Kidney Week

Abstract: SA-PO661

Clinicopathological Differences between Young Children and Adolescents in Childhood IgA Nephropathy

Session Information

• Pediatric Nephrology - 2
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

• 1900 Pediatric Nephrology

Authors

• Shima, Yuko, Wakayama Kenritsu Ika Daigaku, Wakayama, Wakayama, Japan

Yuko Shima, MD, PhD

• Mukaiyama, Hironobu, Wakayama Kenritsu Ika Daigaku, Wakayama, Wakayama, Japan

Hironobu Mukaiyama, MD

• Tanaka, Yu, Wakayama Kenritsu Ika Daigaku, Wakayama, Wakayama, Japan

Yu Tanaka

• Shimabukuro, Wataru, Ryukyu Daigaku Igakubu Daigakuin Igaku Kenkyuka, Nakagami-gun, Okinawa, Japan

Wataru Shimabukuro, MD

• Kaito, Hiroshi, Hyogo Kenritsu Kodomo Byoin, Kobe, Hyogo, Japan

Hiroshi Kaito, MD, PhD

• Tanaka, Ryojiro, Hyogo Kenritsu Kodomo Byoin, Kobe, Hyogo, Japan

Ryojiro Tanaka, MD

• Nozu, Kandai, Kobe Daigaku, Kobe, Hyogo, Japan

Kandai Nozu, MD, PhD

• Iijima, Kazumoto, Kobe Daigaku, Kobe, Hyogo, Japan

Kazumoto Iijima, MD, PhD

• Tokuhara, Daisuke, Wakayama Kenritsu Ika Daigaku, Wakayama, Wakayama, Japan

Daisuke Tokuhara, MD, PhD

• Yoshikawa, Norishige, Shakai Iryo Hojin Aijinkai Takatsuki Byoin, Takatsuki, Osaka, Japan

Norishige Yoshikawa, MD, PhD

• Nakanishi, Koichi, Ryukyu Daigaku Igakubu Daigakuin Igaku Kenkyuka, Nakagami-gun, Okinawa, Japan

Koichi Nakanishi, MD, PhD

Background

Proteinuria remission is the most significant predictive factor for kidney outcome in childhood IgA nephropathy (c-IgAN). In our previous study, younger children were more likely to achieve proteinuria remission and less likely to proteinuria recurrence. Among c-IgAN, there might be differences in clinicopathological findings depending on age regardless of the timing of kidney biopsy. So, the purpose of this study is to clarify the clinicopathological features between younger children whose onset age〈 10 years old and adolescents whose onset age ≧ 10 years old in this study.

Methods

From July 1976 to December 2022, among 567 children with biopsy-proven IgAN at Kobe University and Wakayama Medical University, those with age at onset were available in 557. We investigated clinicopathological differences in 213 (38.2%) younger c-IgAN and the other 344 (61.8%) adolescent c-IgAN. A 1:1 propensity score matching was performed to account for between-group differences (duration from onset to kidney biopsy and kidney biopsy before or after 1990), and 204 matched pairs were obtained.

Results

Adolescent c-IgAN were more detected by school screening program (80.4 vs. 71.1%, p=0.04). Proteinuria was more in younger c-IgAN (0.8 vs. 0.5 g/gCr, p=0.02). The prevalence of tubular atrophy/interstitial fibrosis present was higher in adolescent c-IgAN (44.3 vs.54.9%, p=0.04). The Kaplan-Meier analysis of proteinuria remission showed that younger c-IgAN achieved significantly higher proteinuria remission than ad adolescent c-IgAN (75.4 vs 54.9% at 10 years; 95%CI: 67.4-82.1 vs. 44.8-64.5, p=0.0004).

Conclusion

In adolescent c-IgAN, tubular atrophy/interstitial fibrosis are more likely to be formed regardless of the timing of kidney biopsy, making it difficult to achieve proteinuria remission.