Scaffold protein shows promise as diabetic nephropathy marker
MedWire News: Serum allograft inflammatory factor-1 (AIF-1) could be a marker for diabetic nephropathy, show study findings.
Levels of AIF-1 were related to urinary albumin excretion (UAE) and estimated glomerular filtration rate (eGFR) in patients with Type 2 diabetes, report Michiaki Fukui (Kyoto Prefectural University of Medicine, Japan) and colleagues.
"Recent studies have identified macrophage-mediated injury as an important component in the development of diabetic nephropathy," says the team. In addition, "several studies have reported increased AIF-1 expression in activated macrophages and have implicated AIF-1 as a marker for activated macrophages."
"However, to our knowledge, there are no reports investigating the correlations between serum AIF-1 concentrations, as a marker of activated macrophages, and diabetic nephropathy," remark the researchers.
They therefore investigated the relationship between serum AIF-1 and measures of renal function in 284 outpatients with Type 2 diabetes.
As reported in Diabetes Research and Clinical Practice, serum AIF-1 was positively correlated with UAE, whereas it was inversely correlated with eGFR.
The mean AIF-1 concentration was significantly higher in patients with macroalbuminuria (>300 mg/g creatinine) than in those with microalbuminuria (30-300 mg/g creatinine) or normoalbuminuria (<30 mg/g creatinine), at 110.2 pg/mL versus 84.5 pg/mL and 75.6 pg/mL, respectively.
In addition, mean AIF-1 was significantly higher in patients who had an eGFR of less than 60 mL/min per 1.73 m2, compared with those who had an eGFR of 60-90 mL/min per 1.73 m2 or more than 90 mL/min per 1.73 m2, at respective concentrations of 99.3 pg/mL versus 40.4 pg/mL and 28.7 pg/mL, respectively.
Furthermore, multivariate analysis showed that AIF-1 significantly correlated with UAE and eGFR, even after adjustment for known risk factors for diabetic nephropathy, including duration of diabetes, body mass index, glycated hemoglobin, systolic blood pressure, serum total cholesterol, triglyceride, and smoking status.
"It is mandatory to identify the patient subpopulation at risk for diabetic nephropathy and to develop novel screening markers that predict development and progression of albuminuria," the researchers say.
Large prospective observational and interventional studies are needed to better assess whether serum AIF-1 could be such a marker, they conclude.
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By Sally Robertson