Population pharmacokinetic analysis of sirolimus in Japanese pediatric and adult subjects receiving tablet or granule formulations.

A population pharmacokinetic (PopPK) analysis was conducted using data from 215 Japanese administered oral sirolimus (tablet and granule) including healthy subjects and patients with intractable vascular anomalies and other diseases. The analysis included neonates, infants, and adults, and identified covariates that influence sirolimus pharmacokinetics (PK). The final model was used to predict sirolimus trough concentrations for various dosing regimens and covariates of interest. The results showed that sirolimus trough concentrations were predicted to increase with higher levels of hemoglobin, and that the granule formulation had a 1.23-fold higher exposure than the tablet formulation. Coadministration of CYP3A4 inducers was found to decrease trough concentrations by 54 %. The PK simulations showed that administration of the granule formulation at doses of 0.02, 0.04, 0.06, and 0.08 mg/kg/day in ages <3 months, 3 to <6 months, 6 to <12 months, and ≥1 year, respectively, resulted in >70 % target attainment within the therapeutic trough concentration range (5-15 ng/mL). In conclusion, incorporation of time-varying covariates (body weight and age) into the PopPK model appropriately predicted sirolimus concentrations in Japanese subjects from infants to adult sub-populations. This PopPK model would therefore be able to provide a reference for clinical individualization of sirolimus dosing.

Sirolimus treatment for intractable lymphatic anomalies: an open-label, single-arm, multicenter, prospective trial.

Introduction: Intractable lymphatic anomalies (LAs) include cystic lymphatic malformation (LM; macrocystic, microcystic, or mixed), generalized lymphatic anomaly, and Gorham-Stout disease. LAs can present with severe symptoms and poor prognosis. Thus, prospective studies for treatments are warranted. We conducted a prospective clinical trial of sirolimus for intractable LAs. Methods: This was an open-label, single-arm, multicenter, prospective trial involving five institutions in Japan. All patients with LAs received oral sirolimus once daily, and the dose was adjusted to ensure that the trough concentration remained within 5-15 ng/mL. We prospectively assessed the drug response (response rate for radiological volumetric change in target lesion), performance state, change in respiratory function, visceral impairment (pleural effusion, ascites, bleeding, pain), laboratory examination data, quality of life (QOL), and safety at 12, 24, and 52 weeks of administration. Results: Eleven patients with LAs (9 generalized lymphatic anomaly, 1 cystic LM, 1 Gorham-Stout disease) were treated with sirolimus, of whom 6 (54.5%; 95% confidence interval: 23.4-83.3%) demonstrated a partial response on radiological examination at 52 weeks of administration. No patients achieved a complete response. At 12 and 24 weeks of administration, 8 patients (72.7%) already showed a partial response. However, patients with stable disease showed minor or no reduction after 12 weeks. Adverse events, such as stomatitis, acneiform dermatitis, diarrhea, and fever, were common with sirolimus. Sirolimus was safe and tolerable. Conclusion: Sirolimus can reduce the lymphatic tissue volume in LAs and may lead to improvements in clinical symptoms and QOL.

Determinants of Subtype-Selectivity of the Anthelmintic Paraherquamide A on Caenorhabditis elegans Nicotinic Acetylcholine Receptors.

The anthelmintic paraherquamide A acts selectively on the nematode L-type nicotinic acetylcholine receptors (nAChRs), but the mechanism of its selectivity is unknown. This study targeted the basis of paraherquamide A selectivity by determining an X-ray crystal structure of the acetylcholine binding protein (AChBP), a surrogate nAChR ligand-binding domain, complexed with the compound and by measuring its actions on wild-type and mutant Caenorhabditis elegans nematodes and functionally expressed C. elegans nAChRs. Paraherquamide A showed a higher efficacy for the levamisole-sensitive [L-type (UNC-38/UNC-29/UNC-63/LEV-1/LEV-8)] nAChR than the nicotine-sensitive [N-type (ACR-16)] nAChR, a result consistent with in vivo studies on wild-type worms and worms with mutations in subunits of these two classes of receptors. The X-ray crystal structure of the Ls-AChBP-paraherquamide A complex and site-directed amino acid mutation studies showed for the first time that loop C, loop E, and loop F of the orthosteric receptor binding site play critical roles in the observed L-type nAChR selective actions of paraherquamide A. SIGNIFICANCE STATEMENT: Paraherquamide A, an oxindole alkaloid, has been shown to act selectively on the L-type over N-type nAChRs in nematodes, but the mechanism of selectivity is unknown. We have co-crystallized paraherquamide A with the acetylcholine binding protein, a surrogate of nAChRs, and found that structural features of loop C, loop E, and loop F contribute to the L-type nAChR selectivity of the alkaloid. The results create a new platform for the design of anthelmintic drugs targeting cholinergic neurotransmission in parasitic nematodes.

Infantile Kaposiform hemangioendothelioma in a female patient complicated with severe obstructed jaundice: a case report.

BACKGROUND: Kaposiform hemangioendothelioma (KHE) is a rare locally aggressive vascular neoplasm that occurs mainly in the pediatric population. KHE usually originates just underneath the skin and affects deeper tissues through infiltrative growth; however, visceral tissue involvement is quite rare. CASE PRESENTATION: An 8-month-old girl with jaundice and acholic stool was referred to our hospital for further evaluation of a hepatoduodenal ligament tumor. A blood examination revealed high bilirubin and liver enzyme levels, but no signs of coagulopathy. The first attempt at a diagnostic surgical procedure did not provide sufficient diagnostic information. However, the histopathological diagnosis of the cystic duct excised in the second surgery indicated KHE. Therefore, in our case, KHE was considered a cause of obstructive jaundice. Sirolimus (rapamycin) was initiated, and the patient was discharged 7 months after admission. CONCLUSIONS: In cases of atypical hypervascular lesions in the abdominal cavity, especially in the pediatric population, it is important to consider the possibility of KHE, and surgical intervention with proper strategies is required for diagnosis, followed sequentially by promising treatments.

Bacterial meningitis due to the Streptococcus mitis group in children with cerebrospinal fluid leak.

The Streptococcus mitis group constitutes a part of the oral flora in humans and has been reported to cause infective endocarditis, brain abscesses, sepsis, pneumonia, and peritonitis. However, the S. mitis group rarely causes meningitis in children. We experienced a case of bacterial meningitis due to the S. mitis group in a 14-year-old girl with Gorham-Stout disease undergoing treatment with sirolimus for skull base osteolysis and cerebrospinal fluid (CSF) leak. Antibiotic treatment was initiated with linezolid and levofloxacin due to allergies against ß-lactam antibiotics. On the third treatment day, antibiotics were switched to penicillin G according to CSF culture results, which were positive for penicillin-susceptible S. mitis group. Antibiotic therapy was successfully completed after 14 days without any neurological sequelae. There have apparently been no reports of S. mitis meningitis in pediatric patients with skull base osteolysis and CSF leak as in our case. Our findings suggest that clinicians should be aware of the possibility of S. mitis meningitis for patients with skull base osteolysis and/or CSF leakage.

Neurogenic bladder as a lurking complication in Moebius syndrome.

Moebius syndrome (MBS) is a congenital disorder characterized by facial and abducens palsy, sometimes accompanied with other cranial nerve palsies and comorbid conditions. Anatomical anomalies of the brainstem are assumed to be major etiologies of MBS. Its phenotypic presentation can be variable. We report a female patient with MBS who presented with neurogenic bladder (NB). She was born via normal vaginal delivery. At birth, she showed bilateral abducens palsy and right facial palsy. We diagnosed MBS by cranial computed tomography scan and magnetic resonance imaging. She had recurrent urinary tract infection. Hydronephrosis was noted on ultrasonography and bilateral vesicoureteral reflux (grade 5) on voiding cystourethrography. Urodynamic investigation showed detrusor overactivity and detrusor-sphincter dyssynergia, which follow the pattern of NB resulting from infrapontine-suprasacral lesions. Patients with MBS have lower brainstem dysfunction, and accordingly we should be aware of NB.

Challenge for management without tracheostomy tube after laryngo-tracheal separation in children with neurological disorders.

OBJECTIVES: The present study analyzed surgical outcomes of laryngotracheal separation (LTS) in children with neurological disorders. The purpose of this study was to investigate respiratory impairment and severe complications after LTS in children, and identify the possibility of permanent tracheostomy without a tracheostomy tube as the safest respiratory management method. METHODS: Twenty-eight patients (male:female = 16:12) with neurological disorders (6 months to 32 years) who underwent LTS between January 2012 and April 2018 were reviewed. Tracheal diameter, Cobb angle, and sternocervical spine distance (SCD) were measured to assess the potential risk and possibility of removing tracheostomy tube management. RESULTS: Tracheostomy tube could be removed shortly after LTS in 57% (16/28). However, nine of these patients developed respiratory problems that required tracheostomy tube placement 2 years after LTS. New requirements for a tracheostomy tube as a stent were strongly correlated with SCD (P < .05, odds ratio > 1) as well as tracheal deformity. CONCLUSIONS: Respiratory management in neurologically impaired children after LTS without a tracheostomy tube is challenging because thoracic deformity during physical growth affects tracheal disfiguration. Thoracic deformities and progression of scoliosis should be considered in respiratory management approaches in children with neurological disorders, and long-term follow-up by computed tomography is necessary. LEVEL OF EVIDENCE: IV.

A case of neonatal cytomegalovirus infection with severe thrombocytopenia that was successfully managed with empiric antiviral therapy.

Antiviral therapy against cytomegalovirus (CMV) infection is indicated for symptomatic infection in the fetus and premature neonates. In mature neonates, the benefit of antiviral therapy for severe CMV infection remains controversial. Additionally, when diagnosing symptomatic CMV disease occurring during the early neonatal period, it is difficult to differentiate between congenital and acquired infections. We herein report a neonatal case of CMV infection complicated with severe thrombocytopenia that was successfully managed with antiviral treatment. A 21-day-old male infant presented with low-grade fever and erythema on his extremities. During outpatient follow-up, he developed petechiae and thrombocytopenia (platelet count 17,000/µL). Subsequent serological examination and molecular detection of CMV confirmed the diagnosis of CMV infection. In consideration of the severe thrombocytopenia, antiviral therapy with valganciclovir 32 mg/kg/day was initiated. The platelet counts increased with decreasing CMV loads. After excluding congenital CMV infection, we discontinued antiviral therapy without relapse of the disease. The present case suggests that neonatal cases of severe symptomatic CMV infection may require antiviral therapy while excluding the possibility of congenital infection.

Immunologic Effects of Sirolimus in Patients With Vascular Anomalies.

Emerging data have suggested that sirolimus may be a treatment option for complicated vascular anomalies (VAs). The present study aimed to investigate the immunologic effects of sirolimus treatment for 6 months in patients with VAs. Blood samples obtained from the patients enrolled in 2 multicenter studies to investigate the efficacy of sirolimus for VAs before and after sirolimus treatment for 6 months were used. Data for total white blood cell count, absolute lymphocyte count, serum immunoglobulins (Igs) levels (IgG, IgA, IgM), lymphocyte proliferation assays with mitogens including phytohemagglutinin and concanavalin A, and flow cytometric analysis of lymphocyte subsets were evaluated. A total of 18 patients with VAs receiving sirolimus treatment were included in the study. Comparisons of white blood cell, absolute lymphocyte count, IgG, IgA, IgM, and reaction rates of phytohemagglutinin and concanavalin A revealed no significant differences before and after treatment. No significant differences were observed in the absolute counts of lymphocyte subtypes before and after treatment, except for regulatory T-cell counts, which were significantly decreased after treatment. Severe infections were not observed during sirolimus treatment. The immunologic parameters assessed in the present study were hardly affected by sirolimus treatment for 6 months in patients with VAs.

Low-dose l-isoproterenol versus salbutamol in hospitalized pediatric patients with severe acute exacerbation of asthma: A double-blind, randomized controlled trial.

BACKGROUND: Although the guidelines in most countries do not recommend continuous inhalation of l-isoproterenol to treat pediatric patients with acute severe exacerbation of asthma, lower dose of l-isoproterenol has been widely used in Japan. To determine whether the efficacy of low-dose l-isoproterenol was superior to that of salbutamol, we conducted a double-blind, randomized controlled trial. METHODS: Hospitalized patients aged 1-17 years were eligible if they had severe asthma exacerbation defined by the modified pulmonary index score (MPIS). Patients were randomly assigned (1:1) to receive inhalation of l-isoproterenol (10 µg/kg/h) or salbutamol (500 µg/kg/h) for 12 hours via a large-volume nebulizer with oxygen. The primary outcome was the change in MPIS from baseline to 3 hours after starting inhalation. Trial registration number UMIN000001991. RESULTS: From December 2009 to October 2013, 83 patients (42 in the l-isoproterenol group and 41 in the salbutamol group) were enrolled into the study. Of these, one patient in the l-isoproterenol group did not receive the study drug and was excluded from the analysis. Compared with salbutamol, l-isoproterenol reduced MPIS more rapidly. Mean (SD) changes in MPIS at 3 hours were -2.9 (2.5) in the l-isoproterenol group and -0.9 (2.3) in the salbutamol group (difference -2.0, 95% confidence interval -3.1 to -0.9; P < 0.001). Adverse events occurred in 1 (2%) and 11 (27%) patients in the l-isoproterenol and salbutamol groups, respectively (P = 0.003). Hypokalemia and tachycardia occurred only in the salbutamol group. CONCLUSIONS: Low-dose l-isoproterenol has a more rapid effect with fewer adverse events than salbutamol.

Efficacy and safety of sirolimus treatment for intractable lymphatic anomalies: A study protocol for an open-label, single-arm, multicenter, prospective study (SILA).

INTRODUCTION: Lymphatic anomalies (LAs) refer to a group of diseases involving systemic dysplasia of lymphatic vessels. These lesions are classified as cystic lymphatic malformation (macrocystic, microcystic or mixed), generalized lymphatic anomaly, and Gorham-Stout disease. LAs occur mainly in childhood, and present with various symptoms including chronic airway problems, recurrent infection, and organ disorders. Individuals with LAs often experience progressively worsening symptoms with a deteriorating quality of life. Although limited treatment options are available, their efficacy has not been validated in prospective clinical trials, and are usually based on case reports. Thus, there are no validated standards of care for these patients because of the lack of prospective clinical trials. METHODS: This open-label, single-arm, multicenter, prospective study will assess the efficacy and safety of a mammalian target of the rapamycin inhibitor sirolimus in the treatment of intractable LAs. Participants will receive oral sirolimus once a day for 52 weeks. The dose is adjusted so that the nadir concentration remains within 5-15 ng/ml. The primary endpoint is the response rate of radiological volumetric change of the target lesion confirmed by central review at 52 weeks after treatment. The secondary endpoints are the response rates at 12 and 24 weeks, respiratory function, pleural effusion, ascites, blood coagulation parameters, bleeding, pain, quality of life, activities of daily living, adverse events, side effects, laboratory examinations, vital signs, and pharmacokinetic data. RESULTS: This is among the first multicenter studies to evaluate sirolimus treatment for intractable LAs, and few studies to date have focused on the standard assessment of the efficacy for LAs treatment. Our protocol uses novel, uncomplicated methods for radiological assessment, with reference to the results of our previous retrospective survey and historical control data from the literature. CONCLUSIONS: We propose a multicenter study to investigate the efficacy and safety of sirolimus for intractable LAs (SILA study; trial registration UMIN000028905). Our results will provide pivotal data to support the approval of sirolimus for the treatment of intractable LAs.

Severe anti-GAD antibody-associated encephalitis after stem cell transplantation.

BACKGROUND: General features of anti-glutamic acid decarboxylase (GAD) antibody-associated limbic encephalitis are seizures, cognitive impairment, and imaging findings at the medial temporal lobes. We report a patient affected with remarkably severe anti-GAD antibody-positive encephalitis after hematopoietic stem cell transplantation (HSCT). CASE REPORT: A 5-year-old girl received HSCT due to pineoblastoma. Thirteen months after HSCT, she showed seizure clustering and altered mental status. Her anti-GAD antibody level was high, 65,100 U/mL (reference range < 1.5 U/mL). Her disease was diagnosed as autoimmune encephalitis and she received intravenous immunoglobulin (IVIG) and methylprednisolone. After the therapy, she partially recovered. Encephalitis later relapsed, however, and she showed extremely high anti-GAD antibody, 27 months after HSCT. Although lesions were located in the temporal and occipital lobes by MRI at 5 days after the relapse, very severe whole brain encephalitis was revealed at 13 days after the relapse. Seizures and abnormal encephalogram were resistant to IVIG and methylprednisolone. After plasma exchange, these findings were resolved. MRI revealed diffuse cerebral atrophy, 57 months after the relapse. No relapse has occurred for the past 5 years with decreased anti-GAD antibody after starting bimonthly administration of IVIG. CONCLUSION: This may be the first case of severe and recurrent anti-GAD antibody-associated autoimmune encephalitis after HSCT with specific MRI findings. No relapse has occurred since starting maintenance IVIG.

De Novo Mutations Activating Germline TP53 in an Inherited Bone-Marrow-Failure Syndrome.

Inherited bone-marrow-failure syndromes (IBMFSs) include heterogeneous genetic disorders characterized by bone-marrow failure, congenital anomalies, and an increased risk of malignancy. Many lines of evidence have suggested that p53 activation might be central to the pathogenesis of IBMFSs, including Diamond-Blackfan anemia (DBA) and dyskeratosis congenita (DC). However, the exact role of p53 activation in each clinical feature remains unknown. Here, we report unique de novo TP53 germline variants found in two individuals with an IBMFS accompanied by hypogammaglobulinemia, growth retardation, and microcephaly mimicking DBA and DC. TP53 is a tumor-suppressor gene most frequently mutated in human cancers, and occasional germline variants occur in Li-Fraumeni cancer-predisposition syndrome. Most of these mutations affect the core DNA-binding domain, leading to compromised transcriptional activities. In contrast, the variants found in the two individuals studied here caused the same truncation of the protein, resulting in the loss of 32 residues from the C-terminal domain (CTD). Unexpectedly, the p53 mutant had augmented transcriptional activities, an observation not previously described in humans. When we expressed this mutant in zebrafish and human-induced pluripotent stem cells, we observed impaired erythrocyte production. These findings together with close similarities to published knock-in mouse models of TP53 lacking the CTD demonstrate that the CTD-truncation mutations of TP53 cause IBMFS, providing important insights into the previously postulated connection between p53 and IBMFSs.

Clinical Utility of the Modified Pulmonary Index Score as an Objective Assessment Tool for Acute Asthma Exacerbation in Children.

INTRODUCTION: The Modified Pulmonary Index Score (MPIS) was developed as an objective assessment tool for acute asthma exacerbation in children. Although it is considered reliable, there are no known studies of its clinical utility. The objective of this study was to evaluate the validity of the MPIS for children with acute asthma in a clinical setting. METHODS: In this retrospective study conducted between July 2009 and June 2011 using electronic medical records at the emergency department of a single pediatric medical center in Tokyo, Japan, the MPIS was recorded for patients with acute asthma at initial assessment and after treatment with an inhaled beta-agonist. We evaluated the responsiveness and predictive validity of the MPIS using disposition as an outcome. RESULTS: A total of 2242 patients were assessed using the MPIS (median age, 3 years; 71.2% patients were 5 years or younger). The mean (SD) MPIS at initial assessment was 7.1 (3.6) and was significantly higher for the admission group than for the non-admission group (9.9 [2.9] vs. 5.9 [3.1]; P < 0.001). The receiver operator characteristic curve of the initial MPIS for hospital admission demonstrated moderate predictive ability (area under the curve, 0.83). An MPIS reduction of 3 or more indicated a clinically significant change when the MPIS at initial assessment was between 6 and 10 (risk ratio for admission [95% CI], 0.41 [0.28-0.60]; P < 0.001). CONCLUSION: The MPIS demonstrated good concurrent validity, predictive validity, and responsiveness in a wide range of clinical settings.

Independent risk factors for recurrence of apparent life-threatening events in infants.

The risk factors for recurrent apparent life-threatening event (ALTE) are unclear although the risk of recurrent ALTE is an important consideration for the management of ALTE patients. This study aimed to identify the risk factors for recurrent ALTE. We conducted a secondary analysis of the data from a single center retrospective cohort study in Japan conducted from March 2002 to January 2012, which included children diagnosed with ALTE at a pediatric emergency department (ED) in Tokyo. Among 112 ALTE patients, 18 (16%) had recurrences and 94 (84%) did not. Symptoms of respiratory tract infection (RTI) were more frequent in the recurrent group than in the non-recurrent group (44 vs. 14% p = 0.0055), and the proportion of patients triaged as level 1 was larger in the recurrent group than in the non-recurrent group (31 vs. 7%, p = 0.0312). Pallor was observed more frequently in the recurrent group than in the non-recurrent group (100 vs. 76%, p = 0.0216). Multivariate analysis demonstrated that the independent risk factors of recurrent ALTE were respiratory tract infection symptoms (OR, 5.02; 95% CI, 1.48-16.98). CONCLUSION: ALTE patients who had RTI symptoms at the ED visit for first ALTE should be admitted for close observation of potential recurrences. What is Known: • Approximately 10% of ALTE patients experienced recurrence of ALTE episodes. • The risk of recurrent ALTE is one of the major consideration for the management of ALTE patients at the ED because these patients have higher rates of serious underlying diseases which require interventions. What is New: • Respiratory infection symptoms at ED presentation can be independent risk factors for recurrent ALTE.

Severe and Rapid Progression in Very Early-Onset Chronic Granulomatous Disease-Associated Colitis.

PURPOSE: Chronic granulomatous disease (CGD) is a primary immunodeficiency disease that leads to recurrent infection and hyper-inflammation, occasionally represented by CGD-associated colitis (CGD colitis). Although clinical symptoms of CGD colitis mimic those of ulcerative colitis (UC), there is no reliable standard measurement of disease activity or standard therapeutic strategy for CGD colitis. Here, we examined the clinical manifestation of CGD colitis based on severity using a noninvasive measure of disease activity, the Pediatric Ulcerative Colitis Activity Index (PUCAI), which has been validated and widely used for pediatric UC. METHODS: Sixteen of 35 CGD patients, who were diagnosed with CGD colitis based on colonoscopic and histological findings, were examined using the PUCAI. Both the PUCAI and the physician global assessment (PGA) tool were retrospectively scored by reviewing medical records. RESULTS: Disease activity defined by PUCAI was correlated with PGA, and increased at diagnosis of CGD colitis, especially in patients who were younger than 6 years of age (very early-onset CGD colitis: VEO-CGD colitis) when diagnosed with CGD colitis. All severe patients had a more progressive form of VEO-CGD colitis. Unlike mild and moderate patients, severe patients required multidrug therapy of corticosteroids and immunomodulator/immunosuppressants, and some were eventually treated with hematopoietic stem cell transplantation. CONCLUSIONS: Although the validation of PUCAI in CGD colitis should be considered for future use, our results indicate that noninvasive measures could be effective to measure disease activity and help to determine suitable treatment for CGD colitis. In patients with VEO-CGD colitis, multidrug therapy would need to be considered at an early stage on the basis of disease activity.