Total callosotomy ameliorates epileptic activity and improves cognitive function in a patient with Miller-Dieker syndrome

Miller-Dieker syndrome (MDS) is characterized by facial abnormalities and lissencephaly and is caused by a microdeletion in the region containing the LIS1 gene at chromosome 17p13.3. We report a case in which postnatal neuroimaging revealed severe lissencephaly. A 9-month-old boy presented with infantile spasms syndrome. Because of the refractory course of seizures and continued poor vitality, total corpus callosotomy was performed at 28 months of age. Intraoperative electroencephalogram (EEG) showed that the bilateral synchronous epileptiform discharges disappeared immediately after the disconnection. Postoperatively, the epileptic spasms (ES) in clusters disappeared, and single ES followed by focal seizures became the main symptom. The patient smiled more and became more responsive to stimuli. Postoperative scalp interictal EEG showed desynchronized multifocal spike and wave discharges with a marked decrease in the bilateral synchronous spike and wave discharges. Our findings suggest that the corpus callosum is involved in the mechanism ES in clusters in MDS-associated lissencephaly, and total callosotomy could be a therapeutic option.

Late relapse of anti-N-methyl-d-aspartate receptor encephalitis with amusia and transiently reduced uptake in 123I-iomazenil single-photon emission computed tomography

INTRODUCTION

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis has a high relapse rate at approximately 10-20%. Most relapses occur within 2 years from onset, and 5 years after onset is rare. We report a case of anti-NMDAR encephalitis relapse with amusia 10 years after the initial encephalitis and discuss the usefulness of ¹²³I-iomazenil single-photon emission computerized tomography (IMZ-SPECT) for its diagnosis.

CASE

A 13-year-old left-handed girl presented with a depressed level of consciousness and focal to bilateral tonic-clonic seizures. Cerebrospinal fluid (CSF) analysis showed a mildly increased white blood cell count, elevated neopterin levels, and positive oligoclonal bands. Brain MRI was normal. IMZ-SPECT revealed reduced uptake in the right frontoparietal region. She received intravenous pulse methylprednisolone (IVMP) and high-dose intravenous immunoglobulin for autoimmune encephalitis; her symptoms resolved without neurological deficits. At 23 years old, she had mild right-sided numbness, dysarthria, amusia, and tonic-clonic seizures. Although the CSF analysis and brain MRI were normal, IMZ-SPECT revealed reduced uptake, indicating a relapse of encephalitis. IVMP administration resolved the symptoms. After discharge, the initial and relapse CSF analysis revealed anti-NMDAR antibodies.

CONCLUSION

An anti-NMDAR encephalitis relapse 10 years after onset has never been reported. IMZ-SPECT may help in the diagnosis of anti-NMDAR encephalitis.

A case of focal cortical dysplasia type IIa with pathologically suspected bilateral Rasmussen syndrome

BACKGROUND

Rasmussen syndrome (RS) is a rare neurological disorder characterized by unilateral chronic inflammation, drug-resistant epilepsy, and progressive neurological and cognitive deterioration. There has been no detailed pathological evaluation or finding, including focal cortical dysplasia, for bilateral RS.

CASE REPORT

A 13-year-old boy presented with status epilepticus with focal to bilateral tonic clonic seizure starting from the left upper limb. At the age of 15, epilepsia partialis continua of the right face and upper extremities appeared, and MRI showed hemispheric abnormal signal intensities with left frontal lobe predominance. Three months later, MRI showed extensive abnormal signal intensities in the right occipitoparietal and left temporal lobes. Tacrolimus was useful in preventing recurrence. Because the seizures were intractable, a corpus callosotomy was performed at 16 years along with a concurrent brain biopsy from the bilateral lateral frontal cortices. We detected dysmorphic neurons in addition to inflammatory changes suspicious for RS, leading to a diagnosis of focal cortical dysplasia (FCD) type Ⅱa and suspected bilateral RS. Total callosotomy and vagus nerve stimulation were not sufficiently effective.

CONCLUSIONS

In bilateral RS, FCD may be present in both cerebral hemispheres. In the current case, an autoimmune response to dysmorphic neurons may have contributed to the pathogenesis of intense inflammation.

Evaluation of the Diagnostic Criteria for Anti-NMDA Receptor Encephalitis in Japanese Children

OBJECTIVE

To evaluate the validity of the 2016 clinical diagnostic criteria proposed for probable anti-NMDA receptor (NMDAR) encephalitis in children, we tested the criteria in a Japanese pediatric cohort.

METHODS

We retrospectively reviewed clinical information of patients with neurologic symptoms whose CSF was analyzed for NMDAR antibodies (NMDAR-Abs) in our laboratory from January 1, 2015, to March 31, 2019.

RESULTS

Overall, 137 cases were included. Of the 41 cases diagnosed as probable anti-NMDAR encephalitis (criteria-positive) according to the 2016 criteria, 13 were positive and 28 were negative for anti-NMDAR-Abs. Of the 96 criteria-negative cases, 3 were positive and 93 were negative for anti-NMDAR-Abs. The sensitivity of the criteria was 81.2%, specificity was 76.9%, positive predictive value (PPV) was 31.7%, and negative predictive value was 96.9%. Compared with the true-positive group, the false-positive group contained more male than female patients (male:female, 4:9 in the true-positive vs 19:9 in the false-positive group, p = 0.0425). The majority of the cases with false-positive diagnoses were associated with neurologic autoimmunity.

CONCLUSION

The clinical diagnostic criteria are reliable for deciding to start immunomodulatory therapy in the criteria-positive cases. Low PPV may be caused by a lower prevalence of NMDAR encephalitis or lower level of suspicion for encephalitis in the pediatric population. Physicians should therefore continue differential diagnosis, focusing especially on other forms of encephalitis.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that the proposed diagnostic criteria for anti-NMDAR encephalitis in children has a sensitivity of 81.2% and a specificity of 76.9%.

Intrathecal dexamethasone therapy for febrile infection-related epilepsy syndrome

OBJECTIVE

Increasing reports suggest a role for immunological mechanisms in febrile infection-related epilepsy syndrome (FIRES). The objective of this study was to elucidate the efficacy and safety of intrathecal dexamethasone therapy (IT-DEX).

METHODS

We assessed six pediatric patients with FIRES who were administered add-on IT-DEX in the acute (n = 5) and chronic (n = 1) phases. We evaluated clinical courses and prognosis. We measured cytokines/chemokines in cerebrospinal fluid (CSF) from FIRES patients at several points, including pre- and post-IT-DEX, and compared them with control patients with chronic epilepsy (n = 12, for cytokines/chemokines) or with noninflammatory neurological disease (NIND, n = 13, for neopterin).

RESULTS

Anesthesia was weaned after a median of 5.5 days from IT-DEX initiation (n = 6). There was a positive correlation between the duration from the disease onset to the introduction of IT-DEX and the length of ICU stay and the duration of mechanical ventilation. No patient experienced severe adverse events. Seizure spreading and background activities on electroencephalography were improved after IT-DEX in all patients. The levels of CXCL10, CXCL9, IFN-γ, and neopterin at pre-IT-DEX were significantly elevated compared to levels in epilepsy controls, and CXCL10 and neopterin were significantly decreased post-IT-DEX, but were still higher compared to patients with chronic epilepsy. IL-6, IL-8, and IL-1β were significantly elevated before IT-DEX compared to epilepsy controls, though there was no significant decrease post-treatment.

INTERPRETATION

IT-DEX represents a therapeutic option for patients with FIRES that could shorten the duration of the critical stage of the disease. The effect of IT-DEX on FIRES might include cytokine-independent mechanisms.

De novo ATP1A3 variants cause polymicrogyria

Polymicrogyria is a common malformation of cortical development whose etiology remains elusive. We conducted whole-exome sequencing for 124 patients with polymicrogyria and identified de novo ATP1A3 variants in eight patients. Mutated ATP1A3 causes functional brain diseases, including alternating hemiplegia of childhood (AHC), rapid-onset dystonia parkinsonism (RDP), and cerebellar ataxia, areflexia, pes cavus, optic nerve atrophy, and sensorineural deafness (CAPOS). However, our patients showed no clinical features of AHC, RDP, or CAPOS and had a completely different phenotype: a severe form of polymicrogyria with epilepsy and developmental delay. Detected variants had different locations in ATP1A3 and different functional properties compared with AHC-, RDP-, or CAPOS-associated variants. In the developing cerebral cortex of mice, radial neuronal migration was impaired in neurons overexpressing the ATP1A3 variant of the most severe patients, suggesting that this variant is involved in cortical malformation pathogenesis. We propose a previously unidentified category of polymicrogyria associated with ATP1A3 abnormalities.

Neurocritical care and target immunotherapy for febrile infection-related epilepsy syndrome

Febrile infection-related epilepsy syndrome (FIRES) is an intractable neurological disease characterized by an unexplained refractory status epilepticus triggered by febrile infection. A Consensus definition of FIRES was proposed in 2018, and its clinical features and prognosis are gradually being clarified. However, the development of effective treatments has been hindered as the etiology of this rare disease is as yet unelucidated. The basic approach to the management of FIRES, like other forms of epilepsy, is based on the control of seizures, however seizures are extremely intractable and require intravenous administration of large doses of anticonvulsants, mainly barbiturates. This treatment strategy produces various complications including respiratory depression and drug hypersensitivity syndrome, which make it more difficult to control seizures. Consequently, it is crucial to predict these events and to formulate a planned treatment strategy. As well, it is important to grow out of conventional treatment strategies that rely on only anticonvulsants, and alternative therapies are gradually being developed. One such example is the adoption of a ketogenic diet which may lead to reduced convulsions as well as improve intellectual prognosis. Further, overproduction of inflammatory cytokines in the central nervous system has been shown to be strongly related to the pathology of FIRES which has led to attempts at immunomodulation therapy including anti-cytokine therapy.

Chronic dysfunction of blood-brain barrier in patients with post-encephalitic/encephalopathic epilepsy

PURPOSE

This study aimed to elucidate the characteristics and effects of chronic blood-brain barrier (BBB) dysfunction in patients with post-encephalitic/encephalopathic epilepsy (PEE), using brain images and the cerebral spinal fluid (CSF)/serum albumin ratio (albumin quotient, QAlb) as a marker of BBB function.

METHODS

We examined the albumin levels in CSF and serum samples from 312 patients with refractory epilepsy in our center between 2004 and 2015. Sixty samples from patients with PEE and 97 samples from age- and sex-matched disease controls (DC) were evaluated. We classified PEE patients into a widespread lesion group and a focal lesion group by severity on brain magnetic resonance images in the chronic phase after acute encephalitis/encephalopathy.

RESULTS

Median QAlb was higher in PEE than in DC [median (range) ×10³: PEE 3.6 (1.0-10.3) versus DC 2.7 (1.0-6.7), p = 0.007]. In a linear regression analysis of the relationship between QAlb and patient's age at CSF examination or duration of epilepsy, the slope of the regression line was greater in PEE than in DC. Furthermore, in patients under ten years of age, linear regression analysis of QAlb versus seizure frequency showed a weak but positive correlation. Among PEE patients, seizure frequency was higher in the widespread lesion group than in the focal lesion group [300 (4-3000) versus 30 (1-1500) seizures/month, p <  0.001].

CONCLUSION

Our study suggests that patients with PEE have more severe BBB dysfunction, and that the BBB dysfunction is associated with refractory epilepsy.

A child with acute transverse myelitis requiring permanent pacemaker implantation

We diagnosed a 3-year-old girl with acute transverse myelitis (ATM). She presented with weakness of the limbs and developed urination difficulty and respiratory disturbance. Magnetic resonance imaging revealed a symmetric area of high signal intensity on T2-weighted images involving the lower end of the medulla oblongata to the level of the fourth thoracic vertebra. Anti-aquaporin-4 antibody was negative. She was treated with intravenous methylprednisolone pulse therapy, immunoglobulin therapy, and plasmapheresis; however, her clinical symptoms did not change. At 10 and 20days after symptom onset, cardiac arrest occurred on postural change, requiring cardiopulmonary resuscitation. A permanent pacemaker was implanted 23days after onset. In the presence of sympathetic nerve hypofunction, relative hyperactivity of the parasympathetic nerves may have led to severe bradycardia and cardiac arrest in the presence of an inducer, such as a postural change. This is the first reported case of pacemaker implantation for management of ATM.

[A case of West syndrome with a deletion at chromosome 2q24.3-q31.3]

A male infant suffered from partial seizures at four months of age, and developed West syndrome at eight months of age. ACTH therapy was effective for the West syndrome. However, partial seizures recurred at 14 months of age, which could not be sufficiently controlled with an anti-epileptic drug. A characteristic facial appearance, great toe abnormalities, and developmental retardation were noted. An interstitial deletion of 2q was detected by chromosomal G-banding and array comparative genomic hybridization (CGH) confirmed the deletion as arr 2q24.3q31.3 (166,303,447-180,982.972) ×1 (build19). He presented with clinical findings similar to those of the recently defined 2q31.1 deletion syndrome. The deletion extended to the SCN1A gene, a gene responsible for Dravet syndrome, mapped to the 2q24.3 region. No deletion was noted in the adjacent SCN2A gene. Thus, for interstitial deletions, detailed breakpoints should be identified by array CGH. The frequency of epilepsy varies with deletion ranges in the 2q24-q31 region, suggesting that deletions in the SCN1A gene deletion, as well as in the 2q31.1 region, are involved in the development of West syndrome.

A case of early onset epileptic encephalopathy with de novo mutation in SLC35A2: Clinical features and treatment for epilepsy

INTRODUCTION

Mutations of SLC35A2 that encodes Golgi-localized Uridine diphosphate (UDP)-galactose transporter at Xp11.23 lead to congenital disorders of glycosylation (CDG). Although patients with CDG generally have diverse systemic symptoms, patients with a SLC35A2 mutation manifest predominantly disorders of the central nervous system (CNS).

CASE REPORT

A female infant aged 12months was referred to our center because of intractable seizures. The patient was born with birth weight of 3228g after 40weeks of unremarkable gestation. At the age of 2months, she had partial seizures evolving to epileptic spasms. Her electroencephalogram showed hypsarrhythmia. Her seizures were refractory to antiepileptic drugs. At referral to our center at 12months, she had developmental delay (no head control), widely spaced inverted nipples, external strabismus, and bilateral heterochromia of irises. Blood examinations were normal. Brain magnetic resonance imaging findings included cerebral and cerebellar atrophy, thinning of the corpus callosum, and arachnoid pouch. Whole-exome sequencing detected a de novo frameshift mutation c.950delG (p.Gly317Alafs*32) at exon 4 in SLC35A2. Seizures subsided after the second adrenocorticotropic hormones (ACTH) therapy at 18months. At the age of 36months, although she had intellectual disability with no meaningful words, she was seizure-free and was able to sit without support and showed smiling face a lot.

CONCLUSION

This report reviewed the clinical features of patients with a SLC35A2 mutation. ACTH therapy may be effective for refractory epilepsy in these patients.

A pediatric patient of hemorrhagic acute transverse myelitis

An 11-year-old boy presented with progressive leg hypesthesia but no history of trauma. Dysuria and constipation appeared subsequent to gait difficulty. He was admitted 8days after onset. Spinal magnetic resonance imaging (MRI) revealed longitudinal hyperintensity with cord swelling and hypointensity on T2-weighted images, suggesting severe inflammation and microbleeding change, respectively. Gadolinium contrast-enhanced MRI demonstrated mild enhancement in the lesions. Platelet count and coagulation findings were normal, and cerebrospinal fluid analysis showed no pleocytosis. He was diagnosed with idiopathic acute transverse myelitis (ATM), and intravenous methylprednisolone pulse therapy and plasmapheresis were initiated. On day 14, motor dysfunction aggravated suddenly, accompanied by expanding hemorrhagic lesions. Thereafter, administration of intravenous immunoglobulin, repeated intravenous methylprednisolone pulse therapy and prednisolone for one month resulted in complete recovery four months later. Both anti-aquaporin-4 and anti-myelin oligodendrocyte glycoprotein antibodies were negative. We presented the first pediatric case showing hemorrhagic spinal lesions in the clinical course of ATM. This severe complication should be recognized in the management of ATM.

A case of succinic semialdehyde dehydrogenase deficiency with status epilepticus and rapid regression

BACKGROUND

Clinical phenotypic expression of SSADH deficiency is highly heterogeneous, and some infants may develop refractory secondary generalized seizures.

PATIENT

A 9-month-old boy manifested partial seizures, developing severe status epilepticus, and conventional antiepileptic drugs were ineffective. Use of ketamine contributed to the control of status epilepticus, achieving a reduction in frequency of partial seizures, and improving EEG findings without apparent complications. Diffusion-weighted images showed hyperintensities in the bilateral basal ganglia and fornix, and multiple T2 hyperintensity lesions were detected. (123)I-iomazenil (IMZ) SPECT revealed a decrease in binding of (123)I-iomazenil predominantly in the left temporal region by the 18th day of hospitalization. However, repeated IMZ-SPECT on the 46th day of hospitalization demonstrated almost no accumulation across a broad region, sparing the left temporal region. The patient showed rapid regression, refractory myoclonus, and severe progressive brain atrophy.

CONCLUSION

IMZ-SPECT findings demonstrated reduced benzodiazepine receptor binding and its dynamic changes in an SSADH-deficient patient. Considering the down regulation of the GABAA receptor, ketamine should be included in pharmacotherapeutic strategies for treatment of refractory status epilepticus in SSADH-deficient patients.

Cytokine-related and sodium channel polymorphism as candidate predisposing factors for childhood encephalopathy FIRES/AERRPS

Febrile infection-related epilepsy syndrome (FIRES), or acute encephalitis with refractory, repetitive partial seizures (AERRPS), is an epileptic encephalopathy beginning with fever-mediated seizures. The etiology remains unclear. To elucidate the genetic background of FIRES/AERRPS (hereafter FIRES), we recruited 19 Japanese patients, genotyped polymorphisms of the IL1B, IL6, IL10, TNFA, IL1RN, SCN1A and SCN2A genes, and compared their frequency between the patients and controls. For IL1RN, the frequency of a variable number of tandem repeat (VNTR) allele, RN2, was significantly higher in the patients than in controls (p=0.0067), and A allele at rs4251981 in 5' upstream of IL1RN with borderline significance (p=0.015). Haplotype containing RN2 was associated with an increased risk of FIRES (OR 3.88, 95%CI 1.40-10.8, p=0.0057). For SCN1A, no polymorphisms showed a significant association, whereas a missense mutation, R1575C, was found in two patients. For SCN2A, the minor allele frequency of G allele at rs1864885 was higher in patients with borderline significance (p=0.011). We demonstrated the association of IL1RN haplotype containing RN2 with FIRES, and showed a possible association of IL1RN rs4251981 G>A and SCN2A rs1864885 A>G, in Japanese patients. These preliminary findings suggest the involvement of multiple genetic factors in FIRES, which needs to be confirmed by future studies in a larger number of FIRES cases.

Autoimmune autonomic ganglionopathy in a pediatric patient presenting with acute encephalitis

Autoimmune autonomic ganglionopathy (AAG) is an acquired immune-mediated disorder that leads to systemic autonomic failure. Autoantibodies to the ganglionic nicotinic acetylcholine receptor (gAChR) are detected in 50% of AAG patients. We report the first pediatric case of AAG presenting with acute encephalitis. The patient was a 13-year-old boy who presented with orthostatic hypotension, followed by rapidly progressing disturbance of consciousness. Cerebrospinal fluid analysis revealed significant pleocytosis and increased neopterin concentration. Head MRI showed hyperintensities in bilateral caudate nuclei, putamen, hippocampus, and insula cortex. Severe autonomic dysfunctions such as severe orthostatic hypotension, bradycardia, dysuria, prolonged constipation and vomiting appeared. These symptoms were successfully controlled by repeated immunomodulating therapy with intravenous methylprednisolone pulse therapy and intravenous immunoglobulin. Autoantibodies to the α3 subunit of gAChR were detected at neurological onset, but were undetectable five months later. This observation indicates that AAG should be suspected in patients manifesting acute encephalitis characterized by preceding and prolonged autonomic symptoms, and immunomodulating therapy from an early stage can be effective.

[A clinical study on high-dose erythropoietin therapy for acute encephalopathy or encephalitis]

OBJECTIVE

We performed high-dose erythropoietin therapy (hEPO) for acute encephalopathy or encephalitis (AE), and evaluated its safety and efficacy.

METHODS

We performed hEPO in AE patients with widespread lesions demonstrated by diffusion-weighted imaging, and prospectively investigated changes in hemoglobin levels, adverse events, changes in images, and developmental quotients.

RESULTS

All four patients showed neither an increase in the hemoglobin level nor adverse event possibly related to hEPO. One patient with acute encephalitis showed resolution of the lesion and normal developmental quotient. Two patients who had acute encephalopathy with febrile convulsive status epilepticus showed mild cerebral atrophy in the recovery phase;one had a normal developmental quotient. The patient with acute necrotizing encephalopathy including a brainstem lesion avoided acute-phase death.

CONCLUSION

Two patients showed no sequelae despite images indicating widespread abnormality. hEPO could be performed safely in patients with AE, however further trials are necessary concerning its efficacy.

[Clinical evaluation of six patients with anti-NMDAR encephalitis]

OBJECTIVE

We examined the clinical course and the prognosis of patients with anti-NMDAR encephalitis.

METHODS

We retrospectively evaluated the patients who has distinctive clinical features as anti-NMDAR encephalitis based on their medical records.

RESULTS

There were two male and four female patients with anti-NMDAR encephalitis. They were aged between 13 and 16 years. One of the six, 14 years female patient was negative for anti-NMDAR antibody. All four female patients with anti-NMDAR encephalitis had an ovarian tumor. Neurocognitive dysfunction and epilepsy remained in one female patient with right temporal lobe lesion and one male patient with celebellar abnormalities had mild mental impairment. In three patients including two patients who were examined abdominal MRI for the first time after recovery from the encephalitis, overian tumors became apparent during follow-up. In one of other patients, overian tumors had a tendency to increase in size after recovery.

CONCLUSION

Sequellae were seen in two cases that have abnormalities in brain MRI. As to ovarian tumor, it was considered to be necessary to checkup pelvic MRI for at least four years after the onset of encephalitis.

Abnormal pupillary light reflex with chromatic pupillometry in Gaucher disease

The hallmark of neuronopathic Gaucher disease (GD) is oculomotor abnormalities, but ophthalmological assessment is difficult in uncooperative patients. Chromatic pupillometry is a quantitative method to assess the pupillary light reflex (PLR) with minimal patient cooperation. Thus, we investigated whether chromatic pupillometry could be useful for neurological evaluations in GD. In our neuronopathic GD patients, red light-induced PLR was markedly impaired, whereas blue light-induced PLR was relatively spared. In addition, patients with non-neuronopathic GD showed no abnormalities. These novel findings show that chromatic pupillometry is a convenient method to detect neurological signs and monitor the course of disease in neuronopathic GD.

A case of severe progressive early-onset epileptic encephalopathy: unique GABAergic interneuron distribution and imaging

Early-onset epileptic encephalopathies include various diseases such as early-infantile epileptic encephalopathy with suppression burst. We experimentally investigated the unique clinicopathological features of a 28-month-old girl with early-onset epileptic encephalopathy. Her initial symptom was intractable epilepsy with a suppression-burst pattern of electroencephalography (EEG) from 7 days of age. The suppression-burst pattern was novel, appearing during sleep, but disappearing upon waking and after becoming 2 months old. The EEG showed multifocal spikes and altered with age. Her seizures demonstrated various clinical features and continued until death. She did not show any developmental features, including no social smiling or head control. Head MRI revealed progressive atrophy of the cerebral cortex and white matter after 1 month of age. (123)IMZ-SPECT demonstrated hypo-perfusion of the cerebral cortex, but normo-perfusion of the diencephalon and cerebellum. Such imaging information indicated GABA-A receptor dysfunction of the cerebral cortex. The genetic analyses of major neonatal epilepsies showed no mutation. The neuropathology revealed atrophy and severe edema of the cerebral cortex and white matter. GAD-immunohistochemistry exhibited imbalanced distribution of GABAergic interneurons between the striatum and cerebral cortex. The results were similar to those of focal cortical dysplasia with transmantle sign and X-linked lissencephaly with ARX mutation. We performed various metabolic examinations, detailed pathological investigations and genetic analyses, but could not identify the cause. To our knowledge, her clinical and pathological courses have never been described in the literature.

[Successful treatment for thrombotic microangiopathy with recombinant human soluble thrombomodulin after umbilical cord blood transplantation]

A 1-year-old girl with familial hemophagocytic lymphohistiocytosis underwent umbilical cord blood transplantation. On day 24, she developed renal failure, jaundice and hemolytic anemia, and we diagnosed transplantation-associated thrombotic microangiopathy (TMA). Despite discontinuation of tacrolimus, her condition became even worse. From day 25, we started to administer recombinant human soluble thrombomodulin (rTM). According to the recommendation of the pharmaceutical company, a dose reduction from 380 to 130 IU/kg/day in patients with renal failure, we administered rTM at the reduced dose during the first 2 days. Because the reduced dose was not effective, we administered rTM at the standard dose from day 27. Surprisingly, she began to recover from TMA on the next day, and we continued to administer rTM until day 109. She is alive without evidence of disease eighteen months after transplantation. Adverse events of rTM were severe gastrointestinal hemorrhage and hemorrhagic cystitis, and it was necessary to control hemorrhage by interruption of administration. This case report suggests that rTM may be effective for TMA. Moreover, alteration in the dosage schedule seems to be required according to the condition of patients. Further studies are needed to evaluate the effectiveness and an optimal dose of rTM as a treatment for TMA.

Suppression of specific IgE antibody responses by liposome-conjugated ovalbumin in mice sensitized with ovalbumin via the respiratory tract

BACKGROUND

Previously we have shown that intranasal administration of ovalbumin (OVA) together with cholera toxin (CT) abrogates nasal tolerance to OVA, resulting in the induction of specific IgE antibody (Ab) responses, and that intraperitoneal injection of OVA coupled with liposomes (OVA-liposomes) induces a selective suppression of IgE Ab responses to OVA. Whether OVA-liposomes suppress anti-OVA IgE Ab responses in mice sensitized with CT-combined OVA via the respiratory tract remains to be clarified.

METHODS

In some experiments, mice were given OVA, liposomes or OVA-liposomes with or without CT intranasally three times, at 2-week intervals (weeks 0, 2 and 4). In other experiments, mice were given OVA-liposomes intranasally 2 days before or 1 and 3 weeks after CT-combined OVA (week 0), which was administered intranasally three times, at 2-week intervals (weeks 0, 2 and 4). Two weeks after the third administration of CT-combined OVA (week 0), nasal wash and serum IgA, IgG and IgE Ab responses were assayed.

RESULTS

Pretreatment with OVA-liposomes suppressed IgE Ab responses to CT-combined OVA, with a significantly high production of both nasal IgA and serum IgG Abs. Moreover, treatment with OVA-liposomes 1 and 3 weeks after CT-combined OVA administration also suppressed IgE Ab responses. The suppression of anti-OVA IgE Ab production by OVA-liposomes was accompanied by a simultaneous enhancement of specific IgA and IgG (IgG1, and especially IgG2a) Ab production.

CONCLUSIONS

Postimmunization treatment with OVA-liposomes, as well as preimmunization treatment, suppressed specific IgE Ab responses in mice sensitized intranasally with CT-combined OVA. Allergens conjugated to liposomes may be appropriate for preventing the development of allergies to inhaled or dietary antigens in humans.

Antigen-specific, IgE-selective unresponsiveness induced by antigen-liposome conjugates. Comparison of four different conjugation methods for the coupling of antigen to liposome

BACKGROUND

We have previously reported that ovalbumin (OVA) coupled with liposome via glutaraldehyde (GA) induced OVA-specific- and IgE-selective unresponsiveness in mice.

METHODS

In this study, OVA-liposome conjugates were made using four different coupling protocols: via GA, N-(6-maleimidocaproyloxy) succinimide (EMCS), disuccinimidyl suberate (DSS) and N-succimidyl-3(2-pyridyldithio)propionate (SPDP) and the induction of antigen-specific IgG and IgE antibody production was investigated for each. In addition, antigen-specific cytokine production by spleen cells of mice immunized either with OVA-liposome or with OVA adsorbed with aluminum hydroxide was investigated.

RESULTS

OVA-liposome conjugates coupled via GA or DSS did not induce anti-OVA IgE antibody production but induced substantial anti-OVA IgG antibody production. On the other hand, the induction of anti-OVA IgE unresponsiveness by OVA-liposome conjugates coupled via EMCS or SPDP was incomplete. The amount of interleukin 4 (IL-4) produced by spleen cells stimulated in vitro with OVA correlated well with anti-OVA IgE antibody production in donor mice. However, the production of no other cytokine, i.e., IL-2, IL-5, IL-10 or interferon-gamma, was correlated with in vivo IgE antibody production.

CONCLUSION

OVA-liposome coupled via GA or DSS induced complete suppression of anti-OVA IgE production. The results in this study further suggest that the regulation of IgE antibody production does not necessarily correlate with so-called Th1 cytokine production.

Delayed progression of murine AIDS in C57BL/6 mice pre-immunized with a highly antigenic 10-mer peptide encoded by the murine AIDS defective virus gag p12 gene

C57BL/6 (B6) mice were immunized with a highly antigenic 10-mer peptide (P12-10), which is encoded by the murine AIDS (MAIDS) defective virus gag p12 gene, emulsified in incomplete Freund's adjuvant (ICFA). One week later, the mice were inoculated with the MAIDS virus to see if the immunization affects progression of MAIDS. It was demonstrated that the immunization significantly delayed progression of MAIDS, although it failed to induce appreciable cytotoxic T lymphocyte (CTL) responses against the P12-10 antigen. In contrast, immunization of B6 mice with the P12-10 coupled with liposome induced substantial CTL responses but failed to protect the mice against MAIDS development. This segregation between CTL activity and in vivo protection efficacy might be worth considering when we exploit vaccines for augmenting cellular immunity mediated by CD8+ T cells.

Macrophage inhibition of lymphocyte and tumor cell growth is mediated by 25-hydroxycholesterol in the cell membrane

We have previously reported that a lipid molecule in the membrane fraction of cloned macrophage hybridomas inhibited the growth of lymphocytes and several tumor cell lines. In this study, the inhibitory lipid molecule in the membrane fraction of macrophages was analyzed by thin-layer chromatography and identified as 25-hydroxycholesterol, a family of oxysterols. This conclusion was confirmed by analysis using gas chromatography-mass spectrometry. In addition, both 25-hydroxycholesterol and the lipid molecule recovered from macrophage cell membrane induced apoptosis of the murine T cell lymphoma, BW-5147. These results suggest that an oxysterol expressed in the macrophage cell membrane may participate in the regulation of cell growth through cell contact.

Induction of protection against oral infection with cytotoxin-producing Escherichia coli O157:H7 in mice by shiga-like toxin-liposome conjugate

We have previously reported that purified Shiga-like toxins (SLT), SLT-I and SLT-II coupled with liposomes induced a substantial amount of anti-SLT-I and anti-SLT-II IgG antibody production, respectively, in mice. The levels of anti-SLT antibody in the sera of SLT-liposome-immune mice correlated well with the protection against subsequent challenge with SLT. In this study, mice were immunized intraperitoneally with the mixture of SLT-I-liposome and SLT-II-liposome and protection against oral infection with cytotoxin-producing Escherichia coli O157:H7 was evaluated. All of the mice that received immunization with the mixture of SLT-I-liposome and SLT-II-liposome were protected against subsequent intravenous challenge with 10 LD50 of either SLT-I or SLT-II. Eight weeks after primary immunization, mice were inoculated intragastrically with 10(9) CFU of E. coli O157:H7 strain 96-60. All SLT-liposome-immune mice tested survived without any apparent symptom while control mice died within 5 days. In addition, as shown by other antigen-liposome conjugates, SLT-liposome induced undetectable anti-SLT IgE antibody production while they induced substantial amounts of anti-SLT IgG antibodies. These results suggest that SLT-liposome conjugate may serve as a candidate vaccine that induces protection against cytotoxin-producing E. coli infection.

Induction of protection against tetanus toxin in mice by tetanus toxoid-liposome conjugate

Tetanus toxoid (Ttd) was coupled to liposomes via glutaraldehyde. Intraperitoneal injection in BALB/c mice with Ttd-liposomes induced a substantial amount of anti-Ttd IgG antibody production and an extremely low level of anti-Ttd IgE antibody production. Mice immunized with Ttd-liposomes were successfully protected against a subsequent challenge with a lethal dose of tetanus toxin (Ttx). On the other hand, aluminum hydroxide-adsorbed Ttd (Ttd-alum) and plain Ttd solution induced the production of both IgG and IgE antibodies against Ttd. Moreover, secondary immunization with Ttd-liposomes in mice, in which anti-Ttd IgE antibody production was induced by Ttd-alum led to enhanced anti-Ttd IgG and a limited anti-Ttd IgE antibody production. When Ttd-liposome preparation was lyophilized, the efficacy of Ttd-liposomes was maintained for 6 months at 37 C, suggesting that this vaccine preparation would be stable without refrigeration. These results demonstrate the potential ability of Ttd-liposome conjugates to produce a tetanus vaccine which provides protection against (Ttx) while inducing the least amount of anti-Ttd IgE antibodies.

Ovalbumin coupled either with murine red blood cells or liposome induces IgG but not IgE antibody production

Ovalbumin (OVA) was coupled with murine red blood cells (MRBC) using glutaraldehyde. The OVA-MRBC conjugate induced anti-OVA IgG antibody in mice at almost the same level as OVA in alum. However, no IgE antibody production specific for OVA was observed in OVA-MRBC-injected mice. A significant increase in IGG2a production was obtained with OVA-MRBC immunization, whereas the production of IgG1 predominated in OVA in alum immunization. Am OVA-liposome conjugate induced IgE-specific unresponsiveness in mice in the same manner as OVA-MRBC. Similar results were obtained when antigens other than OVA, such as tetanus toxoid or diphtheria toxoid, were coupled to liposome. These results show the potential of antigen-liposome conjugates for the development of vaccine that induces sufficient IgG antibody production without IgE synthesis.

Inhibition of tumor cell growth by murine splenic adherent cells stimulated with IFN-gamma

We have previously reported that the growth of lymphocytes and tumor cells with lymphocyte lineage was strongly inhibited by a part of cloned macrophage hybridomas. This growth inhibition was accomplished by cell-to-cell contact and found to be attributed to lipid-like molecule(s) in a macrophage hybridoma cell membrane fraction. Instead of macrophage hybridomas, in the present study we utilized splenic adherent cells (SACs) that had been stimulated with IFN-gamma to see whether they inhibited tumor cell growth or not. The results demonstrated that IFN-gamma-stimulated but not unstimulated SACs showed a significant growth inhibition of BW-5147 tumor cells. This growth inhibition was not mainly mediated by prostaglandin E2 secreted from macrophages, since the inhibition was not reduced in the presence of indomethacin. Furthermore, as was reported previously in the case of macrophage hybridomas, the inhibitory activity resides in a lipid fraction of IFN-gamma-stimulated SAC membrane.

Protection against verocytotoxin in mice induced by liposome-coupled verocytotoxin

Purified verocytotoxins (VTs), VT1 and VT2, were coupled to liposomes via glutaraldehyde. During the coupling procedure, both VT1 and VT2 were detoxified. Intraperitoneal injection in BALB/c mice with either VT1-liposome or VT2-liposome induced a substantial amount of anti-VT1 or anti-VT2 IgG antibody production, respectively. Mice immunized with VT2-liposome were protected against intravenous challenge with a lethal dose of VT2 and the degree of protection correlated well with the amount of IgG induced against VT2. Although VT1-liposome failed to induce protection against VT1, the decrease of the body weight observed after the toxin challenge correlated inversely with the amount of anti-VT1 IgG induced, suggesting that VT1 neutralizing antibody was present in VT1-liposome-immune mice. In addition, VT-liposome conjugate induced no detectable anti-VT IgE antibody production. These results demonstrate the potential ability of VT-liposome conjugates for the production of VT vaccine which induces protection against VTs.

Differential stimulation requirements for IL-12 production among clones of macrophage hybridomas

We have previously established cloned macrophage hybridomas by somatic cell fusion of the macrophage tumor P388D1 of DBA/2 (H-2d) origin with splenic adherent cells of CKB mice (H-2k). Several cloned lines displayed the serologic and functional characteristics of macrophages. In this study, we evaluated the ability of these hybridomas to produce IL-12 after combined stimulation with IFN-gamma and lipopolysaccharide (LPS). The patterns of IL-12 production by these cloned macrophages fell into three groups. The first group produced IL-12 on stimulation with LPS in combination with IFN-gamma pretreatment, the second group produced IL-12 on stimulation with LPS regardless of the pretreatment with IFN-gamma, and the third group did not produce IL-12 at all on stimulation with IFN-gamma and LPS. None of the macrophage clones tested produced IL-12 constitutively. The results correlated well with IL-12 p40 mRNA expression in those macrophages as detected by RT-PCR. These results suggest the differential stimulation requirements for IL-12 production among macrophages at a clonal level.

Application of PCR for detection of mycoplasma DNA and pestivirus RNA in human live viral vaccines

PCR techniques were applied for the detection of mycoplasma DNA and pestivirus RNA to 43 lots of live viral vaccines (measles, mumps, rubella, and oral poliomyelitis) produced by six manufacturers in Japan. Although mycoplasma DNA was not detected in any of the vaccines tested, pestivirus RNA was detected in 12 lots (28%). The incidence of contamination among the four viral vaccines was in the range of 20 to 37%, and the incidence among the six manufacturers varied from 0 to 56%.

Biotin deficiency in an infant fed with amino acid formula and hypoallergenic rice

An amino acid formula produced in Japan is not supplemented with biotin since biotin is not permitted as a food additive. Biotin deficiency developed in an 11-month-old Japanese infant who had been diagnosed as a neonate with cow milk and soy bean allergy and fed with an amino acid formula and hypoallergenic rice processed by protease. Serum levels of zinc, essential fatty acids and biotinidase were within the normal range while that of biotin was below the normal range. Urinary 3-hydroxy-isovalerate and slightly elevated levels of plasma branched-chain amino acids disappeared 1 week after oral supplementation with 1 mg day-1 of biotin as did the symptoms of orificial skin lesions, lethargy, hypotonia and alopecia later. In summary, to prevent biotin deficiency, biotin should be added to the Japanese amino acid formula.

Evaluation of current sterility tests for human live viral vaccines

Current sterility tests for human viral vaccines were evaluated. A total of 43 lots of bulk suspension of live viral vaccines (measles, mumps, rubella and oral poliomyelitis) produced by six manufacturers in Japan were evaluated for bacteriostatic and mycoplasmastatic activities. Some of them showed fairly high bacteriostatic and mycoplasmastatic activities, due to antibiotics added during vaccine production. It was concluded that the current sterility test for mycoplasmas is not reliable to detect viable mycoplasmas in live viral vaccines.

Ovalbumin-liposome conjugate induces IgG but not IgE antibody production

Antibody response after immunization with surface-coupled ovalbumin (OVA) of liposomes was investigated in mice. OVA was coupled to the surface of liposome via amino groups using glutaraldehyde. OVA-liposome conjugate induced a significant anti-OVA IgG antibody production in mice. However, no IgE antibody production specific for OVA was observed. Immunization with OVA-liposome induced IgE-specific unresponsiveness even after the subsequent challenge with OVA adsorbed with with aluminium hydroxide (OVA-alum), which induces a high level of IgE antibody production. Furthermore, following the primary immunization with OVA-alum, a secondary challenge with OVA-liposome boosted anti-OVA IgG but not anti-OVA IgE antibody production. These results show the potential of the antigen-liposome conjugate for the development of a vaccine with the least allergic reaction and also for the application of immunotherapy.

IgE-specific unresponsiveness in mice induced by ovalbumin coupled with murine red blood cells

Ovalbumin (OVA) was coupled with murine red blood cells (MRBC) using glutaraldehyde. OVA-MRBC conjugate induced anti-OVA IgG antibody production in mice at almost the same level as OVA in alum. However, no IgE antibody production specific for OVA was observed in OVA-MRBC-injected mice. IgE-specific unresponsiveness was also observed in mice injected with OVA coupled with sheep red blood cells (OVA-SRBC), suggesting that our present observation was not restricted to the property of MRBC. These results show the potential ability of antigen-RBC conjugate for the development of vaccine that induces sufficient IgG antibody production without IgE synthesis.