Hideto Yoshikawa

Clinical features and outcome of patients with IRAK-4 and MyD88 deficiency

Autosomal recessive interleukin-1 receptor-associated kinase (IRAK)-4 and myeloid differentiation factor (MyD)88 deficiencies impair Toll-like receptor (TLR)- and interleukin-1 receptor-mediated immunity. We documented the clinical features and outcome of 48 patients with IRAK-4 deficiency and 12 patients with MyD88 deficiency, from 37 kindreds in 15 countries. The clinical features of IRAK-4 and MyD88 deficiency were indistinguishable. There were no severe viral, parasitic, and fungal diseases, and the range of bacterial infections was narrow. Noninvasive bacterial infections occurred in 52 patients, with a high incidence of infections of the upper respiratory tract and the skin, mostly caused by Pseudomonas aeruginosa and Staphylococcus aureus, respectively. The leading threat was invasive pneumococcal disease, documented in 41 patients (68%) and causing 72 documented invasive infections (52.2%). P. aeruginosa and Staph. aureus documented invasive infections also occurred (16.7% and 16%, respectively, in 13 and 13 patients, respectively). Systemic signs of inflammation were usually weak or delayed. The first invasive infection occurred before the age of 2 years in 53 (88.3%) and in the neonatal period in 19 (32.7%) patients. Multiple or recurrent invasive infections were observed in most survivors (n = 36/50, 72%). Clinical outcome was poor, with 24 deaths, in 10 cases during the first invasive episode and in 16 cases of invasive pneumococcal disease. However, no death and invasive infectious disease were reported in patients after the age of 8 years and 14 years, respectively. Antibiotic prophylaxis (n = 34), antipneumococcal vaccination (n = 31), and/or IgG infusion (n = 19), when instituted, had a beneficial impact on patients until the teenage years, with no seemingly detectable impact thereafter. IRAK-4 and MyD88 deficiencies predispose patients to recurrent life-threatening bacterial diseases, such as invasive pneumococcal disease in particular, in infancy and early childhood, with weak signs of inflammation. Patients and families should be informed of the risk of developing life-threatening infections; empiric antibacterial treatment and immediate medical consultation are strongly recommended in cases of suspected infection or moderate fever. Prophylactic measures in childhood are beneficial, until spontaneous improvement occurs in adolescence. Abbreviations: CRP = C-reactive protein, ELISA = enzyme-linked immunosorbent assay, IFN = interferon, IKBA = I&kgr;B&agr;, IL = interleukin, IL-1R = interleukin-1 receptor, InvBD = invasive bacterial disease, IRAK = interleukin-1 receptor-associated kinase, MyD = myeloid differentiation factor, NEMO = nuclear factor-kappaB essential modulator, NInvBD = noninvasive bacterial disease, TIR = Toll/IL-1R, TLR = Toll-like receptor, TNF = tumor necrosis factor.

Study of influenza-associated encephalitis/encephalopathy in children during the 1997 to 2001 influenza seasons.

The 1997 to 2001 influenza A epidemics in Japan were markedly neurovirulent, and many children died of influenza-associated encephalitis/encephalopathy We studied 20 patients with influenza-associated encephalitis/encephalopathy during the last four influenza seasons. No patients had been previously inoculated with influenza vaccine. Antipyretics were used in 16 patients before the onset of encephalopathy. Although all patients were treated intensively, 5 patients died and 8 had neurologic sequelae. Patients with coagulopathy, hepatic dysfunction, and computed tomographic abnormalities had a poor prognosis. The plasma concentrations of inflammatory cytokines were variable. The neuroradiologic findings could be divided into four categories. These findings indicated that the pathogenesis of the brain damage induced by influenza infection was variable. Further investigation is necessary to determine whether insufficient influenza vaccination or the use of antipyretics is one of the reasons for these epidemics of encephalopathy in Japanese children. (J Child Neurol 2001;16:885-890).

Amniotic tissue transplantation: Clinical and biochemical evaluations for some lysosomal storage diseases

Amniotic epithelial cells has been used for transplantation in patients with lysosomal storage diseases as an enzyme replacement therapy. But its clinical effect is still the question under debate. We performed amniotic tissue transplantation on patients with different lysosomal storage diseases: one with Tay-Sachs disease, one with juvenile Gaucher disease and one with juvenile metachromatic leukodystrophy. The patient having juvenile Gaucher disease received this grafting twice. Objective clinical improvement was observed in the first trial where this patient showed an increase of soluble beta-glucosidase one week after implantation. No clinical or biochemical changes were seen in the other patients. Although there are some advantages to amniotic tissue transplantation, original methods should be modified to cell transplantation in order to avoid graft-versus-host reaction which could happen in repeated implantation.

Secondary renal Fanconi syndrome caused by valproate therapy

Although renal Fanconi syndrome resulting from valproate (VPA) has occasionally been reported, the detailed clinical characteristics of this disease remain unclear. To clarify the clinical features of patients with VPA-induced Fanconi syndrome, we analyzed the clinical and laboratory data of seven affected patients. All patients were children, were severely disabled and required tube feeding. Five patients required treatment with multiple anticonvulsant agents. Hypophosphatemia and hypouricemia were found in all patients. Mild proteinuria, increased excretion of urinary β2-microglobulin (β2MG) and generalized hyperaminoaciduria were present in all patients. The renal biopsy of one patient exhibited tubulointerstitial nephritis without any structural abnormalities of the mitochondria in proximal renal tubular cells. All patients recovered from the Fanconi syndrome after the cessation of VPA therapy without any long-term renal sequellae. These results indicate that young age and being severely disabled with tube feeding and anticonvulsant polytherapy are contributory factors to the development of VPA-induced Fanconi syndrome. Serum phosphate and uric acid concentrations and urinary β2MG levels in addition to serum electrolytes and urinalysis should be examined regularly in patients receiving VPA therapy, especially in those with the contributory factors outlined above. Patients with Fanconi syndrome caused by VPA have a favorable renal outcome.

Midazolam as a first-line agent for status epilepticus in children

Midazolam is a water-soluble benzodiazepine, and has recently emerged as a safe and effective treatment option after ordinary antiepileptic therapy in the management of status epilepticus. However, midazolam as a first-line agent for status epilepticus in children has not been fully investigated. Intravenous midazolam was used for status epilepticus in 27 children (38 convulsive episodes) from January 1997 to December 1999 in our hospital. Among them, 10 patients (16 convulsive episodes) were treated with intravenous midazolam as a first-line agent. The causes of the seizures varied. Midazolam was administered as an intravenous bolus dose (0.1-0.3 mg/kg), followed by continuous intravenous infusion (1-8 microg/kg per min). In all epileptic episodes but one, the seizures stopped within 1 min without any adverse effects. These results were compatible with the previously reported ones. It is important to terminate status epilepticus which can cause brain damage. Midazolam seems to be effective and safe as a first-line therapy for status epilepticus in children.

Renal involvement in children with influenza A virus infection.

Abstract.Renal involvement in influenza A virus infection has been rarely reported. To define the clinical characteristics and the factors contributing to the development of renal involvement in influenza A virus infection, we reviewed the clinical characteristics, laboratory data, pediatric risk of mortality (PRISM) score, and the number of systemic inflammatory response syndrome (SIRS) criteria and dysfunctional organs in 45 hospitalized children with influenza A virus infection. Eleven (24.4%) patients had renal involvement. All patients with renal involvement suffered from sepsis and multiple organ dysfunction syndrome (MODS) and 5 developed acute renal failure (ARF). The incidences of dehydration, hypotension, disseminated intravascular coagulation (DIC), and rhabdomyolysis were significantly higher in patients with renal involvement. PRISM scores, the numbers of SIRS criteria and dysfunctional organs, and mortality rate were also higher in patients with renal involvement. Influenza A RNA was absent in the renal tissues of 3 patients with ARF. These results suggested that renal involvement in influenza A virus infection occurred in patients with sepsis and MODS; dehydration, hypotension, DIC, and rhabdomyolysis were factors contributing to its development; direct viral injury to the kidney did not seem to occur in influenza A virus infection.

Effectiveness of lidocaine infusion for status epilepticus in childhood: A retrospective multi-institutional study in Japan

We evaluated the usefulness of intravenous lidocaine therapy for managing of status epilepticus (SE) during childhood in a retrospective multi-institutional study. Questionnaires were sent to 28 hospitals concerning patients admitted for SE who were managed with lidocaine, assessing patient characteristics, treatment protocols and efficacy. In 279 treated patients, 261 SE occurrences at ages between 1 month and 15 years were analyzed. SE was classified as showing continuous, clustered, or frequently repeated seizures. Considering efficacy and side effects in combination, the usefulness of lidocaine was classified into six categories: extremely useful, useful, slightly useful, not useful, associated with deterioration, or unevaluated. In 148 SE cases (56.7%), lidocaine was rated as useful or extremely useful. Multivariate analysis indicated lidocaine was to be useful in SE with clustered and frequently repeated seizures, and SE attributable to certain acute illnesses, such as convulsions with mild gastroenteritis. Efficacy was poor when SE caused by central nervous system (CNS) infectious disease. Standard doses (approximately 2mg/kg as a bolus, 2mg/kg/h as maintenance) produced better outcomes than lower or higher doses. Poor responders to the initial bolus injection of lidocaine were less likely to respond to subsequent continuous infusion than good initial responders. We recommend lidocaine for use in SE with clustered or frequently repeated seizures, and in SE associated with benign infantile convulsion and convulsions with mild gastroenteritis. Lidocaine should be initiated with a bolus of 2mg/kg. If SE is arrested by the bolus, continuous maintenance infusion should follow; treatment should proceed to different measures when SE shows a poor response to the initial bolus of lidocaine.

Effects of drugs on cholesterol esterification in normal and Niemann-Pick type C fibroblasts: AY-9944, other cationic amphiphilic drugs and DMSO

AY-9944 and other cationic amphiphilic drugs (CADs) have been reported to cause a reduction of acid sphingomyelinase activity in fibroblasts and various tissues in the rat, and DMSO has been known to correct a partial deficiency of acid sphingomyelinase activity in Niemann-Pick type C (NPC) fibroblasts. Furthermore, in the present study we demonstrated that AY-9944 and other CADs caused a marked reduction of cholesterol esterification in control fibroblasts and an excessive intracellular accumulation of unesterified cholesterol as in NPC cells, and that this reduction could partially be corrected by the addition of 2% DMSO to the medium. These characteristics of the drug-treated cells mimic the phenomena seen in NPC fibroblasts. Therefore, fibroblasts treated with CADs may be used as a model of drug-induced lipidosis of NPC. The effect of DMSO suggests the possibility of its usefulness in the treatment of NPC patients.

Purple Glove Syndrome Caused by Oral Administration of Phenytoin

A severely handicapped boy had been treated with phenytoin and his seizures were controlled well. At 10 years of age, a pharmacy gave about 1000 mg of phenytoin instead of the prescribed 100 mg of the drug per day. Several hours after the initial administration, the patient became drowsy and his hands and feet turned dark purple with marked swelling. Four days later, his mother stopped administering the phenytoin to him and took him to hospital. After fluid therapy was started, the swelling and discoloration of both his hands and feet improved gradually and disappeared 11 days after drug discontinuation. Purple glove syndrome is defined as the edema, discoloration, and pain occurring in the distal limb where intravenous phenytoin has been administered. This might be the first report of purple glove syndrome caused by the oral administration of a large quantity of phenytoin. (J Child Neurol 2000;15:762).

Giant somatosensory evoked potentials in the Rett syndrome

Somatosensory evoked potentials (SEP) were recorded in ten patients with the Rett syndrome. Seven cases showed abnormal SEP, and five of these cases showed giant SEP. The five cases with giant SEP were relatively young girls with epilepsy and parieto-central spikes on the electro-encephalogram (EEG). Older patients did not show giant SEP. These giant SEP may be the reflection of cortical hyperexcitability and they may subside as the disease progresses.