GWAS identifies candidate susceptibility loci and microRNA biomarkers for acute encephalopathy with biphasic seizures and late reduced diffusion

Risk Factors of Prehospital Emergency Care for Acute Encephalopathy in Children With Febrile Status Epilepticus

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) often develops in children with febrile status epilepticus (FSE) with neurological sequelae. No study has investigated the associations between prehospital emergency care and AESD onset.

METHODS

We retrospectively collected the data of children with FSE (>30 min) treated in Tottori University Hospital. We evaluated the prehospital emergency care information, investigating its association with AESD development.

RESULTS

We identified 11 patients with AESD and 44 with FSE. The time from onset to the arrival of the emergency medical services (EMS) (OR: 1.12, P = 0.015) and hospital arrival (OR: 1.07, P = 0.009) was positively associated with AESD development. In contrast, oxygen saturation levels in ambulances (OR: 0.901, P = 0.013) are negatively associated with AESD development. The time from onset to arrival at the hospital was associated with the time from onset to the administration of antiseizure medications (ASMs) (correlation coefficient: 0.857, P < 0.001), which was significantly associated with AESD development (OR: 1.04, P = 0.039). The cutoff values were 17 minutes from onset to the arrival of EMS (OR: 27.2, P = 0.003), 38 minutes to hospital arrival (OR: 5.71, P = 0.020), and 50 minutes of administration of ASMs (OR: 7.11, P = 0.009).

CONCLUSIONS

Prolonged time from onset to hospital arrival and hypoxia in ambulances were associated with AESD development. Shortening transport time, improving respiratory management in ambulances, and the early administration of ASMs might play a role in preventing the development of AESD.

Genetic and environmental risk factors of acute infection-triggered encephalopathy

Acute encephalopathy is a constellation of syndromes in which immune response, metabolism and neuronal excitation are affected in a variable fashion. Most of the syndromes are complex disorders, caused or aggravated by multiple, genetic and environmental risk factors. Environmental factors include pathogenic microorganisms of the antecedent infection such as influenza virus, human herpesvirus-6 and enterohemorrhagic Escherichia coli, and drugs such as non-steroidal anti-inflammatory drugs, valproate and theophylline. Genetic factors include mutations such as rare variants of the SCN1A and RANBP2 genes, and polymorphisms such as thermolabile CPT2 variants and HLA genotypes. By altering immune response, metabolism or neuronal excitation, these factors complicate the pathologic process. On the other hand, some of them could provide promising targets to prevent or treat acute encephalopathy.

Severe pediatric acute encephalopathy syndromes related to SARS-CoV-2

Background and objectives

To clarify whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cause acute encephalopathy in children and which are the most common syndromes that cause them and what are the outcomes.

Methods

A nationwide web-based survey among all members of the Japanese Society of Child Neurology to identify pediatric patients aged < 18 years who developed acute encephalopathy in Japan between 1 January 2020 and 31 May 2022 associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction or antigen tests using pharyngeal swabs. Acute encephalopathy was defined as acute onset of impaired consciousness lasting > 24 h or an altered mental state; neurological symptoms arising within 2 weeks of onset of COVID-19 or multisystem inflammatory syndrome in children (MIS-C)/pediatric inflammatory multisystem syndrome (PIMS); evidence of SARS-CoV-2 infection; and reasonable exclusion of other diseases. Patients were divided into the known clinico-radiological acute encephalopathy syndrome group and unexplained or unclassifiable acute encephalopathy group. Outcomes were assessed by pediatric cerebral performance category (PCPC) score at hospital discharge.

Results

Of the 3,802 society members, 217 representing institutions responded, and 39 patients with suspected acute encephalopathy were reported, of which 31 met inclusion criteria. Of these patients, 14 were diagnosed with known clinico-radiological acute encephalopathy syndromes, with acute encephalopathy with biphasic seizures and late reduced diffusion (five patients) being the most common. Five developed acute encephalopathy associated with MIS-C/PIMS. Among 31 patients, 9 (29.0%) had severe sequelae or died (PCPC ≥ 4). Two of three patients with encephalopathy with acute fulminant cerebral edema and two with hemorrhagic shock and encephalopathy syndrome died. The PCPC scores were higher in the known clinico-radiological acute encephalopathy syndrome group than in the unexplained or unclassifiable acute encephalopathy group (P < 0.01).

Discussion

Acute encephalopathy related to SARS-CoV-2 infection was demonstrated to be more severe than that caused by other viruses in Japan. Acute encephalopathy syndromes characterized by specific neuroradiological findings was associated with poor clinical outcomes.

Protective association of HLA-DPB1*04:01:01 with acute encephalopathy with biphasic seizures and late reduced diffusion identified by HLA imputation

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a severe syndrome of acute encephalopathy that affects infants and young children. AESD is a polygenic disorder preceded by common viral infections with high fever. We conducted an association study of human leukocyte antigen (HLA) regions with AESD using HLA imputation. SNP genotyping was performed on 254 Japanese patients with AESD and 799 healthy controls. We conducted 3-field HLA imputation for 14 HLA genes based on Japanese-specific references using data from our previous genome-wide association study. After quality control, 208 patients and 737 controls were included in the analysis of HLA alleles. We then compared the carrier frequencies of HLA alleles and haplotypes between the patients and controls. HLA-DPB1*04:01:01 showed a significant association with AESD, exerting a protective effect against the disease (p = 0.0053, p_corrected = 0.042, odds ratio = 0.43, 95% confidence interval = 0.21-0.80). The allele frequency of HLA-DPB1*04:01:01 was lower in East Asians than in Caucasians, which may partially account for the higher incidence of AESD in the Japanese population. The present results demonstrate the importance of fine-mapping of the HLA region to investigate disease susceptibilities and elucidate the pathogenesis of AESD.

Association of IL-1B rs16944 Polymorphism With Acute Encephalopathy With Biphasic Seizures and Late Reduced Diffusion Is Opposite to That of Febrile Seizures

Objective

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a severe neurologic complication of febrile infectious diseases in children. At the onset, AESD is clinically manifested as febrile status epilepticus. Subsequent damage to the cerebral cortex is ascribed to neurotoxicity. The incidence of AESD is remarkably high in Japan, suggesting the involvement of genetic factors. The expression of interleukin 1 beta (IL-1β), a member of the cytokine family involved in the inflammatory response, is reportedly associated with rs16944, a polymorphism in the upstream region of the IL-1B gene, being higher in TT genotype. Previous association studies of rs16944 with febrile seizures (FS) have demonstrated a significant excess in the TT vs. CC + CT genotype in the Asian population. Here, we conducted a case-control association study of rs16944 in AESD.

Methods

We genotyped rs16944 by Sanger sequencing on 283 patients with AESD. As controls, we used genotyping data of 104 Japanese individuals obtained from the 1,000 Genomes Project. Then, we performed a case-control association study using the chi-square test.

Results

The ratio of individuals with TT vs. those with CC+CT genotype was significantly lower in AESD than in the controls [p-value 0.021, Odds Ratio (OR) 0.52]. This finding was opposite to that of a previously reported FS.

Conclusion

The AESD has a genetic background distinct from FS and is not a severe type of FS.