Symptomatic hypoglycemia in children receiving oral purine analogues for treatment of childhood acute lymphoblastic leukemia

Hypoglycemia Associated With PEG-asparaginase and 6-MP Therapy During Treatment of Acute Lymphoblastic Leukemia in Pediatric Patients: A Case Series

BACKGROUND

Asparaginases are a mainstay treatment for pediatric acute lymphoblastic leukemia (ALL). Recent reports identified hypoglycemia associated with asparaginases. Other reports describe hypoglycemia associated with 6-mercaptopurine (6-MP), another fundamental ALL therapy. Little is known about the risk of hypoglycemia associated with ALL therapy, an adverse event that puts children at risk of decreased level of consciousness, seizures, and possibly negative neurocognitive sequelae.

METHODS

We performed a retrospective chart review of 6 children with hypoglycemia during ALL treatment in our institution from May 2016 to August 2019. Timing and duration of hypoglycemia relative to polyethylene glycol (PEG)-asparaginase, 6-MP, and corticosteroids were determined. Laboratory values of the critical sample were collected.

RESULTS

The median age was 2.75 (interquartile range: 1.88 to 3.63) years. Three patients had trisomy 21. The onset of hypoglycemia was 5 to 19 days after the most recent PEG-asparaginase administration or 6 to 7 months after initiating daily 6-MP. Sixteen hypoglycemic events were documented, and 9/16 had a critical sample drawn. Six events were hypoketotic, associated with PEG-asparaginase. Three were ketotic, associated with 6-MP. Two patients required treatment with diazoxide and cornstarch.

CONCLUSIONS

Hypoglycemia associated with PEG-asparaginase occurred later and lasted longer than previous reports with l-asparaginase, with the likely mechanism being hyperinsulinism. 6-MP was associated with ketotic hypoglycemia.

Incidence and risk factors for hypoglycemia during maintenance chemotherapy in pediatric acute lymphoblastic leukemia

BACKGROUND

Fasting hypoglycemia is a recognized occurrence among pediatric patients with acute lymphoblastic leukemia (ALL) during maintenance therapy. Existing publications describing this finding are limited to small studies and case reports. Our objective was to determine the incidence of hypoglycemia during maintenance chemotherapy and to investigate the association of age, as well as other potential risk factors, with this outcome in pediatric patients with ALL.

PROCEDURE

This retrospective cohort study included individuals 1 to 21 years of age with ALL treated with antimetabolite-containing maintenance chemotherapy at a large children's hospital between January 2011 and December 2014. The primary endpoint was time to first documented episode of hypoglycemia during maintenance therapy, defined as single measurement of plasma glucose <60 mg/dL. Cox regression was used to evaluate the association with age and identify other potential risk factors.

RESULTS

We identified 126 eligible patients, of whom 63% were documented as White, non-Hispanic, 28% as non-White, non-Hispanic, and 9% as Hispanic. Twenty-eight children (22%) had documented hypoglycemia during maintenance therapy. Younger age at the start of maintenance and hepatotoxicity documented during chemotherapy prior to maintenance initiation were associated with hypoglycemia (adjusted HR age = 0.88; 95% CI, 0.78-0.99; adjusted HR prior hepatotoxicity = 3.50; 95% CI, 1.47-8.36).

CONCLUSIONS

Nearly one quarter of children in our cohort had hypoglycemia documented during maintenance chemotherapy. Younger age at maintenance initiation and hepatotoxicity during chemotherapy prior to maintenance initiation emerged as risk factors. These findings highlight the importance of counseling about the risk of, and monitoring for, hypoglycemia, particularly in young children.

Reducing Morning Hypoglycemia Among Children Undergoing Treatment for Acute Lymphoblastic Leukemia

PURPOSE

Hypoglycemia has been observed in children receiving acute lymphoblastic leukemia (ALL) therapy, and it can negatively affect patient outcomes. We documented a 4%-6% prevalence of hypoglycemia among patients in the two clinics in this study. We aim to reduce morning hypoglycemia in children on chemotherapy for ALL at two community pediatric oncology clinics (A and B) by 50% in 9 months.

METHODS

We used the Institute for Healthcare Improvement (IHI) Model for Improvement as the framework. Prolonged hours of fasting for procedural sedation, gaps in the caregivers' knowledge of hypoglycemia risk, and a lack of awareness of the new mercaptopurine administration guidelines were the most likely contributing factors for hypoglycemia. We developed a hypoglycemia prevention educational program for staff and caregivers followed by a knowledge assessment tool.

RESULTS

Each month, the average number of patients seen in both clinics was 43. The monthly average of blood glucose tests in these patients was 94. After implementing the intervention, the percentage of caregivers who received hypoglycemia education reached 88%. Of those, 78% scored ≥ 75% in the knowledge reassessment resurvey. The combined average hypoglycemic episodes in the two clinics decreased by 46%. A higher reduction in hypoglycemic episodes was observed in clinic A (75%) compared with clinic B (17%).

CONCLUSION

Implementing hypoglycemia education led to a significant drop in hypoglycemic episodes among children on ALL therapy. Despite using a similar approach, one of the two clinics showed a more than fourfold improvement compared with the other.

Acute Complications and Survival Analysis of Childhood Acute Lymphoblastic Leukemia: A 15-year Experience

BACKGROUND

We evaluated the acute complications that occurred during the treatment of childhood acute lymphoblastic leukemia (ALL) and documented the survival rates of children with ALL.

MATERIALS AND METHODS

We retrospectively evaluated 110 children with a diagnosis of ALL treated with the Children's Oncology Group protocol from 1999 to 2014. The demographic, clinical, and laboratory data of 110 patients and acute complications of eligible and evaluable 105 patients were recorded.

RESULTS

Of the 110 patients, 65 were male and 45 were female. The mean age at admission was 8.3 ± 5.2 years. Ninety-seven patients (88.2%) had been diagnosed with pre-B-cell ALL, 11 (10%) with T-cell ALL, 1 (0.9%) with mixed phenotype acute leukemia, and 1 (0.9%) with mature B-cell acute leukemia. Of the 110 patients, 40 (36.3%) were in the standard-risk group and 70 (63.7%) were in high-risk group. Of the 110 patients, 105 had been followed up regularly and evaluated for acute complications. Infection was the most common complication (n = 93; 88.5%), followed by gastrointestinal (n = 29; 27.6%), neurologic (n = 28; 26.6%), metabolic/endocrine (n = 16; 15.2%), drug-related hypersensitivity (n = 16; 15.2%), avascular necrosis (n = 13; 12.3%), thrombotic (n = 11; 10.4%), severe psychiatric (n = 2; 1.9%), and various other (n = 12; 11.4%) complications. Of the 110 patients, 98 were assessed in terms of survival analysis. The 5- and 10-year overall survival rates were both 85.9% (standard error [SE], 3.6%). The relapse-free survival rates at 1, 3, and 5 years were 97.9% (SE, 1.5%), 91.3% (SE, 3%), and 86.3% (SE, 3.7%), respectively.

CONCLUSION

Childhood ALL, although categorized as curable malignancy owing to the improvements in treatment strategies in recent years, can cause acute complications affecting various systems. Thus, patients should be treated and followed up by multidisciplinary medical teams with high expertise.

Severe mercaptopurine-induced hypoglycemia in acute lymphoblastic leukemia

Acute lymphoblastic leukemia maintenance chemotherapy includes mercaptopurine, a purine analog with uncommon side effects, that can be life-threatening. We describe a 7-year-old female patient with ALL that presented with altered state of consciousness after maintenance chemotherapy with methotrexate and 6-mercaptopurine, due to severe hypoglycemia with metabolic acidosis. She initiated metabolic corrections with rapid resolution of symptoms. Hypoglycemia secondary to 6-mercaptopurine is a rare and transient side effect. The cause effect relation is difficult to establish, leading to underdiagnosis. Hypoglycemia is preventable without compromising maintenance therapy efficacy.

Severe recurrent nocturnal hypoglycemia during chemotherapy with 6-mercaptopurine in a child with acute lymphoblastic leukemia

Various endocrine dysfunctions occur during chemotherapy, including hypoglycemia. However, reports of hypoglycemia associated with 6-mercaptopurine (6-MP) are rare. Herein, we report an 8-year-old boy with severe symptomatic hypoglycemia likely due to 6-MP during chemotherapy. He had been diagnosed with acute lymphoblastic leukemia 3 years previously and was in the maintenance chemotherapy period. Treatment included oral dexamethasone, methotrexate, and 6-MP, of which only 6-MP was administered daily. Hypoglycemic symptoms appeared mainly at dawn, and his serum glucose dropped to a minimum of 37 mg/dL. Laboratory findings showed nothing specific other than increased serum cortisol, free fatty acids, ketone, alanine aminotransferase, and aspartate aminotransferase. Under the hypothesis of hypoglycemia due to chemotherapy drugs, we changed the time of 6-MP from evening to morning and recommended him to ingest carbohydrate-rich foods before bedtime. Hypoglycemia improved dramatically, and there was no further episode during the remaining maintenance chemotherapy period. To the best of our knowledge, this is the first report of this type of hypoglycemia occurring in an Asian child including Korean.

6-Mercaptopurine augments glucose transport activity in skeletal muscle cells in part via a mechanism dependent upon orphan nuclear receptor NR4A3

The purine anti-metabolite 6-mercaptopurine (6-MP) is widely used for the treatment of leukemia and inflammatory diseases. The cellular effects of 6-MP on metabolism remain unknown; however, 6-MP was recently found to activate the orphan nuclear receptor NR4A3 in skeletal muscle cell lines. We have reported previously that NR4A3 (also known as NOR-1, MINOR) is a positive regulator of insulin sensitivity in adipocytes. To further explore the role of NR4A3 activation in insulin action, we explored whether 6-MP activation of NR4A3 could modulate glucose transport system activity in L6 skeletal muscle cells. We found that 6-MP increased both NR4A3 expression and NR4A3 transcriptional activity and enhanced glucose transport activity via increasing GLUT4 translocation in both basal and insulin-stimulated L6 cells in an NR4A3-dependent manner. Furthermore, 6-MP increased levels of phospho-AS160, although this effect was not modulated by NR4A3 overexpression or knockdown. These primary findings provide a novel proof of principle that 6-MP, a small molecule NR4A3 agonist, can augment glucose uptake in insulin target cells, although this occurs via both NR4A3-dependent and -independent actions; the latter is related to an increase in phospho-AS160. These results establish a novel target for development of new treatments for insulin resistance.

Continuous glucose monitoring: a valuable monitoring tool for management of hypoglycemia during chemotherapy for acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) maintenance therapy (MT) has been occasionally associated with symptomatic hypoglycemia (SH), attributed to purine analog (mercaptopurine [6-MP]). This hypoglycemia has been hypothesized to affect substrate utilization of gluconeogenic precursor alanine in the liver.

CASE REPORT

An overweight 5-year-old boy with ALL was evaluated for SH (lethargy and vomiting) that occurred 8-10 h after fasting while receiving daily 6-MP. Hypoglycemic episodes (>20 episodes per month) occurred predominantly around midmorning but not during the 5-day dexamethasone pulse. The adrenocorticotropic hormone test yielded a normal cortisol response, which ruled out pituitary adrenal suppression. A 12-h overnight fasting glucose was 49 mg/dL, with suppressed insulin response <2 IU/mL, low C-peptide of 0.5 ng/mL, high insulin-like growth factor-binding protein >160 ng/mL, high free fatty acid of 2.64 mmol/L, and negative glucagon stimulation test (change in blood glucose [BG] <5 mg/dL). These results ruled out hyperinsulinism. The patient was placed on cornstarch therapy 5 h prior to dosing with 6-MP. This treatment reduced the SH events to fewer than two episodes per month. To study the efficacy of cornstarch, the patient was fitted with the iPro™ professional continuous glucose monitoring system (CGMS) (Medtronic MiniMed, Northridge, CA) with a preset low alarm at 70 mg/dL, which was worn for a period of 5 days while the patient was on cornstarch. With 1,000 sensor reading the BG range was 65-158 mg/dL, and the percentage mean absolute difference between sensor and finger-stick BG readings (the parent monitored his BG four times a day) was 9.4%. There were no hypoglycemic episodes detected by the CGMS while the patient was on cornstarch. After the cessation of chemotherapy, a 15-h fasting study was performed, and the CGMS was placed. Results showed resolution of hypoglycemia.

CONCLUSIONS

The CGMS helped us devise an effective management plan for our patient. CGMS proved useful as an adjunct to characterize the pattern of hypoglycemia and to validate the benefit of cornstarch in hypoglycemia associated with 6-MP treatment of ALL.

Hypoglycemia and glycemic variability among children with acute lymphoblastic leukemia during maintenance therapy

Symptomatic, chemotherapy-related hypoglycemia is a rare complication associated with the administration of purine analogs. The aim of the study was to evaluate 24 h glucose variability and frequency of hypoglycemia among patients with acute lymphoblastic leukemia (ALL) during maintenance therapy (MT). Eighteen children with ALL underwent continuous glucose monitoring (CGM). The number of episodes of hypoglycemia and glucose variability were analyzed. Serum alanine aminotransferase, asparagine aminotransferase, and γ-glutamyl transferase levels were measured as liver function markers. The mean glucose level in CGM equaled 105 ± 13 mg/dL, with standard deviation (SD) 13.8 ± 6.1 mg/dL, and the mean amplitude of glycemic excursions (MAGE) equaled 44.7 ± 19.9 mg/dL. Eight patients had at least one measurement below 70 mg/dL while four patients had measurements below 50 mg/dL. Children with hypoglycemia in CGM examination had a lower median body mass index standard deviation score (BMI Z-score) (-0.65 [-0.94 to -0.27] vs. -0.14 [-0.29 to 0.35]; p = 0.05) and shorter duration of MT (6.5 [4-15] vs. 22.5 [16.5-28] weeks; p = 0.004). Glucose variability parameters were strongly correlated with BMI Z-score and liver function enzymes. Hypoglycemia, particularly at night-time, may develop as a complication of MT in children with ALL. The risk factors for low glucose level are low BMI Z-score and initiation of MT.

Symptomatic hypoglycemia: an unusual side effect of oral purine analogues for treatment of ALL

Symptomatic hypoglycemia is an unusual complication in children receiving oral purine analogues for treatment of childhood acute lymphoblastic leukemia (ALL). The exact mechanism of the hypoglycemic effect of the antimetabolic therapy remains unclear. Reduced hepatic glycogen stores or impaired hepatic glyconeogenesis may partly explain the hypoglycemia. To prevent hypoglycemia, food containing complex carbohydrates is recommended before sleep. In severe cases of hypoglycemia due to 6-mercaptopurine (6-MP), the dose can be given in the morning and if this fails 6-MP can be discontinued for a short period of time. We report a 3-year-old child who developed severe early morning hypoglycemia episodes that resolved after decreasing 6-MP while receiving non-high risk ALL therapy.

Endocrine complications in pediatric patients with acute lymphoblastic leukemia

Endocrine complications of therapy for acute lymphoblastic leukemia (ALL) are common and are potentially debilitating both during and after therapy. Growth velocity slows during therapy for ALL, especially during the first year; however, children who do not receive cranial irradiation usually reach normal adult height. While growth hormone deficiency generally occurs in patients who have received 24Gy of cranial irradiation, it may also develop in those treated with lower doses (18Gy) of cranial radiation or with only high-dose methotrexate. Obesity commonly occurs during therapy and persists after completion of therapy. Osteopenia can occur early during therapy for ALL and can persist for many years. Adrenal insufficiency should be suspected in any child who has recently received glucocorticoid therapy, and stress doses of steroid should be administered in the event of metabolic stress. Screening of urine is useful for early detection of hyperglycemia during therapy with glucocorticoids and L-asparaginase. The syndrome of inappropriate secretion of anti-diuretic hormone is usually associated with vincristine therapy and may be aggravated by concurrent use of azole antifungals. Finally, patients who have received 18 or 24Gy of cranial irradiation may have clinical or subclinical deficiencies of thyroid hormones.