Safety, efficacy and pharmacokinetics of palivizumab in off-label neonates, infants, and young children at risk for serious respiratory syncytial virus infection: a multicenter phase II clinical trial.

Background: Pediatric patients with certain rare diseases are at increased risk of severe respiratory syncytial virus (RSV) infection. However, the prophylactic use of anti-RSV antibody (palivizumab) in these patients is not indicated at present in Japan. Methods: This first-in-the-world multicenter, uncontrolled, open-label, phase II clinical trial was carried out between 28 July 2019 and 24 September 2021 at seven medical institutions in Japan to investigate the efficacy, safety, and pharmacokinetics of palivizumab in 23 subjects recruited from among neonates, infants, or children aged 24 months or younger who had any of the following conditions: pulmonary hypoplasia, airway stenosis, congenital esophageal atresia, inherited metabolic disease, or neuromuscular disease. At least four continuous doses of palivizumab were administered intramuscularly at 15 mg/kg at intervals of 30 days. Findings: Twenty-three enrolled subjects completed the study. No subject required hospitalization for RSV. Adverse events (AE) did not notably differ from the event terms described in the latest interview form. Five severe AEs required unplanned hospitalization, but resolved without RSV infection. Therapeutically effective concentrations of palivizumab were maintained throughout the study period. Interpretation: Palivizumab might be well tolerated and effective in preventing serious respiratory symptoms and hospitalization due to severe RSV infection, indicating the prophylactic use in the pediatric patients included in this study. Funding: Japan Agency for Medical Research and Development (AMED), grant numbers 19lk0201097h0001 (to MM), 20lk0201097h0002 (to MM), 21lk0201097h0003 (to MM), and 22lk0201097h0004 (to MM). AMED did not have any role in the execution of this study, analysis and interpretation of the data, or the decision to submit the results.

Study protocol: a multicenter, uncontrolled, open-label study of palivizumab in neonates, infants, and preschool children at high risk of severe respiratory syncytial virus infection.

BACKGROUND: The prophylactic use of anti-respiratory syncytial virus (RSV) antibody (palivizumab) for severe RSV infection is not approved in Japan in specified groups of infants with neuromuscular diseases or other rare diseases associated with reduced ventilation competence or difficulty in expectoration, which increase the risk of exacerbation of severe RSV infection. The objective of this study is to investigate the efficacy, safety, and pharmacokinetics of palivizumab in pediatric patients with those rare diseases for which palivizumab is not indicated at present. METHODS/DESIGN: This study is a multicenter, uncontrolled, open-label study planned to be carried out between July 1, 2019 and June 30, 2022 at 7 medical institutions in Japan. The study population will be recruited from among neonates, infants, or children aged 24 months or younger with a condition falling under any of the following 5 disease groups: pulmonary hypoplasia, airway stenosis, congenital esophageal atresia, inherited metabolic disease, or neuromuscular disease. The planned sample size is 18 subjects, including at least 3 subjects per disease group. Throughout the RSV season, at least 4 continuous doses of palivizumab will be administered intramuscularly at 15 mg/kg at intervals of 30 days. The efficacy and safety of palivizumab will be comprehensively evaluated based on the incidence of RSV-related hospitalization, and serum palivizumab concentration, serum anti-palivizumab antibody concentration, and the occurrence of adverse events/reactions after the start of palivizumab treatment. DISCUSSION: This study will evaluate the efficacy and safety of palivizumab in pediatric patients with rare diseases which place them at high risk of severe RSV infection, but which fall outside the current indications for palivizumab prophylaxis. The generated data will have implications for the regulatory approval of prophylactic palivizumab treatment in this patient group. TRIAL REGISTRATION: This study has been prospectively registered in Japic Clinical Trials Information, which is managed and administered by the Japan Pharmaceutical Information Center (registration number: JapicCTI-194946 , registration date: September 10, 2019).

Deep Vein Thrombosis in Severe Motor and Intellectual Disabilities Patients and Its Treatment by Anticoagulants of Warfarin Versus Edoxaban.

Objective: Patients with severe motor and intellectual disabilities (SMID) often develop complications, including paralysis of the extremities due to abnormal muscular tonicity. Furthermore, the incidence of sudden death, which may be caused by pulmonary thromboembolism (PTE), is approximately 4.2%. Deep vein thrombosis (DVT) is attracting attention as an embolic source. In this study, DVT was confirmed in SMID patients by lower extremity venous ultrasound. The oral anticoagulant, warfarin, and novel oral anticoagulant, edoxaban tosilate hydrate, were administered, and their efficacies and safeties were evaluated. Materials and Methods: DVT patients were randomly allocated to warfarin and edoxaban groups. The frequency of hemorrhagic events and incidence of adverse events were investigated to evaluate efficacy and safety. Results: DVT was detected in 14 (8.4%) out of 167 patients. Four (0.067/person-month) hemorrhagic events occurred in the warfarin group from subcutaneous hemorrhage due to bruises caused by postural changes. Three (0.042/person-month) events occurred in the edoxaban group due to nasal hemorrhage caused by tracheal aspiration. There was no significant difference (p=0.5383) between groups. Conclusion: No significant differences were observed in hemorrhagic events between SMID patients with DVT treated with warfarin and edoxaban.

Long-Term Evaluation of Low-Dose Betamethasone for Ataxia Telangiectasia.

BACKGROUND: Ataxia telangiectasia is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectases, immune defects, and a predisposition to malignancy. Quality of life is severely impaired by neurological symptoms. However, curative options for the neurological symptoms are limited. Recent studies have demonstrated short-term improvement in neurological symptoms with betamethasone therapy. However, the long-term and adverse effects of betamethasone are unclear. The aim of this study was to evaluate the long-term effects, benefits, and adverse effects of low-dose betamethasone in ataxia telangiectasia. METHODS: Six patients with ataxia telangiectasia received betamethasone at 0.02 mg/kg/day for two years. After cessation of betamethasone, the patients were observed for two additional years. Neurological assessments were performed, and adverse effects were monitored every three months throughout the four-year study period. RESULTS: Transient improvement of neurological symptom was observed in five of the six patients. However, after two years betamethasone treatment, only one of the six patients showed a slight improvement in the neurological score, one patient showed no change, and the neurological scores of the remaining four patients deteriorated. After the cessation of betamethasone treatment, neurological symptoms worsened in all patients. As an adverse effect of betamethasone, transient adrenal dysfunction was observed in all cases. CONCLUSIONS: Although these findings are in agreement with previous studies suggesting that short-term betamethasone treatment transiently benefits patients with ataxia telangiectasia, the long-term benefits and risks should be carefully considered.

Multicenter, Open-Label, Randomized Controlled Trial of Warfarin and Edoxaban Tosilate Hydrate for the Treatment of Deep Vein Thrombosis in Persons with Severe Motor Intellectual Disabilities.

Sudden death in patients with severe motor and intellectual disabilities (SMID) is sometimes caused in part by pulmonary thromboembolism (PTE), and deep venous thrombosis (DVT) has drawn attention as a possible embolic source. Warfarin, which is a conventional therapeutic agent, is not easy to control appropriately, and daily management can be especially difficult in SMID patients. On the other hand, edoxaban tosilate hydrate, which has been newly approved for insurance coverage for the treatment of DVT, is not listed in the Guidelines for the Diagnosis, Treatment and Prevention of Pulmonary Thromboembolism and Deep Vein Thrombosis (DVT-PTE guidelines). The aim of this study is to evaluate the efficacy and safety of anticoagulation therapy (warfarin vs. edoxaban) in DVT treatment in SMID patients by means of an open-label, randomized controlled trial. The primary endpoint is the incidence of hemorrhagic events during 12 months of follow up.

Circadian Rhythms of Oxidative Stress Markers and Melatonin Metabolite in Patients with Xeroderma Pigmentosum Group A.

Xeroderma pigmentosum group A (XPA) is a genetic disorder in DNA nucleotide excision repair (NER) with severe neurological disorders, in which oxidative stress and disturbed melatonin metabolism may be involved. Herein we confirmed the diurnal variation of melatonin metabolites, oxidative stress markers, and antioxidant power in urine of patients with XPA and age-matched controls, using enzyme-linked immunosorbent assay (ELISA). The peak of 6-sulfatoxymelatonin, a metabolite of melatonin, was seen at 6:00 in both the XPA patients and controls, though the peak value is lower, specifically in the younger age group of XPA patients. The older XPA patients demonstrated an increase in the urinary levels of 8-hydroxy-2'-deoxyguanosine and hexanoyl-lysine, a marker of oxidative DNA damage and lipid peroxidation, having a robust peak at 6:00 and 18:00, respectively. In addition, the urinary level of total antioxidant power was decreased in the older XPA patients. Recently, it is speculated that oxidative stress and antioxidant properties may have a diurnal variation, and the circadian rhythm is likely to influence the NER itself. We believe that the administration of melatonin has the possibility of ameliorating the augmented oxidative stress in neurodegeneration, especially in the older XPA patients, modulating the melatonin metabolism and the circadian rhythm.

Acute encephalitis with refractory, repetitive partial seizures: Pathological findings and a new therapeutic approach using tacrolimus.

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) is characterized by prolonged severe seizures and a high-grade fever. We experienced a boy with severe AERRPS with frequent partial seizures that exhibited right-side predominance. The patient required the continuous intravenous administration of many antiepileptic drugs and respirator management for several months. Methylprednisolone pulse therapy and intravenous immunoglobulin administration were only temporarily effective. The MRI and EEG showed the abnormality in the left occipital lobe. Although occipital lobectomy was performed, his seizures continued. His cerebrospinal fluid exhibited elevated protein and proinflammatory cytokine levels, and was positive for anti-glutamate receptor ε2 antibodies. Pathological examination showed infiltration of many neutrophilic leukocytes, T cells, and microglia in the area exhibiting severe spongiosis. We thought that the exaggerated microglia and T-cell responses were related to the pathogenesis of the patient's seizures, and we therefore initiated treatment with tacrolimus. As a result, many of the daily seizure clusters were ameliorated, and the patient was discharged. We attempted to discontinue the tacrolimus twice, but the patient's seizure clusters recurred each time. This is the first case report of the pathological findings of AERRPS and showing an effective therapeutic approach using tacrolimus. Tacrolimus may be an effective immunosuppressant, especially for patients with severe AERRPS.

Changes in cerebrospinal fluid biomarkers in human herpesvirus-6-associated acute encephalopathy/febrile seizures.

To determine the involvement of oxidative stress in the pathogenesis of acute encephalopathy associated with human herpesvirus-6 (HHV-6) infection, we measured the levels of oxidative stress markers 8-hydroxy-2'-deoxyguanosine (8-OHdG) and hexanoyl-lysine adduct (HEL), tau protein, and cytokines in cerebrospinal fluid (CSF) obtained from patients with HHV-6-associated acute encephalopathy (HHV-6 encephalopathy) (n = 16) and complex febrile seizures associated with HHV-6 (HHV-6 complex FS) (n = 10). We also examined changes in CSF-8OHdG and CSF-HEL levels in patients with HHV-6 encephalopathy before and after treatment with edaravone, a free radical scavenger. CSF-8-OHdG levels in HHV-6 encephalopathy and HHV-6 complex FS were significantly higher than in control subjects. In contrast, CSF-HEL levels showed no significant difference between groups. The levels of total tau protein in HHV-6 encephalopathy were significantly higher than in control subjects. In six patients with HHV-6 infection (5 encephalopathy and 1 febrile seizure), the CSF-8-OHdG levels of five patients decreased after edaravone treatment. Our results suggest that oxidative DNA damage is involved in acute encephalopathy associated with HHV-6 infection.

Cerebrospinal fluid oxidative stress marker levels and cytokine concentrations in a neonate with incontinentia pigmenti.

BACKGROUND: Some children with incontinentia pigmenti exhibit encephalopathic features with severe seizures and disturbed consciousness, from the neonatal through the early infantile period. However, the pathological mechanism of brain lesion development is not fully understood. METHODS: We measured the cerebrospinal fluid levels of cytokines and oxidative stress markers (8-hydroxy-2-deoxyguanosine and the hexanoyl-lysine adduct) in a young girl with incontinentia pigmenti complicated by an encephalopathic event that occurred on her first day of life. Magnetic resonance imaging revealed widespread reduction of water diffusion in the basal ganglia, the periventricular and subcortical white matter, and the corpus callosum. RESULTS: Oxidative stress markers were elevated at 4 days of age but decreased mildly by 25 days of age. Elevated levels of soluble tumor necrosis factor receptor 1 were observed at both 4 and 25 days of age, although tumor necrosis factor-α levels were below the limit of detection. No other cytokine levels were elevated, except for those of interleukin-10 at 25 days of age. CONCLUSIONS: Tumor necrosis factor-α expression and oxidative stress are involved in the pathogenesis of brain lesions in children with incontinentia pigmenti, and elevated cerebrospinal fluid cytokine levels may not be apparent during encephalopathic events.

Melatonin alterations and brain acetylcholine lesions in sleep disorders in Cockayne syndrome.

BACKGROUND: Cockayne syndrome (CS) is a genetic disorder caused by deficient nucleotide excision repair. Patients with CS exhibit progeroid features, developmental delay, and various neurological disorders; they are also known to suffer from sleep problems, which have never been investigated in detail. OBJECTIVE: The aim of this study is to investigate the pathogenesis of sleep disorders in patients with CS. METHODS: We performed a questionnaire survey of the families of patients with CS, enzyme-linked immunosorbent analyses of the melatonin metabolite, 6-sulphatoxymelatonin (6-SM), in the patients' urine, and immunohistochemistry in the hypothalamus, the basal nucleus of Meynert (NbM), and the pedunculopontine tegmental nucleus (PPN) in four autopsy cases. RESULTS: Sleep-wakefulness rhythms were disturbed in patients with CS, and these disturbances seemed to be related to a reduced urinary excretion of 6-SM. In addition, although the hypothalamic nuclei were comparatively preserved, acetylcholine neurons (AchNs) were severely decreased in the NbM and PPN. CONCLUSIONS: AchNs modulate both arousal and rapid eye movement sleep, and selective lesions of AchNs in the PPN and/or NbM in combination with disturbed melatonin metabolism might be involved in the sleep disorders in CS.

Acute limbic encephalitis with focal hyperperfusion on single photon emission computed tomography.

Here we report an 11-year-old boy with acute encephalopathy with neuropsychiatric symptoms. The patient had mildly decreased consciousness, delirious behavior, and affective changes next day of fever onset. Hematologic, biochemical, and metabolic examinations were unremarkable. CSF analysis revealed cell counts of 278 cells/mm(3) and a protein level of 87 mg/dL. Although MRI revealed no abnormal findings, an increase in regional cerebral blood flow was present in the bilateral frontal lobes, mesial temporal lobes, and basal ganglia on single photon emission computed tomography. The measurement of the concentrations of biomarkers such as cytokines in the patient's serum and cerebrospinal fluid revealed elevated levels of IL-4 and TNF-α in the cerebrospinal fluid. Immunohistochemical studies applying control human brain sections did not demonstrate the presence of autoantibodies. We considered that innate immunity rather than autoantibody response may have contributed to the neuropsychiatric symptoms of our patient. These results suggest heterogeneity of patients with acute encephalopathy with neuropsychiatric symptoms.

Deep vein thrombosis in patients with severe motor and intellectual disabilities.

Most patients with severe motor and intellectual disabilities (SMID) have restricted mobility capability and have been bedridden for long periods because of paralysis of the extremities caused by abnormal muscular tonicity due to cerebral palsy and developmental disabilities, and such patients are associated with a high risk for the complications of deep vein thrombosis (DVT). Here, we report 8 patients (34.8%) with DVT among 23 patients with SMID during prolonged bed rest. However, we did not detect thrombosis in the soleal veins, finding it mostly in the superficial femoral and common femoral veins. Regarding laboratory data for the coagulation system, there were no cases with D-dimer above 5 µg/ml. Concerning sudden death in patients with SMID, we have to be very careful of the possibility of pulmonary thromboembolism due to DVT. Therefore, we should consider the particularities of an underdeveloped vascular system from underlying diseases for the evaluation of DVT in patients with SMID. A detailed study of DVT as a vascular complication is very important for smooth medical care of SMID and compression Doppler ultrasonography of the lower extremities, as noninvasive examination, is very helpful. (English translation of Jpn J Phlebol 2012; 23: 17-24).

Autoimmune neurological disorders associated with group-A beta-hemolytic streptococcal infection.

Although central nervous system (CNS) disorders associated with group-A beta-hemolytic streptococcal (GABHS) infection occur only rarely, Sydenham's chorea is a well-recognized disease that can arise following infection. Children may develop a tic, obsessive compulsive disorder (OCD), and extrapyramidal movement subsequent to GABHS infection. These disorders have been termed pediatric autoimmune neuropsychiatric disorders associated with streptococci (PANDAS). Herein we report one case each of acute disseminated encephalomyelitis (ADEM), PANDAS and subacute encephalitis associated with GABHS infection. To evaluate the pathogenesis of the CNS disorders associated with GABHS infection, we measured levels of neurotransmitters, cytokines, anti-neuronal autoantibodies, and performed immunohistochemistry using patient sera to stain human brain sections. All three cases showed psychiatric behavioral disorders. Immunotherapy was effective, and homovanillic acid levels in the cerebrospinal fluid (CSF) were elevated at the acute stage in all three cases. In each case of ADEM and PANDAS, immunohistochemistry demonstrated neuronal impairment in the basal ganglia during the acute stage. Neuronal immunoreactivity was visualized in the cerebral cortex at the acute stage in the case of subacute encephalitis. There was no direct correlation between immunoreactivity of patient sera on the brain sections and positivity of anti-neuronal autoantibodies or CSF biomarkers. The results suggest that autoimmune responses may modulate neurotransmission, and the use of patient serum for immunohistochemistry is a sensitive screening method for the detection of anti-neuronal autoantibodies in CNS disorders associated with GABHS infection.

Lesions of acetylcholine neurons in refractory epilepsy.

We have examined brainstem lesions in patients with refractory epilepsy disorders, including West syndrome (WS), Lennox-Gastaut syndrome (LGS), and dentatorubral-pallidoluysian atrophy (DRPLA). Acetylcholinergic neurons (AchNs) in the pedunculopontine tegmental nucleus (PPN) are involved in mental development, and disruption of neuronal nicotinic acetylcholine receptors can lead to epilepsy. In order to investigate the involvement of lesions of AchNs in refractory epilepsy, we performed immunohistochemical analyses of AchNs in the PPN in autopsy cases who had a past history of WS and/or LGS and in DRPLA cases who showed progressive myoclonic epilepsy. In addition, we performed a preliminary quantification of the levels of acetylcholine, neuropeptides, and monoamine metabolites in the cerebrospinal fluid (CSF) of patients with WS and benign convulsions associated with mild gastroenteritis (CwG). In the PPN analysis, the total number of neurons and the number of AchNs were reduced in WS/LGS and WS cases, while DRPLA cases showed a decrease in the number and percentage of AchNs. In the CSF analysis, WS patients demonstrated a reduction in the levels of inhibitory neuropeptides, while CwG patients showed increased levels of acetylcholine and decreased levels of serotonin metabolites. These data suggest the possible involvement of lesions of AchNs in WS and DRPLA.

[CSF biomarkers in children with acute encephalopathy syndrome].

Viral infection-associated acute encephalopathy in children is a clinical syndrome with high mortality and neurological sequelae. Its main symptoms of acute phase are impaired consciousness and convulsive status epilepticus with hyperpyrexia. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized clinically by biphasic seizures and late MRI abnormalities such as reduced subcortical diffusion. Despite the intensive care, patients with AESD often have severe neurological impairment and it is very difficult to distinguish AESD from febrile seizures in the early phase. Although there is currently no specific biomarker for early diagnosis of acute encephalopathy syndrome, we believe tau protein and 8-hydroxy-2'-deoxyguanosine (8-OHdG) are potential biomarkers which could be useful in following the clinical course and monitoring the efficacy of therapies.

Oxidative stress in developmental brain disorders.

In order to examine the involvement of oxidative stress in developmental brain disorders, we have performed immunohistochemistry in autopsy brains and enzyme-linked immunosorbent assay (ELISA) in the cerebrospinal fluid and urines of patients. Here, we review our data on the hereditary DNA repair disorders, congenital metabolic errors and childhood-onset neurodegenerative disorders. First, in our studies on hereditary DNA repair disorders, increased oxidative DNA damage and lipid peroxidation were carried out in the degeneration of basal ganglia, intracerebral calcification and cerebellar degeneration in patients with xeroderma pigmentosum, Cockayne syndrome and ataxia-telangiectasia-like disorder, respectively. Next, congenital metabolic errors, apoptosis due to lipid peroxidation seemed to cause neuronal damage in neuronal ceroid-lipofuscinosis. Oxidative stress of DNA combined with reduced expression of antioxidant enzymes occurred in the lesion of the cerebral cortex in mucopolysaccharidoses and mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes. In childhood-onset neurodegenerative disorders, increased oxidative DNA damage and lipid peroxidation may lead to motor neuron death in spinal muscular atrophy like in amyotrophic lateral sclerosis. In patients with dentatorubral-pallidoluysian atrophy, a triplet repeat disease, deposition of oxidative products of nucleosides and reduced expression of antioxidant enzymes were found in the lenticular nucleus. In contrast, the involvement of oxidative stress is not definite in patients with Lafora disease. Rett syndrome patients showed changes of oxidative stress markers and antioxidant power in urines, although the changes may be related to systemic complications.

Brain vascular changes in Cockayne syndrome.

Cockayne syndrome (CS) and xeroderma pigmentosum (XP) are caused by deficient nucleotide excision repair. CS is characterized by cachectic dwarfism, mental disability, microcephaly and progeria features. Neuropathological examination of CS patients reveals dysmyelination and basal ganglia calcification. In addition, arteriosclerosis in the brain and subdural hemorrhage have been reported in a few CS cases. Herein, we performed elastica van Gieson (EVG) staining and immunohistochemistry for collagen type IV, CD34 and aquaporin 4 to evaluate the brain vessels in autopsy cases of CS, XP group A (XP-A) and controls. Small arteries without arteriosclerosis in the subarachnoid space had increased in CS cases but not in either XP-A cases or controls. In addition, string vessels (twisted capillaries) in the cerebral white matter and increased density of CD34-immunoreactive vessels were observed in CS cases. Immunohistochemistry findings for aquaporin 4 indicated no pathological changes in either CS or XP-A cases. Hence, the increased subarachnoid artery space may have caused subdural hemorrhage. Since such vascular changes were not observed in XP-A cases, the increased density of vessels in CS cases was not caused by brain atrophy. Hence, brain vascular changes may be involved in neurological disturbances in CS.

Focal encephalopathy with recurrent episodes of epileptic status and cluster mimicking hemiconvulsion-hemiplegia-epilepsy syndrome.

Hemiconvulsion-hemiplegia-epilepsy syndrome is characterized by unilateral convulsions during fever, transient hemiplegia, and subsequent partial epilepsy with atrophy in the cerebrum. A 9-year-old boy with a history of West syndrome and hypoglycemic attacks had three episodes of epileptic status and clusters mimicking HHE syndrome over a 2-year period. Magnetic resonance imaging revealed the involvement of the right and left cerebrums. Because no abnormalities were detected in an endocrine examination, screening tests for metabolic errors, or magnetic resonance spectroscopy, a diagnosis of metabolic errors was not supported. Immunohistochemistry using the patient's sera showed binding of the serum immunoglobulin with neurons in the temporal and occipital cerebral cortices, indicating the possible involvement of autoimmune mechanisms in this case. Focal encephalopathy should be considered in children showing convulsions, psychiatric disorders, and/or involuntary movements for several months in a row. In such cases, immunohistochemistry using the patient's sera may be useful for the investigation of the pathogenesis of the illness.