Two cases of childhood absence epilepsy who showed seizure disappearance after ethosuximide drug eruption

Background

Recent studies suggest potential roles of immune response in the pathophysiology of epilepsy. Anti-seizure medications (ASMs) are known to have side effects of drug eruption caused by immune responses. A few reports in adults have demonstrated disappearance of seizures after an ASM drug eruption episode. In this paper, we described 2 cases of childhood absence epilepsy (CAE) who showed seizure disappearance after ethosuximide (ESM) drug eruption, suggesting the possibility that the epilepsy disappears due to immune responses to ASM.

Case presentation

Case 1 was an 8-year-old girl diagnosed with CAE. She was treated with valproate acid (VPA) initially, and then ESM was administered as an additional treatment. Her epileptic seizure disappeared 4 days after initiation of ESM. However, drug eruption appeared 1 week after the administration of ESM. Even after discontinuation of ESM administration, she maintains no seizure after the drug eruption. Case 2 was a 5-year-old boy diagnosed as CAE. He was treated with VPA initially, and ESM was administered additionally. Drug eruption appeared 1 month after the administration of ESM. Even after ESM was terminated, he maintained seizure freedom after the appearance of eruption.

Conclusions

Epileptic seizures may have been suppressed due to the immune responses caused by ASM eruption. Further studies are needed to elucidate the pathophysiologic effects of drug eruption on epilepsy through immune responses.

Transient low IgG4 levels cause recurrent wheezing requiring multiple hospitalizations in infancy

OBJECTIVES

To investigate whether the immunoglobulin G (IgG4) subclass is associated with recurrent wheezing and/or asthma in infants.

SUBJECTS AND METHODS

From April 2015 to March 2016, 77 infants under 3 years old who attended our hospital were enrolled in four groups (Group 1, controls; Group 2, infants with recurrent wheezing and multiple hospitalizations despite starting inhaled corticosteroids [ICS]; Group 3, infants with recurrent wheezing and without hospitalization after starting ICS; Group 4, allergic infants without wheezing). The relationship between IgG subclasses, especially IgG4, and recurrent wheezing resistant to ICS and requiring multiple hospitalizations in infants was examined.

RESULTS

The serum IgG, IgM, IgA, IgG1, IgG2, and IgG3 levels did not differ significantly among the four groups. The IgG4 level in Group 2 infants (3.1 ± 0.2 mg/dl) was significantly lower than in Groups 1, 3, and 4 (9.9 ± 8.0, 8.4 ± 6.1, and 23.4 ± 18.0 mg/dl). Of the 16 infants in Group 2, 10 could be followed to age 6 years. Nine of them had no recurrent wheezing at 6 years without medication. In addition, their IgG4 levels at age 6 years (16.1 ± 7.1 mg/dl) were significantly increased from those in infancy (3.0 ± 0.1 mg/dl).

CONCLUSION

A transient low IgG4 level in infancy might cause recurrent wheezing and/or asthmatic symptoms in infants, and it may be one of the types of early transient wheezing.

Developmental disorders in school children are related to allergic diseases

BACKGROUND

In children, relationships between developmental disorders such as attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder and allergic diseases remain controversial, because these diseases show age- and sex-related differences. A proper understanding of the relationships between developmental disorders and allergic diseases should improve medical care for both diseases. We confirmed the prevalence of allergic diseases in elementary school-age children with developmental disorders by grade and sex.

METHODS

The subjects were 446 lower grade and 312 upper grade elementary school-age children who had visited our hospital. The prevalence of allergic diseases among subjects with and without developmental disorders by grade and sex was examined using the diagnostic names on medical records.

RESULTS

The prevalence of allergic diseases was significantly higher in lower grade boys and girls with developmental disorders than in those without developmental disorders (boys: OR 3.22, 95%; CI 1.49-6.95; girls: OR: 3.87, 95% CI: 1.27-11.82). The prevalence of allergic diseases was significantly higher in higher grade boys with developmental disorders than in those without developmental disorders (OR: 3.46, 95% CI: 1.59-7.53). Multiple logistic regression analysis in lower grades revealed that ADHD correlated with bronchial asthma (adjusted OR: 3.72, 95% CI: 1.42-9.69) and that autism spectrum disorder correlated with atopic dermatitis (adjusted OR: 4.26, 95% CI: 1.36-13.36). Analyses of children in the upper grades showed that ADHD correlated with atopic dermatitis (adjusted OR: 5.06, 95% CI: 1.28-20.05).

CONCLUSIONS

Elementary school-age children with developmental disorders were more likely to have allergic diseases. The types of allergic diseases related to developmental disorders differed by grade and sex.

Prevalence of β2-agonist inhalation for outpatients in a pediatric emergency center during enterovirus D68 epidemic

Background

Enterovirus D68 (EV-D68) has been reported to have caused severe bronchial asthma attacks and hospitalization epidemics in Japan in September 2015.

Objective

To investigate the prevalence of β₂-agonist inhalation in a pediatric emergency center during a period of increased hospitalization for bronchial asthma, which was suggested to be associated with EV-D68.

Methods

We investigated the prevalence of β₂-agonist inhalation in a pediatric emergency center in Saga city, Japan, from April 2013 to October 2015, and also clarified the trends in bronchial asthma hospitalization in the same area during that time.

Results

The prevalence of β₂-agonist inhalation in the pediatric emergency center, September 2015 was highest when EV-D68 became widespread. The monthly average for β₂-agonist inhalation during the study period was 91 cases, but the count in September 2015 was 255 cases. Hospitalized cases of bronchial asthma in September 2015 were increased for age ≥3 years and not increased for age <3 years, but the prevalence of β₂-agonist inhalation at the pediatric emergency center was increased even under the age of 3 years.

Conclusion

During the epidemic period for EV-D68, cases requiring β₂-agonist inhalation were increased. The EV-D68 epidemic may be related to not only severe cases requiring hospitalization, but also exacerbation of relatively mild symptoms of bronchial asthma.

Administration of the adrenaline auto-injector at the nursery/kindergarten/school in Western Japan

Background

In view of the increasing prevalence of food allergies, there has been an associated increase in frequency of situations requiring an emergency response for anaphylaxis at the home, childcare facilities and educational institutions.

Objective

To clarify the situation of adrenaline auto-injector administration in nursery/kindergarten/school, we carried out a questionnaire survey on pediatric physicians in Western Japan.

Methods

In 2015, self-reported questionnaires were mailed to 421 physicians who are members of the West Japan Research Society Pediatric Clinical Allergy and Shikoku Research Society Pediatric Clinical Allergy.

Results

The response rate was 44% (185 physicians) where 160 physicians had a prescription registration for the adrenaline auto-injector. In the past year, 1,330 patients were prescribed the adrenaline auto-injector where 83 patients (6% of the prescribed patients) actually administered the adrenaline auto-injector, of which 14 patients (17% of the administered patients) self-administered the adrenaline auto-injector. “Guardians” at the nursery/kindergarten and elementary school were found to have administered the adrenaline auto-injector the most. Among 117 adrenaline auto-injector prescription-registered physicians, 79% had experienced nonadministration of adrenaline auto-injector at nursery/kindergarten/school when anaphylaxis has occurred. The most frequent reason cited for not administering the adrenaline auto-injector was “hesitation about the timing of administration.”

Conclusion

If the adrenaline auto-injector was administered after the guardian arrived at the nursery/kindergarten/school, it may lead to delayed treatment of anaphylaxis in which symptoms develop in minutes. Education and cooperation among physicians and nursery/kindergarten/school staff will reduce the number of children suffering unfortunate outcomes due to anaphylaxis.

Acute alcohol intoxication in a 15-day-old neonate

We describe a 15-day-old newborn girl who was fed with formula milk that was accidentally diluted with sake (Japanese wine prepared from fermented rice). The clinical features were flushed skin, tachycardia and low blood pressure indicating circulatory failure, somnolence and metabolic acidosis without hypoglycemia. The serum ethanol concentration was 43.0 mg/dL at 3 h after intake. The patient recovered under intravenous fluid replacement without complications. Follow-up examinations at 1, 2, 3, 6 and 12 months confirmed normal psychomotor development.

Delayed anti-CD3 therapy results in depletion of alloreactive T cells and the dominance of Foxp3+ CD4+ graft infiltrating cells

The engineered Fc-nonbinding (crystallizable fragment-nonbinding) CD3 antibody has lower mitogenicity and a precise therapeutic window for disease remission in patients with type 1 diabetes. Before anti-CD3 can be considered for use in transplantation, the most effective timing of treatment relative to transplantation needs to be elucidated. In this study anti-CD3F(ab')2 fragments or saline were administered intravenously for 5 consecutive days (early: d1-3 or delayed: d3-7) to mice transplanted with a cardiac allograft (H2(b)-to-H2(k); d0). Survival of allografts was prolonged in mice treated with the early protocol (MST = 48 days), but most were rejected by d100. In contrast, in mice treated with the delayed protocol allografts continued to survive long term. The delayed protocol significantly inhibited donor alloreactivity at d30 as compared to the early protocol. A marked increase in Foxp3(+) T cells (50.3 ± 1.6%) infiltrating the allografts in mice treated with the delayed protocol was observed (p < 0.0001 vs. early (24.9 ± 2.1%)) at d10; a finding that was maintained in the accepted cardiac allografts at d100. We conclude that the timing of treatment with anti-CD3 therapy is critical for inducing long-term graft survival. Delaying administration effectively inhibits the alloreactivity and promotes the dominance of intragraft Foxp3(+) T cells allowing long-term graft acceptance.

Lack of an association between E-selectin gene polymorphisms and risk of Kawasaki disease

BACKGROUND

Coronary artery lesions (CAL) are a serious complication of Kawasaki disease (KD). The increased serum E-selectin level during the acute phase of KD and the association of E-selectin gene (SELE) polymorphisms with the prevalence of coronary artery disease in adults suggest a possible association between SELE polymorphisms and the development of CAL in KD patients.

METHODS

The subjects consisted of 177 KD patients, including 59 with and 118 without CAL, and 305 healthy controls. Two single nucleotide polymorphisms (SNP) of SELE, 98G>T (rs1805193) and Ser128Arg (rs5361), were genotyped by direct sequencing and the high-resolution melting curve method, respectively. The allele distributions were assessed using the chi-squared test.

RESULTS

There were no significant differences in the T allele frequency at 98G>T between KD patients and controls (1.4% vs 1.0%, P = 0.55) or between KD patients with and without CAL (1.7% vs 1.3%, P = 0.77). Similarly, there were no differences in the distribution of the C allele (128Arg) at Ser128Arg between KD patients and controls (4.5% vs 3.4%, P = 0.40) or between KD patients with and without CAL (4.2% vs 4.7%, P = 0.86).

CONCLUSION

Although no association was detected between these SELE polymorphisms and the prevalence of KD or the development of CAL, this may have been due to the study limitations, including a low frequency of the minor alleles and a small sample size. A larger-scale association study is needed in order for a definitive conclusion to be made as to whether these SNP are associated with susceptibility to KD or not.

Does Chlamydia pneumoniae infection trigger to development of asthma in wheezy infants?

The role of Chlamydia pneumonia (CP) infection in infantile asthma remains obscure. CP infection was serologically determined (Immunoglobulin M antibody titer of index (ID) > or = 2.00) in wheezing infants who were then re-examined at 3 years of age to determine whether asthma is associated with CP infection. Wheezing infants with CP infection progressed to asthma more frequently than those who were not infected. These findings may suggest that CP infection triggers the development of asthma in wheezy infants.

Febrile seizures: characterization of double-stranded RNA-induced gene expression

An association has long been suspected between febrile seizures and interleukin-1beta, the most potent endogenous pyrogen. Interleukin-1beta production increases after double-stranded RNA stimulation in leukocytes of febrile seizure patients. To elucidate the genetics of the immune response, the gene expression pattern after double-stranded RNA stimulation was investigated using DNA microarray. Compared with the control group, expression of the genes ACCN4 (sodium channel), KCNC3 (potassium channel), GABRE (gamma-aminobutyric acid receptor epsilon subunit), RIPK2 (receptor interacting protein kinase-2), TLR4 (toll-like receptor-4), IL26 (interleukin-26), and TNF (tumor necrosis factor), and CASP1 (caspase-1) was increased in the febrile seizure group (P < 0.01). Because RIPK2 and CASP1 are associated with interleukin-1beta production, increased expression might cause increased interleukin-1beta production in the febrile seizure patients. The induced expression of several ion channel genes by double-stranded RNA may affect neuronal excitability which leads to seizure susceptibility during infection.

The development of asthma in wheezing infants with Chlamydia pneumoniae infection

Chlamydia pneumoniae infection might play a role in the pathology of asthma, but its role in infantile asthma remains obscure. The presence of Chlamydia pneumoniae was serologically determined in wheezing infants who were then re-examined 1-year later to determine whether or not asthma is associated with this type of infection. Wheezing infants progressed to asthma more frequently after infection with Chlamydia pneumoniae than those who were not infected. These findings suggested that Chlamydia pneumoniae infection triggers asthma in wheezy infants.

Imbalance Between Leukotriene Synthesis and Catabolism Contributes to the Pathogenesis of Allergic Diseases

Recently, there has been great progress in elucidating the biochemistry of the arachidonic acid (AA) metabolism. The abnormal production of leukotrienes (LTs), due to the unbalanced-regulation of synthesizing and catabolizing enzymes, is probably induced by many bioactive substances, including Th2 cell-derived cytokines. Imbalances in these processes may play an important role in allergic reactions and other inflammatory diseases, thus making them potentially prime therapeutic targets for these diseases. Further studies on the regulation of LT-synthesis and catabolism are therefore required to clarify the importance of these imbalances on the initiation and progression of allergic and inflammatory diseases.

Expression and production of aberrant PAX5 with deletion of exon 8 in B-lineage acute lymphoblastic leukaemia of children

Summary We investigated PAX5 expression in childhood B-lineage acute lymphoblastic leukaemia (ALL). Seven of 21 children with B-lineage ALL had multiple PAX5 variants, while 14 children and healthy controls showed full-length (FL) and one variant PAX5. By Western blotting, healthy controls displayed Pax5-FL, while one short Pax5, derived from the deletion of exon 8 (Pax5-DeltaE8) was produced in 90% of ALL samples, as well as in ALL cell lines. PAX5-DeltaE8 lacked more than 50% of the transactivation domain, indicating that aberrant Pax5 production might lead to the arrest of B-cell differentiation, contributing to the pathogenesis of B-lineage ALL.

Estradiol activates mast cells via a non-genomic estrogen receptor-alpha and calcium influx

BACKGROUND

Allergic airway diseases are more common in females than in males during early adulthood. A relationship between female hormones and asthma prevalence and severity has been suggested, but the cellular and molecular mechanisms are not understood.

OBJECTIVE

To elucidate the mechanism(s) by which estrogens enhance the synthesis and release of mediators of acute hypersensitivity.

METHODS

Two mast cell/basophil cell lines (RBL-2H3 and HMC-1) and primary cultures of bone marrow derived mast cells, all of which naturally express estrogen receptor-alpha, were examined. Cells were incubated with physiological concentrations of 17-beta-estradiol with and without IgE and allergens. Intracellular Ca(2+) concentrations and the release of beta-hexosaminidase and leukotriene C(4) were quantified.

RESULTS

Estradiol alone induced partial release of the preformed, granular protein beta-hexosaminidase from RBL-2H3, BMMC and HMC-1, but not from BMMC derived from estrogen receptor-alpha knock-out mice. The newly synthesized LTC(4) was also released from RBL-2H3. Estradiol also enhanced IgE-induced degranulation and potentiated LTC(4) production. Intracellular Ca(2+) concentration increased prior to and in parallel with mediator release. Estrogen receptor antagonists or Ca(2+) chelation inhibited these estrogenic effects.

CONCLUSION

Binding of physiological concentrations of estradiol to a membrane estrogen receptor-alpha initiates a rapid onset and progressive influx of extracellular Ca(2+), which supports the synthesis and release of allergic mediators. Estradiol also enhances IgE-dependent mast cell activation, resulting in a shift of the allergen dose response.

dsRNA enhances eotaxin-3 production through interleukin-4 receptor upregulation in airway epithelial cells

The exacerbation of asthma during viral infections is mainly explained by neutrophils infiltrating into the airways. However, enhanced functions of eosinophils are also observed. The aim of this study was to reveal the mechanism of how eosinophils are activated during and after viral infection of the airways, using a model of viral infection. A synthetic double-stranded RNA, poly inosinic-cytidyric acid (poly(IC)), was transfected to a human airway epithelial cell line (BEAS-2B) and the primary bronchial epithelial cells, to mimic a viral infection. The production of chemokines from the cells was investigated. The transfection of poly(IC), alone, marginally affected the eotaxin-3 production of the cells. However, the transfection of poly(IC) prior to interleukin (IL)-4 stimulation enhanced eotaxin-3 production. Poly(IC) transfection increased mRNA and protein expressions of IL-4 receptor (R)alpha and IL-2Rgamma, components of the IL-4R. In BEAS-2B cells, IL-4-mediated phosphorylation of signal transducer and activator of transcription six was enhanced in poly(IC) transfected cells. This was reversed by the addition of anti-IL-4Ralpha antibody, suggesting the role of an increased number of IL-4 receptors in enhanced IL-4-induced eotaxin-3 production. Poly(IC)-induced upregulation of IL-4Ralpha was inhibited by treatment with cycloheximide or dexamethasone. In conclusion, these results suggest that viral airway infection may enhance interleukin-4-induced eotaxin-3 production through upregulation of the interleukin-4 receptor in airway epithelial cells.

Interleukin-18 primes human basophilic KU812 cells for higher leukotriene synthesis

The human basophilic cell line KU812 that is an established tool for studying the function of human basophils, is differentiated into mature basophils by interleukin (IL-3) or other agents. However, whether leukotrienes (LTs)-synthesis is affected by cytokines in KU812 cells remains unknown. KU812 cells were incubated with IL-3, IL-4, IL-6, IL-13 or IL-18 for up to 14 days. The A23187 stimulated- and IgE cross-linked-synthesis of LTC(4) and LTB(4) were measured using an enzyme immunoassay (EIA). The expression of messenger RNA (mRNA) for LT-synthesizing enzymes was examined by reverse transcriptase polymerase chain reaction (RT-PCR), and the expression of 5-lipoxygenase (5-LO) was examined by immunostaining. Incubation with IL-3 (10 ng/ml) and IL-18 (10 ng/ml) induced the expression of 5-LO. A23187stimulated LT-synthesis and IgE cross-linked LT-synthesis were enhanced after incubation with IL-3 or IL-18. These results indicated that IL-3 and IL-18 primed human basophils for higher LT-synthesis. Thus, both IL-3 and IL-18 might be important factors for regulating LT-synthesis during the differentiation of human basophils.

Expression of CD180, a toll-like receptor homologue, is up-regulated in children with Kawasaki disease

Kawasaki disease (KD) is an acute febrile illness in childhood characterized by the formation of aneurysms in coronary arteries. It is believed that KD is caused by infectious agents because of its epidemic waves and high incidence of familial occurrence. Because an increase in the levels and dysfunction of B cells in peripheral blood was reported in KD, we investigated the expression of cluster of differentiation 180 (CD180), a toll-like receptor homologue, in the B cells of children with KD, and in those with bacterial or viral infections. The percentages of CD180 positive B cells were significantly higher in children with KD or viral infections than in those with bacterial infections or in healthy controls. When the expression levels of CD180 were compared by using the mean fluorescent intensity ratio of patients to healthy controls, the level of CD180 expression was also significantly up-regulated in children with KD or viral infections. To clarify the effect of viral infection on the expression of CD180, B cells were stimulated with poly inosinic-cytidyric acid [poly(IC)], a synthetic double-stranded RNA. Poly(IC) clearly enhanced CD180 expression in B cells in vitro, both at the protein and messenger RNA levels. These results suggest that similar mechanisms may be involved in the up-regulation of B cell CD180 expression in patients with either KD or viral infections.

Mutations of syntaxin 11 and SNAP23 genes as causes of familial hemophagocytic lymphohistiocytosis were not found in Japanese people

Although mutations of perforin, MUNC13-4 and syntaxin 11 genes have been found in children with familial hemophagocytic lymphohistiocytosis (FHL), the incidence of each genetic subtype varies in different ethnic groups. We evaluated mutations of syntaxin 11 and SNAP23 genes in 30 Japanese FHL patients. The patients had no mutations and 10% had one polymorphism (146G>A) of syntaxin 11, while no mutation of SNAP23 was observed. Our results indicate that aberrations in the SNARE system may not cause FHL in Japanese families.

Squamous cell carcinoma-related antigen in children with acute asthma

BACKGROUND

Increased serum levels of squamous cell carcinoma-related antigen (SCCA) have been observed in patients with allergic disorders, such as atopic dermatitis and bronchial asthma. T(H)2 cytokines, which are known to be involved in the pathogenesis of allergic disorders, stimulate new synthesis of SCCA in cultured human airway epithelial cells.

OBJECTIVE

To investigate whether SCCA levels increase during acute exacerbations of asthma in children and whether the T(H)2 cytokines, interleukin 4 (IL-4) and IL-13, are associated with SCCA levels.

METHODS

Serum levels of SCCA, IL-4, and IL-13 were measured by enzyme immunoassay during the acute phase of an asthma exacerbation (on hospital admission) and in the recovery phase (after symptoms had subsided).

RESULTS

In the 35 children who participated in this study, serum levels of SCCA were significantly elevated in the acute phase (mean +/- SD, 3.09 +/- 2.03 ng/mL) compared with the recovery phase (mean +/- SD, 1.47 +/- 0.64 ng/mL) of an asthma exacerbation (P < .001). In 12 children, the IL-13 levels were observed to correlate with SCCA levels during the recovery phase (r = 0.68, P = .02) but not during the acute phase of an asthma exacerbation.

CONCLUSIONS

Serum SCCA levels increase during the acute phase of an asthma exacerbation. During this phase, the increased synthesis of SCCA is not associated with IL-13 but rather mediated by other undefined stimuli. IL-13 may contribute to the basal production of SCCA in asthmatic children.

Genetic subtypes of familial hemophagocytic lymphohistiocytosis: correlations with clinical features and cytotoxic T lymphocyte/natural killer cell functions

Mutations of the perforin (PRF1) and MUNC13-4 genes distinguish 2 forms of familial hemophagocytic lymphohistiocytosis (FHL2 and FHL3, respectively), but the clinical and biologic correlates of these genotypes remain in question. We studied the presenting features and cytotoxic T lymphocyte/natural killer (CTL/NK) cell functions of 35 patients for their relationship to distinct FHL subtypes. FHL2 (n = 11) had an earlier onset than either FHL3 (n = 8) or the non-FHL2/FHL3 subtype lacking a PRF1 or MUNC13-4 mutation (n = 16). Deficient NK cell activity persisted after chemotherapy in all cases of FHL2, whereas some patients with FHL3 or the non-FHL2/FHL3 subtype showed partial recovery of this activity during remission. Alloantigen-specific CTL-mediated cytotoxicity was deficient in FHL2 patients with PRF1 nonsense mutations, was very low in FHL3 patients, but was only moderately reduced in FHL2 patients with PRF1 missense mutations. These findings correlated well with Western blot analyses showing an absence of perforin in FHL2 cases with PRF1 nonsense mutations and of MUNC13-4 in FHL3 cases, whereas in FHL2 cases with PRF1 missense mutations, mature perforin was present in low amounts. These results suggest an association between the type of genetic mutation in FHL cases and the magnitude of CTL cytolytic activity and age at onset.

High frequency of QPY allele and linkage disequilibrium of granzyme-B in Epstein-Barr-virus-associated hemophagocytic lymphohistiocytosis

Mediation of Epstein-Barr virus (EBV)-specific cytotoxicity in T lymphocyte via the perforin/granzyme pathway has been demonstrated; therefore, a study involving cytolytic molecules was essential for the clarification of hemophagocytic lymphohistiocytosis (HLH) pathogenesis. This investigation, which analysed the frequency of three allelic mutations of granzyme-B (55Q/R, 95P/A and 247Y/H) in patients with EBV-HLH and infectious mononucleosis, identified the high prevalence of the QPY haplotype in EBV-HLH patients in comparison with healthy controls. A > G polymorphism was also detected in intron 5; furthermore, nearly complete linkage disequilibrium was observed among these polymorphisms. The recessive role of the QPY haplotype of granzyme-B might be responsible for the pathogenesis of EBV-HLH. Cytotoxicity and DNA fragmentation of cytotoxic T lymphocytes did not differ among patients characterized by the QPY/QPY, RAH/RAH and QPY/RAH genotypes. This finding suggested that DNA fragmentation in target cells is mediated not only by granzyme-B but also by other molecules, including other granzymes or Fas.

Upregulation of Interleukin-4 Receptor by Interferon-γ

Airway epithelial cells produce a number of chemokines, including eotaxins. Among the three known eotaxins, T helper (Th) type 2 cytokines have been observed to induce the expression of eotaxin-3 mRNA. This study investigated the effect of interferon (IFN)-gamma, a Th1 cytokine, on Th2 cytokine-induced eotaxin-3 production in a bronchial epithelial cell line, BEAS-2B. BEAS-2B cells produced eotaxin-3 after stimulation with the Th2 cytokines interleukin (IL)-13 and IL-4. When BEAS-2B cells were cultured with varying concentrations of IFN-gamma for 24 h, dose-dependent inhibition of Th2 cytokine-induced eotaxin-3 mRNA expression and protein production was observed. This was associated with downregulation of signal transducer and activator of transcription 6 activation. On the other hand, 2-d pretreatment of BEAS-2B cells with IFN-gamma dose-dependently enhanced Th2 cytokine-induced eotaxin-3 mRNA expression and production. IFN-gamma also increased the mRNA expression and protein production of IL-4 receptor (R) alpha in a time- and dose-dependent manner. In addition, IL-2Rgamma, a component of the type 1 IL-4R, was also upregulated by IFN-gamma. These results indicate that IFN-gamma has opposite effects on Th2 cytokine-induced eotaxin-3 production in BEAS-2B cells, depending on the length of exposure. Because high levels of IFN-gamma are produced during viral infection, airway viral infection may affect allergic airway inflammation in vivo by modulation of eotaxin-3 production.

Disodium cromoglycate suppresses the induction of cysteinyl leukotriene synthesis during granulocytic differentiation in HL-60 cells

OBJECTIVES

Disodium cromoglycate (DSCG) and nedocromil sodium are anti-asthma drugs that have a variety of physiological and biological effects. We examined whether DSCG affects the induction of cysteinyl Leukotriene (cysLT) synthesis during dimethyl sulfoxide (DMSO)-induced granulocytic differentiation in HL-60 cells.

METHODS

HL-60 cells were differentiated to mature granulocyte-like cells by DMSO in the presence or absence of DSCG for 5 days. Then, we measured A23187-stimulated production of LTC4, an initial product of cysLTs. We also examined the mRNA expression and enzyme activity of LTC4 synthase and other LT-synthetic enzymes.

RESULTS

The amount of LTC4 production was 732.0+/-19.0 pg/10(6) cells in DMSO-differentiated HL-60 cells. The value was significantly decreased to 420.7+/-22.7 pg/10(6) cells in the presence of DSCG at 100 microg/ml. The DMSO-induced mRNA expression and enzyme activity of LTC4 synthase was also suppressed by DSCG.

CONCLUSIONS

Our results indicate that DSCG suppresses the DMSO-induced LTC4 synthase-activity by inhibiting mRNA expression of LTC4 synthase, which might be a novel anti-allergic action of DSCG.

Protein-losing gastroenteropathy and retinitis associated with cytomegalovirus infection in an immunocompetent infant: a case report

A 6-week-old immunocompetent girl developed protein-losing gastroenteropathy (PLGE) and retinitis associated with cytomegalovirus (CMV) infection. At presentation, CMV antigenaemia (6 cells/46,000 white blood cells) and its DNA were detected in the patient's blood and in the mother's milk. Intravenous ganciclovir and gamma-globulin rapidly ameliorated all symptoms and CMV antigenaemia disappeared. No immunological defects were identified in this patient. To the best of our knowledge, this case involves the youngest known immunocompetent patient demonstrating CMV-induced PLGE and retinitis.

CONCLUSION

breast-feeding by a cytomegalovirus-positive mother can be a primary cause of early onset cytomegalovirus infection in infants.

Macrolide antibiotics inhibit prostaglandin E2 synthesis and mRNA expression of prostaglandin synthetic enzymes in human leukocytes

We investigated the action of macrolide antibiotics, which are considered to have anti-inflammatory activity, on lipopolysaccharide (LPS)-stimulated prostaglandin (PG) E2 synthesis and the expression of mRNAs for cytosolic phospholipase A2 (cPLA2), cyclooxygenase (COX)-1, and COX-2 in human leukocytes. The production of LPS-stimulated PGE2 was significantly increased in peripheral polymorphonuclear leukocytes (PMNLs) and in mononuclear leukocytes (MNLs). Amounts of mRNAs for COX-2 and cPLA2, but not for COX-1, were enhanced by LPS in PMNLs and MNLs. The LPS-enhanced PGE2 synthesis and the expression of cPLA2 and COX-2 mRNAs were inhibited by clarithromycin, azithromycin and dexamethasone in PMNLs and MNLs. The mRNA expression of COX-1 in PMNLs was decreased by clarithromycin and azithromycin. Macrolide antibiotics inhibited PGE2 synthesis in human leukocytes by suppressing cPLA2, COX-1, and COX-2 mRNA expression. These data indicate one mechanism of macrolide anti-inflammatory activity.

A polymorphism in the promoter of the CD14 gene (CD14/-159) is associated with the development of coronary artery lesions in patients with Kawasaki disease

OBJECTIVE

To investigate whether a polymorphism in the CD14 gene is associated with Kawasaki disease (KD).

STUDY DESIGN

We extracted DNA from the whole blood of 69 control children and 67 patients with KD. We determined a polymorphism in the CD14 gene at position -159 upstream from the major transcription site (CD14/-159) by restriction fragment assay. We then investigated the association between CD14/-159 and the onset of KD and development of coronary artery lesion (CAL).

RESULTS

The genomic and allelic frequencies of the polymorphism were not different between normal children and KD patients. The KD patients with TT genotypes at CD14/-159 had more CAL complications than those with CT and CC (OR, 4.05; 95% CI, 1.34-12.22). The frequencies of the T allele was significantly higher than that of the C allele in KD patients with CAL (OR, 2.20; 95% CI, 1.23-3.94). Their data were confirmed in the patients whether the patients were treated with intravenous gamma-globulin. KD patients with TT genotypes had significantly higher levels of C-reactive protein and vascular endothelial growth factor, which had previously been reported as risk factors for CAL, than those with CC genotypes.

CONCLUSION

These results indicate that the T allele and TT genotype at CD14/-159 are risk factors for CAL in KD, and that the development of CAL in KD may be related to the magnitude of CD14 toll-like receptor response.

Dexamethasone accelerates catabolism of leukotriene C4 in bronchial epithelial cells

Leukotriene (LT)C4, a potent chemical mediator in bronchial asthma, is metabolised to the less active LTE4 via LTD4 in two consecutive reactions catalysed by enzymes of the glutamyl transpeptidase and dipeptidase families. The activities of these catabolic enzymes may be influenced by glucocorticosteroids. This study was conducted to examine whether this inactivation of LTC4 is affected by dexamethasone (DEX) in transformed human bronchial epithelial cells and normal human bronchial epithelial cells. After incubation with DEX for 0-5 days, cells were resuspended in the presence of exogenous LTC4, and conversion of LTC4 to LTE4 was measured using high-performance liquid chromatography. Gamma-glutamyl transpeptidase (GGT) and GGT-related enzyme (GGTRE) messenger ribonucleic acid (mRNA) expression were examined using reverse transcriptase-polymerase chain reaction analysis, and GGT activity by enzyme assay. Conversion to LTE4 was accelerated by DEX pretreatment. GGTRE but not GGT mRNA expression was enhanced after incubation with DEX. The results indicate that dexamethasone transcriptionally upregulates the activity of gamma-glutamyl transpeptidase-related enzyme in human bronchial epithelial cells, which accelerates inactivation of leukotriene C4 via conversion to leukotriene E4. This is a novel mechanism of glucocorticosteroids in human bronchial epithelial cells.

Engraftment and dissemination of T lymphocytes from primary haemophagocytic lymphohistiocytosis in scid mice

Although primary haemophagocytic lymphohistiocytosis (HLH) is a genetic disorder of T lymphocytes, it remains unclear why T lymphocytes of primary HLH patients preferentially infiltrate the central nervous system and peripheral blood, in addition to the reticuloendothelial systems. We engrafted Herpesvirus saimiri (HVS)-immortalized T-lymphocyte lines established from primary HLH patients into severe combined immunodeficient (scid) mice and examined their capacity to infiltrate mouse organs. A diffuse infiltration of human T lymphocytes was detected in each organ of scid mice treated with 1 x 10(6) T lymphocytes from all four primary HLH patients assessed, whereas no infiltration of T lymphocytes from healthy individuals was observed in any organ. The infiltration of T lymphocytes was mainly observed in the lung, brain and peripheral blood, in association with haemophagocytosis. These cells were positive for HLA-DR, CD3 and either CD8 or CD4, but negative for CD68. Certain markers of proliferation and apoptotic activities were highly positive in these cells. There was no difference between the infiltration pattern of T lymphocytes of primary HLH patients with a perforin deficiency and those without. By Southern blot analysis, T lymphocytes infiltrating mouse organs were observed to be polyclonal. These findings suggest that our murine model implementing HVS-immortalized human T lymphocytes is suitable to clarify the pathogenesis of primary HLH.

Leukotriene synthesis is increased by transcriptional up-regulation of 5-lipoxygenase, leukotriene A4 hydrolase, and leukotriene C4 synthase in asthmatic children

Leukotrienes (LTs) are recognized to be important mediators in asthma. Recent studies revealed that LT synthesis is controlled by the regulation of LT-synthesizing enzymes. We determined the synthesis of LTB4 and LTC4 by specific radioimmunoassay, and the messenger RNA (mRNA) expression of LT-synthesizing enzymes by reverse transcriptase polymerase chain reaction in peripheral polymorphonuclear leukocytes, which were obtained from controls and asthmatic children. The synthesis of LTB4 and LTC4, and the mRNA expression of 5-lipoxygenase, LTA4 hydrolase, and LTC4 synthase were enhanced in the patients. The mRNA expression of LT-synthesizing enzymes was up-regulated, resulting in increased LT synthesis, which may play an important role in the pathogenesis of childhood asthma.

Essential roles of perforin in antigen-specific cytotoxicity mediated by human CD4+ T lymphocytes: analysis using the combination of hereditary perforin-deficient effector cells and Fas-deficient target cells

Although the cytotoxic mechanisms of murine CTLs have been investigated extensively using various mutant and knockout mice, those of human CTLs, especially CD4+ CTLs, are still obscure. To clarify the roles of perforin in Ag-specific cytotoxicity mediated by human CD4+ CTLs, alloantigen-specific and HSV-specific human CD4+ T lymphocyte bulk lines and clones were established from a patient with hereditary perforin deficiency and her healthy father, and their cytotoxic activities were investigated. Alloantigen-specific CD4+ T lymphocytes expressing perforin exerted cytotoxicity against Fas-negative as well as Fas-positive allogeneic B lymphoblastoid cell lines established from members of a family with hereditary Fas deficiency. Perforin-deficient, but not perforin-expressing, CD4+ T lymphocytes failed to show strong cytotoxicity against HSV-infected autologous B lymphoblastoid cells. Perforin-deficient CD4+ T lymphocytes could exert relatively low level cytotoxicity against allogeneic IFN-gamma-treated keratinocytes. Although cytotoxicity mediated by perforin-expressing CD4+ CTLs was almost completely inhibited by concanamycin A, a potent inhibitor of the perforin-mediated cytotoxic pathway, cytotoxicity against IFN-gamma-treated keratinocytes mediated by perforin-deficient CD4+ T lymphocytes was inhibited only partially by concanamycin A, but was inhibited significantly by antagonistic anti-Fas Ab and anti-Fas ligand Ab. The combination of perforin-deficient effector T lymphocytes and Fas-negative target cells used in the present study provides a novel experimental system for studying the detailed mechanisms of human CTL-mediated cytotoxicity. The present data demonstrate that perforin-negative CD4+ CTLs can exert cytotoxicity against Fas-sensitive target cells; however, perforin plays essential roles in Ag-specific cytotoxicity mediated by human CD4+ as well as CD8+ CTLs.

Thromboxane synthesis is increased by upregulation of cytosolic phospholipase A2 and cyclooxygenase-2 in peripheral polymorphonuclear leukocytes during bacterial infection in childhood

Prostaglandins (PGs) and thromboxane (TX) are important mediators of inflammation. Recent studies revealed that PG and TX synthesis is controlled by the regulation of PG- and TX-synthesizing enzymes. In this study, we examined the TX synthesis and the expression of TX-synthesizing enzymes in activated peripheral polymorphonuclear leukocytes (PMNs) obtained from children with bacterial infection. Blood samples were obtained from controls and patients with bacterial infection. A23187-stimulated production of TXB(2), a stable metabolite of TXA(2) in PMNs, was measured by a specific radioimmunoassay. The mRNA expression of cytosolic phospholipase A(2) (cPLA(2)), cyclooxygenase (COX)-1, COX-2, and TXA(2) synthase was determined by RT-PCR. The synthesis of TXB(2) in PMNs was significantly increased in the patients [925.0 (550.0-1100.0) pg/10(6) cells], compared with the controls [550.0 (450.0-775.0) pg/10(6) cells]. The mRNA expression for cPLA(2) and COX-2 in PMNs was also enhanced in the patients. The results indicate that TX production in PMNs is significantly increased through possible transcriptional mechanisms of cPLA(2) and COX-2 during bacterial infection in children. The upregulation of TXA(2) synthesis may contribute to the process of acute inflammatory reaction caused by bacterial infection.

Identification of simultaneous mutation of fibrinogen alpha chain and protein C genes in a Japanese kindred

Afibrinogenaemia usually induces a bleeding tendency during infancy, whereas protein C deficiency increases susceptibility to thrombosis in children or adolescence. Mutations of these genes have been, therefore, established as independent risk factors for coagulation disorders. We describe the homozygous mutation of the fibrinogen alpha chain gene and additional heterozygous mutation of the protein C gene in a male infant who showed prolonged umbilical bleeding after birth. On examination, the plasma fibrinogen was undetectable, and the activity and antigen level of protein C were reduced. The patient showed no fibrinogen Aalpha chain as well as Bbeta and gamma chains by Western blotting. The sequencing analysis showed the homozygous deletion of 1238 bases from intron 3 at position 2008 to intron 4 at position 3245 in the fibrinogen alpha chain gene. Both parents were heterozygous carriers of this mutation. In this patient, an additional mutation was also detected in the protein C gene: the heterozygous deletion of exon 7 at position 6161-6163 or 6164-6166, resulting the deletion of one amino acid (Lys150 or 151). His mother was also a carrier of this mutation. As the simultaneous mutation of the fibrinogen alpha chain and protein C genes has not been previously reported, the influence of the interaction between these two mutations on the clinical manifestations of this patient should be carefully monitored for a long period.

Induction of thromboxane A2 synthesizing enzymes in DMSO-induced granulocytic differentiation of HL-60 cells

Human leukemia (HL)-60 cells were differentiated by several agents, and prostaglandins (PGs) and thromboxane (TX) synthesizing activity increased in response to the differentiation of the cells. We examined the expression of messenger RNA (mRNA) for TX-synthesizing enzymes, cyclooxygenase (COX)-1, COX-2 and TXA(2) synthase, in dimethyl sulfoxide (DMSO)-differentiated HL-60 cells by reverse transcriptase polymerase chain reaction (RT-PCR), and A23187-stimulated TXB(2) production, a stable metabolite of TXA(2), by radioimmunoassay (RIA). A23187-stimulated TXB(2) production, and mRNA abundance for COX-2, were not detected in non-treated HL-60 cells. TXA(2) synthase mRNA were barely detected in non-treated HL-60 cells. DMSO-induced HL-60 cells gained induction of TXB(2) synthesis and mRNA for COX-2 and TXA(2) synthase during granulocytic differentiation. COX-1 mRNA was constitutively expressed. A23187-stimulated TXB(2) production in DMSO-treated cells was inhibited by NS-398, a specific COX-2 inhibitor. These results demonstrated that TXB(2) production in granulocytic HL-60 cells was regulated at both the enzyme level of COX-2 and TXA(2) synthase.

In vitro cleavage of the MLL gene by topoisomerase II inhibitor (etoposide) in normal cord and peripheral blood mononuclear cells

The correlation between infant leukemia and in utero exposure to topoisomerase II (topo-II) inhibitor has been clarified. We examined the in vitro effect of topo-II inhibitor (etoposide) on cleavage of the MLL gene in cord and peripheral blood mononuclear cells (MNCs). Southern blot analysis showed cleavage of the MLL gene in peripheral blood MNCs of infants when the MNCs were exposed to etoposide. MNCs were incubated with etoposide at various concentrations (1 to 50 microM), and a ligation-mediated polymerase chain reaction (LM-PCR) was used to detect double strand breaks (DSBs) of DNA in intron 8 of the MLL breakpoint cluster region. PCR products obtained with LM-PCR were subcloned and sequenced to identify the breakpoint in the MLL gene. The PCR products indicated DSBs of the MLL gene were obtained without any difference in the incidence between 3 different samples (cord and peripheral blood from infants and children). Sequencing analysis showed that the DSBs occurred on the telomeric side of intron 8 and near exon 9. There was no evidence that the cord blood was more susceptible to MLL DNA breakage by topo-II inhibitor than were other cells. Instability of the partner gene during the fetal period could be associated with the pathogenesis of infant leukemia.

Expression of prostaglandin H synthase-2 in human brain tumors

Numerous studies have demonstrated that prostaglandin H synthase-2 (PHS-2) is involved in gastrointestinal carcinogenesis, and that nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit PHS, can reduce the risk of colon cancer. In brain tumors, elevated prostaglandin production and its correlation to anaplastic grade of gliomas have been demonstrated. To determine whether the increased prostaglandin production is due to enhanced expression of PHS-2 and whether the up-regulation of PHS-2 has any correlation to histopathological findings in brain tumors, we evaluated the profile of PHS expression in several human glioma cell lines and surgical specimens from patients with various types of brain tumors. In glioma cell lines, five out of six cell lines showed constitutive expression of PHS-2, whereas PHS-1 was weakly expressed in all of them. All surgical specimens, except an ependymoma, which expressed both isozymes equally, expressed PHS-2 mRNA predominantly. Immunohistochemistry of various types of brain tumors, including six glioblastomas, nine astrocytomas, six meningiomas, five medulloblastomas, four craniopharyngiomas, three ependymomas, three neurinomas, two oligodendrogliomas, two malignant lymphomas, two dysembryoplastic neuroepitherial tumors and one metastatic brain tumor showed PHS-2 staining in most cases. In gliomas, astrocytomas (grade 2 and 3) were strongly stained, but the staining intensity of glioblastomas was relatively weak. Meningiomas and a metastatic brain tumor were also strongly stained. Our data thus suggest that most brain tumors express PHS-2, which may also play a role in tumorigenesis in the brain.

A novel pharmacologic action of glucocorticosteroids on leukotriene C4 catabolism

Leukotriene (LT) C(4), a potent chemical mediator in human bronchial asthma, is metabolized to less active LTE(4) via LTD(4) in 2 consecutive enzymatic reactions by gamma-glutamyl transpeptidases and dipeptidases. We examined whether this inactivation process of LTC(4) was affected by fluticasone propionate, beclomethasone dipropionate, disodium cromoglycate, and salbutamol sulfate in transformed human bronchial epithelial cells. Fluticasone propionate and beclomethasone dipropionate accelerated LTC(4) catabolism by inducing activity of a LTC(4)-degrading enzyme, gamma-glutamyl transpeptidase-related enzyme (gamma-GTPRE), in transformed human bronchial epithelial cells. The activation of gamma-GTPRE might be regulated transcriptionally. This is a novel regulatory mechanism by which glucocorticosteroids exert antiasthma activities.

New induction of leukotriene A(4) hydrolase by interleukin-4 and interleukin-13 in human polymorphonuclear leukocytes

Interleukin (IL)-4, IL-10, and IL-13, Th2 cell-derived cytokines, play major roles in the pathophysiology of allergic diseases. These cytokines up-regulate or down-regulate the production of arachidonic acid metabolites. In this study, we have investigated the effect of IL-4, IL-10, IL-13, and other cytokines on A23187-stimulated synthesis of leukotriene (LT) B(4) in human polymorphonuclear leukocytes (PMNs). Production of LTB(4) was measured by specific radioimmunoassay and high performance liquid chromatography. Messenger RNA (mRNA) expression of cytosolic phospholipase A(2) (cPLA(2)), 5-lipoxygenase (5-LO), and LTA(4) hydrolase, which were involved in the synthesis of LTB(4), was determined by reverse transcription-polymerase chain reaction and Northern blot analysis. Protein synthesis of their enzymes was determined by Western blot analysis. IL-4 and IL-13 enhanced A23187-stimulated LTB(4) synthesis and increased mRNA expression and protein synthesis of LTA(4) hydrolase, but not those of cPLA(2) or 5-LO. These results indicate that IL-4 and IL-13 transcriptionally or post-transcriptionally up-regulate the synthesis of LTB(4), a potent chemotactic factor to PMNs, at the enzyme level of LTA(4) hydrolase, and this up-regulation mechanism may participate in the development of allergic inflammation. (Blood. 2000;96:601-609)

Ulinastatin, an elastase inhibitor, inhibits the increased mRNA expression of prostaglandin H2 synthase-type 2 in Kawasaki disease

Kawasaki disease is an inflammatory disease of unknown cause that causes panvasculitis, including coronary arteritis. Polymorphonucleocytosis in the early stage of the illness suggests the implication of neutrophils in the pathogenesis of the disease. In the acute phase of Kawasaki disease, mRNA expression of prostaglandin H2 synthase (PHS)-2, as determined by reverse transcription-polymerase chain reaction, was markedly enhanced, and thromboxane A2 (TXA2)-synthesizing activity was increased in polymorphonuclear leukocytes (PMNL). This up-regulation of PHS-2 was suppressed by ulinastatin (a neutrophil-elastase inhibitor) treatment. Lipopolysaccharide-induced enhancement of PHS-2 mRNA was also inhibited by therapeutic doses of ulinastatin in vitro by use of PMNL from healthy volunteers. Thus, ulinastatin inhibits arachidonate PHS metabolism by inhibiting new induction of PHS-2 at the mRNA level, which is a novel pharmacologic action of this substance. Ulinastatin treatment is possibly an additional therapeutic approach to Kawasaki disease.

High expression but no internal tandem duplication of FLT3 in normal hematopoietic cells

The FLT3 gene encodes a tyrosine kinase receptor that regulates proliferation and differentiation of hematopoietic cells. Recently, the internal duplication of FLT3 has been observed in hematological malignancies, suggesting the involvement of these mutations in leukemogenesis. The authors analyzed the expression of FLT3 mRNA and the incidence of its internal tandem duplication in normal hematopoietic and blood samples by reverse transcription-polymerase chain reaction (RT-PCR). Mononuclear cells (MNCs) in cord blood and bone marrow highly expressed FLT3 mRNA, whereas MNCs and polymorphonuclear cells (PMNs) in peripheral blood showed low or undetectable levels of FLT3. When the ratio of FLT3/beta-actin PCR products was calculated, the level of FLT3 mRNA expression was significantly higher in cord blood MNCs (n = 42) than that in peripheral MNCs (n = 14) or PMNs (n = 10). Although several PCR bands with different sizes were observed, no internal tandem duplication of FLT3 was detected in these normal blood samples. These findings indicate that the expression of FLT3 is lineage specific and consistently decreases during hematopoietic differentiation. The internal duplication of FLT3 is restricted in hematological malignancies and may occur at a specific stage in leukemogenesis.

Induction of cytosolic phospholipase A2 and prostaglandin H2 synthase-2 by lipopolysaccharide in human polymorphonuclear leukocytes

Polymorphonuclear leukocytes (PMNs) produce arachidonic acid (AA) metabolites including thromboxane A2 (TXA2). These cells are the first line of defense against bacterial invasion, which often causes endotoxin shock. TXA2 which plays an important role in the pathogenesis of endotoxin shock is synthesized by three consecutive enzyme activation, cytosolic phospholipase A2 (cPLA2), prostaglandin H2 synthase (PHS type 1 and type 2) and TXA2 synthase. Among them, cPLA2- and PHS-2 activity is known to be transcriptionally and/or posttranscriptionally up-regulated by various bioactive substances including lipopolysaccharide (LPS), a bacterial endotoxin, in many cell types. We investigated the action of LPS on TXA2 synthesis in human PMNs. A23187-stimulated production of thromboxane B2 (TXB2, a stable metabolite of TXA2), assayed by specific radioimmunoassay (RIA), was significantly increased from 566.7+/-44.1 pg/10(6) cells to 966.7+/-44.1 pg/10(6) cells (p<0.05) after 6 h-exposure to LPS at the concentration of 100 ng/ml. Messenger RNA for PHS-2, PHS-1, TXA2 synthase and cPLA2, which was assessed by reverse transcription-polymerase chain reaction (RT-PCR), was expressed in PMNs without LPS stimulation. Although PHS-2 was putatively an inducible enzyme, abundance of mRNA for PHS-2 in PMNs without LPS stimulation was detectable. Messenger RNA abundance for PHS-2 and cPLA2, but not for PHS-1 and TXA2 synthase, was enhanced by LPS-treatment, indicating that the increased production of TXB2 was attributable to the up-regulation of cPLA2 and PHS-2. We conclude that (1) PHS-2 plays a more important role than PHS-1 in the production of TXA2 in human PMNs and (2) TXA2 synthesis in human PMNs is transcriptionally up-regulated by new induction of cPLA2 as well as PHS-2, when the cells encounter endotoxin producing bacteria.

Effect of dexamethasone on leukotriene synthesis in DMSO-stimulated HL-60 cells

Human leukemia (HL) 60 cells were differentiated by dimethylsulfoxide (DMSO) treatment to granulocyte-like cells, leukotriene (LT) synthesizing activity of which was increased in response to the differentiation of the cells. Four synthesizing enzymes, cytosolic phospholipase A2 (cPLA2), 5-lipoxygenase (5-LO), LTA4 hydrolase and LTC4 synthase, and an enzyme associated protein, 5-lipoxygenase activating protein (FLAP) are involved in the generation of LTC4 and LTB4. We examined the expression of messenger RNA (mRNA) for these LT synthesizing enzymes and an associated protein in DMSO differentiated HL-60 cells by reverse transcriptase polymerase chain reaction (RT-PCR). The production of LTC4 and LTB4, measured by radioimmunoassay (RIA), was increased after the incubation with DMSO for more than 3 days. Messenger RNA abundance for 5-LO, LTC4 synthase and LTA4 hydrolase was increased, that for FLAP was stable, but that for cPLA2 was decreased. These results indicate that DMSO induced increase of LT synthesis is associated with the increase of mRNA expression of 5-LO, LTC4 synthase and LTA4 hydrolase, although the precise regulatory mechanisms of the increased mRNA expression are not determined. We also investigated an action of dexamethasone (DEX) on DMSO-induced enhancement of LT synthesis. DEX suppressed DMSO induced increase of LTC4 synthesis, but rather enhanced DMSO induced LTB4 production. The DEX attenuated the DMSO-induced increase of mRNA expression for LTC4 synthase, but showed no effect on that for LTA4 hydrolase. The inhibition of LTC4 synthesis is associated with the suppression of mRNA expression for LTC4 synthase. However, increased LTB4 synthesis by DEX is regulated by the mechanisms which are independent from mRNA level of LTA4 hydrolase.

Direct evidence that LTC4 and LTB4 but not TXA2 are involved in asthma attacks in children

There are substantial numbers of reports showing that leukotrienes (LTs) play important roles in adult asthma. No definite evidence has been demonstrated that LTs are involved in asthma attacks in children, although it is highly expected. In this report, we demonstrated that the levels of LTB4 and LTC4 but not thromboxane B2 (TXB2), a stable metabolite of TXA2, were significantly elevated in the bronchoalveolar lavage fluid, which was obtained from intubated and mechanically ventilated children with severe asthma attacks. This is direct evidence that LTB4 and LTC4 predominantly participate in asthma attacks in pediatric patients.

High frequency of fusion transcripts of exon 11 and exon 4/5 in AF-4 gene is observed in cord blood, as well as leukemic cells from infant leukemia patients with t(4;11)(q21;q23)

The MLL gene located on chromosome 11q23 and its translocation to the AF-4 gene located on chromosome 4q21 play a pivotal role in leukemogenesis in infancy. Studies of identical leukemic twins have provided evidence of the MLL rearrangement as a fetal event during pregnancy. We analyzed the presence and frequency of the MLL/AF-4 rearrangement in normal cord blood. Although no chimeric mRNA of MLL or AF-4 was detected in 65 cord blood samples, in-frame fusion transcripts of exon 11 and exon 4 or 5 of the AF-4 gene were detected in three of the samples by a nested polymerase chain reaction. When primers of exon 11 and exon 5 of the AF-4 gene were used, two forms of fusion transcripts (AF-4 exon 11/4 or exon 11/5) were detected in 20 of the 65 cord blood samples (31%) and also four of six leukemic cell samples with t(4;11) (67%), whereas such transcripts were not observed in any of 21 peripheral blood samples nor in fetal fibroblasts. These findings suggest that the in-frame fusion of exon 11 and exon 4 or 5 of the AF-4 gene frequently occurs in hematopoietic cells during the intrauterine period, even in a healthy fetus. Although it is unknown whether the proteins of the AF-4 fusion transcripts have some functions, the instability of the AF-4 gene may be associated with the leukemogenesis of infant leukemia.

[Inhibitory effects of saiboku-to and compornent herbs on the production of peptide leukotrienes (LTs) and LTB4]

We investigated the effects of Saiboku-to, Syoseiryu-to and compornent herbs of these two Kampo-Medicines (Saiko, Hange, Bukuryo, Ogon, Koboku, Taiso, Ninjin, Kanzo, Soyo, Syokyo, Keihi, Gomisi, Saisin, Syakuyaku, Mao and Kankyo) on the production of peptide leukotrienes (LTs) and LTB4 in cultured rat basophilic leukemia (RBL)-1 cells. Cultured RBL-1 cells were stimulated with Ca ionophore, A23187, at 10(-5) M in the absence or presence of various concentrations of these substances, and the production of peptide LTs and LTB4 was measured by reversed phase-high performance liquid chromatography (RP-HPLC). The production of LTs was dose-dependently suppressed by the addition of Saibokuto. Saiboku-to (100 micrograms/ml) showed 35% and 30% inhibition on the production of peptide LTs and LTB4, respectively. These inhibitory actions of Saiboku-to on LT-synthesis were attributable to the effects of its component herbs, Ogon, Koboku and Kanzo. On the other hand, Syoseiryu-to showed no inhibitory action on LT-production. these results indicate that anti-allergic action of Saiboku-to is, at least in part, attributable to its inhibitory action on LT-synthesis.

[Diagnostic value of glass microfibre-based basophil histamine release test in food allergic children. Comparison with specific IgE antibody and skin scratch test]

We evaluated the diagnostic value of the glass microfibre-based histamine release test (HRT), which allows measurements to be performed using small amounts of whole blood, in 50 children with food allergy case histories. The patients were evaluated by radioallergosorbent tests (RAST), skin scratch tests (ST) and food challenge tests. Of the 50 patients, 39 had a confirmed clinical diagnosis of food allergy from food challenge tests and case histories, and were affected by a total of 60 positive allergens (egg 37, milk 11, soy beans 4, wheat 5, rice 3). The concordance, sensitivity, and specificity of HRT with the clinical diagnosis were 85.3%, 66.7% and 92.1%, those of RAST were 59.4%, 90.0% and 48.2%, and those of ST were 84.7%, 71.8% and 88.7%, respectively. The positive predictive values of HRT, RAST and ST were 75.5%, 38.8% and 66.7%. The false positive ratio of HRT (24.5%) was the lowest among all the tests. There was a significant correlation between HRT and RAST (r = 0.513, p < 0.001). However, the concordance of HRT with respect to RAST was 56.0%. The concordance and specificity of HRT in relation to the clinical diagnosis were higher than RAST and the same as ST. The sensitivity of RAST was higher than that of HRT. From these results, we concluded that RAST is good for the screening of allergens and that HRT is a useful diagnostic method for the confirmation of a clinical allergy.