Trends in the off‐label use of β‐blockers in pediatric patients

The use of US Food and Drug Administration (FDA)‐approved drugs for the treatment of an unapproved indication or in an unapproved age group, or at doses or route of administration not indicated on the label is known as off‐label use. Off‐label use may be beneficial in circumstances when the standard‐of‐care treatment has failed, and/or no other FDA‐approved medications are available for a particular condition. In pediatric patients, off‐label use may increase the risk of adverse events as pharmacokinetic and pharmacodynamic data are limited in children. Approximately 73% of off‐label drugs currently prescribed for various conditions do not have sufficient scientific evidence for safety and efficacy. For example, β‐blockers are a class of drugs with FDA‐approval for very few indications in pediatrics but are commonly used for various off‐label indications. Interestingly, the proportion of off‐label use of β‐blockers in adults is at about 52% (66.2 million) of the total number of β‐blockers prescribed. The frequency of off‐label use of β‐blockers in children is also high with limited data on the indications as well as safety and efficacy. We present trends in off‐label use of β‐blockers in children to discuss drug safety and efficacy and include recommendations for pediatric providers.     

TCR α+β+/CD19+ cell–depleted hematopoietic stem cell transplantation for pediatric patients

TCR α⁺β⁺/CD19⁺ cell depletion is an emerging technique for ex vivo graft manipulation in HSCT. We report 20 pediatric patients who underwent TCR α⁺β⁺/CD19⁺ cell–depleted HSCT in four Australian centers. Conditioning regimen was dependent on HSCT indication, which included immunodeficiency (n = 14), Fanconi anemia (n = 3), and acute leukemia (n = 3). Donor sources were haploidentical parent (n = 17), haploidentical sibling (n = 2), or matched unrelated donor (n = 1). Mean cell dose was 8.2 × 10⁸/kg TNC, 12.1 × 10⁶/kg CD34⁺ cells, and 0.4 × 10⁵/kg TCR α⁺β⁺ cells. All patients achieved primary neutrophil and platelet engraftment, with average time to neutrophil engraftment 11 days (range 8‐22) and platelet engraftment 24 days (range 12‐69). TRM at 1 year was 15%. Rate of grade II‐IV aGVHD at 1 year was 20% with no grade III‐IV aGVHD seen. CMV reactivation occurred in 81% of CMV‐positive recipients, with one patient developing CMV disease. Average time to CD4 recovery (>400 × 10⁶/L) was 258 days. Overall survival for the cohort at 5 years was 80%. This report highlights the initial experience of TCR α⁺β⁺/CD19⁺ cell–depleted HSCT in Australian centers, with high rates of engraftment, low rates of aGVHD, and acceptable TRM.     

Effect of PMX‐DHP for sepsis due to ESBL‐producing E. coli in an extremely low‐birthweight infant

We report a case of early onset sepsis caused by (CTX for cefotaximase and M for Munich)‐type extended‐spectrum β ‐lactamase‐producing Escherichia coli (ESBL E. coli) in a preterm infant weighing 601 g. He was given meropenem and treated for endotoxin absorption with polymyxin B‐immobilized fibers with only 8 mL of priming volume. The patient survived without any short‐term neurological or respiratory sequelae. The choice of antibiotics is particularly important in seriously ill neonates with sepsis due to ESBL‐producing organisms. Polymyxin B hemoperfusion might be an innovative therapy for severe neonatal sepsis and could improve outcome even in an extremely low‐birthweight infant.     

Urinary β2‐microglobulin and bronchopulmonary dysplasia: Trends in preterm infants

Background

The developmental process of bronchopulmonary dysplasia (BPD) is not identical between very preterm infants born small for gestational age (SGA) and those born appropriate for gestational age (AGA). In this study, we compared the pattern of the inflammatory response in infants of each group, by measuring urinary β2‐microglobulin (Uβ2M) as an alternative, concise, and less‐invasive biomarker.

Methods

Uβ2M and clinical details were examined at birth and at 4 weeks of age in 146 very preterm infants.

Results

Of the 57 infants diagnosed with BPD, 18 were SGA, and 39 were AGA. Uβ2M at birth was significantly lower in SGA BPD infants than in AGA BPD infants, but it increased with time. The prevalence of chorioamnionitis (CAM) was significantly lower in SGA BPD infants than in AGA BPD infants, while that of pregnancy‐induced hypertension was the opposite.

Conclusions

Exposure to prenatal factors other than CAM may sensitize fetal lungs to become vulnerable to postnatal inflammation in very preterm SGA infants with BPD.     

Neurocognitive function in patients with β‐thalassemia major

Background: Children with β‐thalassemia major (β‐TM) have multiple risk factors for developing cognitive impairment. The aim of the present study was to evaluate cognitive function in patients with β‐TM. Methods: Twenty children with β‐TM were enrolled into the study and were compared with a control group consisting of 21 healthy children. All participants were evaluated with neuropsychological tests and event‐related potentials (ERP). Results: All of the participants had normal IQ scores, but the patient group had significantly lower full‐scale, performance, and verbal IQs compared with the control group (P < 0.05). The number of children with visuomotor dysfunction was higher in the patient group compared with the control group (P < 0.05). In the P300 test, the patient group had significantly prolonged N1, P2 and N2 latencies at the FZ, and a prolonged N1 latency at the Cz compared with the control group (P < 0.05). The patient group also had lower N1 and P3N4 amplitudes at the Fz, and lower N1, N1P2 and P3N4 amplitudes at the Cz when compared with the control group (P < 0.05). Mismatch negativity latency and duration were longer in the patient group (P < 0.05). Conclusions: Neuropsychological tests are safe, and reliable for the diagnosis of cognitive impairment in β‐TM patients, and the use of ERP may facilitate early diagnosis. The number of β‐TM patients in the present study was limited, however, and larger numbers of patients are required in further studies.     

Liver transplantation from a deceased donor with β‐thalassemia intermedia is not contraindicated: A case report

The use of extended criteria donors who might have previously been deemed unsuitable is an option to increase the organ supply for transplantation. This report presents a pediatric case of a successful liver transplantation from a donor with β‐thalassemia intermedia. A patient, 6‐year‐old female, with a diagnosis of cryptogenic liver cirrhosis underwent deceased donor liver transplantation from a thalassemic donor. Extreme hyperferritinemia was detected shortly after transplantation. The most probable cause of hyperferritinemia was iron overload secondary to transplantation of a hemosiderotic liver. Hepatocellular injury due to acute graft rejection might have contributed to elevated ferritin levels by causing release of stored iron from the hemosiderotic liver graft. Iron chelation and phlebotomy therapies were started simultaneously in the early postoperative period to avoid iron‐related organ toxicity and transplant failure. Follow‐up with monthly phlebotomies after discharge yielded a favorable outcome with normal transplant functions. Thalassemia intermedia patients can be candidates of liver donors to decrease pretransplant waitlist mortality. After transplantation of a hemosiderotic liver, it is important to monitor the recipient in terms of iron overload and toxicity. Early attempts to lower iron burden including chelation therapy and/or phlebotomy should be considered to avoid organ toxicity and transplant failure.     

Impaired β‐cell sensitivity to glucose and maximal insulin secretory capacity in adolescents with type 2 diabetes

Elder DA, Woo JG, D’Alessio DA. Impaired β‐cell sensitivity to glucose and maximal insulin secretory capacity in adolescents with type 2 diabetes. Background: Adults with type 2 diabetes mellitus (T2DM) have broad impairments in β‐cell function, including severe attenuation of the first‐phase insulin response to glucose, and reduced β‐cell mass. In adolescents with T2DM, there is some evidence that β‐cell dysfunction may be less severe. Our objective was to determine β‐cell sensitivity to glucose and maximal insulin secretory capacity (AIR_max) in teenagers with T2DM. Methods: Fifteen adolescents with T2DM [11 F/4 M, age 18.4 ± 0.3 yr, body mass index (BMI) 39.8 ± 2.2 kg/m²] and 10 non‐diabetic control subjects (7 F/3 M, age 17.4 ± 0.5 yr, BMI 41.5 ± 2.2 kg/m²) were studied. T2DM subjects had a mean duration of diabetes of 48.8 ± 6.4 months, were treated with conventional therapies, and had good metabolic control [hemoglobin A1c (HbA1c) 6.7 ± 1.2%]. Insulin and C‐peptide were determined before and after a graded glucose infusion and after intravenous arginine at a whole blood glucose level of ≥22 mM. Results: The insulin response to increasing plasma glucose concentrations was blunted in the diabetic compared with control subjects (34.8 ± 11.9 vs. 280.5 ± 57.8 pmol/mmol; p < 0.0001), and AIR_max was also significantly reduced in the diabetic group (1868 ± 330 vs. 4445 ± 606; p = 0.0005). Conclusion: Even adolescents with well‐controlled T2DM have severe impairments of insulin secretion. These data support β‐cell dysfunction as central in the pathogenesis of T2DM in young people, and indicate that these abnormalities can develop over a period of just several years.