The questioning for routine monthly monitoring of proteinuria in patients with β-thalassemia on deferasirox chelation.
BACKGROUND
Iron chelation therapy is one of the mainstays of the management of the patients with β-thalassemia (BT) major. Deferasirox is an oral active iron chelating agent. Proteinuria is one of the potential renal adverse effects of deferasirox, and monthly follow-up for proteinuria is suggested by Food and Drug Administration and European Medicine Agency.


METHODS
We aimed to investigate the necessity for monthly monitoring for proteinuria among patients with BT on deferasirox. A retrospective laboratory and clinic data review was performed for patients with BT major or intermedia who were treated with deferasirox chelation therapy. All patients were monitored for proteinuria for every 3 or 4 weeks after the initiation of deferasirox with serum creatinine and spot urine protein/creatinine ratios.


RESULTS
The median follow-up time of the 37 (36 BT major and one BT intermedia) patients was 44 months. Seven patients (18.9%) developed significant proteinuria (ratio ≥0.8). Of the 1490 measurements, 12 tests (0.8%) were proteinuric. Urine proteinuria resolved in all of the patients during the follow-up. The risk of proteinuria was higher at ages below a cut-off point of 23 years (p = 0.019). Patients, who were on deferasirox at doses above a cut-off dose of 29 mg/kg/day, were found to have higher risk of proteinuria development (p = 0.004).


CONCLUSIONS
Proteinuria resolves without any complication or major intervention according to our results. Potentially more risky groups (age below 23 years old and receivers above a dose of 29 mg/kg/day) might be suggested to be followed monthly, besides monitoring all of the patients.
a Division of Pediatric Hematology , Hacettepe University , Ankara , Turkey.
Turan
T
Bayhan
a Division of Pediatric Hematology , Hacettepe University , Ankara , Turkey.
Şule
Ş
Ünal
b Faculty of Medicine , Hacettepe University , Ankara , Turkey.
Ozan
O
Ünlü
b Faculty of Medicine , Hacettepe University , Ankara , Turkey.
Hakan
H
Küçüker
b Faculty of Medicine , Hacettepe University , Ankara , Turkey.
Anıl Doğukan
AD
Tutal
c Department of Biostatistics , Hacettepe University , Ankara , Turkey.
Erdem
E
Karabulut
a Division of Pediatric Hematology , Hacettepe University , Ankara , Turkey.
Fatma
F
Gümrük
D000293:Adolescent; D000328:Adult; D001565:Benzoates / Q000009:adverse effects* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D000077588:Deferasirox; D005260:Female; D006801:Humans; D008297:Male; D011507:Proteinuria / Q000139:chemically induced / Q000175:diagnosis / Q000652:urine*; D012189:Retrospective Studies; D014230:Triazoles / Q000009:adverse effects* / Q000627:therapeutic use; D055815:Young Adult; D017086:beta-Thalassemia / Q000097:blood / Q000188:drug therapy* / Q000652:urine*
D001565:Benzoates; D014230:Triazoles; D000077588:Deferasirox
Deferasirox; proteinuria; thalassemia