Urinary fibrin/fibrinogen degradation products measured using an anti-fibrinogen antibody predict orthostatic proteinuria.

Abstract

BACKGROUND:

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).

METHODS:

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).

RESULTS:

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%.

CONCLUSION:

Comparison of uFDP levels in supine/upright urine can be reliable for diagnosing OP and for differentiating it from active GN.

• Authors: Hiroaki Kanai, Emi Sawanobori, Anna Kobayashi, Miwa Goto, Kosuke Higashida, Kanji Sugita
• Journal: Pediatrics international : official journal of the Japan Pediatric Society (Pediatr Int) Vol. 60 Issue 7 Pg. 639-644 (Jul 2018) ISSN: 1442-200X [Electronic] Australia
• PMID: 29654610 (Publication Type: Journal Article, Observational Study)
• Copyright: © 2018 Japan Pediatric Society.

Chemical References

• Fibrin Fibrinogen Degradation Products
• Fibrinogen
• Creatinine

Topics

• Adolescent
• Child
• Child, Preschool
• Creatinine (urine)
• Diagnosis, Differential
• Female
• Fibrin Fibrinogen Degradation Products (urine)
• Fibrinogen (metabolism, urine)
• Glomerulonephritis (diagnosis, urine)
• Humans
• Japan
• Male
• Posture
• Proteinuria (diagnosis, urine)
• Retrospective Studies
• Urinalysis (methods)