PKD1 group, larger proportion of patients were classified into 1C~1E of Mayo classification [1A: 6 (3.1%), 1B: 44 (23.0%), 1C: 76 (39.8%), 1D: 38 (19.9%), 1E: 27 (14.1%) vs 1A: 5(10%), 1B: 17(34.0%), 1C: 18 (36.0%), 1D: 9 (18.0%), 1E: 1 (2.0%) ] , which indicated worse prognosis in PKD1 group compared with PKD2 group at the baseline. The hazard ratio for renal event among PKD1 group, compared with PKD2 group was 2.45 (95% CI: 1.14-6.40; P=0.0196). The event free survival rates in patients with PKD1 truncating mutation and those with non-truncating mutation were 34.6% and 29.8%, respectively, but their difference was not statistically significant (Hazard ratio 1.1, 95% CI: 0.65-1.84; P=0.70).

Conclusion

This is the one of the largest cohort studies of ADPKD patients with gene analysis in JAPAN. In Japanese ADPKD, patients with PKD1 mutation had significantly worse renal prognosis than those with PKD2 mutation, as reported in American and European population.