Ifosfamide-induced renal Fanconi syndrome with associated nephrogenic diabetes insipidus in an adult patient

A case of ifosfamide-induced acute kidney injury, Fanconi syndrome, and nephrogenic diabetes insipidus

Ifosfamide, a cytotoxic antineoplastic drug, can induce rare complications of Fanconi syndrome and nephrogenic diabetes insipidus (DI). Ifosfamide-induced Fanconi syndrome tends to occur in patients with certain risk factors including young age, high cumulative ifosfamide dose, and coadministration of cisplatin. Nephrogenic DI causes polyuria from impaired urinary concentrating ability due to resistance to arginine vasopressin (AVP) at the collecting duct. These complications are serious and potentially fatal. Here, we describe a case of a middle-aged man without risk factors who was admitted for the management of acute kidney injury and electrolyte derangements after his fourth cycle of chemotherapy including ifosfamide for synovial sarcoma. He was found to have hypokalemia, hypophosphatemia, renal glycosuria, and aminoaciduria, likely from Fanconi syndrome, which were managed by electrolyte replacement therapy. In addition, polyuria and hypernatremia were considered due to nephrogenic DI, which partially responded to desmopressin treatment. This case highlights the importance of the routine electrolytes monitoring after ifosfamide treatment.

The conundrum of the complex relationship between acute kidney injury and cardiac arrhythmias

Acute kidney injury (AKI) is defined by a rapid increase in serum creatinine levels, reduced urine output, or both. Death may occur in 16%-49% of patients admitted to an intensive care unit with severe AKI. Complex arrhythmias are a potentially serious complication in AKI patients with pre-existing or AKI-induced heart damage and myocardial dysfunction, fluid overload, and especially electrolyte and acid-base disorders representing the pathogenetic mechanisms of arrhythmogenesis. Cardiac arrhythmias, in turn, increase the risk of poor renal outcomes, including AKI. Arrhythmic risk in AKI patients receiving kidney replacement treatment may be reduced by modifying dialysis/replacement fluid composition. The most common arrhythmia observed in AKI patients is atrial fibrillation. Severe hyperkalemia, sometimes combined with hypocalcemia, causes severe bradyarrhythmias in this clinical setting. Although the likelihood of life-threatening ventricular arrhythmias is reportedly low, the combination of cardiac ischemia and specific electrolyte or acid-base abnormalities may increase this risk, particularly in AKI patients who require kidney replacement treatment. The purpose of this review is to summarize the available epidemiological, pathophysiological, and prognostic evidence aiming to clarify the complex relationships between AKI and cardiac arrhythmias.

[Renal toxicity of anticancer drugs]

The renal toxicity of anticancer drugs is a clinical challenge because of the intrinsic toxicity of some anticancer drugs and because the cancer itself. Indeed, cancer patients are exposed to all types of renal disorders (obstructive, functional, organic because of radiotherapy, paraneoplastic glomerulopathy, thrombotic microangiopathy…). The therapeutic index of anticancer drugs is often narrow and the doses used for optimal efficacy are high. Improving safety requires a better dose adjustment, which depends on the correct evaluation of the renal function. Prevention remains important as the mortality associated with acute renal failure is very high.

Ifosfamide-induced nephrogenic diabetes insipidus responsive to supraphysiologic doses of intravenous desmopressin

Nephrogenic diabetes insipidus (DI) refers to the reduction in the ability of the kidney to concentrate urine, which can be caused by partial or complete resistance at the site of action of anti-diuretic hormone (ADH) in the collecting tubules. Ifosfamide-induced nephrogenic DI typically occurs concomitantly in patients who have other signs of tubular toxicity consistent with Fanconi syndrome including glucosuria, aminoaciduria, and hypophosphatemia. We present a case of a 36-year-old female with recurrent synovial cell sarcoma of the pleural membranes, treated with ifosfamide-based chemotherapy, who was admitted to the hospital for the management of polyuria, hypotension, as well as electrolyte derangements including hypokalemia, hypophosphatemia and non-anion gap metabolic acidosis, 1 week after receiving a cumulative ifosfamide dose of 7.5 g/m². Nephrogenic DI was indicated by polyuria as well as a urine osmolality to plasma osmolality ratio of less than 1.5 following a trial of intravenous desmopressin, but the patient’s acute kidney injury on presentation precluded the early employment of thiazides and non-steroidal anti-inflammatory drugs (NSAIDs). Instead, the patient’s polyuria and urine osmolality improved only after the administration of repetitive supraphysiologic doses of intravenous desmopressin. Our case reiterates that patients with non-hereditary nephrogenic DI may have partial rather than complete resistance to ADH and highlights that desmopressin may be considered in patients with ifosfamide-induced nephrogenic DI to prevent severe volume depletion, especially in patients who have persistent symptomatic polyuria despite maintaining a careful fluid balance and pharmacological therapy with NSAIDs and diuretics, or if the patient’s clinical condition precludes the use of these strategies.

Bendamustine-induced nephrogenic diabetes insipidus - A case report

INTRODUCTION

In patients with relapsed or refractory lymphoma, high-dose chemoimmunotherapy with subsequent autologous hematopoietic cell transplantation (HCT) is a standard of care. Bendamustine, an alkylating agent, is used in the BeEAM (bendamustine, etoposide, cytarabine, melphalan) protocol for conditioning therapy before autologous HCT in patients with relapsed or refractory lymphoma who are eligible for transplant. There is no consensus regarding an optimal salvage regimen and the approach varies according to toxicity.

CASE REPORT

We present a case of partial nephrogenic diabetes insipidus after receiving bendamustine, as part of the BeEAM protocol.Management and outcome: The patient was managed with parenteral fluid administration and intranasal desmopressin before the condition resolved on its own.

DISCUSSION

We summarize published reports of bendamustine-induced diabetes insipidus.

Renal Tubular Acidosis and Management Strategies: A Narrative Review

Renal tubular acidosis (RTA) occurs when the kidneys are unable to maintain normal acid−base homeostasis because of tubular defects in acid excretion or bicarbonate ion reabsorption. Using illustrative clinical cases, this review describes the main types of RTA observed in clinical practice and provides an overview of their diagnosis and treatment. The three major forms of RTA are distal RTA (type 1; characterized by impaired acid excretion), proximal RTA (type 2; caused by defects in reabsorption of filtered bicarbonate), and hyperkalemic RTA (type 4; caused by abnormal excretion of acid and potassium in the collecting duct). Type 3 RTA is a rare form of the disease with features of both distal and proximal RTA. Accurate diagnosis of RTA plays an important role in optimal patient management. The diagnosis of distal versus proximal RTA involves assessment of urinary acid and bicarbonate secretion, while in hyperkalemic RTA, selective aldosterone deficiency or resistance to its effects is confirmed after exclusion of other causes of hyperkalemia. Treatment options include alkali therapy in patients with distal or proximal RTA and lowering of serum potassium concentrations through dietary modification and potential new pharmacotherapies in patients with hyperkalemic RTA including newer potassium binders.

Renal and Hepatic Health After Childhood Cancer

Childhood cancer survivors (CCSs) are at risk for renal and hepatic complications related to curative cancer treatments. Although acute renal and hepatic toxicities of cancer treatments are well described, data regarding long-term and late-occurring sequelae or their associations with acute sequelae are less robust. This article highlights the literature on the prevalence of and risk factors for late renal and hepatic toxicity in CCSs. Studies investigating these outcomes are needed to inform surveillance practices and the development of future frontline cancer treatment protocols.

The growing pains of ifosfamide

Ifosfamide is a commonly used chemotherapeutic known to have numerous adverse kidney manifestations. In this issue of Clinical Kidney Journal, Ensergueix et al. report a multicentric observational retrospective French study on 34 adult patients with tubular dysfunction and /or kidney dysfunction following ifosfamide treatment. Of these patients, 18% had isolated proximal tubular dysfunction, 14% had isolated acute kidney injury (AKI), 18% had isolated chronic kidney disease (CKD) and 50% had a combination of proximal tubular dysfunction and AKI. Concomitant treatment with cisplatin was identified as a risk factor for the development of AKI, and cisplatin and age were associated with estimated glomerular filtration rate at last follow-up. Interestingly, the cumulative dose of ifosfamide was not associated with renal outcomes. This report highlights the need for additional studies on the prevalence, spectrum and management of ifosfamide-associated nephrotoxicity and clearly demonstrates that patients who received ifosfamide should be followed long term to detect proximal tubular dysfunction and CKD early.

Proximal renal tubular acidosis with and without Fanconi syndrome

Proximal renal tubular acidosis (RTA) is caused by a defect in bicarbonate (HCO₃⁻) reabsorption in the kidney proximal convoluted tubule. It usually manifests as normal anion-gap metabolic acidosis due to HCO₃⁻ wastage. In a normal kidney, the thick ascending limb of Henle’s loop and more distal nephron segments reclaim all of the HCO₃⁻ not absorbed by the proximal tubule. Bicarbonate wastage seen in type II RTA indicates that the proximal tubular defect is severe enough to overwhelm the capacity for HCO₃⁻ reabsorption beyond the proximal tubule. Proximal RTA can occur as an isolated syndrome or with other impairments in proximal tubular functions under the spectrum of Fanconi syndrome. Fanconi syndrome, which is characterized by a defect in proximal tubular reabsorption of glucose, amino acids, uric acid, phosphate, and HCO₃⁻, can occur due to inherited or acquired causes. Primary inherited Fanconi syndrome is caused by a mutation in the sodium-phosphate cotransporter (NaP_i-II) in the proximal tubule. Recent studies have identified new causes of Fanconi syndrome due to mutations in the EHHADH and the HNF4A genes. Fanconi syndrome can also be one of many manifestations of various inherited systemic diseases, such as cystinosis. Many of the acquired causes of Fanconi syndrome with or without proximal RTA are drug-induced, with the list of causative agents increasing as newer drugs are introduced for clinical use, mainly in the oncology field.

Partial Fanconi Syndrome Induced by Ifosfamide

Several commonly used chemotherapeutic agents, antibiotics, antivirals, and antiepileptic medications can cause partial or full Fanconi syndrome, disorders which can generally be described as transport defects in the proximal renal tubule, associated with non-anion gap metabolic acidosis. Fanconi syndrome is underreported and therefore often missed in the clinical setting. Herein, we present a case report that details the course of a 64-year-old female with a history of stage IV undifferentiated pleomorphic sarcoma who after her sixth chemotherapeutic cycle (adriamycin, ifosfamide, and mesna) developed severe hypokalemia, hypophosphatemia, and proteinuria without glycosuria, eventually diagnosed with partial Fanconi syndrome. The aim of this report is to highlight the importance of routine serum and urine monitoring in patients undergoing therapy with potentially nephrotoxic agents to avoid potentially fatal renal nephrotoxicity, including partial and full Fanconi syndrome.

Ifosfamide-induced Fanconi syndrome with diabetes insipidus

Ifosfamide-induced Fanconi syndrome is a rare complication that typically occurs in young patients due to a cumulative dose of ifosfamide > 40-60 g/m(2), a reduction in kidney mass, or concurrent cisplatin treatment. It is usually characterized by severe and fatal progression accompanied by type II proximal renal tubular dysfunction, as evidenced by glycosuria, proteinuria, electrolyte loss, and metabolic acidosis. Diabetes insipidus is also a rare complication of ifosfamide-induced renal disease. We herein describe a case involving a 61-year-old man who developed ifosfamide-induced Fanconi syndrome accompanied by diabetes insipidus only a few days after the first round of chemotherapy. He had no known risk factors. In addition, we briefly review the mechanisms and possible therapeutic options for this condition based on other cases in the literature. Patients who receive ifosfamide must be closely monitored for renal impairment to avoid this rare but fatal complication.

Proximal renal tubular acidosis: a not so rare disorder of multiple etiologies

Proximal renal tubular acidosis (RTA) (Type II RTA) is characterized by a defect in the ability to reabsorb HCO₃ in the proximal tubule. This is usually manifested as bicarbonate wastage in the urine reflecting that the defect in proximal tubular transport is severe enough that the capacity for bicarbonate reabsorption in the thick ascending limb of Henle's loop and more distal nephron segments is overwhelmed. More subtle defects in proximal bicarbonate transport likely go clinically unrecognized owing to compensatory reabsorption of bicarbonate distally. Inherited proximal RTA is more commonly autosomal recessive and has been associated with mutations in the basolateral sodium-bicarbonate cotransporter (NBCe1). Mutations in this transporter lead to reduced activity and/or trafficking, thus disrupting the normal bicarbonate reabsorption process of the proximal tubules. As an isolated defect for bicarbonate transport, proximal RTA is rare and is more often associated with the Fanconi syndrome characterized by urinary wastage of solutes like phosphate, uric acid, glucose, amino acids, low-molecular-weight proteins as well as bicarbonate. A vast array of rare tubular disorders may cause proximal RTA but most commonly it is induced by drugs. With the exception of carbonic anhydrase inhibitors which cause isolated proximal RTA, drug-induced proximal RTA is associated with Fanconi syndrome. Drugs that have been recently recognized to cause severe proximal RTA with Fanconi syndrome include ifosfamide, valproic acid and various antiretrovirals such as Tenofovir particularly when given to human immunodeficiency virus patients receiving concomitantly protease inhibitors such as ritonavir or reverse transcriptase inhibitors such as didanosine.

Fanconi's syndrome and nephrogenic diabetes insipidus in an adult treated with ifosfamide

Fanconi's syndrome is a serious condition characterized by type II proximal renal tubular dysfunction, with urinary loss of glucose, amino acids, phosphate, bicarbonate, and potassium. Ifosfamide-induced Fanconi's syndrome is reported in about 1.4-5% of children being treated for solid tumors, yet only a few cases have been reported in adults. We describe a 54-year-old man who came to the hospital with symptoms of neutropenic fever 4 days after his fourth cycle of ifosfamide and doxorubicin treatment for recurrent sarcoma with metastases to the lung. During admission, he was noted to have severe renal tubular dysfunction; ifosfamide-induced nephrogenic diabetes insipidus and Fanconi's syndrome were suspected. He received supportive therapy that resulted in incomplete resolution of signs and symptoms. The patient was discharged after a 5-day hospital stay when his white blood cell count increased from 0.1-2.5 × 10(3) /mm(3) and his fever had resolved. Use of the Naranjo adverse drug reaction probability scale indicated a probable relationship (score of 7) between the patient's development of diabetes insipidus and Fanconi's syndrome and his use of ifosfamide. This dual diagnosis of diabetes insipidus and Fanconi's syndrome in an adult makes this case unusual, as well as therapeutically challenging. We conducted a review of the existing literature regarding ifosfamide-induced Fanconi's syndrome and describe the proposed mechanisms and therapeutic options. This case suggests that patients treated with ifosfamide should be monitored closely for renal function to identify, and perhaps prevent, these rare adverse events. Preliminary animal models show promise for adding N-acetylcysteine to ifosfamide treatment, but more research is necessary before using this drug as a therapeutic option.

Pathological femoral fractures due to osteomalacia associated with adefovir dipivoxil treatment for hepatitis B: a case report

We present a case of a 62-year-old man who underwent total hip arthroplasty for treatment of pathologic femoral neck fracture associated with adefovir dipivoxil-induced osteomalacia. He had a 13-month history of bone pain involving his shoulders, hips, and knee. He received adefovir dipivoxil for treatment of lamivudine-resistant hepatitis B virus infection for 5 years before the occurrence of femoral neck fracture. Orthopedic surgeons should be aware of osteomalacia and pathological hip fracture caused by drug-induced renal dysfunction, which results in Fanconi’s syndrome.

Osteomalacia as a late metabolic complication of Ifosfamide chemotherapy in young adults: illustrative cases and review of the literature

Purpose. Ifosfamide is a drug commonly used in the management of sarcomas and other solid tumours. One potential toxicity of its use is renal tubular damage, which can lead to skeletal abnormalities; rickets in children and osteomalacia in adults. We aimed to characterise this rare complication in adults. Patients. Three illustrative patient cases treated in our institution are presented. All were treated for sarcoma, and received varying doses of ifosfamide during their therapy. Methods. We performed a review of the literature on the renal tubular and skeletal complications of ifosfamide in adults. Papers were identified by searches of PubMed using the terms "osteomalacia," "nephrotoxicity," "Fanconi syndrome," "ifosfamide," and "chemotherapy" for articles published between 1970 and 2006. Additional papers were identified from review of references of relevant articles. Results. There are only four case reports of skeletal toxicity secondary to ifosfamide in adults; the majority of data refer to children. Risk factors for development of renal tubular dysfunction and osteodystrophy include platinum chemotherapy, increasing cumulative ifosfamide dose, and reduced nephron mass. The natural history of ifosfamide-induced renal damage is variable, dysfunction may not become apparent until some months after treatment, and may improve or worsen with time. Discussion. Ifosfamide-induced osteomalacia is seldom described in adults. Clinicians should be vigilant for its development, as timely intervention may minimise complications.

Idiopathic Fanconi's syndrome with nephrogenic diabetes insipidus in a child who presented as vitamin D resistant rickets--a case report and review of literature

Fanconi's syndrome is a complex of multiple tubular dysfunctions of proximal tubular cells occurring alone or in association with a variety of inherited (primary) or acquired (secondary) disorders. It is characterized by aminoaciduria, normoglycemic glycosuria, tubular proteinuria without hematuria, metabolic acidosis without anion gap and excessive urinary excretion of phosphorous, calcium, uric acid, bicarbonate, sodium, potassium and magnesium. Diabetes insipidus is a disease of collecting tubules and a child mainly presents with dehydration and hypernatremia. We report the first case of idiopathic Fanconi's syndrome along with nephrogenic diabetes insipidus (NDI) in a child who presented to us as resistant rickets. Medline search did not reveal any case of nephrogenic diabetes insipidus associated with idiopathic Fanconi's syndrome. We hypothesized that the NDI may be due to severe hypokalemia induced tubular dysfunction. The child was treated for hypophosphatemic rickets with severe metabolic acidosis and the treatment for NDI was also given. Now he has healed rickets and normal blood pH, sodium and osmolarity.

Fanconi's Syndrome Associated with Prolonged Adefovir Dipivoxil Therapy in a Hepatitis B Virus Patient

Adefovir dipivoxil (ADV) is commonly used as an antiviral agent in the treatment of chronic hepatitis B or human immunodeficiency virus infection. Nephrotoxicity has been shown to occur at daily dosages of 60-120 mg. Fanconi's syndrome is a generalized dysfunction of the renal proximal tubular cells, which is usually accompanied by complications. Here we report a case of Fanconi's syndrome in a chronic hepatitis B patient who had been treated with a prolonged regimen of ADV at 10 mg/day. A 47-year-old man complained of severe back and chest-wall pain. He had chronic hepatitis B and had been treated with ADV at a daily dose of 10 mg for 38 months. He was hospitalized because of severe bone pain, and laboratory and radiologic findings suggested a diagnosis of Fanconi's syndrome with osteomalacia. After discontinuation of the ADV, he recovered and was discharged from hospital. His laboratory findings had normalized within 2 weeks. This case indicates that Fanconi's syndrome can be acquired by a chronic hepatitis B patient taking ADV at a conventional dosage of 10 mg/day. Therefore, patients treated with long-term ADV should be checked regularly for the occurrence of ADV-induced Fanconi's syndrome.

Acquired Fanconi syndrome after treatment with capecitabine, irinotecan, and bevacizumab

OBJECTIVE

To describe a case of acquired Fanconi syndrome after treatment with capecitabine, irinotecan, and bevacizumab.

CASE SUMMARY

A 77-year-old female with metastatic colon cancer presented with vomiting and diarrhea. The patient had been diagnosed with stage IIIC (T3, N2, M0) colon cancer 18 months earlier and was initially treated with FOLFOX6 (regimen of oxaliplatin, fluorouracil, and leucovorin) after her hemicolectomy. She was switched to a capecitabine/oxaliplatin regimen after 4 cycles due to central access problems. She did well until 10 months after her cancer diagnosis, when metastasis was discovered. She was started on reduced doses of capecitabine, irinotecan, and bevacizumab. After her eleventh cycle, she presented to the hospital with the above symptoms. Laboratory test results showed hypokalemia, hypocalcemia, hypophosphatemia, and hypouricemia. The patient had not been started on any new medications other than chemotherapy for over 1 year. The electrolyte derangements were new, since the patient had laboratory values checked every 3 weeks. Despite daily intravenous replacements, the electrolyte abnormalities persisted. Laboratory evaluations demonstrated the presence of euglycemic glucosuria and a high fractional excretion of phosphorus in the setting of hypophosphatemia. Fanconi syndrome was confirmed by demonstration of aminoaciduria.

DISCUSSION

Fanconi syndrome is a disorder characterized by proximal tubular dysfunction resulting in electrolyte wasting. In the acquired form, medications and multiple myeloma are the most common causes. Based on the Naranjo probability scale, a drug was the probable cause of Fanconi syndrome in our patient. However, because multiple drugs were involved, it was not possible to determine which one was the culprit.

CONCLUSIONS

This is the first case of Fanconi syndrome reported after the administration of capecitabine, irinotecan, and bevacizumab. More studies are needed to confirm this association.

Endocrine sequelae of cancer and cancer treatments

INTRODUCTION

Exposure to cancer and its treatments, including chemotherapy and radiotherapy, may result in late adverse effects including endocrine dysfunction. Endocrine disorders are the most commonly reported long-term complications of cancer treatment, especially by adult survivors of childhood cancers. This review will explore the endocrinologic adverse effects from non-endocrine cancer therapies.

METHODS

Searches including various Internet-based medical search engines such as PubMed, Medline Plus, and Google Scholar were conducted for published articles.

RESULTS

One hundred sixty-nine journal articles met the inclusion criteria. They included case reports, systematic analyses, and cohort reports. Endocrine disorders including hypothalamus dysfunction, hypopituitarism, syndrome of inappropriate anti-diuretic hormone secretion, diabetes insipidus, growth hormone disorders, hyperprolactinemia, gonadotropin deficiency, serum thyroid hormone-binding protein abnormalities, hypothyroidism, hyperthyroidism, hypomagnesium, hypocalcemia, hyperparathyroidism, hyperparathyroidism, adrenal dysfunction, gonadal dysfunction, hypertriglyceridemia, hypercholesterolemia, diabetes mellitus, and glycosuria were identified and their association with cancer therapies were outlined.

DISCUSSION/CONCLUSIONS

The journal articles have highlighted the association of cancer therapies, including chemotherapy and radiotherapy, with endocrine dysfunction. Some of the dysfunctions were more often experienced than others. Especially in patients treated with radiotherapy, some endocrinologic disorders were progressive in nature.

IMPLICATIONS FOR CANCER SURVIVORS

Recognition and awareness of endocrine sequelae of cancer treatments may permit for early detection and appropriate follow-up care for cancer survivors, thus improving their overall health and quality of life.

Combined renal tubular acidosis and diabetes insipidus in hematological disease

BACKGROUND

A 39-year-old male with multiple myeloma was admitted for treatment with melphalan and autologous stem cell reinfusion. He presented with hypokalemia and hyperchloremic non-anion-gap metabolic acidosis with a high urinary pH. He also had hypomagnesemia, hypophosphatemia, hypouricemia, proteinuria and glucosuria. The patient subsequently developed polyuria with a low urine osmolality, hypernatremia and, finally, acute renal failure.

INVESTIGATIONS

Physical examination, blood and urine analyses, kidney biopsy and tonicity balance.

DIAGNOSIS

Fanconi syndrome with proximal (type II) renal tubular acidosis caused by myeloma kidney. Renal tubular acidosis was complicated by probable nephrogenic diabetes insipidus and acute renal failure.

MANAGEMENT

Potassium supplementation, sodium bicarbonate therapy, intravenous fluid therapy and dialysis.

Osteomalacia due to chemotherapy-induced Fanconi syndrome in an adult patient

BACKGROUND

Chemotherapy-induced Fanconi syndrome is a dangerous condition that could lead to severe electrolyte disturbances and rarely to osteomalacia.

CASE

A patient treated with ifosfamide for a metastatic cervix squamous-cell carcinoma was admitted for diffuse, symmetric bilateral pain in bones and articulations. The diagnosis work-up revealed that she suffered from osteomalacia due to a chemotherapy-induced Fanconi syndrome. The patient recovered completely with oral calcitriol supplements.

CONCLUSIONS

This very rare chemotherapy-complication suggests that detection of potential tubular dysfunction, by regular serum electrolyte monitoring of patients receiving ifosfamide, may be a reasonable approach to diagnose early chemotherapy-induced Fanconi syndrome, even in adults.

A tubule cell model for ifosfamide nephrotoxicity

Mechanisms leading to ifosfamide (IF)-induced renal damage have not been fully elucidated. Recent work suggests that localized renal tubular metabolism of IF and the production of the nephrotoxic chloroacetaldehyde may lead to nephrotoxicity. Presently no pharmacological method to reduce IF nephrotoxicity has been identified. The objectives of this study were to establish a tubule cell model for IF nephrotoxicity, to verify whether renal proximal tubular cells have the necessary cytochrome P450 (CYP) enzymes to oxidize IF, and whether they can metabolize IF to chloroacetaldehyde. CYP3A, and 2B mRNA and protein were identified in LLCPK-1 cells. The cells metabolized the R- and S-IF enantiomers to their respective 2- and 3-dechloroethylifosfamide metabolites, by-products of chloroacetal dehyde formation. Metabolite production was both time and concentration-dependent. IF did not affect cell viability. In contrast, glutathione-depleted cells showed time and dose-dependent damage. The presence of the relevant CYP enzymes in renal tubular cells along with their ability to metabolize IF to its 2- and 3-dechloroethylifosfamide metabolites suggests that nephrotoxic damage may result from the localized production of chloroacetaldehyde. Glutathione is a major defence mechanism against IF toxicity, thus pharmacological methods for replenishing intracellular glutathione may be effective in modulating IF-induced nephrotoxicity. Key words: LLCPK-1, metabolism, ifosfamide, renal, CYP3A, CYP2B.