Kidney Week

Abstract: PO1796

IgA Nephropathy Complicated with Crohn Disease: A Clinical and Pathological Study of Kidney Biopsied Cases

Session Information

• Glomerular Diseases: IgA, C3G, and FSGS
  October 22, 2020 | Location: On-Demand
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1202 Glomerular Diseases: Immunology and Inflammation

Authors

• Akiyama, Minako, Department of Anatomy, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan

Minako Akiyama,

• Kousuke, Shimomura, Tokyo Yamate Medical Center, Shinjuku-ku, Tokyo, Japan

Shimomura Kousuke,

• Yoshimoto, Shaho, Tokyo Yamate Medical Center, Shinjuku-ku, Tokyo, Japan

Shaho Yoshimoto,

• Sako, Minako, Tokyo Yamate Medical Center, Shinjuku-ku, Tokyo, Japan

Minako Sako,

• Kodama, Makoto, Tokyo Yamate Medical Center, Shinjuku-ku, Tokyo, Japan

Makoto Kodama,

• Abe, Keiko, Tokyo Yamate Medical Center, Shinjuku-ku, Tokyo, Japan

Keiko Abe,

• Sano, Mariko, Department of Anatomy, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan

Mariko Sano,

• Kang, Dedong, Department of Anatomy, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan

Dedong Kang,

• Takaki, Takashi, Department of Anatomy, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan

Takashi Takaki,

• Wada, Yukihiro, Division of Nephrology, Department of Medicine, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan

Yukihiro Wada,

• Iyoda, Masayuki, Department of Microbiology and Immunology, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan

Masayuki Iyoda,

• Honda, Kazuho, Department of Anatomy, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan

Kazuho Honda,

Background

Intestinal immunity is closely related with the pathogenesis and progression of renal diseases, called as “entero-renal linkage”. To figure out the association between IgA nephropathy (IgAN) and Crohn's disease (CD), we performed the clinico-pathological study of IgAN patients with (CD-IgAN) and without CD (NOS-IgAN).

Methods

We enrolled 29 patients diagnosed with IgAN by renal biopsy in Tokyo Yamate Medical Center from 2009 to 2017. The patients were divided into CD-IgAN (n=18) and NOS-IgAN (n=11) and investigated their clinical and pathological findings. IgA subclasses and galactose-deficient IgA1 (Gd-IgA1) on glomerulus were examined by immunohistochemistry.

Results

No significant difference in the grades of urinary protein and hematuria was observed between CD-IgAN and NOS-IgAN, but CD-IgAN had elevated serum creatinine (sCr) and lower rate in clinical remission after steroid treatment as compared to NOS-IgAN. Pathologically, CD-IgAN had remarkably higher levels of global glomerulosclerosis (%), grades of interstitial fibrosis and tubular atrophy (IF/TA) than NOS-IgAN. Immunohistochemically, IgA1 was a dominant subclass and Gd-IgA1 was frequently detected in glomerular mesangium in both groups. No difference was noted in the extents of IgA1, IgA2 and Gd-IgA1 deposition, depending on the presence or absence of CD.

Conclusion

From the results of the subclasses and galactose-deficiency of the IgA molecules, no difference was suggested in the etiology and pathogenesis between CD-IgAN and NOS-IgAN. However, advanced glomerular sclerosis and tubulointerstitial fibrosis in renal pathology and highly resistant clinical features to medical treatments in CD-IgAN suggest that the intestinal immunity and other clinical factors associated with CD may promote and activate the inflammatory process of IgAN.