title: Ambulatory blood pressure and tubulointerstitial injury in patients with IgA nephropathy.
abstract: BACKGROUND
  Few studies have been conducted to assess the ambulatory blood pressure (ABP) in IgA nephropathy (IgAN) patients. This study aimed to determine the relationships between ABP and renal histopathological findings assessed using the Oxford classification (OC) and the Japanese classification (JC), which have recently established histopathological criteria for IgAN.
  
  
  METHODS
  This cross-sectional study included biopsy-diagnosed IgAN patients, in whom both a renal biopsy and ABP measurement were performed. The histopathological findings were assessed using the OC and the JC and were analyzed in relation to the ABP.
  
  
  RESULTS
  A total of 111 IgAN patients were included. The score of interstitial fibrosis and tubular atrophy (T score) using the OC was a significantly associated factor with both the daytime and nighttime ABP values. In contrast, the other histopathological scores, including mesangial hypercellularity, endocapillary hypercellularity and segmental glomerulosclerosis, did not show significant associations with the ABP. The histological grade (H-grade) using the JC, which was based on the sum of injured glomeruli, was associated with the daytime ABP, but not with the nighttime ABP. The associations between the T score using the OC (%) and the daytime and nighttime ABP values were independent of age, gender, renal function, proteinuria and the use of antihypertensive medications, whereas the H-grade using the JC (%) did not show significant associations after adjusting for these clinical parameters.
  
  
  CONCLUSIONS
  These results suggest that the T score using the OC is the most relevant renal histopathological parameter associated with abnormalities of circadian blood pressure in IgAN patients.
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Haruhara
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Tsuboi
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Koike
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Kanzaki
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Okabayashi
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Miyazaki
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kawamura
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ogura
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokoo
keywords: IgA nephropathy; Oxford classification; ambulatory blood pressure; renal biopsy; tubulointerstitial fibrosis