Altered serum levels of platelet-derived growth factor receptor ß and cluster of differentiation 13 suggest a role for pericytes in West syndrome.

BACKGROUND: Pericytes play a role in the maintenance of the blood-brain barrier and neuroinflammation, attracting attention as to whether they are also involved in the pathogenesis of epilepsy.This study aimed to explore the relationship between West syndrome and pericytes. METHODS: Eighteen Japanese pediatric West syndrome patients and nine controls aged 2 years or younger were retrospectively enrolled in this study. We assessed theserumlevels of pericyte markers, serum PDGFRß (platelet-derived growth factor receptorß),CD13 (aminopeptidase N), and 27 cytokines in 17 pediatric patients with West syndrome and the control group. RESULTS: Patients with West syndrome exhibited significantly increased CD13 and decreased PDGFRß levels, compared with controls but not serum cytokine levels. These values did not differ significantly between symptomatic and idiopathic West syndrome. CONCLUSION: Pericytes might be implicated in the pathogenesis of West syndrome.

Association of the Mannose-Binding Lectin 2 BB Genotype with COVID-19-Related Mortality.

Mannose-binding lectin (MBL) is crucial in first-line immune defenses. There are still many unknown factors regarding the mechanisms causing variability in the clinical course of coronavirus disease 2019 (COVID-19). In Japan, there have been few reports to date regarding the association between MBL and COVID-19. It has been demonstrated that the MBL2 gene B variant at codon 54 (rs1800450) is associated with variabilities in the clinical course of COVID-19. We aimed to investigate how the level of serum MBL and the codon 54 variant of MBL (rs1800450) affect the disease severity of COVID-19. A total of 59 patients from the fourth wave and 49 patients from the fifth wave in Japan were analyzed based on serum MBL levels using ELISA and the genotype of MBL2 codon 54 using PCR reaction. There was no significant association between serum MBL levels and age. MBL2 genotype was independent of age, there was no significant difference in different COVID-19 severities, MBL genotypes, and serum MBL levels. Binary logistic regression analysis to identify predisposing factors for severe COVID-19 symptoms demonstrated that patients with the BB genotype had a higher risk of death from COVID-19. Our results quantitatively demonstrated that the BB genotype might be a factor associated with death from COVID-19.

Detailed Molecular Interactions between Respiratory Syncytial Virus Fusion Protein and the TLR4/MD-2 Complex In Silico.

Molecular interactions between respiratory syncytial virus (RSV) fusion protein (F protein) and the cellular receptor Toll-like receptor 4 (TLR4) and myeloid differentiation factor-2 (MD-2) protein complex are unknown. Thus, to reveal the detailed molecular interactions between them, in silico analyses were performed using various bioinformatics techniques. The present simulation data showed that the neutralizing antibody (NT-Ab) binding sites in both prefusion and postfusion proteins at sites II and IV were involved in the interactions between them and the TLR4 molecule. Moreover, the binding affinity between postfusion proteins and the TLR4/MD-2 complex was higher than that between prefusion proteins and the TLR4/MD-2 complex. This increased binding affinity due to conformational changes in the F protein may be able to form syncytium in RSV-infected cells. These results may contribute to better understand the infectivity and pathogenicity (syncytium formation) of RSV.

Chemokine/Interleukin Imbalance Aggravates the Pathology of Respiratory Syncytial Virus Infection.

(1) Background: Almost 100% of children are initially infected by respiratory syncytial virus (RSV) by the age of 2 years, with 30% to 40% of children developing lower respiratory tract infections, of which 1% to 3% become severe. The severity of RSV-induced disease correlates with the influx of leukocytes, which leads to damage of the airways. We hence performed an immunological study based on the assumption that a chemokine/interleukin imbalance affects respiratory disorders caused by bronchiolitis and severe pneumonia. (2) Methods: The subjects were 19 infants without any underlying diseases, who developed respiratory symptoms owing to RSV infection. The subjects were stratified by their symptom severity, and chemokine and interleukin levels in their serum and tracheal aspirate fluid (TAF) were measured. (3) Results: The data of TAF, which were only obtained from subjects with severe symptoms, indicated that levels of inflammatory interleukins were much lower than the levels of chemokines. Three out of 6 subjects with severe symptoms showed below detectable levels of IL-6. TNF-α and IFN-γ levels were also lower than those of chemokines. The main increased CCL chemokines were CCL21 and CCL25, and the main increased CXCL chemokines were CXCL5, 8, 10, 12, and CX3CL1 in the lower respiratory region. Multiple regression analysis demonstrated that serum CX3CL1 and IL-6 levels were most strongly associated with symptom severity. This is the first report to date demonstrating that serum CX3CL1 level is associated with the severity of RSV infection. (4) Conclusions: Our results demonstrated that specific chemokines and the imbalance of cytokines are suspected to be associated with aggravated symptoms of RSV infection.

A Case of Focal Segmental Glomerulosclerosis in a Young Girl with a Very Low Birth Weight.

In Japan, the prevalence of low birth weight (LBW) has been estimated to be approximately 10%, which is the highest among developed countries. This high prevalence might affect the occurrence of LBW-associated diseases in the adult population of Japan. LBW has been recognized as a contributing factor to post-adaptive focal segmental glomerulosclerosis (FSGS) in adulthood; however, few reports to date have evaluated the clinical and pathological characteristics of post-adaptive FSGS. A 13-year-old girl was referred to our hospital owing to mild proteinuria, which was detected at a school urinary screening. She was born at a gestational age of 23 weeks, with a very LBW of 630 g. Dipstick urinalysis revealed grade (2+) proteinuria. Her serum creatinine level was 1.02 mg/dL, and she was diagnosed as having stage 2 chronic kidney disease (CKD). Her serum uric acid level was 7 mg/dL. Furthermore, her mother and 16-year old brother had hyperuricemia. A percutaneous renal biopsy leads to a diagnosis of FSGS. After 3 years of treatment with an angiotensin receptor blocker, her proteinuria decreased. However, her serum creatinine level was 1.07 mg/dL, and she still had stage 2 CKD. We considered that in this patient, the first hit was her LBW, and the second hit was hyperuricemia. The second hit might be associated with the development of CKD. The birth history of patients is not usually confirmed by nephrologists. Our case demonstrates that obtaining information regarding the preterm birth and LBW of patients is important in the diagnosis of noncommunicable diseases because school urinary screening is not routinely performed in countries other than Japan.

A 17-year-old boy with lymphocytic infundibuloneurohypophysitis who developed non-alcoholic steatohepatitis effectively treated with growth hormone.

Summary: We encountered a case of childhood-onset lymphocytic infundibuloneurohypophysitis, based on the MRI and endocrinological findings, with decreased function of the anterior and posterior lobes of the pituitary. Three years after the diagnosis, the patient developed non-alcoholic steatohepatitis (NASH), which was effectively treated by growth hormone (GH) supplementation. The present case demonstrated that NASH can be effectively treated by short-term GH supplementation, even in late childhood. Learning points: In recent years, the efficacy of growth hormone replacement therapy in normalizing the liver function of adult-onset growth hormone deficiency patients with non-alcoholic steatohepatitis (NASH) has been reported. Lymphocytic infundibuloneurohypophysitis is a very rare disease, particularly in childhood. We here presented a rare case of a child with lymphocytic infundibuloneurohypophysitis who developed NASH and showed substantial improvement in liver function after growth hormone treatment.

Involvement of Peripheral Monocytes with IL-1ß in the Pathogenesis of West Syndrome.

Neuroinflammation has been implicated in the pathogenesis of West syndrome (WS). Inflammatory cytokines, including interleukin-1ß(IL-1ß), have been reported to be associated with epilepsy. However, the assessment of cytokine changes in humans is not always simple or deterministic. This study aimed to elucidate the immunological mechanism of WS. We examined the intracellular cytokine profiles of peripheral blood cells collected from 13 patients with WS, using flow cytometry, and measured their serum cytokine levels. These were compared with those of 10 age-matched controls. We found that the WS group had significantly higher percentages of inter IL-1ß, interleukin-1 receptor antagonist (IL-1RA)-positive monocytes, and interferon gamma (IFN-γ) in their CD8+ T cells than the control group. Interestingly, the group with sequelae revealed significantly lower levels of intracellular IFN-γ and IL-6 in their CD8+ T and CD4+ T cells, respectively, than the group without sequelae. There was no correlation between the ratios of positive cells and the serum levels of a particular cytokine in the WS patients. These cytokines in the peripheral immune cells might be involved in the neuroinflammation of WS, even in the absence of infectious or immune disease. Overall, an immunological approach using flow cytometry analysis might be useful for immunological studies of epilepsy.

Detailed Evolutionary Analyses of the F Gene in the Respiratory Syncytial Virus Subgroup A.

We performed evolution, phylodynamics, and reinfection-related antigenicity analyses of respiratory syncytial virus subgroup A (RSV-A) fusion (F) gene in globally collected strains (1465 strains) using authentic bioinformatics methods. The time-scaled evolutionary tree using the Bayesian Markov chain Monte Carlo method estimated that a common ancestor of the RSV-A, RSV-B, and bovine-RSV diverged at around 450 years ago, and RSV-A and RSV-B diverged around 250 years ago. Finally, the RSV-A F gene formed eight genotypes (GA1-GA7 and NA1) over the last 80 years. Phylodynamics of RSV-A F gene, including all genotype strains, increased twice in the 1990s and 2010s, while patterns of each RSV-A genotype were different. Phylogenetic distance analysis suggested that the genetic distances of the strains were relatively short (less than 0.05). No positive selection sites were estimated, while many negative selection sites were found. Moreover, the F protein 3D structure mapping and conformational epitope analysis implied that the conformational epitopes did not correspond to the neutralizing antibody binding sites of the F protein. These results suggested that the RSV-A F gene is relatively conserved, and mismatches between conformational epitopes and neutralizing antibody binding sites of the F protein are responsible for the virus reinfection.

Correlation between Cerebrospinal Fluid IL-12 Levels and Severity of Encephalopathy in Children.

The roles of cytokines in the cerebrospinal fluid (CSF) of patients with acute encephalopathy remain unclear and controversial. In this study, the profiles of 26 cytokines and others were determined in 17 children with infection-associated neurological complications. Interleukin (IL)-12 levels were found to be high in a few of the patients. A comparison of the IL-12 levels in the CSF of patients demonstrated that IL-12 (p70) is almost always increased in those with encephalopathy. Levels of IL-12 in the CSF were highly correlated with the levels of PDGF-bb and IL-RA. IL-12 levels were found to be weakly correlated with IFN-γ levels, and strongly correlated with VEGF levels. These results demonstrate that IL-12 levels may affect the clinical symptoms of pediatric patients with encephalopathy.

Cardiac Complications Caused by Respiratory Syncytial Virus Infection: Questionnaire Survey and a Literature Review.

We investigated 22 cases of patients with myocarditis during respiratory syncytial virus (RSV) infection by a questionnaire survey, and performed a literature search to clarify their characteristics. The age distribution was divided into 2 groups, that is, 1 group comprised of patients younger than 4-years old and the other comprised patients older than 15 years. ECG demonstrated disturbance of the conduction system (AV block) in 7 out of 18 patients (38.8%), myocardial damage (ST-T change) in 9 out of 18 patients (50.0%), and tachycardia in 3 out of 18 patients (16.6%). Echocardiography displayed a robust decrease in left-heart function in 12 out of 14 patients. The outcome was 2 deaths, 1 pacemaker placement, 4 patients with mild sequel. Our data suggest that RSV myocarditis caused by RSV infection can be divided into 3 different pathophysiologies, characterized by disturbance of the conduction system, myocardial damage, and increase of autonomy.

Experimental and Clinical Evidence of the Effectiveness of Riboflavin on Migraines.

Riboflavin, a water-soluble member of the B-vitamin family, plays a vital role in producing energy in mitochondria and reducing inflammation and oxidative stress. Migraine pathogenesis includes neuroinflammation, oxidative stress, and mitochondrial dysfunction. Therefore, riboflavin is increasingly being recognized for its preventive effects on migraines. However, there is no concrete evidence supporting its use because the link between riboflavin and migraines and the underlying mechanisms remains obscure. This review explored the current experimental and clinical evidence of conditions involved in migraine pathogenesis and discussed the role of riboflavin in inhibiting these conditions. Experimental research has demonstrated elevated levels of various oxidative stress markers and pro-inflammatory cytokines in migraines, and riboflavin's role in reducing these marker levels. Furthermore, clinical research in migraineurs showed increased marker levels and observed riboflavin's effectiveness in reducing migraines. These findings suggest that inflammation and oxidative stress are associated with migraine pathogenesis, and riboflavin may have neuroprotective effects through its clinically useful anti-inflammatory and anti-oxidative stress properties. Riboflavin's safety and efficacy suggests its usefulness in migraine prophylaxis; however, insufficient evidence necessitates further study.

Role of Neuroinflammation and Blood-Brain Barrier Permutability on Migraine.

Currently, migraine is treated mainly by targeting calcitonin gene-related peptides, although the efficacy of this method is limited and new treatment strategies are desired. Neuroinflammation has been implicated in the pathogenesis of migraine. In patients with migraine, peripheral levels of pro-inflammatory cytokines, such as interleukin-1ß (IL-1ß) and tumor necrosis factor-α, are known to be increased. Additionally, animal models of headache have demonstrated that immunological responses associated with cytokines are involved in the pathogenesis of migraine. Furthermore, these inflammatory mediators might alter the function of tight junctions in brain vascular endothelial cells in animal models, but not in human patients. Based on clinical findings showing elevated IL-1ß, and experimental findings involving IL-1ß and both the peripheral trigeminal ganglion and central trigeminal vascular pathways, regulation of the Il-1ß/IL-1 receptor type 1 axis might lead to new treatments for migraine. However, the integrity of the blood-brain barrier is not expected to be affected during attacks in patients with migraine.

Towards a Treatment for Neuroinflammation in Epilepsy: Interleukin-1 Receptor Antagonist, Anakinra, as a Potential Treatment in Intractable Epilepsy.

Febrile Infection-Related Epilepsy Syndrome (FIRES) is a unique catastrophic epilepsy syndrome, and the development of drug-resistant epilepsy (DRE) is inevitable. Recently, anakinra, an interleukin-1 receptor antagonist (IL-1RA), has been increasingly used to treat DRE due to its potent anticonvulsant activity. We here summarized its effects in 38 patients (32 patients with FIRES and six with DRE). Of the 22 patients with FIRES, 16 (73%) had at least short-term seizure control 1 week after starting anakinra, while the remaining six suspected anakinra-refractory cases were male and had poor prognoses. Due to the small sample size, an explanation for anakinra refractoriness was not evident. In all DRE patients, seizures disappeared or improved, and cognitive function improved in five of the six patients following treatment. Patients showed no serious side effects, although drug reactions with eosinophilia and systemic symptoms, cytopenia, and infections were observed. Thus, anakinra has led to a marked improvement in some cases, and functional deficiency of IL-1RA was indicated, supporting a direct mechanism for its therapeutic effect. This review first discusses the effectiveness of anakinra for intractable epileptic syndromes. Anakinra could become a new tool for intractable epilepsy treatment. However, it does not currently have a solid evidence base.

The Neuroinflammatory Role of Pericytes in Epilepsy.

Pericytes are a component of the blood-brain barrier (BBB) neurovascular unit, in which they play a crucial role in BBB integrity and are also implicated in neuroinflammation. The association between pericytes, BBB dysfunction, and the pathophysiology of epilepsy has been investigated, and links between epilepsy and pericytes have been identified. Here, we review current knowledge about the role of pericytes in epilepsy. Clinical evidence has shown an accumulation of pericytes with altered morphology in the cerebral vascular territories of patients with intractable epilepsy. In vitro, proinflammatory cytokines, including IL-1ß, TNFα, and IL-6, cause morphological changes in human-derived pericytes, where IL-6 leads to cell damage. Experimental studies using epileptic animal models have shown that cerebrovascular pericytes undergo redistribution and remodeling, potentially contributing to BBB permeability. These series of pericyte-related modifications are promoted by proinflammatory cytokines, of which the most pronounced alterations are caused by IL-1ß, a cytokine involved in the pathogenesis of epilepsy. Furthermore, the pericyte-glial scarring process in leaky capillaries was detected in the hippocampus during seizure progression. In addition, pericytes respond more sensitively to proinflammatory cytokines than microglia and can also activate microglia. Thus, pericytes may function as sensors of the inflammatory response. Finally, both in vitro and in vivo studies have highlighted the potential of pericytes as a therapeutic target for seizure disorders.

A Case of Primary Ciliary Dyskinesia Caused by a Mutation in OFD1, Which Was Diagnosed Owing to Clostridium difficile Infection.

We report a Japanese 5-year-old boy with primary ciliary dyskinesia (PCD) which was diagnosed owing to Clostridium difficile (CD) infection caused by prolonged antibiotic exposure. He had intractable otitis media with effusion (OME) and had abdominal pain and diarrhea for 4 months after starting antibiotics administration. His stool contained CD toxin. After vancomycin treatment, his symptoms improved and his stools did not contain CD toxin. His past medical history included frequent pneumonia. We, therefore, performed electron microscopy of the biopsy specimen from his nasal mucosa and genetic testing, and he was diagnosed with PCD. PCD is a rare inherited genetic disease causing ciliary dysfunction, which is very difficult to diagnose because some children without PCD also develop the same symptoms. Therefore, children who have intractable OME, rhinosinusitis, frequent pneumonia, or bronchitis and are taking antibiotics for long periods of time should be checked for underlying diseases, such as PCD.

Hepcidin Levels and Pathological Characteristics in Children with Fatty Liver Disease.

PURPOSE: Hepcidin levels have previously been reported to be correlated with liver damage. However, the association between hepcidin levels and liver fibrosis in children with fatty liver disease remains unclear. This study therefore aimed to investigate the pathophysiology of fibrosis in children with fatty liver disease and its association with hepcidin levels. METHODS: This retrospective case series included 12 boys aged 6-17 years who were diagnosed with nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH) at the Tokyo Medical University Hospital. Sixteen liver biopsy samples from 12 subjects were analyzed. Serum hepcidin levels were assayed using enzyme-linked immunosorbent assay. Immunostaining for hepcidin was performed, and the samples were stratified by staining intensity. RESULTS: Serum hepcidin levels were higher in pediatric NAFLD/NASH patients than in controls. Conversely, a significant inverse correlation was observed between hepcidin immunostaining and Brunt grade scores and between hepcidin scores and gamma-glutamyltranspeptidase, hyaluronic acid, and leukocyte levels. We observed inverse correlations with a high correlation coefficient of >0.4 between hepcidin immunostaining and aspartate aminotransferase, alanine aminotransferase, total bile acid, and platelet count. CONCLUSION: There was a significant inverse correlation between hepcidin immunoreactivity and fibrosis in pediatric NAFLD patients; however, serum hepcidin levels were significantly higher, suggesting that these patients experienced a reduction in the hepcidin-producing ability of the liver in response to iron levels, leading to subsequent fibrosis. Therefore, hepcidin levels can be used as markers to identify the progression of fibrosis in patients with NAFLD.

Links between Immune Cells from the Periphery and the Brain in the Pathogenesis of Epilepsy: A Narrative Review.

Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood-brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures.