Cystatin C levels in patients with beta-thalassemia during deferasirox treatment.
Deferasirox (Exjade) is a once-daily, oral iron chelator approved for the treatment of transfusional iron overload. This study was conducted to analyze changes in cystatin C concentration, an endogenous marker of glomerular filtration rate (GFR), in patients with thalassemia receiving daily deferasirox therapy over a period of at least 9 months. One hundred and fifty beta-thalassemia patients were treated with deferasirox at doses of 20-40 mg/kg/day for 9 consecutive months. Cystatin C concentrations were measured at regular intervals and GFR was calculated according to the cystatin C-based prediction equation. Plasma concentrations of NGAL protein and NT-proBNP were also monitored as indicators of renal function and LVEF, respectively. Serum ferritin concentration was also measured to assess iron overload. Throughout the 9 months of deferasirox treatment cystatin C concentration remained stable (p>0.850). The baseline cystatin C mean values were 0.97+/-0.27 mg/L and reached a maximum of 1.01+/-0.29 mg/L at 4 months of treatment. No correlation was found between cystatin C and NGAL concentrations (p>0.674). Cystatin C and NT-proBNP concentrations correlated positively with a binomial equation (p<0.004), as also did cystatin C and serum ferritin (p<0.001). These findings suggest that slight changes of cystatin C during deferasirox treatment may not reflect renal injury. However hemodynamic signals such as LVEF alterations and iron mobilization do appear to affect changes in cystatin C concentration.
Papassotiriou
Ioannis
I
Department of Clinical Biochemistry, "Aghia Sophia" Children's Hospital, Athens, Greece. biochem@paidon-agiasofia.gr
Margeli
Alexandra
A
Hantzi
Eugenia
E
Delaporta
Polyxeni
P
Sergounioti
Athanassia
A
Goussetis
Evgenios
E
Ladis
Vassilios
V
Kattamis
Antonis
A
D000209:Acute-Phase Proteins; D000293:Adolescent; D000328:Adult; D001565:Benzoates / Q000627:therapeutic use*; D002648:Child; D055316:Cystatin C / Q000097:blood*; D000077588:Deferasirox; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007502:Iron Chelating Agents / Q000627:therapeutic use*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011518:Proto-Oncogene Proteins / Q000097:blood; D014230:Triazoles / Q000627:therapeutic use*; D055815:Young Adult; D017086:beta-Thalassemia / Q000188:drug therapy*
D000209:Acute-Phase Proteins; D001565:Benzoates; D055316:Cystatin C; D007502:Iron Chelating Agents; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D010446:Peptide Fragments; D011518:Proto-Oncogene Proteins; D014230:Triazoles; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D000077588:Deferasirox