Predictive ability of creatinine clearance estimate models in pediatric bone marrow transplant patients

Haematological and renal toxicity of radiation therapy in neuroblastoma paediatric patients

PURPOSE

The objective of this study was to evaluate the renal and hematologic toxicity in paediatric patients with adrenal high-risk neuroblastoma who have received radiation therapy (RT) as part of radical treatment.

MATERIAL AND METHODS

Pediatric patients diagnosed with high-risk adrenal neuroblastoma who received RT as part of the definitive treatment between January 2004 and May 2020 in a single institution were selected. Complete blood counts (CBC) and creatinine clearance (CrCl) pre-RT and post-RT were compared through the Wilcoxon signed-rank test and correlated with survival analysis by Cox regression.

RESULTS

Forty-two children with a median age of 3 years at diagnosis and 2.8 years of follow-up were selected. A significant and acute decrease in lymphocytes was found (p = 0.002) 1 month from RT. Patients with a drop higher than 50% of the previous value experimented a significant reduction in overall survival (55 vs 10%; p = 0.031). At the end of the follow-up, a significant increase in all blood counts was observed. With respect to renal function, an acute and significant decrease in CrCl was observed tin patients younger than 4 years who received RT (p = 0.013). However, it was not clinically relevant.

CONCLUSION

Our data suggest that acute lymphopenia occurs after RT and could be associated with a poorer prognosis. Other blood counts are reduced after RT and all of them are in physiological range at the end of follow-up. Our cohort presented excellent renal outcomes without any case of chronic renal dysfunction.

Renal Function Outcomes of High-risk Neuroblastoma Patients Undergoing Radiation Therapy

PURPOSE

To analyze the renal function outcomes in patients undergoing radiation therapy for neuroblastoma.

METHODS AND MATERIALS

The clinical metrics of renal function were analyzed in patients undergoing radiation therapy for high-risk neuroblastoma from 2000 to 2015. The blood urea nitrogen (BUN) and creatinine values before radiation therapy were compared with last available follow-up values and analyzed with the clinical circumstances, including follow-up length, age at primary irradiation, nephrectomy, and radiation technique. The creatinine clearance was estimated using the Shull method.

RESULTS

With a median follow-up period of 3.5 years, none of the 266 patients studied developed a chronic renal insufficiency. For all patients, the creatinine level increased from 0.44 to 0.51 mg/dL and the BUN increased from 10.53 to 15.52 mg/dL. Three patients required antihypertensive medication. The patients who underwent intensity modulated radiation therapy did not experience increased creatinine levels during the follow-up period; however, they had a reduced median follow-up length compared with patients treated with anteroposterior/posteroanterior beams (4.7 vs 3.3 years). A longer follow-up length was associated with an increased creatinine level. The preradiation therapy creatinine level increased with patient age, similar to that of the last follow-up creatinine level, suggesting that the changes in creatinine could likely be explained by physiologic increases associated with aging rather than radiation-induced renal damage. The creatinine clearance did not decrease in any circumstance.

CONCLUSIONS

The present cohort had excellent renal outcomes after radiation therapy for neuroblastoma. No patient developed chronic renal insufficiency, and the small increases in BUN and creatinine we observed correlated, as expected, with increases in patient age. The results of the present study revealed a possible advantage for intensity modulated radiation therapy in preserving renal function; however, the follow-up length is a recognized confounding variable. The kidneys are vital structures to consider when planning radiation therapy for neuroblastoma patients, and we have found encouraging evidence that modern techniques to spare them in the setting of multiple treatment-related insults have been successful.

Pharmacokinetics and pharmacodynamics of continuous-infusion meropenem in pediatric hematopoietic stem cell transplant patients

This study explored the pharmacokinetics and the pharmacodynamics of continuous-infusion meropenem in a population of pediatric hematopoietic stem cell transplant (HSCT) patients who underwent therapeutic drug monitoring. The relationship between meropenem clearance (CLM) and estimated creatinine clearance (CLCR) was assessed by nonlinear regression. A Monte Carlo simulation was performed to investigate the predictive performance of five dosing regimens (15 to 90 mg/kg of body weight/day) for the empirical treatment of severe Gram-negative-related infections in relation to four different categories of renal function. The optimal target was defined as a probability of target attainment (PTA) of ≥90% at steady-state concentration-to-MIC ratios (C SS/MIC) of ≥1 and ≥4 for MICs of up to 8 mg/liter. A total of 21 patients with 44 meropenem C SS were included. A good relationship between CLM and estimated CLCR was observed (r (2) = 0.733). Simulations showed that at an MIC of 2 mg/liter, the administration of continuous-infusion meropenem at doses of 15, 30, 45, and 60 mg/kg/day may achieve a PTA of ≥90% at a C SS/MIC ratio of ≥4 in the CLCR categories of 40 to <80, 80 to <120, 120 to <200, and 200 to <300 ml/min/1.73 m(2), respectively. At an MIC of 8 mg/liter, doses of up to 90 mg/kg/day by continuous infusion may achieve optimal PTA only in the CLCR categories of 40 to <80 and 80 to <120 ml/min/1.73 m(2). Continuous-infusion meropenem at dosages up to 90 mg/kg/day might be effective for optimal treatment of severe Gram-negative-related infections in pediatric HSCT patients, even when caused by carbapenem-resistant pathogens with an MIC of up to 8 mg/liter.

Agreement among measurements and estimations of glomerular filtration in children with cancer

BACKGROUND

Glomerular filtration is an important route of elimination for many types of chemotherapy. Accurate estimation of glomerular filtration at the bedside is essential in the management of children with cancer. Bedside formulae for the estimation of glomerular filtration have not been validated in children with cancer. We investigated the accuracy of three formulae (the original Schwartz, Counahan-Barratt, and revised Schwartz equations) against measurement of the glomerular filtration rate (GFR) in a cohort of children with cancer.

PROCEDURE

This was a retrospective review of existing data from a single institution. The electronic medical record was queried for subjects meeting inclusion criteria during a 3.5 year time frame. Bland-Altman analyses were used to assess agreement among current formulae and estimating the GFR compared to the measured, or index GFR. Logistic regression was performed to identify potential variables with an effect on the estimation of GFR.

RESULTS

None of the three estimation formulae provided a reliable estimate of the index GFR. The mean difference was lowest between the revised Schwartz and the index GFR compared to the other two formulae and the index GFR. For the original Schwartz equation, age and prior receipt of chemotherapy were significant predictors of under- and overestimation. For the revised Schwartz equation, one age group (6-12 years) and a diagnosis of neuroblastoma actively receiving chemotherapy were positive risk factors for overestimation of the GFR.

CONCLUSION

Currently available estimation formulae for GFR may not be appropriate for children with cancer.

Advances in critical care of the pediatric hematopoietic stem cell transplant patient

Hematopoietic stem cell transplant (SCT) remains a curative option for a variety of malignant and non-malignant disorders in children. Following transplant a proportion of SCT recipients become critically ill and need intensive care. Critical illness may occur in the setting of transplant complications such as graft versus host disease (GVHD), idiopathic pneumonia syndrome (IPS), veno-occlusive disease (VOD) and transplant associated thrombotic microangiopathy (TA-TMA). Hence, familiarity with recent advances in the transplant process and complications is crucial for the intensivist. This article will highlight common complications encountered in the critically ill SCT recipient.

Impact of renal function on treatment options and outcomes in advanced non-small cell lung cancer

INTRODUCTION

Certain chemotherapeutic agents commonly used for advanced non-small cell lung cancer (NSCLC) require minimum threshold renal function for administration. To determine how such requirements affect treatment options, we evaluated renal function patterns in this population.

METHODS

We performed a single-center retrospective analysis of patients treated for stage IV NSCLC from 2000 to 2007. Associations between patient characteristics, calculated creatinine clearance (CrCl), and clinical outcomes were determined using univariate and multivariate analyses, Cox proportional hazard models, and mixed model analysis.

RESULTS

298 patients (3930 creatinine measurements) were included in the analysis. Patients had a median of 5 (interquartile range [IQR] 4-18) Cr measurements. Median baseline CrCl was 96 mL/min (IQR 74-123 mL/min); median nadir CrCl was 78 mL/min (IQR 56-100mL/min). Renal function was associated with age (P<0.001), race (P=0.009), and gender (P=0.001). 23% of patients had a recorded CrCl<60 mL/min (threshold for cisplatin), with median onset 83 days after diagnosis and median time to recover to ≥60 mL/min of 27 (IQR 3-85) days; 11% of patients had a recorded CrCl<45 mL/min (threshold for pemetrexed), with median onset 122 days after diagnosis and median recovery time of 36 (IQR 3-73) days. For both thresholds, approximately 35% of patients had no documented recovery.

CONCLUSIONS

In this cohort of patients treated for stage IV NSCLC, renal function falls below commonly used thresholds for cisplatin and for pemetrexed in fewer than a quarter of patients. However, these declines may preclude administration of these drugs for prolonged periods.

Renal function after hematopoietic stem cell transplantation in children

OBJECTIVES

The aim of this study was to assess glomerular and tubular renal function after HSCT in children in a prospective trial.

METHODS

Renal function was assessed prospectively before HSCT (on day -10), on days +30, +100, and at least 6 months after transplantation in 34 patients (21 females/13 males) with a mean age of 8.2 years. The following parameters were investigated: glomerular filtration rate (GFR) by creatinine clearance (CrCl), cystatin C (CysC)-based formula and plasma clearance of radiolabeled diethylenetriaminepentaacetic acid ((99m)Tc-DTPA), urinary excretion of beta(2)-microglobulin (beta(2)M), beta-N-acetylglucosaminidase (beta-NAG), fractional excretion of sodium (FE(Na)) and fractional tubular phosphate reabsorption (TP/CrCl).

RESULTS

Nine patients (26.4%) suffered from acute renal insufficiency within the first 100 days after transplantation. All patients who developed acute renal insufficiency were treated successfully without renal replacement therapy. Age, sex, primary diagnosis, sepsis, veno-occlusive disease, acute graft versus host disease, and use of vancomycin were not significant risk factors for the development of acute renal insufficiency. The medians (99m)Tc-DTPA-based GFR of patients after HSCT showed a statistically significant decrease when compared with pre-transplant values. beta-NAG excretion was significantly elevated in the first 30 days after HSCT.

CONCLUSION

Acute and chronic renal impairment can be developed in patients who undergo HSCT even though the pre-transplant renal function is in normal limits and the conditioning regimen does not include TBI. Both glomerular and tubular renal function evaluation should be part of a long-term follow-up in children following HSCT.

Calculated versus measured creatinine clearance for dosing methotrexate in the treatment of primary central nervous system lymphoma

BACKGROUND

High-dose methotrexate (HDMTX) (>or=3 g/m2), the cornerstone of therapy for primary CNS lymphoma (PCNSL), is commonly dosed using a measured 24 h creatinine clearance (CrCl) every 2-4 weeks. Because these collections are cumbersome and at times unreliable, the use of a calculated CrCl was evaluated as a potential alternative.

METHODS

A retrospective analysis was performed on data from all 287 treatment cycles from the 25 patients with PCNSL who participated in a multi-center phase II clinical trial of HDMTX conducted by the New Approaches to Brain Tumor Therapy (NABTT) CNS Consortium.

RESULTS

The 25 patients had a median age of 61 years (range 32-75). Seventeen (68%) were men. The patients received a median of 14 (range 2-21) HDMTX treatments. For 256 of 287 treatments (89%), data were available to compare the measured and calculated (using the Cockcroft-Gault equation) CrCl. The average measured CrCl was 93 ml/min (95% CI, 89-96 ml/min), and the average calculated CrCl was 107 ml/min (95% CI, 102-112 ml/min). The Pearson correlation coefficient (r) was 0.49 (P<0.0001) between the measured and calculated CrCl. The average MTX dose determined using measured CrCl was 14.1 g (95% CI, 13.6-14.5 g), and the average MTX dose determined using calculated CrCl was 14.7 g (95% CI, 14.2-15.1 g). MTX doses based on measured and calculated CrCl were significantly correlated (r=0.72, P<0.0001). Of the 256 HDMTX treatments evaluated, 158 (62%) had reliable 48 h serum MTX levels documented. Forty-seven levels (30%) were within target range (0.3-1 micromol/l), 99 levels (62%) were below target range (<0.3 micromol/l), 12 levels (8%) were in the range associated with mild toxicity range (>1-3 micromol/l), and no levels were in the range associated with severe toxicity (>3 micromol/l). Of these 158 treatments, the use of a calculated rather than measured CrCl would have yielded an identical MTX dose for 48 treatments (30%), a higher MTX dose for 62 treatments (40%), and a lower MTX dose for 48 treatments (30%). This distribution was not significantly different among the subsets of below target, within target range, and above target MTX levels (P=0.87).

CONCLUSIONS

In this cohort of patients with PCNSL, there is significant correlation between the calculated and measured CrCl. MTX doses determined using calculated and measured CrCl are not significantly different. For these patients, there is no clear association between the method of determining CrCl and serum MTX levels. As a result, calculated CrCl is a reasonable alternative to measured CrCl in this patient population and would avoid the inconvenience and potential inaccuracies associated with measured CrCl.

Comparison of Tc-99 measurement of glomerular filtration rate vs. calculated creatinine clearance to assess renal function pretransplant in pediatric patients undergoing hematopoietic stem cell transplantation

We compared the results of Tc-99 evaluation of glomerular filtration rate (GFR) vs. the calculation of the creatinine clearance (CCrC) as a predictor for the development of renal insufficiency in pediatric patients following hematopoietic stem cell transplantation (HSCT). We reviewed 95 consecutive patients receiving autologous (n = 37) or allogeneic (n = 58) HSCT at Children's Memorial Hospital between January, 1995 and February, 1998. Diagnoses included leukemia (n = 43), solid tumor (n = 27), bone marrow failure syndrome (n = 12), non-malignant disease (n = 8), CNS tumors (n = 5) and immunodeficiency (n = 3). Tc-99 GFR was compared with a calculated creatinine clearance derived from the Schwartz formula (CCrC) prior to HSCT. These measures of renal function were compared with the patient's subsequent clinical course to determine if patients who developed renal insufficiency of sufficient magnitude as to require continuous veno-venous hemofiltration (CVVH) or dialysis, could have been identified. Overall comparison of the two methods of evaluation of renal function showed low correlation with values obtained by CCrC, which were consistently higher in most patients (r-value 0.01 in the regression analysis and a p = 0.08 95% CI -24.15 to 1.48). When stratified for age, correlation between the two methods was excellent only in children younger than 5 yr of age p = 0.02 95%, CI 0.032-0.49). Eleven patients required therapy with CVVH or dialysis but neither CCrC nor Tc-99 GFR prior to transplant predicted this event. Patients who received TBI were statistically more prone to develop renal insufficiency than those without TBI (p < 0.0001, 95% CI 0.25-0.008). Neither the Tc-99 GFR nor the CCrC was predictive of the development of renal insufficiency in HSCT patients as the majority of patients who required dialysis had normal Tc-99 GFR prior to transplant. The characteristics found in the patients who developed renal insufficiency and required dialysis include: the use of total body irradiation as part of the transplant-conditioning regimen (p < 0.0001) and the use of continuous infusion CSA (p = 0.04).

Intrahepatic arterial administration of low-dose methotrexate in patients with severe hepatic graft-versus-host disease: An open-label, uncontrolled trial

BACKGROUND

Hepatic grafr-versus-host disease (GVHD) is associated with significant morbidity and mortality. Standard therapy includes systemically administered immunosuppressive drugs. More recent reports have described catheter-directed intrahepatic arterial (IHA) delivery of low-dose methotrexate (MTX) and methylprednisolone in the treatment of corticosteroid-resistant severe hepatic GVHD.

OBJECTIVE

This article reports on MTX toxicity and the variability in plasma drug concentrations after IHA administration of low-dose MTX in patients with severe hepatic GVHD.

METHODS

In this open-label, uncontrolled pilot study, MTX and methylprednisolone were administered via the hepatic artery in patients with corticosteroid-resistant grade III or IV GVHD of the liver. Patients also received standard therapy. MTX concentrations were measured in the hepatic artery 5 and 10 minutes after injection and in peripheral venous blood at 1, 2, and 24 hours.

RESULTS

Six patients (5 males [83.3%], I female [16.7%]; median age, 32 years; range, 8-42 years) were enrolled in the study. No hepatotoxicity was observed after IHA administration of MTX. In 5 patients with normal renal function, plasma drug concentrations 24 hours after administration of MTX ranged from 0.01 to 0.12 micromol/L (mean [SD], 0.043 [0.042] micromol/L). In 1 patient with renal failure, plasma MTX concentrations were 1.0 micromol/L 24 hours after administration and 0.07 micromol/L 5 days after administration. The severe hematologic and renal toxicity observed in this patient may have contributed to his death. Adverse events in patients with GVHD and normal renal function, who had normal plasma MTX concentrations, were comparable to those that have been reported after administration of an intravenous infusion.

CONCLUSIONS

In patients with GVHD and normal renal function, IHA administration of low-dose MTX was not associated with liver or bone marrow toxicity. Further study is needed to determine the optimal protocols for treating corticosteroid-resistant hepatic GVHD.

Simple estimation of the glomerular filtration rate in sick Thai children

The objective of this study was to establish an appropriate formula for the estimation of creatinine clearance (CCr) in sick Thai children, and to evaluate the accuracy of using the Schwartz formula. Children aged between 0 and 19 years with various diseases and varying levels of renal function (but remained stable) were studied. Height in centimetres (L) and weight in kilograms (W), time of urine collection and urine volume were measured to provide urine flow (mL/min (V)) measurements. Body surface area (m2; SA) was also assessed. Quantitative urinary and plasma creatinine concentration (UCr and PCr, respectively) were determined. Creatinine clearance was calculated by using the following formula: UCr x V x 1.73/(PCr x SA). The linear association between CCr and L/PCr derived from these data was compared with the Schwartz formula by using bootstrap statistics. One-hundred and sixty children were studied. A least squares straight-line regression through the origin of CCr against L/PCr provided a good fit to the data. Our dataset revealed no evidence of an age or sex affect on the relationship. Creatinine clearance was estimated by using the following formula: 0.465 x (L/PCr), in which the calculated 95% confidence interval of the coefficient was 0.44-0.49. A comparison of this coefficient with that for the Schwartz formula for children aged > or =1 year (0.55), using 1000 bootstrapped resamples, showed an incompatibility between the two coefficients (P < 0.00005). In conclusion, we suggest estimating CCr in sick Thai children of either sex by using a modification of the Schwartz formula in which the coefficient equals 0.465.

End-stage renal disease after high-dose carboplatinum in preparation of autologous stem cell transplantation

Stem cell transplantation is one therapy employed in the management of children with high-risk solid tumors. However, this therapy is not without risk, having been associated with multiple end-organ toxicities. Both acute renal failure and chronic renal insufficiency have been reported in marrow transplant recipients, primarily in the context of the use of calcineurin inhibitors and radiation therapy. This report reviews our experience in managing an adolescent with metastatic Ewing's sarcoma who developed rapid progression to end-stage renal disease following a pretransplant conditioning regimen with high-dose carboplatinum. She had not received radiation or prior cisplatinum therapy. The possible reasons for the patient's highly unusual course and recommendations on ways to prevent this complication are discussed.

Renal function after autologous bone marrow transplantation in children: a long-term prospective study

We measured glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and the concentrating capacity of the kidneys in children after autologous BMT. Twenty-six patients had received TBI in their conditioning regimen and 14 patients had received chemotherapy only. Median follow-up was 10 years. Mean GFR before BMT was close to normal in both groups. Mean GFR decreased from 124 [CI 114,134] ml/min/1.73 m(2) before BMT to 99 [CI 82,115] ml/min/1.73 m(2) 6 months after BMT in the + TBI group (P < 0.001). There was no significant change in the -TBI group. Mean ERPF before BMT was high: 1110 [95% CI 830,1390] ml/min/1.73 m(2) in the + TBI group and 910 [CI 570,1250] ml/min/1.73 m(2) in the - TBI group. Six months after BMT, there was a tendency to a decrease in ERPF in the +TBI group, to 760 [CI 580,940] ml/min/1.73 m(2) (P = 0.064). After this initial decrease, GFR and ERPF remained essentially unchanged in both groups. The mean concentrating capacity of the kidneys was normal before and after BMT. In seven patients chronic renal impairment developed after BMT (GFR <70 ml/min/1.73 m(2)). All had received TBI. They had also received more nephrotoxic antibiotics than the other patients. We conclude that TBI was the principal cause of deterioration of renal function after BMT, possibly by limiting compensatory hyperperfusion and resulting in a fall in GFR. Antibiotic treatment may have contributed.

Renal function in long-term survivors of stem cell transplantation in childhood. A prospective trial

The aim of this prospective study was to assess glomerular and tubular renal function before, and 1 and 2 years after hematological stem cell therapy (HSCT) in children and adolescents. 137 consecutive patients undergoing HSCT, for malignant diseases, were included in a prospective trial. Forty-four patients were followed for up to 1 year after HSCT and 36 for up to 2 years, without relapse. Ninety healthy school children were used as a control group. The following parameters were investigated: inulin clearance (GFR), urinary excretion of albumin, alpha1-microglobulin (alpha1-MG), calcium, beta-N-acetylglucosaminidase (beta-NAG) and Tamm-Horsfall protein (THP), tubular phosphate reabsorption (TP/Cl(cr)) and percent reabsorption of amino acids (TAA). Significantly lower GFR was found 1 and 2 years after HSCT but within the normal range in the period before HSCT. There was no correlation between GFR within the first month after HSCT and long-term outcome of GFR. Tubular dysfunction was found in 14-45% of patients 1 and 2 years after HSCT depending on the parameter investigated. Pathological values 1 and 2 years after HSCT were found for alpha1-MG excretion in 40% and 39%, respectively, for TP/Cl(cr) in 44% and 45%, for beta-NAG in 26% and 19%. Median TP/Cl(cr) was significantly lower 2 years after HSCT than before. TAA was mildly impaired in 7/14 patients before, in 5/29 one and in 9/29 2 years after HSCT, but median TAA was within normal range at all times. The median excretion of albumin, THP and calcium was within the normal range at all investigations. No influence of ifosfamide pre-treatment on the severity of tubulopathy was found. The investigation of tubular renal function should be part of a long-term follow-up in children after HSCT.