title: Effect of hematuria on the outcome of immunoglobulin A nephropathy with proteinuria.
abstract: BACKGROUND
  The relationship between hematuria and histological lesions, the effect of hematuria on response to steroid therapy, and the outcome in patients with immunoglobulin A nephropathy (IgAN) remain undetermined.
  
  
  OBJECTIVE
  The aim of this study was to clarify the effect of hematuria on histological findings, response to steroid treatment, and the outcome in IgA nephropathy.
  
  
  METHODS
  Seventy-five patients with IgAN and proteinuria > 1 g/day and treated with prednisolone were divided into two groups: those with low (≤20/high-power field [HPF]) urinary red blood cell (U-RBC) counts (L-RBC group, n=55) and those with high (>20/HPF) U-RBC counts (H-RBC group, n=20). Their clinical and histological characteristics, the relationship between hematuria and histological lesions, renal outcomes, and risk factors for progression were compared.
  
  
  RESULTS
  Except for U-RBC counts, the clinical and histological findings according to the Oxford classification of the two groups were similar. U-RBC counts were not correlated with active histological lesions. Median proteinuria in both groups decreased soon after starting steroid therapy. Median U-RBC also decreased after starting steroids, and it became similar between both groups at 2 years after treatment. The 20-year renal survival rate was also similar between the H-RBC and the L-RBC group (45.2% versus 58.0%, P=0.5577). Multivariate Cox regression analysis showed that the lower estimated glomerular filtration rate (eGFR) was an independent risk factor for progression.
  
  
  CONCLUSIONS
  A higher degree of hematuria at renal biopsy in patients with IgAN was not associated with active pathological lesions, such as cellular and fibro-cellular crescents, resistance to steroid treatment and poor outcome.
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Iwasaki
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Moriyama
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kayu
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Takei
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kosaku
authors.initials: K
authors.lastname: Nitta
keywords: Hematuria; IgA nephropathy; Proteinuria; Renal function; Urinary red blood cells