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Biomedical subjects

R Sumazaki

Publications and source records attributed to R Sumazaki.

At least 19 recordsLinked to original sources
PubMed2001

SH2D1A mutations in Japanese males with severe Epstein-Barr virus--associated illnesses.

X-linked lymphoproliferative disease (XLP), a genetic disorder characterized by immunodeficiency to Epstein-Barr virus (EBV) infection, has been linked to mutations in the SH2D1A gene. To search for the occurrence of SH2D1A mutations in Japan, we performed genetic analysis of the SH2D1A gene in 40 males presenting with severe EBV-associated illnesses, including fulminant infectious mononucleosis, EBV-positive lymphoma, and severe chronic active EBV infection. SH2D1A mutations were detected in 10 of these 40 patients. Five of these 10 cases were sporadic. Patients with SH2D1A mutations displayed severe acute infectious mononucleosis with hyperimmunoglobulin M, hypogammaglobulinemia, and B-cell malignant lymphoma. By contrast, chronic active EBV infection was not associated with SH2D1A mutations. XLP survivors exhibited normal levels of circulating EBV-DNA during convalescence, suggesting that SH2D1A protein is not directly responsible for control of EBV replication. Thus, genetic analysis of the SH2D1A gene is particularly useful in the diagnosis of sporadic cases and carriers of XLP. (Blood. 2001;98:1268-1270)

Adolescent↗
PubMed1999

Persistence and clinical outcome of hepatitis G virus infection in pediatric bone marrow transplant recipients and children treated for hematological malignancy.

The natural course and the clinical significance of hepatitis G virus (HGV) infection were investigated in 106 pediatric patients who received chemotherapy for hematological malignancy or underwent bone marrow transplantation (BMT) using HGV-RNA and antibodies to the HGV-E2 protein (anti-E2). HGV markers were detected in 21 patients (19.8%; HGV-RNA in 19 and anti-E2 in 2). Longitudinal analysis of these HGV-infected patients showed that 1 had anti-E2 before the initial blood transfusion, 14 had persistent viremia, and 6 became clear of circulating HGV-RNA after completion of therapy, although 5 of the 6 HGV-cleared patients never developed anti-E2. Reactivation of HGV infection during chemotherapy was observed in two anti-E2-positive, HGV-RNA-negative patients; the reappearance of the same HGV strain was confirmed by phylogenetic analysis. Among BMT survivors without other known causes of liver dysfunction, HGV-RNA-positive patients had a higher peak serum alanine amino transferase (ALT) value than negative patients. Contrary to previous reports, immunosuppressed patients can apparently recover from HGV infection without detectable anti-E2 and some patients who supposedly recovered from HGV infection can nonetheless suffer exacerbation when subsequently immunosuppressed.

Adolescent↗
PubMed1999

A magnetic resonance abnormality correlating with permeability of the blood-brain barrier in a child with chemical meningitis during central nervous system prophylaxis for acute leukemia.

Chemical meningitis developed in a boy with acute lymphoblastic leukemia during central nervous system (CNS) prophylaxis. Cerebrospinal fluid examination showed pleocytosis and a high protein level. There were no malignant cytological findings. Calculated permeability of albumin across the blood-brain barrier (BBB) was more elevated than that of immunoglobulin or alfa2-macroglobulin. Magnetic resonance imaging (MRI) revealed diffuse pachymeningeal enhancement without any intracerebral lesion. Subsequent CNS prophylaxis was postponed. CSF findings and BBB permeability returned to normal, correlating well with the decrease of MRI abnormality.

Albumins↗
PubMed1999

Transfusion-transmitted virus infection in China: prevalence in blood donors and in patients with liver diseases.

BACKGROUND: Prevalence of transfusion-transmitted virus (TTV) infection among blood donors and in patients with liver diseases in China was studied. METHODS: DNA was extracted from serum and amplified by seminested polymerase chain reaction with reported primer sets from a conserved region of the TTV genome. RESULTS: TT Virus DNA was detected in 55 of 196 blood donors (28%); 31% (40 of 127) in the north and 22% (15 of 69) in the south. TT Virus DNA was also detected in 14 of 31 patients (45%) with non-A-non-G fulminant hepatitis and in eight of 25 patients (32%) with non-A-non-G chronic hepatitis. The rate of TTV viraemia in these patients with liver disease was comparable to that in blood donors. TT Virus DNA sequencing of 12 isolates showed that the prevalence of genotype 2 was significantly higher than that reported in Japan (66.7 vs 2.6%, P < 0.001). Furthermore, genotyping assays based on restriction fragment length polymorphism were carried out on all 88 TTV DNA-positive samples. It was found that 42 isolates (47.7%) belonged to genotype 1 and 40 (45.5%) to genotype 2. It was of particular interest that the prevalence of genotype 1 in patients with non-A-non-G fulminant hepatitis was significantly higher than that in blood donors (10/14 vs 22/55, P < 0.05). CONCLUSIONS: The data indicate that TTV infection is common in China and that the pathogenic potential of TTV toward the liver (if any) may differ between genotypes.

Adult↗
PubMed1998

Natural course of HGV infection in haemophiliacs.

The natural course of hepatitis G virus (HGV) infection was clarified in 70 haemophiliacs by testing for HGV RNA and antibodies against HGV envelope protein (anti-E2). None of 12 patients treated with only virus-inactivated coagulation factors were infected with HGV. Of 58 patients who received non-inactivated products, 28 (48%) were positive for HGV RNA and/or anti-E2. Of 16 patients with anti-E2, 14 were negative for the viral RNA, and had recovered from HGV infections. HCV antibodies were detected in 59 patients, and eight patients were successively negative for HCV RNA. Thus, the recovery rate of HGV infection (14/28, 50%) was higher than that of HCV (8/59, 14%) (P<0.001). Longitudinal study revealed that anti-E2 developed either during viraemia or some years after seronegativity for HGV RNA. Hence the antibody response itself seemed not to play a major role in the clearance of HGV though anti-E2 was associated with the clearance of HGV RNA. In conclusion, HGV and HCV are prevalent in patients treated with unsterilized coagulation factor concentrates. However, in contrast to HCV, spontaneous recovery is frequently observed in HGV infections.

Adolescent↗
PubMed1998

Humoral immune and clinical responses to food antigens following acute diarrhoea in children.

OBJECTIVE: To investigate the effect of acute watery diarrhoea in children upon humoral immune responses to food antigens and the subsequent development of food allergy. METHODOLOGY: Serum antibodies to cows' milk, beta-lactoglobulin, alpha-lactalbumin, bovine serum albumin and ovalbumin were measured in 30 children with acute diarrhoea in the acute phase and 1 month after recovery. The children were followed for 1 year to assess the development of food allergy. RESULTS: IgG antibeta-lactoglobulin titres for the study group increased 1 month after recovery compared to the titres during the acute phase (P = 0.02). Antibody concentration for the other antigens studied did not rise. Four children developed positive IgE antibodies to one or more of the allergens after the diarrhoeal episode, although the titres were very low. None showed evidence of allergy to cows' milk or egg during the year-long follow-up. CONCLUSIONS: Acute diarrhoea in children resulted in increased production of IgG antibody to beta-lactoglobulin and had a priming effect for development of positive IgE antibody to cows' milk. Clinical food allergy was not observed in any of the children during the year-long follow-up.

Animals↗
PubMed1997

Resolution of protein-losing hypertrophic gastropathy by eradication of Helicobacter pylori.

UNLABELLED: There is as yet no consensus about the need for treatment of Helicobacter pylori infections, except for H. pylori-associated peptic ulcer. We present a 3-year-old boy with a 3-month history of oedema and hypoproteinaemia associated with hypertrophic gastropathy. Abdominal scintigram using intravenous 99mTc-labelled human serum albumin scintigraphy and direct measurement of protein in gastric juice proved that serum proteins were massively secreted in the stomach. Histological findings of mucosal inflammation were observed and H. pylori was isolated from the gastric mucosa. The protein loss promptly stopped within 2 weeks of the beginning of eradication therapy. CONCLUSION: Protein-losing hypertrophic gastropathy may be induced by Helicobacter pylori-associated gastritis and should therefore be carefully evaluated by histological and bacteriological examination to provide a basis for eradication of H. pylori.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1997

Immune response to food antigens: kinetics of food-specific antibodies in the normal population.

The role of food-specific antibodies in the pathogenesis of food allergy is controversial. The first step in solving this controversy may be the assessment of antibody response to food antigens in the normal population. Most of the existing data in this field come from studies that used assays of different standards. This study investigated food-specific antibodies in the normal population using standardized assays. Normal levels of antibody titers were also derived for use as reference. Two hundred and eight individuals from different age groups participated. Immunoglobulin G (IgG) antibodies to cow's milk and its component proteins, and to hen's egg ovalbumin, IgA and IgM antibodies to beta-lactoglobulin and ovalbumin were measured by enzyme-linked immunosorbent assay. The sepharose-radioallergosorbent test was used to measure IgE antibodies to cow's milk and ovalbumin. Titers of IgG antibodies to cow's milk and its component proteins revealed an age-related trend, peaking in the 5 months-1 year age group and then decreased to negligible values in adults. A similar trend was observed with IgG anti-ovalbumin antibodies. Temporal association was less evident for antibodies of other classes. Only six subjects had positive IgE antibodies to cow's milk, while none had positive IgE anti-ovalbumin antibody. The prevalences of IgG antibodies to cow's milk, its component proteins, and ovalbumin are influenced by age and feeding habits. Cross-reactivity to related food antigens is common. The presence of IgE antibodies to food antigens is not a physiological phenomenon.

Animals↗
PubMed1997

Circulating antibodies to common food antigens in Japanese children with IDDM.

OBJECTIVE: To investigate the humoral immune response to common food antigens in Japanese children with IDDM. RESEARCH DESIGN AND METHODS: IgG antibodies to cow's milk, beta-lactoglobulin, bovine serum albumin (BSA), alpha-lactalbumin, and hens egg ovalbumin were examined by enzyme-linked immunosorbent assay in the sera of 33 patients with IDDM, ages 11.8 +/- 3.4 years. The data were compared with that of 50 normal subjects, ages 10.3 +/- 5.1 years, who acted as control subjects. A positive antibody to a food antigen was defined as an antibody titer greater than the 95th percentile value in normal subjects. RESULTS: Children with IDDM had significantly higher median titers of IgG antibodies to beta-lactoglobulin and ovalbumin (P = 0.03 and P = 0.0005 respectively). More children with IDDM than control subjects had positive IgG antibody to ovalbumin (21 vs. 6%, P = 0.04). Titers, as well as the number of positive antibodies to other food antigens, including BSA, did not differ between the two groups. CONCLUSIONS: Japanese children with IDDM show an enhanced humoral immune response to beta-lactoglobulin and ovalbumin, a phenomenon that may be related to the pathogenesis of the disease.

Adolescent↗
PubMed1996

Rapidly progressive hepatitis C in a patient with common variable immunodeficiency.

UNLABELLED: A 15-year-old girl with common variable immunodeficiency contracted hepatitis C, which progressed to liver cirrhosis and finally to hepatic failure 5 years later. Since she was agammaglobulinaemic, hepatitis C virus (HCV) infection was diagnosed on the basis of HCV-RNA detection. Quantification of her sera showed high levels of HCV-RNA (more than 10(7) copies of RNA/mL), which implied active viral replication. There were no other hepatotoxic factors except HCV infection. The initial liver biopsy at 16 years of age and the autopsy confirmed a rapid progression in liver histopathological change over 4 years. CONCLUSION: Contrary to the widely held view of a benign short-term prognosis in paediatric hepatitis C, progressive fatal liver disease can develop in some patients with HCV infection. Such a rapid progression of liver injury provides the rationale for antiviral therapy in at least certain high risk groups of these children. Hepatitis C may progress rapidly in an immune deficiency condition.

Adolescent↗
PubMed1996

Genotyping of hepatitis C virus: coinfection by multiple genotypes detected in children with chronic posttransfusion hepatitis C.

The distribution of genotypes of the hepatitis C virus (HCV) was studied in 24 children with chronic posttransfusion hepatitis C. Genotypes were determined by reverse transcription-nested polymerase chain reaction with type-specific primers. Twenty (83%) were infected by a single genotype: 14 by type II [1b], 3 by III [2a], and 3 IV [2b]. Four (17%) were coinfected by two genotypes. The amount of blood transfusion given to the patients infected by multiple genotypes was significantly larger than to those infected by a single genotype (mean +/- SD, 15.2 +/- 14.4 vs 78.6 +/- 42.0 U). Three of the four patients infected by multiple genotypes were considered to be immunocompromised by anticancer therapy for malignant disease. Eighteen patients showed a raised level of alanine aminotransferase throughout the follow-up, while the remaining six patients (three of type II [1b], two of IV [2b], and one of III [2a] + IV [2b]) achieved biochemical remission. Liver biopsy was performed on 19 patients. Compared to those with type III [2a] or IV [2b], those with type II [1b] appeared to show more severe histological changes with higher histological activity index scores, although there was no significant difference. The positive rates of antibody to C100-3 or 5-1-1 in patients with type III [2a] or IV [2b] were lower than in those with type II [1b] (33 and 33 vs 43 and 50%), whereas the antibody to C33C or C22-3 was detected in nearly all patients regardless of their genotypes. In the present study, we found a high incidence of multiple-genotype infection among children with chronic posttransfusion hepatitis C.

Adolescent↗
PubMed1995

Successful treatment of invasive thoracopulmonary mucormycosis in a patient with acute lymphoblastic leukemia.

BACKGROUND: Pulmonary mucormycosis associated with hematologic malignancy is an uncommon, but important opportunistic fungal pneumonia that is usually a fatal infection. Only a few survivors of pulmonary mucormycosis have been reported. METHODS: A case report of invasive thoracopulmonary mucormycosis during remission-induction therapy for acute lymphoblastic leukemia and a review of the literature are presented. RESULTS: The fungal lesions extended to both lungs, the left ribs, and intercostal muscles. Percutaneous needle biopsy and immunostaining of the fungal hyphae established the diagnosis of thoracopulmonary mucormycosis. The patient was treated with granulocyte-colony stimulating factor (G-CSF) and intravenous amphotericin B for 9 weeks and the lesions in the right lung disappeared. Left pneumonectomy and partial resection of the chest wall were later performed. The left lung was grossly necrotic and contained a large cavity and bronchopulmonary fistula. Thereafter, antileukemic therapy was resumed and completed without recurrence of mucormycosis or leukemia. CONCLUSIONS: In the management of mucormycosis, the addition of G-CSF to the conventional treatment may substantially improve outcome.

Adolescent↗
PubMed1995

Mother-to-infant transmission of hepatitis C virus: a prospective study.

UNLABELLED: To investigate the risk of mother-to-infant transmission of hepatitis C virus (HCV) and the natural course of HCV-infected infants, we prospectively studied 31 offspring of pregnant women who were anti-HCV positive and anti-HIV negative. Sera were serially tested for anti-HCV by the second-generation ELISA-test (ELISA-2) and for HCV-RNA by the polymerase chain reaction procedure. The mean period of follow up was 19 months (range 6-41 months). The presence of HCV-RNA in the mothers was associated with a high titre of anti-HCV by ELISA-2 or a positivity of the second generation recombinant immunoblot assay. At birth, 26 babies were positive for anti-HCV. Passively transferred maternal antibodies became undetectable within 2-15 months. HCV-RNA was detected in only 3 infants (9.7%) within 1-4 weeks after birth and persisted thereafter. The genotype of HCV-RNA in each of the infants was consistent with that of their mother. These 3 showed chronic transaminase elevation during the follow up that started at 1-2 months of age, although they revealed no clinical symptoms. Reelevation of anti-HCV titre was observed in the HCV-infected infants within 10 months of age, suggesting an endogenous production of anti-HCV. The mean titre of HCV-RNA in three mothers of infected infants was higher than that in the mothers of uninfected infants (10(5.3 +/- 0.3) vs 10(4.4 +/- 0.2)/ml). CONCLUSION: Our findings indicate that HCV was most likely to have been transmitted from mothers to infants at the time of delivery and that it was capable of evoking the chronic carrier state.

Carrier State↗