Kanai Hiroaki, Sawanobori Emi, Kobayashi Anna, Goto Miwa, Higashida Kosuke, Sugita Kanji
Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.
Pediatr Int. 2018 Jul;60(7):639-644. doi: 10.1111/ped.13576.
The aim of this study was to assess the diagnostic value of urinary fibrin/fibrinogen degradation products (uFDP) measured using an anti-fibrinogen antibody in patients with orthostatic proteinuria (OP), and their use in differentiating between OP and glomerulonephritis (GN).
uFDP were measured using first urine in the morning (supine) and non-first urine during a hospital visit (upright) and then normalized to urine creatinine (uFDP/Cr, ng/mgCr). We compared (i) OP patients (n = 16); (ii) those in remission from nephrotic syndrome (NS, n = 14) and from GN (IgA nephropathy [IgAN], n = 14; Henoch-Schönlein purpura nephritis [HSPN], n = 12); and (iii) those with active GN (IgAN, n = 12; HSPN, n = 19).
The uFDP/Cr ratio increased from supine to upright urine in patients with OP (P < 0.001), but decreased in one case. uFDP were excreted in supine urine in 94% of OP patients, with no excretion in NS remission patients or in 92% of GN remission patients (P < 0.001 for both). uFDP/Cr in supine urine was similar between the OP and active GN patients (P = 0.40), whereas proteinuria in supine urine was in the normal range in all OP patients, but was significantly higher in upright urine in the OP patients (P < 0.001). In upright urine, urinary protein/creatinine ratio was significantly lower in patients with OP than in those with active GN (P = 0.005). A uFDP/Cr ratio cut-off of 1,108 ng/mgCr in upright urine correctly differentiated OP from active GN, with a sensitivity of 87.5% and a specificity of 100%.
Comparison of uFDP levels in supine/upright urine can be reliable for diagnosing OP and for differentiating it from active GN.
本研究旨在评估使用抗纤维蛋白原抗体检测的尿纤维蛋白/纤维蛋白原降解产物（uFDP）在体位性蛋白尿（OP）患者中的诊断价值，以及其在鉴别OP与肾小球肾炎（GN）中的应用。
使用晨尿（卧位）和就诊期间的非晨尿（立位）检测uFDP，然后将其标准化为尿肌酐（uFDP/Cr，ng/mgCr）。我们比较了：（i）OP患者（n = 16）；（ii）肾病综合征（NS，n = 14）和GN（IgA肾病[IgAN]，n = 14；过敏性紫癜肾炎[HSPN]，n = 12）缓解期患者；以及（iii）活动性GN患者（IgAN，n = 12；HSPN，n = 19）。
OP患者卧位到立位尿液中uFDP/Cr比值升高（P < 0.001），但有1例降低。94%的OP患者卧位尿中排出uFDP，NS缓解期患者或92%的GN缓解期患者卧位尿中无uFDP排出（两者P均< 0.001）。OP患者与活动性GN患者卧位尿中的uFDP/Cr相似（P = 0.40），而所有OP患者卧位尿中的蛋白尿均在正常范围内，但OP患者立位尿中的蛋白尿显著更高（P < 0.001）。立位尿中，OP患者的尿蛋白/肌酐比值显著低于活动性GN患者（P = 0.005）。立位尿中uFDP/Cr比值截断值为1,108 ng/mgCr时可正确鉴别OP与活动性GN，灵敏度为87.5%，特异度为100%。
比较卧位/立位尿液中的uFDP水平对诊断OP以及将其与活动性GN鉴别具有可靠性。
