Urinary type IV collagen in nondiabetic kidney disease.
BACKGROUND
Type IV collagen is one of the major components of basement membrane. In diabetic nephropathy, it is already known that urinary excretion of type IV collagen increases with the disease progression. However, in nondiabetic kidney disease, urinary type IV collagen (u-IVc) levels have not been extensively investigated. The aim of this study was to evaluate u-IVc levels in various nephropathies except diabetic nephropathy.


METHODS
u-IVc levels were measured cross-sectionally from 527 biopsy-proven nondiabetic renal disease patients at tertiary care hospitals by one-step sandwich enzyme immunoassay.


RESULTS
On simple regression analyses, u-IVc levels had positive correlation with age, blood pressure, urinary protein (u-Prot), urinary β(2) microglobulin, urinary N-acetyl-β-D-glucosaminidase, HbA(1)c, and selectivity index (SI), while u-IVc had negative correlation with eGFR and serum albumin. Multiple regression analyses revealed that u-IVc was positively correlated with u-Prot, HbA(1)c and SI. Among biopsy-proven nondiabetic nephropathies, elevation of u-IVc was distinctively observed in membranous nephropathy and anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis.


CONCLUSIONS
u-IVc levels were elevated with the increase in u-Prot, HbA(1)c and SI. In addition, among nondiabetic kidney disease, elevation of u-IVc was observed in patients with membranous nephropathy and ANCA, which might reflect the thickening of basement membrane or severe kidney damage.
Furumatsu
Yoshiyuki
Y
Department of Nephrology, Osaka University Graduate School of Medicine, Osaka, Japan.
Nagasawa
Yasuyuki
Y
Shoji
Tatsuya
T
Yamamoto
Ryohei
R
Iio
Kenichiro
K
Matsui
Isao
I
Takabatake
Yoshitsugu
Y
Kaimori
Jun-ya
JY
Iwatani
Hirotsugu
H
Kaneko
Tetsuya
T
Tsubakihara
Yoshiharu
Y
Imai
Enyu
E
Isaka
Yoshitaka
Y
Rakugi
Hiromi
H
D000293:Adolescent; D015415:Biomarkers / Q000652:urine; D002648:Child; D024141:Collagen Type IV / Q000652:urine*; D003430:Cross-Sectional Studies; D048909:Diabetes Complications / Q000453:epidemiology / Q000652:urine; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007674:Kidney Diseases / Q000453:epidemiology* / Q000652:urine*; D008297:Male; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
D015415:Biomarkers; D024141:Collagen Type IV