Uroepithelial and nephrotubular toxicity in patients receiving ifosfamide/mesna: measurement of urinary N-acetyl-beta-D-glucosaminidase and beta-2-microglobulin

Failed back surgery syndrome: a new strategy by the epidural injection of MESNA

PURPOSE

Evaluate the efficacy and safety of MESNA (sodium 2-mercaptoethanesulfonate) injection into the epidural space in the FBSS.

METHODS

We designed a prospective phase II longitudinal study. Six consecutive patients were enrolled. Patients underwent one peridural injection per week for 3 weeks. NRS and ODI were investigated before and 48 h after injections, and at 1 week, 1 month and 2 months after the last procedures. Opioids intake is investigated before procedures and 1 week, 1 month and 3 months after the last procedures. Lumbosacral MRI is performed before the first procedure, at the end and 3 months after the last procedures.

RESULTS

From baseline, at 3 months, NRS in standing, sitting and lying position improved, respectively, of 34.29, 30.56 and 26.47%; ODI improved of 20.3%; the average decrease in morphine intake was 20.54%. No difference in MR images was found. Conclusions Our preliminary results suggest that MESNA might be an efficacy alternative to common practice.

Contrast Dose-to-Creatinine Clearance Ratio as a Potential Indicator of Risk for Radiocontrast-Induced Nephropathy

OBJECTIVES

Identification of risk factors is important for preventing radiocontrast-induced nephropathy (RCIN). Contrast dose and renal function have been shown in most but not all studies to be risk factors for RCIN. We are investigating the ratio of contrast dose to creatinine clearance (D/CrCL) as a risk indicator. Theory shows that the D/CrCL ratio equals the area under the concentration-time curve (AUC), an accepted measure of systemic exposure. This study investigated the correlation between calculated D/CrCL and experimentally measured AUC for the contrast agent iodixanol.

MATERIALS AND METHODS

Experimental data on AUC from a phase 1 study of iodixanol were plotted against the D/CrCL ratio and the degree of correlation was determined.

RESULTS

Experimentally determined AUC data correlate highly with the D/CrCL ratio.

CONCLUSIONS

The D/CrCL ratio is a rapid and accurate way to estimate AUC for an iodinated x-ray contrast agent without the need for multiple blood samples.

The effectiveness of sodium 2-mercaptoethane sulfonate (mesna) in reducing capsular formation around implants in a rabbit model

The development of capsular contracture is the most common complication associated with the insertion of breast implants. The authors studied the role of sodium 2-mercaptoethane sulfonate (mesna) in reduction of capsular formation in a rabbit model. Two 40-cc textured saline implants were placed dorsally into each of the 20 rabbits in the study. At the time of insertion of the implants, 10 ml of a 10% solution of mesna was instilled into one of the pockets and normal saline was instilled into the other. The implants were removed and a capsulectomy was performed at 5 months. The capsules were examined histologically for qualitative differences between the two groups. Quantitative analysis of the thickness of the capsule and the myofibroblast populations was also performed and compared between the two groups. The mean total thickness of the capsule around the implants was 496.8 microm in the mesna-treated group compared with 973.7 microm in the saline-treated group (p < 0.001). Likewise, the thickness of the myofibroblast layer was reduced in the mesna-treated group at 283.2 microm versus 555 microm in the saline-treated group (p < 0.0001). The capsules were also relatively less vascular in the mesna-treated group. Because of its ability to reduce the extent of capsular formation and to diminish development of myofibroblasts in the capsules, mesna would appear to be a useful adjunct in the prevention of capsular contracture formation.

Chemically Assisted Capsulectomy in the Rabbit Model: A New Approach

Capsular contracture remains the most common adverse sequela of aesthetic and reconstructive breast surgery when breast implants are used. Capsulectomy may be technically difficult and can result in damage to the neighboring tissues. The aim of this study was to verify the efficacy of sodium 2-mercaptoethane sulfonate (mesna) as a facilitator of periprosthetic dissection when instilled locally at the time of capsulectomy. Two 40-cc textured saline implants were placed dorsally into each of 20 rabbits. After 5 months, capsulectomy was performed after the removal of the implants. Mesna was used to highlight the junction between scar and normal tissue and to help separate the tissues during the capsulectomy in one of the two capsules in each rabbit. Saline was used for the same purpose in the other. The blood loss, duration of operation, and difficulty of dissection as experienced by the surgeon were recorded during the course of the operation. The capsules were also examined histologically for their thickness and graded according to their degree of intactness at the conclusion of the procedure. The histological grading based on the intactness of the removed capsule (p = 0.005), the operating time (p = 0.003), and the subjective evaluation of the difficulty of the procedure (p = 0.003) were significantly better in the mesna group. There was no significant difference in the blood loss between the two groups. Because of its ability as a chemical dissector, mesna may be a useful aid in capsulectomy. Clinical studies to confirm this evidence are required.

Toward proteomics in uroscopy: urinary protein profiles after radiocontrast medium administration

Previous attempts to use urinary protein profiles for diagnostic purposes have been rather disappointing with respect to their clinical validity, in part because of the insufficient reproducibility, sensitivity, and rapidity of available techniques. Therefore, a newly developed, high-throughput technique, namely surface-enhanced laser desorption/ionization (SELDI) ProteinChip array-time of flight mass spectrometry, was studied, to assess its applicability for protein profiling of urine and to exemplify its use for a group of patients receiving radiocontrast medium. Assessment of the accuracy, sensitivity, and reproducibility of SELDI in test urinary protein profiling was performed. Renal function was studied in 20 male Sprague-Dawley rats before and after intravenous administration of either 1.25 g/kg ioxilan (n = 10) or hypertonic saline solution (n = 10) as a control. Urine samples from 25 patients undergoing cardiac catheterization were obtained before, immediately after, and 6 to 12 h after the procedure. Administration of ioxilan to rats resulted in changes in the abundance of proteins of 9.9, 18.7, 21.0, and 66.3 kD. For patients, even in uncomplicated cases of radiocontrast medium infusion during cardiac catheterization, perturbations in the protein composition occurred but returned to baseline values after 6 to 12 h. Proteins with molecular masses of 9.75, 11.75, 23.5, and 66.4 kD changed in abundance. For patients with impaired renal function, these changes were not reversible within 6 to 12 h. As a proof of principle, one of the peaks, i.e., that at 11.75 kD, was identified as beta(2)-microglobulin. SELDI is a promising tool for the detection, identification, and characterization of trace amounts of proteins in urine. Even for patients without renal complications, proteins with a broad range of molecular masses either appear in or disappear from the urine. Some of these might represent markers of impending nephropathy.

Pneumoperitoneum produces reversible renal dysfunction in animals with normal and chronically reduced renal function

Laparoscopic surgery with intraperitoneal insufflation is associated with acute oliguria. Although in healthy patients, this impairment is transient and without any apparent sequelae, as the scope of laparoscopic surgery expands, subtle renal injury may become clinically significant, particularly when applications expand to patients with reduced baseline renal function. We have investigated the changes in renal function during and after pneumoperitoneum in animals with reduced renal mass to identify both acute alterations and long-term impairments, if any. Twelve swine underwent surgical reduction in renal mass to produce chronic renal insufficiency. Glomerular filtration rate (GFR) was determined by inulin clearance for each animal before and after ablation to establish the degree of renal impairment (mean 22%; range 18%-31% of normal). The animals were followed during a stepwise insufflation as a study of pneumoperitoneum-induced changes in chronic renal failure. Urine output declined dramatically (-80% at 20 mm Hg), the GFR fell (-63% at 20 mm Hg), and renal blood flow declined (mean -12%; range -9% to -19%) over the course of the test. These values did not return to baseline during a 90-minute observation period after release of the pneumoperitoneum. Acute renal failure occurred despite aggressive hydration with maintenance of central venous pressure and only modest changes in cardiac output. The animals were exposed to a 6-hour CO2 pneumoperitoneum to 20 mm Hg to model the insult of complex laparoscopy. This exposure resulted in elevation of the amount of N-methyl-beta-D-glucosaminidase being shed into the urine in addition to the previously indicated impairments. The animals were allowed to recover for 1 week, and then GFR was again measured. The GFR returned to the preexposure chronic renal failure levels for both the group as a whole and individual animals. The magnitude and duration of the alteration in urine output, GFR, and renal blood flow suggest that regulatory mechanisms rather than simple mechanical forces are involved in the acute changes. No long-term impact on renal function from the acute renal injury was identified, even in animals with existing renal insufficiency.

Nephrotoxicity of high-dose ifosfamide/carboplatin/etoposide in adults undergoing autologous stem cell transplantation

The objective of this study was to evaluate nephrotoxicity in adult patients treated with high-dose ifosfamide, carboplatin, and etoposide followed by autologous stem cell transplantation. We conducted a retrospective analysis of clinical and laboratory data from 131 patients with various malignancies who received treatment with escalating doses of ifosfamide, carboplatin, and etoposide followed by autologous stem cell transplantation as part of a phase I/II therapeutic trial. Abnormalities in glomerular filtration were evaluated by measuring peak creatinine levels and tubular dysfunction by the lowest recorded serum levels of potassium, magnesium, and bicarbonate, at different time periods after administration of ifosfamide, carboplatin, and etoposide, and after autologous stem cell transplantation. For the entire group of 131 patients, peak creatinine levels were > 1.5 mg/dL but < 3.0 mg/dL in 37% and levels were > 3.0 mg/dL in 11% at some time during their hospital stay. At the time of discharge, creatinine levels were 1.6 mg/dL to 3.0 mg/dL in 25% of patients and were > 3 mg/dL in 5%. Immediately after high-dose therapy, peak creatinine levels were significantly higher in patients receiving higher doses of ifosfamide compared to those receiving lower doses (P < 0.00001) and those receiving intermediate doses (P < 0.005). There was a dramatic decrease in serum bicarbonate, potassium, and magnesium levels immediately after chemotherapy, and they remained significantly decreased throughout the patient's hospital stay, despite massive replacement efforts (P ranging between < 0.008 and < 0.001). This is the largest adult population study documenting the incidence and severity of ifosfamide/carboplatin/etoposide-associated acute nephrotoxicity. Renal dysfunction was dose related and reversible in the majority of patients.

A prospective evaluation of ifosfamide-related nephrotoxicity in children and young adults

BACKGROUND

Ifosfamide has been associated with proximal renal tubular dysfunction resembling Fanconi-like syndrome and leading to rickets in young children. The characteristic manifestations of this nephrotoxicity include phosphaturia and hypophosphatemia, glycosuria, aminoaciduria, renal tubular acidosis, and urinary loss of low molecular weight serum proteins. However, the relationship between acute ifosfamide nephrotoxicity, which is frequently subclinical, and long term renal damage is unclear. In this prospective study, the laboratory features of ifosfamide-induced acute nephrotoxicity were characterized further and correlated with the development of chronic nephropathy.

METHODS

The renal function of newly diagnosed children and young adults with high risk sarcomas was followed during therapy with a high dose ifosfamide-containing regimen. Serum and urine were collected regularly immediately before and after 5-day cycles of ifosfamide throughout treatment for determination of the fractional excretion of electrolytes (sodium, potassium, phosphate, magnesium, calcium) and glucose and urinary excretion of amino acids and beta 2-microglobulin.

RESULTS

Significant changes in the renal threshold of phosphate excretion, the fractional excretion of calcium and glucose, and the urinary excretion of beta 2-microglobulin were observed when comparing pretreatment values with those at the end of a 5-day treatment cycle. The median renal threshold of phosphate excretion decreased from 1.22 to 0.82 mmol/L (P < 0.0001). The median fractional excretions of calcium and glucose increased from 1.05% to 1.68% (P < 0.0001) and 0.05% to 0.08% (P = 0.0006), respectively. Beta 2-microglobulin excretion increased by 70-fold from 0.02 to 1.42 mg/mmol (P < 0.0001). Except for glucose and beta 2-microglobulin excretion, renal parameters returned to baseline before the next ifosfamide treatment cycle. Acute aminoaciduria was observed in 21 of 23 patients. Chronic nephrotoxicity, as defined by the development of a Fanconi-like syndrome or chronic tubular electrolyte loss requiring oral supplementation, developed in the three patients with the highest urinary excretion of beta 2-microglobulin after ifosfamide therapy.

CONCLUSIONS

Prospectively, high dose ifosfamide was associated with a 4% incidence of Fanconi-like syndrome; however, evidence of acute reversible subclinical nephrotoxicity was observed for all patients. Severe beta 2-microglobulinuria appeared to be a prognostic laboratory indicator for the development of chronic nephrotoxicity.