Diabetologie und Stoffwechsel 2015; 10 - P81
DOI: 10.1055/s-0035-1549587

C-terminal agrin fragment (CAF) – a potential new biomarker for prediction of diabetic kidney disease

M Roos 1, S Kopf 2, S Hettwer 3, D Oikonomou 2, M von Eynatten 1, U Heemann 1, D Steubl 1, PP Nawroth 2, A Bierhaus 2, P Humpert 4
  • 1Klinikum Rechts der Isar, Nephrologie, München, Germany
  • 2Klinik für Endokrinologie, Stoffwechsel und Klinische Chemie (Innere Medizin I), Heidelberg, Germany
  • 3Neurotune, Zürich, Switzerland
  • 4Stoffwechselzentrum Rhein-Pfalz, Mannheim, Germany

Background: Serum creatinine and albuminuria fail in terms of sensitivity and specifity as prognostic biomarkers for monitoring renal damage and the progression to diabetic nephropathy. C-terminal agrin fragment (CAF, 22 kDa) is a promising new biomarker for kidney function. This study evaluated the usefulness of CAF as a biomarker for diabetic nephropathy in type 2 diabetes patients.

Methods: CAF serum and urine levels were assessed by ELISA in a cross-sectional setting in 138 patients with type 2 diabetes with diabetic nephropathy and 26 healthy controls. Associations of CAF with renal function and metabolic markers were studied.

Results: CAF serum levels significantly correlated with creatinine

(r = 0.56) and with estimated GFR (r =-0.65). Diabetes patients with advanced renal failure (stages 2+3) showed significantly higher serum CAF values compared to patients with stage 1 (63.8pM vs. 95.0pM vs. 128.4pM; p < 0.001). Patients with macroalbuminuria had significant higher serum CAF levels compared to patients with normalbuminuria or microalbuminuria (80.4pM vs. 76.1pM vs. 108.1pM; p < 0.01). Multivariable linear regression analysis showed significant independent associations of increased CAF levels with decreased estimated GFR (β=-0.60, T =-9.1, p < 0.001). Multivariable linear regression analysis showed a highly significant positive association of urinary CAF with urinary high molecular adiponectin excretion (β= 0.63, T = 7.2, p < 0.001), a novel marker for metabolic renal damage.

Conclusions: Serum CAF could be a valuable biomarker of renal function while urinary CAF could be an indicator of the degree renal damage Future prospective studies will have to clarify the importance of CAF for the prediction of renal events.