Abstract: FR-PO721

Clinical Impact of Peritubular Capillaritis on Renal Prognosis in ANCA-Associated Glomerulonephritis

Session Information

Category: Glomerular

  • 1004 Clinical/Diagnostic Renal Pathology and Lab Medicine

Authors

  • Hara, Satoshi, Kanazawa Graduate School of Medicine, Kanazawa, Ishikawa, Japan
  • Suzuki, Fae, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
  • Mizushima, Ichiro, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
  • Ito, Kiyoaki, Kanazawa universtiy, Kanazawa, Japan
  • Fujii, Hiroshi, Division of Rheumatology, Department of Internal Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Kanazawa, Japan
  • Yamada, Kazunori, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
  • Kawano, Mitsuhiro, Division of Rheumatology, Kanazawa University Hospital, Kanazawa, Japan
Background


A predictive histopathologic classification of anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis has been widely used; however, the classification is based on only glomerular lesions, and tubulointerstitial lesions including peritubular capillaritis (PTCitis) are excluded. The present study was aimed to clarify the clinical impact of PTCitis on renal prognosis in ANCA-associated glomerulonephritis.

Methods


Sixty-one patients of ANCA-associated glomerulonephritis, diagnosed by kidney biopsy at our center between January 2003 and May 2016, were included in the study. PTCitis is defined as infiltration of inflammatory cells at least one leukocyte in ≧10% of cortical PTCs with ≧3 leukocytes in most severely involved PTC. According to the presence/absence of PTCitis, patients were retrospectively divided into 2 groups [PTCitis (+) or PTCitis (-)], and clinical and histological findings correlated with PTCitis were estimated. The primary predictor was the presence of PTCitis. The primary endpoint was the cumulative percentage of patients who developed end-stage renal disease.

Results


PTCitis was detected in 39 of 61 (63.9%) cases. Clinically, age, gender, serum C-reactive protein, kidney function, urinary protein were all insignificant between PTCitis (+) and PTCitis (-) groups. Histologically, arteritis of small artery and interstitial fibrosis were evident in PTCitis (+) group (p=0.005, p=0.033, respectively), although histological subclass type and tubular atrophy were not different. Renal survival at 6 months was 87.2% in PTCitis (+) group compared with 86.4% in PTCitis (-) group (p=0.96). When adjusted by renal function and other histologic parameters, PTCitis was not an independent predictor for renal survival (hazard ratio, 1.3; 95%confidence interval 0.3-6.1; p=0.71).

Conclusion

PTCitis may not affect renal prognosis in ANCA-associated glomerulonephritis, while PTCitis is correlated with interstitial fibrosis. The further studies of larger population would be required.