Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) stimulates primitive and definitive erythropoiesis in mouse embryos expressing hGM-CSF receptors but not erythropoietin receptors.

Although erythropoietin (EPO) and its receptor (EPOR) are crucial for the proliferation, survival, and terminal differentiation of erythroid progenitors, it remains to be elucidated whether EPOR-unique signaling is required for erythropoiesis. To address this issue, human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor (hGMR)-transgenic mice and heterozygous EPOR mutant mice were crossed by in vitro fertilization. In methylcellulose clonal culture of fetal liver (FL) cells of generated hGMR-expressing EPOR(-/-) embryos at embryonic day (E) 12.5 of gestation, hGM-CSF stimulated erythroid colony formation under serum-containing and serum-free conditions. Analysis of globin expression in individual erythrocyte-containing colonies formed from E12.5 FL cells showed that hGM-CSF supports primitive and definitive erythropoiesis even in EPOR(-/-) embryos. In comparison of activities between hGM-CSF and EPO in hGMR-expressing EPOR(+/+) embryos, the 2 substances supported the formation of similar numbers of erythroid colonies in clonal culture of E12.5 FL cells; enhanced adult, but not embryonic, globin synthesis; and induced increase of GATA-1 expression and decrease of erythroid Kruppel-like factor and cMyb expression in the FL cells. On the other hand, in E8.0 yolk sac erythropoiesis, both substances had a similar effect on erythroid colony formation, but hGM-CSF induced an increase of beta-major globin expression, while EPO did not. All together, the results of the present study demonstrated that hGM-CSF can stimulate the proliferation and differentiation of primitive and definitive erythroid cells independently of EPOR signal if they express hGMR, and the activity is comparable to that of EPO in definitive, but not primitive, erythropoiesis.

Generation of definitive hematopoietic stem cells from murine early yolk sac and paraaortic splanchnopleures by aorta-gonad-mesonephros region-derived stromal cells.

There is controversy as to whether murine definitive hematopoiesis originates from yolk sac (YS) or the intraembryonic region. This study reports the generation of definitive hematopoietic stem cells (HSCs) from both early YS and intraembryonic paraaortic splanchnopleures (P-Sp) on AGM-S3 stromal cells derived from the aorta-gonad-mesonephros (AGM) region at 10.5 days post coitum (dpc). YS and P-Sp cells at 8.5 dpc generated no definitive hematopoiesis-derived colony-forming cells in cocultures with AGM-S3 cells, but spleen colony-forming cells and HSCs capable of reconstituting definitive hematopoiesis in adult mice simultaneously appeared on day 4 of coculture. Precursors for definitive HSCs were present in YS and P-Sp at 8.0 dpc, a time when YS and embryo were not connected by blood vessels. It is proposed that precursors with the potential to generate definitive HSCs appear independently in YS and intraembryonic P-Sp and that the P-Sp or AGM region affords the microenvironment that facilitates generation of definitive hematopoiesis from precursors.

Prompt and durable hematopoietic reconstitution by unrelated cord blood transplantation in a child with Fanconi anemia.

We describe here the case of an 8-year-old girl with Fanconi anemia (FA) whose hematopoiesis was successfully restored by unrelated umbilical cord blood (UCB) transplantation. The patient became resistant to androgen therapy, and developed intracranial hemorrhage and dyserythropoiesis. Her hematopoietic recovery after the transplantation was excellent and a complete chimerism has been durably maintained. UCB should be considered as a stem cell source for transplantation when a patient with FA does not have an HLA-identical unaffected sibling donor.

Improvement in bronchiolitis obliterans organizing pneumonia in a child after allogeneic bone marrow transplantation by a combination of oral prednisolone and low dose erythromycin.

We report a 13-year-old boy who developed dyspnea at rest 1 year after the occurrence of cGVHD following an allogeneic bone marrow transplant (BMT). Pulmonary function data, imaging studies, lung biopsy, and bronchoalveolar lavage were consistent with the diagnosis of bronchiolitis obliterans organizing pneumonia (BOOP). Although reports suggest that oral methylprednisolone or methylprednisolone pulse therapies improve BOOP after BMT, we treated our patient with a combination of oral prednisolone (1 mg/kg) and low dose erythromycin (10 mg/kg) to avoid the side-effects of high-dose steroids. With this therapy, our patient showed clinical and radiological improvements within 1 week. The steroids were tapered off 12 months later and erythromycin was given for 14 months. We conclude that therapy consisting of a combination of oral prednisolone and low-dose erythromycin for BOOP after BMT may minimize the dose and duration of steroid use.

Massive pericardial and pleural effusion with anasarca following allogeneic bone marrow transplantation.

A 10-year-old girl presented with massive pericardial/pleural effusion with anasarca 216 days after an allogeneic bone marrow transplantation from her HLA-matched sibling for relapsed acute lymphoblastic leukemia. She did not show any other symptoms of chronic graft-versus-host disease (GVHD). The antinucleolar antibody was elevated in the blood and the pleural fluid. The lymphocytes in the fluid were mostly CD8+/HLA-DR+, and a majority of CD8+ cells in the blood expressed CD57. These data suggested that she had chronic GVHD. Immunosuppressive therapy including prednisolone, cyclosporin A, high-dose methylprednisolone, tacrolimus (FK506), and methotrexate had no effect, and the patient died of Aspergillus pneumonia 183 days after the presentation of the disease. Although it has not been described before, isolated serositis with edema should be recognized as a clinical feature of chronic GVHD.

Expansion of human NOD/SCID-repopulating cells by stem cell factor, Flk2/Flt3 ligand, thrombopoietin, IL-6, and soluble IL-6 receptor.

Here, we demonstrate a significant ex vivo expansion of human hematopoietic stem cells capable of repopulating in NOD/SCID mice. Using a combination of stem cell factor (SCF), Flk2/Flt3 ligand (FL), thrombopoietin (TPO), and a complex of IL-6 and soluble IL-6 receptor (IL-6/sIL-6R), we cultured cord blood CD34(+) cells for 7 days and transplanted these cells into NOD/SCID mice. Bone marrow engraftment was judged successful when recipient animals contained measurable numbers of human CD45(+) cells 10-12 weeks after transplantation. When cells were cultured with SCF+FL+TPO+IL-6/sIL-6R, 13 of 16 recipients were successfully engrafted, and CD45(+) cells represented 11.5% of bone marrow cells in engrafted recipients. Cells cultured with a subset of these factors were less efficiently engrafted, both as measured by frequency of successful transplantations and prevalence of CD45(+) cells. In animals receiving cells cultured with all 4 factors, human CD45(+) cells represented various lineages, including a large number of CD34(+) cells. The proportion of CD45(+) cells in recipient marrow was 10 times higher in animals receiving these cultured cells than in those receiving comparable numbers of fresh CD34(+) cells, and the expansion rate was estimated at 4.2-fold by a limiting dilution method. Addition of IL-3 to the cytokine combination abrogated the repopulating ability of the expanded cells. The present study may provide a novel culture method for the expansion of human transplantable hematopoietic stem cells suitable for clinical applications.

Analysis of IgG subclasses in chronic active Epstein-Barr virus infection.

BACKGROUND: Although elevated serum levels of immunoglobulins are frequently observed in patients with chronic active Epstein-Barr virus (EBV) infection, there have been no reports concerning levels of IgG subclasses. METHODS: Serum levels of IgG subclasses were measured by the enzyme-linked immunosorbent assay (ELISA) in 30 children with severe chronic active EBV infection. RESULTS: Serum levels of IgG1 were elevated in most patients, except for one who showed an abnormally low level of IgG1 and progressive hypogammaglobulinemia. Serum levels of IgG2, IgG3 and IgG4 in the patients were comparable to those in control children, while abnormally low levels of IgG2, IgG3 and IgG4 were observed in six, three and four cases, respectively. CONCLUSION: Although not always susceptible to bacterial infections, low levels of IgG2 were frequently observed in patients with chronic active EBV infection and elevated IgG1 is responsible for the increase of serum IgG in these patients.

A variant of myelokathexis with hypogammaglobulinemia: lymphocytes as well as neutrophils may reverse in response to infections.

A 7-year-old boy with prolonged and marked leukopenia diagnosed at 6 months of age is described. The polymorphonuclear cells presented no hypersegmented nuclei or concentrated nuclear chromatin, although vacuolated myeloid cells appeared in bone marrow smears. Neutrophils reversed in response to administration of G-CSF. His leukocyte counts were 400-1000/microL during afebrile periods and increased to 2000-3000/microL in response to infections. The increased leukocyte was usually neutrophils, but lymphocytes also increased at EB-virus infection. The serum IgG decreased gradually and was 364 mg/dL at 7 years of age. Antibody responses were normal and recurrent otitis media has been the patient's only problem. Granulocytopenia with hypogammaglobulinemia of this patient mimics myelokathexis with hypogammaglobulinemia, and lymphocytes also increased at viral infections.

Strong response of T cells in infants with dual infection by Epstein-Barr virus and cytomegalovirus.

BACKGROUND: Although a reversed CD4/CD8 ratio and increased proportion of CD8+ HLA-DR+ T cells are well known as the characteristic immune response in infectious mononucleosis (IM), it has not been elucidated whether these immune responses are affected by patient age and pathogenetic viruses. METHODS: T cell subsets were analyzed by two-color flow cytometry using fluorescein isothiocyanate- and phycoerythrin-conjugated monoclonal antibodies in 115 infants and children aged from 4 months to 10 years with IM due to Epstein-Barr virus (EBV), cytomegalovirus (CMV) and dual infection with both viruses. RESULTS: A reversed CD4/CD8 ratio and increased proportions of CD4+/HLA-DR+ T cells, CD8+ T cells and CD8+/HLA-DR+ T cells became more prominent as the age of the patients became older. No differences were observed in proportions of T cell subsets between EBV- and CMV-infection among patients aged from 6 to 17 months. Although the responses of these T cells were weak in infants with single virus infection by EBV and CMV, markedly strong T cell responses comparable with those in older children were observed in infants with EBV/CMV dual infection. Clinical symptoms were more severe in patients with EBV/CMV dual infection than those with EBV or CMV alone. CONCLUSION: The manner of these T cell responses in the acute phase of IM was considered to be age dependent, although strong T cell responses and severe disease were observed in EBV/CMV dual infection irrespective of patient age.

Persistently high Epstein-Barr virus (EBV) loads in peripheral blood lymphocytes from patients with chronic active EBV infection.

Chronic active Epstein-Barr virus infection (CAEBV) is a severe illness with unusual EBV activation that persists for years, and its pathogenesis is largely unknown. After the creation of an accurate and reproducible polymerase chain reaction system to quantify EBV DNA, virus loads in peripheral blood lymphocytes (PBL) were determined in 54 children: 15 with CAEBV, 16 with infectious mononucleosis (IM), and 23 healthy children. Children with CAEBV and those with IM had high virus loads. Lower loads were detected in 47% of seropositive healthy donors. There were two distinct differences between children with CAEBV and those with IM: The former had greater viral replication (10(3)-10(7) copies/2.5x10(5) PBL) than those with IM, and viral replication declined in children with IM whereas active replication persisted for years in subjects with CAEBV. Persisting high virus loads are a possible diagnostic criterion for CAEBV. EBV loads may enable classification and prognosis of EBV infections.

Effective control of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis with immunochemotherapy. Histiocyte Society.

The familial form of hemophagocytic lymphohistiocytosis (HLH) is a lethal disorder. Although the prognosis for Epstein-Barr virus-associated HLH (EBV-HLH) remains uncertain, numerous reports indicate that it can also be fatal in a substantial proportion of cases. We therefore assessed the potential of immunochemotherapy with a core combination of steroids and etoposide to control EBV-HLH in 17 infants and children who met stringent diagnostic criteria for this reactive disorder of the mononuclear phagocyte system. Treatment of life-threatening emergencies was left to the discretion of participating investigators and typically included either intravenous Ig or cyclosporin A (CSA). Five patients (29%) entered complete remission during the induction phase (1 to 2 months), whereas 10 others (57%) required additional treatment to achieve this status. In 2 cases, immunochemotherapy was ineffective, prompting allogeneic bone marrow transplantation. Severe but reversible myelosuppression was a common finding; adverse late sequelae were limited to epileptic activity in one child and chronic EBV infection in 2 others. Fourteen of the 17 patients treated with immunochemotherapy have maintained their complete responses for 4+ to 39+ months (median, 15+ months), suggesting a low probability of disease recurrence. These results provide a new perspective on EBV-HLH, showing effective control (and perhaps cure) of the majority of EBV-HLH cases without bone marrow transplantation, using steroids and etoposide, with or without immunomodulatory agents.

Serodiagnosis of infectious mononucleosis in children.

BACKGROUND: Although anti-viral capsid antigen (VCA)-immunoglobin M (IgM) is the most reliable serological marker of primary Epstein-Barr virus (EBV) infection, it could only be detected in limited cases of infectious mononucleosis in children. We analyzed anti-EBV antibodies by an enzyme-linked immunosorbent assay (ELISA), a sensitive method for detecting IgM antibody and compared these results with those obtained by a conventional indirect immunofluorescence (IF) method. METHODS: Anti-Epstein-Barr virus early antigen (EA)-IgM and nuclear antigen 1 (EBNA1)-IgG were examined by an ELISA assay in 180 sera from 70 infants and children with infectious mononucleosis, diagnosed serologically by standard IF methods. RESULTS: Although by IF, VCA-IgM was detected in only 37 of 70 (52.9%) of the sera from the acute phase of the disease, by ELISA, EA-IgM was detected in 65/70 (92.9%) of these sera. Among infants less than 12 months of age. EA-IgM was positive in 11/13 cases (84.6%) while VCA-IgM was detected in only 3/13 cases (23.1%). Anti-Epstein-Barr virus nuclear antigen 1-IgG was not detected by ELISA in the sera from the acute phase of infectious mononucleosis. Anti-EBNA was not detected by IF in about one-third of the sera during 6-8 months after onset of the disease, whereas by ELISA, EBNA1-IgG was detected in 93.0%. Sera that were positive or negative for both EA-IgM and EBNA1-IgG by ELISA were observed in several cases after the patients recovered from the disease. CONCLUSIONS: Although serodiagnosis by the combination of ELISA for EA-IgM and EBNAI-IgG was more sensitive than IF methods, especially in the case of infants and young children, several patients during convalescence and recovery might be judged as seronegative or as being in highly reactivated states.

Interferon-alpha potentiates priming-dependent FMLP-induced neutrophil superoxide generation in a patient with chronic myeloid leukemia.

A 13 year old girl diagnosed as having chronic myeloid leukemia (CML) was treated with interferon-alpha (IFN-alpha) alone and 4 months later hematological remission was obtained. In the course of the IFN-alpha treatment there was neither infectious sign nor side effects. In this study we have examined the effect of IFN-alpha on superoxide O2- generation by polymorphonuclear neutrophils (PMN). The PMN of the patient generated less O2- than PMN from normal controls. When patient PMN were cultured in the presence of 1000 U/mL IFN-alpha, enhancement of the formyl-methionyl-leucyl-phenylalanine induced O2- generation following priming with tissue necrosis factor-alpha was observed. Over the course of the IFN-alpha therapy, such O2- generation was gradually restored. It is suggested that CML PMN are in the resting condition in terms of their ability to generate O2- and that IFN-alpha is effective in inducing O2- generation by CML PMN.

Fetal valproate syndrome with reduction deformity of limb.

A case is reported of a female infant having multiple anomalies, including epicanthic folds, hypertelorism, bifid nasal bridge, shallow philtrum, low-set ears, brain atrophy, cleft palate, hemangioma on the chest, and reduction deformity of the left upper limb. This is the first case where an infant who was exposed to sodium valproate intra-uterine has a reduction deformity of the upper limb.

Defective natural killer cell activity and deficient production of interferon-gamma in children with acute lymphoblastic leukemia.

Natural killer (NK) cell activity, OK-432-augmented-NK cell activity, concentrations of interferon-gamma (IFN-gamma) in the culture supernatants of lymphocytes stimulated with OK-432, and subsets of NK cells and memory T cells were analyzed in 42 children with acute lymphoblastic leukemia (ALL) receiving maintenance chemotherapy. Natural killer and augmented-NK cell activities, and concentrations of IFN-gamma in the supernatants of cultured lymphocytes, were significantly lower in the patients with ALL than in age-matched control children. Among the NK cell subsets, proportions of CD57+ cells in the patients with ALL were significantly higher than in the controls, and proportions of a memory T cell subset (CD4+ CD29+ T cells) in the patients were also significantly higher than in the controls. These results suggest that the function of NK cells and memory T cells that are considered as IFN-gamma producing cells, may be defective in ALL, and that CD57+ cells and CD4+ CD29+ cells may be resistant to or recover rapidly from suppression by cytotoxic chemotherapy.

[Fluconazole therapy for pediatric patients with severe candidal infections].

Three children with severe candidal infections were treated with fluconazole (FLCZ). An excellent effect or a partial effect was obtained in each case. Case 1 was a boy with candida esophagitis. He had been treated for relapsed ALL and became febrile with severe swallowing pain. FLCZ was administered intravenously and he became afebrile after 10 days of the therapy. Case 2 was a boy with candida pneumonitis. He had been treated for relapsed ALL and became febrile with diffuse infiltration in chest X-ray. FLCZ was administered intravenously and he became afebrile transiently, though fever and abnormal X-ray shadows reappeared soon and died of pneumonia and leukemic infiltrations. Case 3 was a girl with candida pneumonitis. She had been treated for relapsed neuroblastoma and became febrile and dyspneic. She was treated with intravenous FLCZ with no effects and died of pneumonia. All three patients showed positive results in 2 of 3 markers for candida infection, including, Cand-Tec, D-arabinitol and fungal index. FLCZ was well tolerated and no adverse effects or abnormal laboratory test results were observed. FLCZ was considered as an effective and safe antifungal agent in the treatment for fungal infections in children.

Defective activity of Epstein-Barr virus (EBV) specific cytotoxic T lymphocytes in children with chronic active EBV infection and in their parents.

Antibodies of Epstein-Barr virus (EBV), EBV-specific cytotoxic T lymphocyte (EBVCTL) activity and the lymphocyte subset of CTL were examined in 13 Japanese children with chronic active EBV infection (CAEBV) and their parents (eight fathers and 10 mothers). Anti-virus-capsid antigen (VCA)-IgG antibody titers ranged from 1:640 to 1:5120 in the patients with CAEBV and from 1:40 to 1:640 in the parents. While anti-VCA-IgM antibody was detected in three patients, anti-VCA-IgA antibody in five and anti-early-antigen (EA)-IgG antibody in 11, no antibody was detected in the parents except anti-EA antibody, which was positive in the mothers of cases 5 and 13 (1:10 and 1:40). Anti-EBV-associated nuclear antigen (EBNA) antibody was < or = 1:10 in six out of 13 patients with CAEBV and in 10 out of 18 parents tested. Epstein-Barr virus activity was significantly lower (P < 0.005) both in the children with CAEBV and in their parents than in seropositive age-matched controls. Proportions of a CTL subset (CD8+ CD11- lymphocytes) in the patients with CAEBV were significantly higher (P < 0.005) than in controls, while those in the parents were at the same level as in controls. Defective EBVCTL activity and anti-EBNA-antibody responses were frequently observed both in children with CAEBV and in their parents, which may suggest that the abnormal immune response to EBV may be based on a familial disorder, though no familial involvement has been reported in Japanese children with CAEBV.

IgG subclass imbalance in children with acute lymphoblastic leukemia receiving maintenance chemotherapy.

Serum levels of IgG subclasses were measured in 18 children with acute lymphoblastic leukemia (ALL) receiving maintenance chemotherapy and in 36 age-matched controls in order to attempt to analyse the effects of chemotherapy. The IgG subclasses were measured by enzyme linked immunosorbent assay. Serum IgG1, IgG2 and IgG4 levels in the patients were significantly (p less than 0.01, p less than 0.005, p less than 0.005) lower than in the controls, but serum IgG3 levels in patients were as high as in controls. Suppression on IgG2 and IgG4 were more profound than IgG1. In six children, the levels of the IgG subclasses were measured at diagnosis, during maintenance chemotherapy and one year after cessation of chemotherapy. The levels of the four IgG subclasses at diagnosis and after cessation of chemotherapy were as high as those in control children except for the IgG4 levels in the post-chemotherapy group. IgG2 and IgG4 may be more susceptible to suppression by chemotherapy than IgG1 and IgG3 may not be suppressed by chemotherapy.

[Clinical studies of panipenem/betamipron in pediatrics].

We conducted clinical studies on panipenem/betamipron (PAPM/BP), a newly developed parenteral carbapenem antibiotic, for its clinical application in the field of pediatrics. 1. A clinical study was performed on 13 children with infections, including 6 with acute bronchopneumonia, 1 each with acute pharyngitis, acute bronchitis, sepsis, staphylococcal scalded skin syndrome, urinary tract infection, subcutaneous abscess and furuncle. PAPM/BP was administered by intravenous drip infusion. Doses varied from 12 to 27 mg/kg body weight were given t.i.d. or q.i.d. Lengths of treatment ranged from 4 to 25 days. Clinical efficacies were excellent in 3 and good in 9 cases, with an efficacy rate of 92%. 2. No adverse reactions were observed. In laboratory tests, elevations of GOT, GPT and urobilinogen were observed in 3 cases. It was concluded that PAPM/BP was a promising drug for the treatment of bacterial infections in children.