The relation between urinary angiotensinogen and proteinuria in renal AA amyloidosis patients.

OBJECTIVE

The aim of this study was to evaluate the relationship of local intrarenal renin angiotensin system (RAS) with proteinuria in patients with renal AA amyloidosis.

METHODS

Thirty-two patients with renal AA amyloidosis (19 male, mean age: 45 ± 13 years) and sixteen healthy controls (5 male, mean age: 32 ± 5 years) were included in this study. Spot urine samples were obtained to measure urinary angiotensinogen (AGT) using human AGT-ELISA, urinary creatinine and protein levels. Logarithmic transformations of urinary AGT-creatinine ratio log(UAGT/Ucre) and urinary protein-to-creatinine ratio (UPCR) were done to obtain the normal distributions of these parameters.

RESULTS

Log(UAGT/UCre) was significantly higher in patients compared with the controls (1.88 ± 0.92 µg/g vs. 1.25 ± 0.70 µg/g; p = 0.023). Importantly a significantly positive correlation was found between log(UAGT/Ucre) and logUPCR in patients (r = 0.595, p = 0.006).

CONCLUSIONS

Urinary AGT levels are higher in renal AA amyloidosis patients than in controls. Also, there is a significant positive correlation between urinary AGT and proteinuria in renal AA amyloidosis.