Evaluation of serious adverse events in patients treated with protocols including methotrexate infusions

A Risk Scoring Model for High-Dose Methotrexate-Induced Liver Injury in Children With Acute Lymphoblastic Leukemia Based on Gene Polymorphism Study

A study on 70 acute lymphoblastic leukemia (ALL) children (age ≤16 years) treated with high-dose methotrexate (HD-MTX) in Sichuan Provincial People’s Hospital was conducted. The aim of the study was to establish a risk-scoring model to predict HD-MTX-induced liver injury, considering gene polymorphisms’ effects. Data screening was performed through t-test, chi-square test, and ridge regression, and six predictors were identified: age, MTRR_AA, MTRR_AG, SLCO1B1_11045879_CC, albumin_1 day before MTX administration, and IBIL_1 day before MTX administration (p < 0.1). Then, the risk-scoring model was established by ridge regression and evaluated the prediction performance. In a training cohort (n = 49), the area under the curve (AUC) was 0.76, and metrics including accuracy, precision, sensitivity, specificity, positive predictive value, and negative predictive value were promising (0.86, 0.81, 0.76, 0.91, 0.81, 0.88, respectively). In a test cohort (n = 21), the AUC was 0.62 and negative predictive value was 0.80; other evaluation metrics were not satisfactory, possibly due to the limited sample size. Ultimately, the risk scores were stratified into three groups based on their distributions: low- (≤48), medium- (49–89), and high-risk (>89) groups. This study could provide knowledge for the prediction of HD-MTX-induced liver injury and reference for the clinical medication.

Folinic acid over rescue of high dose methotrexate: How problematic citations conserve discredited concepts

BACKGROUND

The outdated axiom that the dose of Folinic acid (FA) rescue used after high dose Methotrexate (HDMTX) should be kept to a minimum in order to prevent a reduction of prognosis ("over rescue") continues to be expressed even though the concept has been seriously challenged. Study aim The ways "problematic citations" are used to support an old theory, such as this, was examined.

RESULTS

Ten patterns of "problematic citation" use were identified. In 8 of these patterns the articles used were scientifically sound and the problem was with the articles citing them. However in 2 other pattens, the articles and their conclusions were flawed and citing them, apparently, resulted from accepting the presented data or conclusions as sound and valid. The patterns were 1. Claims based on data that are not present in the cited article. 2. Selective inclusion of data from cited articles. 3. Citation of misleading data presented only in the abstract. 4. Reporting trends as statistically significant. 5. Copying the citations used by others without checking the article. 6. Acceptance of illusionary truth in spite of knowledge to the contrary. 7. Citation of reports not relevant to the population under discussion 8. Presenting opinions as facts without any citation. 9. Selective presentation of data sets that support the thesis while ignoring the data sets that show the opposite results. 10. Use of a title expressing what the authors intended to show but not what was found.

IMPLICATIONS

The containing acceptance of this old insupportable conjecture, in part, because of "problematic citations" has resulted in unnecessary neurocognitive damage to patients and may have resulted in the misconception that it is the outcome of HDMTX that may have lead to its abandonment in favour of more toxic therapies. Realisation that this is a significant problem in data analysis should lead authors and reviewers to be even more carefully in checking all references. The importance of high-quality reviews is clearly evident. The effect of "Canonization of false facts" is a serious impairment to the acceptance of new hypotheses that better express reality and could lead to improved treatment results. Authors are advised only to cite articles they have read in entirety not relying on the title, abstract or previous use and to check the content of citations before submission.

Neurotoxicity after high-dose methotrexate (MTX) is adequately explained by insufficient folinic acid rescue

PURPOSE

To challenge the view that the dose of folinic acid rescue after high-dose methotrexate (MTX) has no significance in the prevention of neurotoxicity and to present the minority view that neurotoxicity can be prevented by an adequate dose of folinic acid, without compromising treatment results. Several fallacies that led to the misunderstanding of post MTX neurotoxicity are presented.

METHODS

Data mining using search engines was used to find relevant publications, and an e-mail survey of more than 60 authors of articles in this field was performed. All relevant articles identified were read in their entirety.

RESULTS

Examples of clinical studies with neurotoxicity following inadequate rescue are given. Some studies demonstrated no neurotoxicity when adequate doses of folinic acid rescue were started 24-36 h after the start of HDMTX rescue even after mega doses of MTX. Rescue started after 42 h was associated with neurotoxicity except in patients with low serum MTX levels after 24 and 36 h. ALL protocols with neurotoxicity, especially BFM-like protocols, are presented. Protocol is reported in which single protocol changes prevented neurotoxicity.

CONCLUSIONS

From the published data, when folinic acid rescue is given in a sufficiently high enough dose and is started 24-36 h after the beginning of the methotrexate exposure, and virtually all forms of post MTX neurotoxicity can be prevented without compromising therapeutic results.

How long can folinic acid rescue be delayed after high-dose methotrexate without toxicity?

To determine the optimal time of folinic acid rescue after methotrexate (MTX) treatment in patients with ALL, we selected and evaluated relevant studies that included doses, rescue delay, and side effects. Rescue at 42-48 hours resulted in considerable toxicity, except when low doses of MTX were used (1 g/m(2)) or serum MTX levels remained consistently low at 24, 30, and 36 hours. Rescue started at 30-36 hours was safe. In the absence of evidence that later rescue improves prognosis, we suggest that folinic acid rescue (105 mg/m(2)) be started no later than 36 hours from the start of MTX (5-6 g/m(2)).

Challenging the clinical relevance of folinic acid over rescue after high dose methotrexate (HDMTX)

THE HYPOTHESIS

The use of adequate folinic acid rescue (in clinically relevant doses) after high dose methotrexate will prevent neurotoxicity without reducing treatment results.

METHODS

A literature search was performed to test the hypothesis that no evidence for the existence of folinic acid over-rescue of high-dose methotrexate (MTX) in clinically relevant situations exists (evidence that too much folinic acid reduced cure rate).

EMPIRICAL DATA

Examples of folinic acid over-rescue after lower doses of MTX were found and has been cited as evidence of over rescue of high dose MTX. Mega doses of folinic acid, used when toxic levels of MTX occurred, also could neutralize the MTX effect. Data were found to support the contention that higher levels of MTX require disproportionally higher folinic acid doses for rescue. Careful examination of the available studies after HDMTX yielded more convincing alternative explanations for reduction in cure rate than over rescue. Little convincing evidence for the existence of over rescue after HDMTX was found.

DISCUSSION

The rescue of high-dose MTX with an appropriate dose of folinic acid that can prevent toxicity, especially neurotoxicity, was not shown to reduce the therapeutic effect. No evidence was found that higher doses of folinic acid after high dose MTX reduces the therapeutic effect.

CONSEQUENCES OF THE HYPOTHESIS

Acceptance of the hypothesis can prevent harm being caused (especially brain damage) by reversing the trend of dose reduction in FA rescue. The recognition that the use of higher folinic acid doses is safe, can prevent neurotoxicity, and does not reduce prognosis has important implications for the development of effective non toxic treatment protocols.

Evaluation of renal function in Turkish children receiving BFM-95 therapy for acute lymphoblastic leukemia

This study examined renal function in 42 children with acute lymphoblastic leukemia (ALL) treated according to BFM-95 protocol. Fifteen (group 1) were investigated longitudinally at 3 time points: before (T1), 4 weeks after (T2), and 2-6 months after (T3) consolidation therapy with high-dose methotrexate (HDMTX). The frequency of abnormalities in glomerular and tubular tests were nil at T1 and ranged from 13 to 40% at T2 and 7 to 33% at T3 in group 1. Twenty percent of the patients (n = 10) in group 2, who were examined at a single time point 7-36 months after consolidation, had glomerular and tubular abnormalities. There was only mild tubular abnormality in 5.8% of patients (n = 17) in group 3, who were examined at a single time point a mean of 56.1 +/- 12.5 months after completion chemotherapy. These data show that consolidation therapy with HDMTX is frequently associated with acute renal toxicity in children with ALL but does not leave clinically significant late sequelae.

Methotrexate induces cell swelling and necrosis in renal tubular cells

BACKGROUND

The present study was carried out to investigate if methotrexate (MTX) has a direct lethal effect in renal tubular cells, and if so, to further clarify the mechanisms of cell death.

MATERIALS AND METHODS

Renal tubular cells (LLC-PK(1) cells) were incubated with MTX (0.01 microM, 0.1 microM, and 1 microM), either alone or in combination with 0.1 microM amiloride (Na(+)/H(+) antiporter inhibitor) or 1 microM carbachol (M-cholinergic agonist). Cell viability was then determined by means of trypan blue (TB) exclusion tests and MTT assays.

RESULTS

After 4 hr incubation with 0.1 microM MTX the number of viable cells was decreased by 18% in comparison with control cells, and the proportion of dead cells was increased by 38%. Cell death induced by MTX was time-dependent and did not show apoptotic features. On the contrary, cell swelling was discovered. This cell death was prevented by co-incubating the cells with amiloride or carbachol.

CONCLUSIONS

MTX induces cell swelling and cell death in renal tubular LLC-PK(1) cells. The tubular cell death induced by MTX is time-dependent. Cell death can be prevented by co-incubating with amiloride, thus indicating that the Na(+)/H(+) antiporter and possibly other volume regulatory factors in renal tubular cells are involved in MTX-induced renal failure.

Renal function during and after treatment for acute lymphoblastic leukemia in children

Renal function tests (cystatin C, serum and urine creatinine, creatinine clearance, serum and urine beta(2)-microglobulin, microalbuminuria, osmolality) were performed in 21 children at the diagnosis and during the treatment for acute lymphoblastic leukemia (ALL) (group I) and in 37 children (group II) treated for ALL 3.9+/-3.7 years before the study. The results were compared to 20 healthy children. Mean values of renal tests were in normal range at all points of analysis in groups I and II compared to the control group. Transitory higher cystatin C values (but in normal range) were observed after methotrexate administration and after the end of treatment. Deteriorated renal function was observed in one child during the treatment (after each protocol) and in five children treated previously for ALL. In conclusion, combined treatment for ALL is not associated with severe or long-term impairment of renal function.

Evaluation of kidney damage in patients with acute lymphoblastic leukemia in long-term follow-up: value of renal scan

In order to evaluate potential long-term kidney damage of childhood leukemia and risk factors affecting renal damage, we studied 116 children treated for acute lymphoblastic leukemia (ALL) using the St. Jude Total XI and XIII protocols in 1991-1998. The median follow-up period after the completion of treatment was 35 months. The following parameters were examined: urinalysis, urinary creatinine (Cr), calcium (Ca), phosphorus, beta2-microglobulin, glomerular filtration rate (GFR), tubular phosphorus reabsorption (TPR), and renal function tests. Radiological evaluation included renal ultrasonography (US), and renal scans with DMSA or MAG-3 were performed. Blood chemistry and renal US patients were normal in all patients except two. GFR, TPR, urinary Ca/Cr, beta2-microglobulin, and renal scan were abnormal in 19.0%, 16.4%, 13.8%, 6.0%, and 40.5% of patients, respectively. The abnormality rate in GFR was significantly higher in patients <2 years of age. TPR abnormality was found to be significantly higher in patients who did not have G-CSF. An abnormal renal scan was associated with Hb < 10 g/dL, kidney infiltration, or hypertension at presentation and also occurred patients who underwent methotrexate treatment with frequent intervals during the follow-up period. Patients should be followed-up after cessation of therapy with the conventional tests mentioned above. In case of any abnormality, further detailed tests should be performed; renal scan seems to be more predictive for renal damage.

Effects of sodium in hydration solution on plasma methotrexate concentrations following high-dose methotrexate in children with acute lymphoblastic leukemia

PURPOSE

To test whether a higher sodium dose in the hydration solution may facilitate faster methotrexate (MTX) elimination as compared with a lower sodium dose following high-dose MTX (HDMTX) treatment.

METHODS

Intravenous solutions with alternate doses of sodium (regimen A 70 mEq/l, regimen B 100 mEq/l) were given to 30 children with acute lymphoblastic leukemia in two courses of HDMTX in a randomized crossover fashion. The plasma MTX concentrations every 24 h from the beginning of MTX administration and the adverse events associated with HDMTX were compared between the two hydration regimens.

RESULTS

The plasma MTX concentrations were similar in the two hydration regimens at 24 h (A 50.9+/-7.4 vs B 40.9+/-5.4 microM, means+/- SE, P=0.17), but was significantly lower in regimen B at 48 and 72 h (A 0.65+/-0.17 vs B 0.27+/-0.03 microM, P=0.04; and A 0.14+/-0.03 vs B 0.05+/-0.01 microM, P=0.003). The time during which MTX plasma concentrations exceeded 0.1 microM was significantly longer in regimen A than in regimen B (A 3.83+/-0.18 vs B 3.13+/-0.06 days, P=0.001). The incidences of adverse events were similar between the two regimens ( P=0.78), and severe adverse events were not seen in either regimen.

CONCLUSIONS

Hydration with a higher sodium dose facilitated faster MTX elimination following HDMTX. Sodium may have a beneficial effect on MTX-induced nephrotoxicity.

Effects of high-dose methotrexate on the hemostatic system in childhood acute lymphoblastic leukemia

BACKGROUND

Thromboembolic and hemorrhagic complications are significant causes of death in patients with malignancy. These are well-known with the use of certain drugs. This study was planned to investigate whether there was any effect of high-dose methotrexate on the hemostatic system in childhood acute lymphoblastic leukemia.

PROCEDURE

To evaluate the hemostatic system, we investigated coagulation screening tests (prothrombin time, activated partial thromboplastin time, and fibrinogen), coagulation inhibitors (protein C, protein S, and antithrombin III), and fibrinolytic system (fibrin degradation products and tissue plasminogen activator). These parameters were measured in 35 cycles of high dose-methotrexate (3 g/m(2)) of 20 childhood acute lymphoblastic leukemia cases at baseline and on days 1 and 7 after the therapy.

RESULTS

We found that high-dose methotrexate administration adversely affected both the coagulation system (prolonged prothrombin time and activated partial thromboplastin time and decreased fibrinogen levels) and coagulation inhibitors (decreased protein C, protein S, antithrombin III) on day 1 after chemotherapy compared to the baseline values. The hemostatic parameters began to improve on day 7 after chemotherapy, except for fibrin degradation products. Tissue plasminogen activator levels were not changed with the therapy.

CONCLUSIONS

Coagulation cascade (prolonged prothrombin time and activated partial thromboplastin time and decreased fibrinogen) and coagulation inhibitors (decreased protein C, protein S, and antithrombin III levels) have been found to be affected by high-dose methotrexate therapy, but these transient changes did not cause clinical thromboembolic or hemorrhagic complications.

High-dose methotrexate in childhood all

An event-free survival is currently achieved in 70-80% of children diagnosed with acute lymphocytic leukemia (ALL). A decline in the long-term sequalae from therapy is a challenge at present. Due to the high incidence of central nervous system (CNS) relapse in ALL patients, cranial irradiation was introduced as a prophylactic measure in the beginning of the 1970s. Cranial irradiation, however, may cause secondary malignancies in the CNS. In recent years neurotoxicities have been demonstrated to follow cranial irradiation in a large proportion of ALL patients. Because of these deleterious effects, most ALL protocols are limited to the combination intrathecal and intravenous methotrexate as the standard for CNS prophylaxis. In the 1970s, an intermediate dose was administered, while from the 1980s a high dose of methotrexate was combined with intrathecal methotrexate. The regular methotrexate dose of later years has been in the range of 5-8 g/m2. The intravenous methotrexate dose has actually varied from 2 to 33.6 g/m2. The highest dose, 33.6 g/m2, has been without intrathecal instillation. In a study from Norway, high-dose methotrexate (6-8 g/m2) was used, and only two (2.2%) of 89 ALL cases showed CNS relapse, both of reversible kind. In the United Kingdom, a randomized controlled study was started in 1990. Results published so far are based on a segment of cases characterized by standard risk and white blood cell count below 50 x 10(9); a 4% reduction in CNS relapse was found for high-dose methotrexate in comparison to those treated only with long-term intrathecal methotrexate. The use of methotrexate unalterably warrants some precautions. Rescue therapy with folinic acid is usually started 36 h after initiating the methotrexate infusion. Steps are also taken to secure adequate intake of fluids and alkalinization of the urine. Provided irradiation is avoided, neurotoxicities rarely occur. For regular high-dose methotrexate adverse effects mostly involve mucositis and myelosuppresion.

Therapeutic drug monitoring of antimetabolic cytotoxic drugs

Therapeutic drug monitoring is not routinely used for cytotoxic agents. There are several reasons, but one major drawback is the lack of established therapeutic concentration ranges. Combination chemotherapy makes the establishment of therapeutic ranges for individual drugs difficult, the concentration-effect relationship for a single drug may not be the same as that when the drug is used in a drug combination. Pharmacokinetic optimization protocols for many classes of cytotoxic compounds exist in specialized centres, and some of these protocols are now part of large multicentre trials. Nonetheless, methotrexate is the only agent which is routinely monitored in most treatment centres. An additional factor, especially in antimetabolite therapy, is the existence of pharmacogenetic enzymes which play a major role in drug metabolism. Monitoring of therapy could include assay of phenotypic enzyme activities or genotype in addition to, or instead of, the more traditional measurement of parent drug or drug metabolites. The cytotoxic activities of mercaptopurine and fluorouracil are regulated by thiopurine methyltransferase (TPMT) and dihydropyrimidine dehydrogenase (DPD), respectively. Lack of TPMT functional activity produces life-threatening mercaptopurine myelotoxicity. Very low DPD activity reduces fluorouracil breakdown producing severe cytotoxicity. These pharmacogenetic enzymes can influence the bioavailability, pharmacokinetics, toxicity and efficacy of their substrate drugs.

Clinical and pharmacokinetic risk factors for high-dose methotrexate-induced toxicity in children with acute lymphoblastic leukemia--a logistic regression analysis

The clinical and pharmacokinetic risk factors for toxicity after high-dose methotrexate (MTX) in children with acute lymphoblastic leukemia were evaluated using a multivariate statistical analysis. Plasma samples were collected after 44 24-h infusions of MTX (5 or 8 g/m2) in 13 children (age 3.3-12.9 years) and subsequently analyzed by HPLC to determine the MTX and 7-hydroxymethotrexate (7-OHMTX) concentrations. Toxicity was evaluated according to the WHO criteria. Severe toxicity was not observed. Oral mucositis (WHO grade > or = 1) was significantly related to a high plasma MTX concentration at 28 h after starting the infusion (p = 0.013), a low ratio of plasma 7-OHMTX/MTX at 66 h after starting the infusion (p = 0.049), and a slow clearance of MTX (p = 0.048). The risk of leukopenia (WHO grade > or = 2) increased significantly with the number of courses (p = 0.02). Increasing age and a long exposure to a high MTX concentration in plasma (AUC) were significant risk factors (p = 0.047 and p = 0.009, respectively) for developing elevated liver enzymes (ALAT) (WHO grade > or = 2). This study shows how a statistical model can be used to identify clinical and pharmacokinetic factors that may influence MTX-induced toxicity. The therapeutic ratio could thereby potentially be improved.

Long-term survival and quality of life in patients treated with a national all protocol 15-20 years earlier: IDM/HDM and late effects?

In a follow-up matched control study the 93 (70.5%) survivors of 132 children treated with a national protocol for acute lymphoblastic leukemia (ALL) and 5 survivors of the other 21 cases of ALL in childhood diagnosed in the same period were evaluated. Thus it was also a population-based study. The national treatment protocol was used in the period 1975-1980. Methotrexate (MTX) infusions combined with intrathecal MTX were used as prophylaxis against neuroleukemia instead of irradiation. Neither doxorubicin (Adriamycin) nor cyclophosphamide was used in the protocol. A questionnaire covering demographic data, number of offspring, learning problems, level of athletic performance, education, and work status as well as medical information was used. Forms were received from 94 (96%) of the 98 adult surviving cases and corresponding controls in the family. Interviews were performed in the remaining four cases (4%). There were no statistical differences between the two groups with respect to physical and mental health and quality of life. Hospital records of all patients were also checked for possible late effects. There was no definite case of secondary malignant neoplasm; however, there was one case of prolactinoma and only one case of serious sequelae (hemiparesis during therapy), probably due to intrathecal and intravenous MTX.

On the prognostic value of systemic methotrexate clearance in childhood acute lymphocytic leukemia

The prognostic value of systemic methotrexate clearance (ClMTX) during high-dose therapy was evaluated in a cohort of 42 children with acute lymphocytic leukemia (ALL). As part of an extensive chemotherapy protocol, they had received a total of 293 methotrexate (MTX) infusions in the 6-8 g/m2 dose range. At the termination of the study, when they had all been followed up for 3.5 years or more, 26 of these patients were still in continuous complete remission, whereas 16 had suffered relapse. The intrapatient variability in ClMTX during the eight courses was up to six-fold. In 67% of the patients, the maximum level of ClMTX reached at least twice the minimum value. The coefficients of variation for the intra- and interindividual variability in ClMTX were 9-57% and 26-41%, respectively. The cumulative probability of relapse, estimated by the Kaplan-Meier procedure, was increased for patients with a high ClMTX during the initial treatment course, but the difference was not significant on a 5% level. There was no significant relationship between high individual median ClMTX and subsequent relapse of ALL. However, ClMTX during the initial infusion, the time-dependent mean for ClMTX, and the individual patient's median ClMTX, were significant predictors for event-free survival in a Cox proportional hazards regression analysis. The present study demonstrates gross pharmacokinetic variability and unpredictable values of ClMTX in subsequent courses after standardized administration of MTX to paediatric patients with ALL. In spite of the association between ClMTX and prognosis shown by some of the analyses, estimates of ClMTX rates may not necessarily be related to disease outcome in a way that can be exploited to the benefit of the individual patient.

Magnetic resonance imaging and neurological evaluation after treatment with high-dose methotrexate for acute lymphocytic leukaemia in young children

This study evaluates the occurrence of permanent cerebral white matter changes and neurological abnormalities in children treated at a young age for acute lymphocytic leukaemia. Our pilot treatment protocol did not include central nervous system irradiation, but intrathecal methotrexate and high-dose methotrexate infusions followed by very intensive folinic acid rescue. We examined 12 children in complete remission and off therapy 18 months to 9.5 years after their last methotrexate infusion. They were below 5 years of age at diagnosis and therefore expected to be at special risk of neurotoxic sequelae. Cerebral magnetic resonance imaging in the 11 cases thus evaluated did not reveal white matter abnormalities or other signal changes as signs of permanent treatment-related sequelae. We did not observe any pathological clinical neurological findings likely due to methotrexate.