Glomerular Density and Volume in Renal Biopsy Specimens of Children with Proteinuria Relative to Preterm Birth and Gestational Age.
OBJECTIVE
A low total nephron number, which is associated with low birth weight (LBW), may indicate increased susceptibility to early-onset renal diseases in children. However, few studies have assessed renal biopsy findings in LBW children. We examined the relationship between LBW and glomerular density (GD) and/or glomerular volume (GV) in renal biopsy samples as a surrogate for total nephron number.


METHODS
Renal biopsy findings of children of LBW were compared with those of age-matched control subjects of normal birth weight (NBW) who were histopathologically diagnosed with FSGS or minimal change nephrotic syndrome (MCNS) from 1995 to 2011. The GD and GV were estimated on the basis of measurements obtained by computerized image analysis.


RESULTS
A total of 31 subjects (mean age 11 years; eight with low birth weight-FSGS [LBW-FSGS], 10 with normal birth weight-FSGS [NBW-FSGS], and 13 with normal birth weight-minimal change nephrotic syndrome [NBW-MCNS]) were analyzed. The mean birth weight of each group was 777 g (629-1000), 3110 g (2888-3358), and 3120 g (2748-3398), respectively (median [25th-75th percentile]). Age, body mass index, BP, and degrees of globally sclerotic glomeruli at biopsy were comparable between the groups. The GD was lower (LBW-FSGS, 1.4±0.6/mm2; NBW-FSGS, 3.3±1.2/mm2; and NBW-MCNS, 3.6±1.1/mm2;P<0.05) and the GV was greater (LBW-FSGS, 4.1 [3.1-5.1]×106µm3; NBW-FSGS, 1.6 [1.5-2.1]×106µm3; and NBW-MCNS, 1.3 [1.1-1.8]×106µm3[median, (25th-75th percentile)];P<0.05) in patients with LBW-FSGS than in the other patient groups. The GD showed close positive correlations with birth weight (r=0.48) and gestational age (r=0.54), independent of renal function and degree of global glomerular sclerosis.


CONCLUSIONS
A low GD together with marked glomerular enlargement characterizes renal biopsy samples of children born with a LBW at an early stage of gestation.
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Kentaro
K
Koike
Department of Pediatrics, Niigata University Medical and Dental Hospital, Niigata, Japan.
Yohei
Y
Ikezumi
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Nobuo
N
Tsuboi
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Go
G
Kanzaki
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Kotaro
K
Haruhara
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Yusuke
Y
Okabayashi
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Takaya
T
Sasaki
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Makoto
M
Ogura
Department of Pediatrics, Niigata University Medical and Dental Hospital, Niigata, Japan.
Akihiko
A
Saitoh
Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
Takashi
T
Yokoo
D000293:Adolescent; D001706:Biopsy; D001724:Birth Weight; D016022:Case-Control Studies; D002648:Child; D005260:Female; D005865:Gestational Age; D005923:Glomerulosclerosis, Focal Segmental / Q000473:pathology; D006801:Humans; D007230:Infant, Low Birth Weight; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D009402:Nephrosis, Lipoid / Q000473:pathology; D009929:Organ Size; D047928:Premature Birth / Q000473:pathology*; D011507:Proteinuria
biopsy; birth weight; blood pressure; body mass index; child; female; gestational age; glomerulosclerosis, focal segmental; humans; infant, low birth weight; infant, newborn; kidney; kidney glomerulus; nephrons; nephrosis, lipoid; pregnancy; premature birth; proteinuria; sclerosis; segmental glomerulosclerosis