Para-capillary electron-dense deposits reduce glomerular filtration in patients with primary glomerular diseases.
BACKGROUND
Electron-dense deposits are often found around glomerular capillary lumens in patients with glomerulonephritis, forming a portion of the blood-urine barrier (BUB).


METHODS
Four hundred and four patients with primary glomerular diseases or donors for living-related kidney transplantation who underwent both percutaneous renal biopsy and renal clearance tests were included in the study. Sodium thiosulfate and paraamino hippurate double-clearance studies were performed with catheterized urinary collection. The filtration fraction (FF) was determined as follows: FF = sodium thiosulfate clearance/paraamino hippurate clearance (CPAH: ). Histomorphometric analyses were performed in 53 patients with overt para-capillary electron-dense deposits (PCEDD) by electron microscopic observations.


RESULTS
Patients with membranous nephropathy and membranoproliferative glomerulonephritis showed significantly lower levels of FF than the donors for living-rebated kidney transplantation (normal controls). FF levels were significantly lower in patients with PCEDD than in those without (P < 0.001), while the levels of mean blood pressure and CPAH: were comparable in the two groups. The PCEDD/BUB ratio demonstrated a significant negative correlation with FF (P < 0.0001; r(2) = 0.331). Patients with a ratio of 0.5 or more showed significantly lower FF levels than those with a ratio of 0.25 or less.


CONCLUSIONS
PCEDD significantly affected FF levels in patients with primary glomerular diseases. FF may not be an accurate indicator of intraglomerular blood pressure in patients with overt PCEDD.
Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences, 1-754 Asahimachi-Dori, Niigata 951-8510, Japan.
Sachiko
S
Fukase
Junichiro J
JJ
Kazama
Honami
H
Mori
Seitaro
S
Iguchi
Tetsuro
T
Takeda
Mitsuhiro
M
Ueno
Shinichi
S
Nishi
Ichiei
I
Narita
Fumitake
F
Gejyo
D000328:Adult; D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D005921:Glomerulonephritis / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007678:Kidney Glomerulus / Q000033:anatomy & histology / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011507:Proteinuria