Nakamura Tsukasa, Sugaya Takeshi, Ebihara Isao, Koide Hikaru
Department of Medicine, Shinmatsudo Central General Hospital, Chiba, Japan.
Am J Nephrol. 2005 Sep-Oct;25(5):447-50. doi: 10.1159/000087826. Epub 2005 Aug 23.
Microscopic hematuria without proteinuria is a common clinical finding in cases of immunoglobulin A (IgA) nephropathy and of thin basement membrane nephropathy. Liver-type fatty acid-binding protein (L-FABP) is expressed in renal proximal tubules and is reported to be a useful marker of the progression of chronic glomerulonephritis.
To assess urinary L-FABP levels for differential diagnosis in patients with microscopic hematuria but without proteinuria.
This was a multi-center retrospective study. Thirty adult patients who underwent renal biopsy for microscopic hematuria and 20 healthy adult volunteers were included in this study. Urinary L-FABP levels were measured by enzyme-linked immunosorbent assay and compared, particularly between those diagnosed with IgA nephropathy and those diagnosed with thin basement membrane nephropathy.
Twelve (40%) patients had IgA nephropathy, 6 (20%) had thin basement membrane nephropathy and 12 (40%) had normal biopsy findings. The urinary L-FABP level was significantly higher in patients with IgA nephropathy (38.4 +/- 26.8 microg/g Cr) than in healthy subjects (5.8 +/- 4.0 microg/g Cr) (p < 0.01); however, the level in patients with thin basement membrane nephropathy or normal biopsy results was comparable to that in healthy subjects. Follow-up data were available for 11 of the 12 patients with IgA nephropathy who initially had no proteinuria. After 24 months, 4 of the 11 were found to have proteinuria, and the urinary L-FABP level had increased from 40.6 +/- 30.5 microg/g Cr to 58.8 +/- 40.5 microg/g Cr (p < 0.01).
Our data suggest that the urinary L-FABP level can be used to discriminate between IgA nephropathy and thin basement membrane nephropathy in patients with microscopic hematuria.
无蛋白尿的镜下血尿是免疫球蛋白A（IgA）肾病和薄基底膜肾病患者常见的临床发现。肝型脂肪酸结合蛋白（L-FABP）在肾近端小管中表达，据报道是慢性肾小球肾炎进展的有用标志物。
评估尿L-FABP水平在无蛋白尿的镜下血尿患者鉴别诊断中的作用。
这是一项多中心回顾性研究。本研究纳入了30例因镜下血尿接受肾活检的成年患者和20名健康成年志愿者。采用酶联免疫吸附测定法测量尿L-FABP水平并进行比较，尤其是在诊断为IgA肾病的患者和诊断为薄基底膜肾病的患者之间。
12例（40%）患者患有IgA肾病，6例（20%）患有薄基底膜肾病，12例（40%）活检结果正常。IgA肾病患者的尿L-FABP水平（38.4±26.8μg/g肌酐）显著高于健康受试者（5.8±4.0μg/g肌酐）（p<0.01）；然而，薄基底膜肾病患者或活检结果正常的患者的水平与健康受试者相当。12例最初无蛋白尿的IgA肾病患者中有11例有随访数据。24个月后，11例中有4例出现蛋白尿，尿L-FABP水平从40.6±30.5μg/g肌酐升至58.8±40.5μg/g肌酐（p<0.01）。
我们的数据表明，尿L-FABP水平可用于鉴别镜下血尿患者的IgA肾病和薄基底膜肾病。
