title: Renal biopsy findings and clinical indicators of patients with hematuria without overt proteinuria.
abstract: BACKGROUND
  Whether to perform a renal biopsy for isolated hematuria remains a matter of controversy. We performed renal biopsy in hematuria without overt proteinuria patients and reported the proportion of glomerulonephritis, pathological activities, and statistical analysis of indicators associated with glomerulonephritis.
  
  
  METHODS
  Among 203 patients who underwent renal biopsy in Okubo Hospital, Japan, between January 2008 and October 2013, we identified 56 patients who fulfilled the criteria: (1) urine dipstick examination shows equal to or greater than ± blood on three or more visits, (2) proteinuria <0.3 g/day (g/g Cr), (3) eGFR ≧60 ml/min/1.73 m(2), and (4) no current medication for renal disease. We investigated biopsy findings and compared the clinical indicators in the IgA nephropathy (IgAN) and non-IgAN group.
  
  
  RESULTS
  The pathological diagnosis was IgAN in 35 cases (62 %), thin basement membrane disease (TBMD) in 7 (13 %), minor glomerular abnormality (MGA) in 6 (11 %), glomerular basement membrane (GBM) abnormality in 5 (9 %), and others in 3 (5 %). The histological grade of IgAN was I in 90 % and II in 10; 31 % of patients had some crescentic lesions. Comparisons between the IgAN and non-IgAN group revealed significant differences in age of onset (26 ± 13 vs. 34 ± 17 years, p = 0.04), serum IgA (340 ± 114 vs. 220 ± 101 mg/dl, p < 0.01), proteinuria (0.08 [0-0.25] vs. 0 [0-0.23] g/day [g/gCr], p < 0.01), and the presence of poikilocytes (40 vs. 10 %, p = 0.02).
  
  
  CONCLUSIONS
  The proportion of IgAN in hematuria without overt proteinuria was high and the pathological activities were variable. Patients with hematuria without overt proteinuria should continue their medical follow-up and the best timing of biopsy may be controversial for these patients who have multiple risk factors of IgAN.
authors: Department of Medicine, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. yhoshino@kc.twmu.ac.jp.
authors: Yoshie
authors: Y
authors: Hoshino
authors: Department of Nephrology, Okubo Hospital Tokyo Metropolitan Health and Medical Treatment Corporation, Tokyo, Japan.
authors: Toshie
authors: T
authors: Kaga
authors: Department of Nephrology, Okubo Hospital Tokyo Metropolitan Health and Medical Treatment Corporation, Tokyo, Japan.
authors: Yasutomo
authors: Y
authors: Abe
authors: Department of Nephrology, Okubo Hospital Tokyo Metropolitan Health and Medical Treatment Corporation, Tokyo, Japan.
authors: Mariko
authors: M
authors: Endo
authors: Department of Nephrology, Okubo Hospital Tokyo Metropolitan Health and Medical Treatment Corporation, Tokyo, Japan.
authors: Sachiko
authors: S
authors: Wakai
authors: Department of Medicine, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
authors: Ken
authors: K
authors: Tsuchiya
authors: Department of Medicine, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
authors: Kosaku
authors: K
authors: Nitta
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001706:Biopsy; D005260:Female; D050533:Glomerular Basement Membrane / Q000473:pathology; D005921:Glomerulonephritis / Q000473:pathology; D005922:Glomerulonephritis, IGA / Q000473:pathology; D006417:Hematuria / Q000473:pathology*; D006801:Humans; D007668:Kidney / Q000473:pathology*; D007678:Kidney Glomerulus / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000473:pathology*; D055815:Young Adult
keywords: Hematuria without overt proteinuria; IgA nephropathy; Renal biopsy