Pharmacokinetics, Safety, and Efficacy of Gadopiclenol in Pediatric Patients Aged 2 to 17 Years.

OBJECTIVES: The aim of this study was to evaluate the pharmacokinetic (PK) profile, safety, and efficacy of gadopiclenol, a new high-relaxivity gadolinium-based contrast agent, in children aged 2 to 17 years. MATERIALS AND METHODS: Children scheduled to undergo contrast-enhanced magnetic resonance imaging of the central nervous system (CNS cohort) or other organs (body cohort) were included sequentially into 3 age groups (12-17, 7-11, and 2-6 years). Gadopiclenol was administered at the dose of 0.05 mmol/kg. A sparse sampling approach was applied, with 4 blood samples per child collected up to 8 hours postinjection. Population PK modeling was used for the analysis, including the CNS cohort and adult subjects from a previous study. Adverse events were recorded, and efficacy was assessed for all children. RESULTS: Eighty children were included, 60 in the CNS cohort and 20 in the body cohort. The 2-compartment model with linear elimination from the central compartment developed in adults was also suitable for children. Pharmacokinetic parameters were very similar between adults and children. Terminal elimination half-life was 1.82 hours for adults and 1.77 to 1.29 hours for age groups 12-17 to 2-6 years. The median clearance ranged from 0.08 L/h/kg in adults and 12-17 years to 0.12 L/h/kg in 2-6 years. The median central and peripheral volumes of distribution were 0.11 to 0.12 L/kg and 0.06 L/kg, respectively, for both adults and children. Simulations of plasma concentrations showed minor differences, and median area under the curve was 590 mg·h/L for adults and 582 to 403 mg·h/L for children. Two patients (2.5%) experienced nonserious adverse events considered related to gadopiclenol: a mild QT interval prolongation and a moderate maculopapular rash. Despite the limited number of patients, this study showed that gadopiclenol improved lesion detection, visualization, and diagnostic confidence. CONCLUSIONS: The PK profile of gadopiclenol in children aged 2 to 17 years was similar to that observed in adults. Thus, there is no indication for age-based dose adaptation, and comparable plasma gadopiclenol concentrations are predicted to be achieved with body weight-based dosing in this population. Gadopiclenol at 0.05 mmol/kg seems to have a good safety profile in these patients and could improve lesion detection and visualization, therefore providing better diagnostic confidence.

OBJECTIVES: The aim of this study was to evaluate the pharmacokinetic (PK) profile, safety, and efficacy of gadopiclenol, a new high-relaxivity gadolinium-based contrast agent, in children aged 2 to 17 years. MATERIALS AND METHODS: Children scheduled to undergo contrast-enhanced magnetic resonance imaging of the central nervous system (CNS cohort) or other organs (body cohort) were included sequentially into 3 age groups (12­17, 7­11, and 2­6 years). Gadopiclenol was administered at the dose of 0.05 mmol/kg. A sparse sampling approach was applied, with 4 blood samples per child collected up to 8 hours postinjection. Population PK modeling was used for the analysis, including the CNS cohort and adult subjects from a previous study. Adverse events were recorded, and efficacy was assessed for all children. RESULTS: Eighty children were included, 60 in the CNS cohort and 20 in the body cohort. The 2-compartment model with linear elimination from the central compartment developed in adults was also suitable for children. Pharmacokinetic parameters were very similar between adults and children. Terminal elimination half-life was 1.82 hours for adults and 1.77 to 1.29 hours for age groups 12­17 to 2­6 years. The median clearance ranged from 0.08 L/h/kg in adults and 12­17 years to 0.12 L/h/kg in 2­6 years. The median central and peripheral volumes of distribution were 0.11 to 0.12 L/kg and 0.06 L/kg, respectively, for both adults and children. Simulations of plasma concentrations showed minor differences, and median area under the curve was 590 mg·h/L for adults and 582 to 403 mg·h/L for children. Two patients (2.5%) experienced nonserious adverse events considered related to gadopiclenol: a mild QT interval prolongation and a moderate maculopapular rash. Despite the limited number of patients, this study showed that gadopiclenol improved lesion detection, visualization, and diagnostic confidence. CONCLUSIONS: The PK profile of gadopiclenol in children aged 2 to 17 years was similar to that observed in adults. Thus, there is no indication for age-based dose adaptation, and comparable plasma gadopiclenol concentrations are predicted to be achieved with body weight­based dosing in this population. Gadopiclenol at 0.05 mmol/kg seems to have a good safety profile in these patients and could improve lesion detection and visualization, therefore providing better diagnostic confidence.

Observational study on the incidence of nephrogenic systemic fibrosis in patients with renal impairment following gadoterate meglumine administration: the NSsaFe study.

BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a rare life-threatening condition strongly associated with the administration of gadolinium-based contrast agents in patients with severe or endstage renal impairment. PURPOSE: To prospectively determine the incidence of NSF in patients with renal impairment after administration of gadoterate meglumine. STUDY TYPE: Prospective. POPULATION: In all, 540 patients with moderate, severe, or endstage renal impairment, scheduled to undergo a routine contrast-enhanced MRI with gadoterate meglumine. Mean age was 69.7 ± 12.7 years (range: 21-95) with 58.4% of males. FIELD STRENGTH/SEQUENCE: 1.5T or 3.0T, sequence according to each site practice. ASSESSMENT: Medical history, indication(s) for current MRI and adverse events were recorded for each patient. Patients were followed up over 2 years after administration with three visits separated by at least 3 months to detect any signs/symptoms suggestive of NSF. STATISTICAL TESTS: Descriptive. RESULTS: Renal impairment was graded as moderate for 69.4% of patients, severe for 16.0% and endstage for 12.1%; 2.6% had undergone a kidney transplant. Estimated glomerular filtration rate ranged from 4 to 59 mL/min/1.73 m2 except one value of 74 mL/min/1.73 m2 in a patient with kidney transplant. Central nervous system exploration was the main MRI indication (34.7%) and mean dose injected was 0.22 ± 0.09 mL/kg. Overall, 446 patients (82.6%) attended at least one follow-up visit and completed the NSF questionnaire and 329 (60.9%) attended the 2-year visit. No suspicion of NSF was reported in all 446 patients, including 119 patients with severe or endstage renal impairment. No deaths and no adverse events were reported during the MRI examination and the usual period of follow-up after gadoterate meglumine administration. DATA CONCLUSION: No cases of NSF were observed in the 446 patients with moderate to endstage renal impairment followed up over a maximum of 2 years after injection of gadoterate meglumine. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 4 J. Magn. Reson. Imaging 2020;51:607-614.

Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease).

BACKGROUND: Infantile cortical hyperostosis (ICH)/Caffey disease is an inflammatory collagenopathy of infancy, manifested by subperiosteal bone hyperplasia. Genetically, ICH was linked with heterozygosity for an R836C mutation in the COL1A1 gene. Although an autosomal-recessive trait is also suspected, it has not been proven thus far. METHODS: A case of an infant male born to consanguineous parents is reported, presenting with classical findings, course, and clinical outcome of ICH. Whole-exome sequencing (WES) was performed in order to identify a possible underlying genetic defect. RESULTS: WES analysis revealed a novel homozygous nonsense mutation in lysine 2 of fetuin-A, encoded by the ALPHA-2-HS-GLYCOPROTEIN (AHSG) gene (c.A4T; p.K2X). Fetuin-A is an important regulator of bone remodeling and an inhibitor of ectopic mineralization. By enzyme-linked immunosorbent assay (ELISA), we show a complete deficiency of this protein in the patient's serum, compared to controls. CONCLUSION: A novel homozygous nonsense mutation in AHSG gene has been found in ICH patient with a typical phenotype, resulting in fetuin-A deficiency. This finding postulates an autosomal-recessive mode of inheritance in ICH, which, unlike the autosomal-dominant inheritance associated with COL1A1, is associated with AHSG and fetuin-A deficiency.

Efficacy of fluid loading as a countermeasure to the hemodynamic and hormonal changes of 28-h head-down bed rest.

After exposure to microgravity, or head-down bed rest (HDBR), fluid loading is often used with the intent of increasing plasma volume and maintaining mean arterial pressure during orthostatic stress. Nine men (aged 18-32 years) underwent three randomized trials with lower body negative pressure (LBNP) before and after: (1) 4-h of sitting with fluid loading (1 g sodium chloride/125 mL of water starting 2.5-h before LBNP), (2) 28-h of 6-degree HDBR without fluid loading, and (3) 28-h of 6-degree HDBR with fluid loading. LBNP was progressive from 0 to -40 mmHg. After 28-h HDBR, fluid loading did not protect against the loss of plasma volume (-280 ± 64 mL without fluid loading, -207 ± 86 with fluid loading, P = 0.472) nor did it protect against a drop of mean arterial pressure (P = 0.017) during LBNP (Post-28 h HDBR response from 0 to -40 mmHg LBNP: 88 ± 4 to 85 ± 4 mmHg without fluid loading and 93 ± 4 to 88 ± 5 mmHg with fluid loading, P = 0.557 between trials). However, fluid loading did protect against the loss of stroke volume index and central venous pressure observed after 28-h HDBR. Fluid loading also attenuated the increase of angiotensin II seen after 28-h HDBR and throughout the LBNP protocol (Post-28 h HDBR response from 0 to -40 mmHg LBNP: 16.6 ± 3.4 to 23.7 ± 5.0 pg/mL without fluid loading and 6.1 ± 0.8 to 12.2 ± 2.3 pg/mL with fluid loading, P < 0.001 between trials). Our results indicate that fluid loading did not protect against plasma volume loss due to HDBR or change blood pressure responses to LBNP. However, changes in central venous pressure, stroke volume and fluid regulatory hormones could potentially influence longer duration studies and those with more severe orthostatic stress.

Multidisciplinary design and implementation of a day program specialized for the frontotemporal dementias.

To supervise activities for patients with frontotemporal dementias presents major challenges to day programs typically equipped to care for more elderly, frail patients. In this article, we present the development and immediate outcomes of integrating a day program specialized for patients with frontal lobe disturbances into an already established day program. Planning required new collaborations between the ambulatory memory clinic and the day program staff. Immediate outcomes have included relief of burden for an under-served group of caregivers and behavioral management that more seamlessly combines strategies for medication titration, environmental adjustments, and activity participation.