Pediatric N-Methyl-d-Aspartate (NMDA) Receptor Encephalitis, With and Without Herpes Encephalitis.

OBJECTIVE: To compare clinical, diagnostic, management, and outcome factors in children with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis and a history of herpes simplex encephalitis (HSE) to children with NMDAR encephalitis without a history of HSE. METHODS: All patients with anti-NMDAR antibodies in cerebrospinal fluid treated at our institution between 2012 and 2019 were identified and divided into those with a history of HSE (HSE+NMDAR group) and those without a history of HSE (NMDAR-only group). Demographic data, clinical characteristics, immunotherapy, and outcome data were collected on all patients and compared between the 2 groups. RESULTS: Seventeen patients were identified with anti-NMDAR antibodies in cerebrospinal fluid, 6 of whom had a history of HSE. Mean age in the HSE+NMDAR cohort was significantly younger in the HSE+NMDAR cohort, as 5 of the 6 patients were infants. Of HSE+NMDAR patients, 50% had behavioral symptoms, 67% had movement disorders, and 100% had seizures at disease nadir. In the NMDAR-only group, 100% had behavioral symptoms, 73% had movement disorders, and 73% had seizures at nadir. HSE+NMDAR patients received a median of 1 immunotherapy, compared to a median of 4.5 immunotherapies in the NMDAR-only group. CONCLUSION: Behavioral symptoms were more common in NMDAR-only patients, whereas seizures were more common in HSE+NMDAR patients. Both groups had significant disability at disease nadir, with more improvement in disability over time in the NMDAR-only group. HSE+NMDAR patients received fewer immunotherapies than NMDAR-only patients. Outcomes of infants with HSE appear to primarily reflect sequelae from HSE.

BAFF/APRIL system in pediatric OMS: relation to severity, neuroinflammation, and immunotherapy.

BACKGROUND: B-cell dysregulation has been implicated but not fully characterized in pediatric opsoclonus-myoclonus syndrome (OMS), a neuroblastoma-associated neuroinflammatory disorder. OBJECTIVE: To assess the role of B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL), two critical B cell-modulating cytokines, as potential biomarkers of disease activity and treatment biomarkers in OMS. METHODS: Soluble BAFF and APRIL were measured in cerebrospinal fluid (CSF) and serum by ELISA in 433 children (296 OMS, 109 controls, 28 other inflammatory neurological disorders (OIND)). BAFF-R receptors on circulating CD19+ B cells were measured by flow cytometry. A blinded scorer rated motor severity on the OMS Evaluation Scale. Immunotherapies were evaluated cross-sectionally and longitudinally. RESULTS: The mean CSF BAFF concentration, which was elevated in untreated OMS and OIND, correlated with OMS severity category (P = 0.006), and reduction by adrenocorticotropic hormone or corticotropin (ACTH) (-61%) or corticosteroids (-38%) was seen at each level of severity. In contrast, CSF APRIL was normal in OMS and OIND and unaffected by immunotherapy. When the entire OMS dataset was dichotomized into 'high' versus 'normal' CSF BAFF concentration, the phenotype of the high group included greater motor severity and number of CSF oligoclonal bands, and a higher concentration of inflammatory chemokines CXCL13 and CXCL10 in CSF and CXCL9 and CCL21 in serum. Serum APRIL was 6.7-fold higher in the intravenous immunoglobulins (IVIg) group, whereas serum BAFF was 2.6-fold higher in the rituximab group. The frequency of B cell BAFF-R expression was similar in untreated and treated OMS. Longitudinal studies of CSF BAFF revealed a significant decline in ACTH-treated patients (with or without rituximab) (P < 0.0001). Longitudinal studies of serum APRIL showed a 2.9-fold increase after 1 to 2 g/kg IVIg monotherapy (P = 0.0003). CONCLUSIONS: Striking distinctions in BAFF/APRIL signaling were found. OMS displayed heterogeneity in CSF BAFF expression, which met many but not all criteria as a potential biomarker of disease activity. We speculate that CSF BAFF may have more utility in a biomarker panel than as a stand-alone biomarker, and that the selective upregulation of both serum APRIL by IVIg and BAFF by rituximab, as well as downregulation of CSF BAFF by ACTH/steroids, may have utility as treatment biomarkers.

Key role of CXCL13/CXCR5 axis for cerebrospinal fluid B cell recruitment in pediatric OMS.

To study aberrant B cell trafficking into the CSF in opsoclonus-myoclonus syndrome (OMS), chemoattractants CXCL13 and CXCL12, and B cell frequency and CXCR5 expression, were evaluated. CSF CXCL13 concentration and the CSF/serum ratio were higher in untreated OMS than controls, related directly to OMS severity and inversely to OMS duration, and correlated with CSF B cell frequency and oligoclonal bands. CXCL12 showed the opposite pattern. Selective accumulation of CXCR5+ memory B cells in CSF was found. In ACTH-treated OMS, CXCL13, but not CXCL12, was lower. These data implicate the chemokine/chemoreceptor pair CXCL13/CXR5 in B cell recruitment to the CNS in OMS. CXCL13 and CXCL12 may serve as reciprocal biomarkers of disease activity, but CXCL13 also had utility as a treatment biomarker.

Adult T-cell leukemia/lymphoma in an adolescent presenting with skin lesions.

Adult T-cell leukemia/lymphoma is a T-cell malignancy caused by the human T-cell lymphotropic virus-I. Adult T-cell leukemia/lymphoma is primarily a disease of adults due to the long latency period between initial infection and development of leukemia. We present a case of acute adult T-cell leukemia/lymphoma in an adolescent. Skin lesions had appeared 3 years earlier and were the initial sign of human T-cell lymphotropic virus-I infection and T-cell malignancy. Her disease failed to respond to both intensive chemotherapy and antiviral therapy. Cutaneous lesions are sometimes the initial sign of adult T-cell leukemia/lymphoma and early recognition is imperative.

Differential activation of c-fos and caspase-3 in hippocampal neuron subpopulations following neonatal hypoxia-ischemia.

Neonatal hypoxia-ischemia (HI) induces immediate early gene (IEG) c-fos expression as well as neuron death. The precise role of IEGs in neonatal HI is unclear. We investigated the temporal and spatial patterns of c-Fos expression in postnatal day 7 mice after unilateral carotid ligation and exposure to 8% oxygen. mRNA levels of c-fos quantitated by real-time polymerase chain reaction (PCR) increased nearly 40-fold (log 1.2 +/- 0.4) in the ipsilateral hippocampus 3 hr following neonatal HI, then returned to basal levels within 12 hr, although no change was observed in c-jun mRNA. Frozen coronal brain sections were stained with cresyl violet or used for immunohistochemical detection of c-Fos, cleaved caspase-3, glial fibrillary acidic protein (GFAP), and the mature neuron marker NeuN. c-Fos immunoreactivity increased throughout the injured hippocampus 3 hr after HI but became restricted to the CA2-3 subregion and the dentate gyrus (DG) at 6-12 hr and declined by 24 hr. In contrast, cleaved (activated) caspase-3 immunoreactivity was most abundant in the ipsilateral CA1 region at 3-6 hr after neonatal HI, then became more prominent in CA2-3 and DG. Double-labeling experiments showed c-Fos and cleaved caspase-3 immunoreactivity localized in spatially distinct neuron subpopulations. Prominent c-Fos immunoreactivity was observed in surviving CA2-3 and external granular DG neurons, and robust cleaved caspase-3 immunoreactivity was observed in pyknotic CA1, CA2-3, and subgranular DG neurons. The differential expression of c-Fos in HI-resistant hippocampal subpopulations vs. cleaved caspase-3 in dying neurons suggests a neuroprotective role for c-Fos expression in neonatal HI.

Selective involvement of BH3-only Bcl-2 family members Bim and Bad in neonatal hypoxia-ischemia.

Perinatal hypoxic-ischemic injury is a common cause of neurologic disability mediated in part by Bcl-2 family-regulated neuronal apoptosis. The Bcl-2 protein family consists of both pro- (e.g. Bax, Bad, Bid, Bim) and anti-apoptotic (e.g. Bcl-2, Bcl-X(L)) proteins that regulate mitochondrial outer membrane integrity, cytochrome c release and caspase activation. Previous studies have implicated Bax as an important mediator of neuronal death in several models of brain injury, including neonatal hypoxia-ischemia (HI). In this study, we assessed the roles of several members of the pro-apoptotic BH3 domain-only Bcl-2 sub-family in an in vivo mouse model of neonatal HI. Seven-day old control and gene-disrupted mice underwent unilateral left carotid ligation followed by 45 min exposure to 8% oxygen and the extent of brain injury was assessed 2 days later. Following HI, mice deficient in Bad or Bim exhibited reduced activated caspase-3 and glial fibrillary acidic protein immunostaining in their brains compared to similarly treated control animals. Measurement of hippocampal area showed decreased parenchymal loss in both Bad- and Bim-deficient mice versus control animals. In contrast, loss of Bid, another BH3-only protein, provided no protection from neonatal HI brain injury. These results indicate that Bad and Bim are selectively involved in neuron death following neonatal HI and may be targets for therapeutic intervention.

Bcl-2 family regulation of neuronal development and neurodegeneration.

Neuronal cell death is a key feature of both normal nervous system development and neuropathological conditions. The Bcl-2 family, via its regulation of both caspase-dependent and caspase-independent cell death pathways, is uniquely positioned to critically control neuronal cell survival. Targeted gene disruptions of specific bcl-2 family members and the generation of transgenic mice overexpressing anti- or pro-apoptotic Bcl-2 family members have confirmed the importance of the Bcl-2 family in the nervous system. Data from studies of human brain tissue and experimental animal models of neuropathological conditions support the hypothesis that the Bcl-2 family regulates cell death in the mature nervous system and suggest that pharmacological manipulation of Bcl-2 family action could prove beneficial in the treatment of human neurological conditions such as stroke and neurodegenerative diseases.