Kidney Week

Abstract: FR-PO266

Ifosfamide-Induced Fanconi Syndrome: A Complication that Cannot Be Overlooked

Session Information

• Onconephrology: From AKI to CKD and Everything in Between
  November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Onconephrology

• 1700 Onconephrology

Authors

• Alves, Italo Rafael Correia, Hospital das Clinicas, Recife, Pernambuco, Brazil

Italo Rafael Correia Alves,

• Xavier, Lucas Silva, Hospital das Clinicas, Recife, Pernambuco, Brazil

Lucas Silva Xavier,

• Valenca, Andrea C.E.P, Hospital das Clinicas, Recife, Pernambuco, Brazil

Andrea C.E.P Valenca,

• Costa, Denise Maria Do Nascimento, Hospital das Clinicas, Recife, Pernambuco, Brazil

Denise Maria Do Nascimento Costa,

• Santos, Thais OC, Hospital das Clinicas, Recife, Pernambuco, Brazil

Thais OC Santos,

• Gueiros, Ana Paula, Hospital das Clinicas, Recife, Pernambuco, Brazil

Ana Paula Gueiros,

Introduction

Fanconi syndrome (FS) is a severe dysfunction of the proximal tubule, which causes urinary loss of glucose, amino acids, phosphorus, bicarbonate and potassium. Ifosfamide (IFO)-induced FS is reported in 1.4-5% of children being treated for solid tumors, but few cases have been reported in adults. We describe a case of FS in an adult who was taking IFO for sarcoma treatment.

Case Description

A male, aged 29, diagnosed with cervical fibrosarcoma at the age of 13. In September 2021, with the third recurrence of the disease, he initiated chemotherapy (CT) with IFO, vincristine and actinomycin D. On the 24^th week of CT, after 48g/m² of IFO, the patient presented muscle weakness and renal dysfunction (Cr mg/dL 1.3), and CT was suspended. In September 2022, six months after interrupting CT, he was admitted with disabling muscle weakness (unable to walk) and polyuria (8.0 L/day). Laboratory: Cr 4.2; potassium (mEq/L) 2.6, phosphorus (mg/dL) 1.7, pH 7.19, bicarbonate (mEq/L) 13, chlorine 113 mEq/L, sodium 135 mEq/L, anion gap 12; urine: density 1007, glucose 4+ (normal blood glucose), no hematuria, 24h proteinuria 1.3 g/day, potassium in isolated sample 59 mEq/L and phosphorus excretion fraction 94%. After correcting electrolytes and metabolic acidosis, the patient’s weakness improved significantly, urine output normalized and Cr was 3.2. He is currently undergoing outpatient follow-up, using chelated phosphorus, potassium citrate, sodium bicarbonate and potassium chloride. January 2023 exams: Cr 3.3, phosphorus 3.2, potassium 4.6, bicarbonate 18.

Discussion

IFO toxicity appears to be dose dependent and occurs mainly with cumulative doses greater than 45 g/m². It is believed that IFO nephrotoxicity is due to the action of metabolites, acrolein and chloroacetaldehyde in the renal tubules. It is important that oncologists and nephrologists are aware of the possibility of FS and nephrogenic diabetes insipidus with the use of IFO, so as to avoid serious and fatal complications. Our patient presented muscle weakness and altered renal function, IFO was suspended, but FS was not diagnosed at the time. We emphasize the importance of monitoring renal function and electrolytes in cancer patients undergoing CT, mainly because a wide range of old and new drugs is available.