Stability of cord blood RNA measured by house keeping transcripts: relevance for large-scale studies of childhood leukaemia.
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Core Binding Factor Alpha 2 Subunit↗
Biomedical subjects
H O Madsen
Publications and source records attributed to H O Madsen.
Mannose-binding lectin and its genetic variants.
Mannose-binding lectin (MBL) is a collagen-like serum protein that mediates activation of the complement system and is of importance for host defence. Common variant alleles situated both in the promoter and structural region of the human MBL gene (MBL2) influence the stability and the serum concentration of the protein. Epidemiological studies have suggested that genetically determined variation in MBL serum concentration influences the susceptibility to and the course of different types of infections, autoimmune, metabolic and cardiovascular diseases, but this is still a subject of debate. The fact that these genetic variations are very frequent indicates a dual role for MBL in host defence. In this survey, we summarize the current molecular understanding of human MBL genetics.
Alleles↗
Chronic myeloid leukaemia with BCR-ABL fusion genes located to both chromosomes 9, cyclic leukocytosis and nodal T-lymphoblastic transformation--durable complete remission following imatinib therapy.
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Antineoplastic Agents↗
Evidence for involvement of clonally expanded CD8+ T cells in anticancer immune responses in CLL patients following nonmyeloablative conditioning and hematopoietic cell transplantation.
We have analyzed the clonotype composition of CD8+ T cells following nonmyeloablative (NMA) conditioning and hematopoietic cell transplantation (HCT), of patients with chronic lymphocytic leukemia (CLL). Consecutive analyses of blood samples taken up to 2 years following HCT, demonstrated that CD8+ T-cell clonality was highly dynamic in the early phases after HCT, but became more stable after 4-5 months. Moreover, donor lymphocyte infusion (DLI) given for disease progression in one of the patients led to establishment of recurrent as well as new T-cell clonotypes. This coincided with disease remission, strongly suggesting that these T cells were engaged with anti-CLL cytotoxicity. To examine the functional capacity of stable clonally expanded T cells after HCT, CD8+ T cells isolated post-transplant from the recipients were stimulated ex vivo with CLL cells and subsequently analyzed by FACS for surface expression of the marker for cytotoxic activity, CD107a. Stimulation with CLL cells indeed led to surface expression of CD107a, and clonotype analyses of sorted cells demonstrated that CD107a positive T cells were stably expanded following HCT. Our data suggest that clonally expanded CD8+ T-cell clones participate in the ongoing T-cell response against CLL cells following HCT with NMA conditioning.
CD8-Positive T-Lymphocytes↗
A comparison of T-, B- and NK-cell reconstitution following conventional or nonmyeloablative conditioning and transplantation with bone marrow or peripheral blood stem cells from human leucocyte antigen identical sibling donors.
This retrospective study compares the reconstitution of T, B and NK cells in three groups of patients transplanted for haematological malignancies with grafts from their HLA-identical sibling donors. In all, 15 patients received PBSC after a nonmyeloablative conditioning regimen consisting of fludarabine and 200 cGy TBI, 13 patients received PBSC after myeloablative conditioning and 37 patients received BM after myeloablative conditioning. In the nonmyeloablative group, the NK cells normalised after 1 month, the CD8+ T cells normalised after 3 months, the CD4+ T cells reached near normal values after 9 months and the B cell values were reduced until 12 months after transplant. In the two myeloablative groups, recipients of PBSC had a significantly higher number of CD4+ T cells after 4 months (P=0.004) and after 12 months (P=0.001), than recipients of BM. We found no differences in the T cell reconstitution between the two PBSC groups. This was of interest as the recipients of nonmyeloablative conditioning were older (P<0.001) and had a higher occurrence of chronic GVHD (P<0.05) than the recipients of myeloablative conditioning. In contrast, the recipients of nonmyeloablative conditioning had a delayed B cell recovery when compared to the patients who received myeloablative conditioning (P=0.04).
Adolescent↗
Presence of clone-specific markers at birth in children with acute lymphoblastic leukaemia.
Recent studies have suggested that development of childhood acute lymphoblastic leukaemia may often be initiated in utero. To provide further evidence of an prenatal origin of childhood leukaemia, we conducted a molecular biological investigation of nine children with B-precursor acute lymphoblastic leukaemia carrying the chromosomal translocation t(12;21), the most common subtype of all childhood acute lymphoblastic leukaemia. Specifically, for each child we identified the non-constitutive chromosomal sequences made up by the t(12;21) fusion gene. From these, leukaemia clone-specific DNA primers were constructed and applied in nested polymerase chain reaction analyses of DNA extracted from the patients' Guthrie cards obtained at birth. Leukaemia clone-specific fusion gene regions were demonstrated in Guthrie card DNA of three patients, age 2 years 11 months, 3 years 4 months, and 5 years 8 months at leukaemia diagnosis. Our findings are consistent with previous observations, and thus provide further evidence that the development of t(12;21) B-precursor acute lymphoblastic leukaemia may be initiated in utero. Review of the current literature moreover indicates that age at leukaemia may be inversely correlated with the burden of cells with leukaemia clonal markers, i.e. leukaemia predisposed cells at birth, and that certain types of childhood acute lymphoblastic leukaemia develop as a multiple step process involving both pre- and postnatal genetic events.
Adolescent↗
Cerebrospinal fluid levels of nitric oxide metabolites predict response to methylprednisolone treatment in multiple sclerosis and optic neuritis.
The role of nitric oxide (NO) in multiple sclerosis (MS) is not clear. We found increased cerebrospinal fluid concentrations of the NO degradation products nitrate (NO(x)) in clinically definite MS but not in clinically isolated syndromes. High CSF concentrations of NO(x) correlated with long attack duration. Patients carrying the truncated CC chemokine receptor allele CCR5 Delta32 had lower serum concentration of NO(x) at later attack stages. NO(x) concentrations did not change after methylprednisolone treatment but high concentrations were associated with more pronounced treatment responses. These findings suggest an association of high CSF levels of NO(x) with more severe disease activity in relapsing-remitting MS.
Adult↗
Disease severity in Danish multiple sclerosis patients evaluated by MRI and three genetic markers (HLA-DRB1*1501, CCR5 deletion mutation, apolipoprotein E).
As the understanding of the autoimmune inflammatory response in multiple sclerosis (MS) expands, polymorphic genes involved in this process become possible candidates that may determine the severity of disease. Therefore, three candidate genes DRB1*1501, CCR5 and apolipoprotein E (APOE) were examined in a population-based patient sample (n = 70) to assess an association between disease progression measured by clinical disability and MRI parameters. The total lesion area (TLA) on T2-weighted images was measured with a semi-automated threshold technique. Patients with the CCR5delta32 allele showed a non-significant trend towards a smaller lesion burden (TLA/years duration), but were not associated to a milder EDSS/years duration. Our data support previous assumptions of a modulation of severity in MS by the CCR5delta32 genotype, which may convey less inflammation and tissue destruction. Carriers of the DRB1*1501 and APOE-epsilon4 allels did not reveal more severe disease progression, neither by the EDSS/years of duration nor by the TLA/years duration. This study was performed on a population-based sample in a genetically homogeneous Danish population but, due to the limited number of patients examined, weak associations between candidate genes and disease variables cannot be excluded.
Adult↗
CXCR3 expression on CD34(+) hemopoietic progenitors induced by granulocyte-macrophage colony-stimulating factor: II. Signaling pathways involved.
CXCR3, known to have four ligands (IFN-gamma inducible protein 10 (gamma IP-10), monokine induced by IFN-gamma (Mig), I-TAC, and 6Ckine), is predominantly expressed on memory/activated T lymphocytes. We recently reported that GM-CSF induces CXCR3 expression on CD34(+) hemopoietic progenitors, in which gamma IP-10 and Mig induce chemotaxis and adhesion. Here we further report that stimulation with GM-CSF causes phosphorylation of Syk protein kinase, but neither Casitas B-lineage lymphoma (Cbl) nor Cbl-b in CD34(+) hemopoietic progenitors can be blocked by anti-CD116 mAb. Specific Syk blocking generated by PNA antisense completely inhibits GM-CSF-induced CXCR3 expression in CD34(+) progenitors at both mRNA and protein as well as at functional levels (chemotaxis and adhesion). Cbl and Cbl-b blocking have no such effects. Thus, GM-CSF binds to its receptor CD116, and consequently activates Syk phosphorylation, which leads to induce CXCR3 expression. gamma IP-10 and Mig can induce Syk, Cbl, and Cbl-b phosphorylation in CD34(+) progenitors by means of CXCR3. gamma IP-10 or Mig has induced neither chemotaxis nor adhesion in GM-CSF-stimulated Cbl-b-blocked CD34(+) hemopoietic progenitors, whereas SDF-1alpha induces both chemotaxis and adhesion in these cells. Interestingly, gamma IP-10 and Mig can induce chemotaxis and adhesion in GM-CSF-stimulated Syk- or Cbl-blocked CD34(+) hemopoietic progenitors. Thus, Cbl-b, but not Syk and Cbl phosphorylation, is essential for gamma IP-10- and Mig-induced chemotaxis and adhesion in CD34(+) hemopoietic progenitors. This study provides a useful insight into novel signaling transduction pathways of the functions of CXCR3/gamma IP-10 and Mig, which may be especially important in the cytokine/chemokine environment for mobilization, homing, and recruitment during proliferation, differentiation, and maturation of hemopoietic progenitor cells.
Adaptor Proteins, Signal Transducing↗
Autoreactivity, backstimulation and reproducibility in a helper T lymphocyte precursor assay.
Helper T lymphocyte precursor (HTLp) frequencies determined by limiting dilution analysis (LDA) have a predictive value for alloreactivity in allogeneic bone marrow transplantation. Methodological problems in LDA include autoreactivity in the responder or stimulator cell populations and interleukin 2 (IL-2) production by the stimulator cells as a response to the responder cells (backstimulation). The extent and impact of these aspects for IL-2 production and HTLp frequency determination were studied by autologous and allogeneic mixed lymphocyte reactions with healthy volunteers and HTLp determinations from bone marrow transplantation donor/recipient pairs. We found that autoreactivity occurred in the unirradiated cells with a reproducible inter-individual variation. The immunogenicity of the stimulator cells was preserved after gamma irradiation with 50 Gy and the risks of autoreactivity and backstimulation were limited. Higher doses of irradiation decreased the immunogenicity. Immune reactions to antigens present in the serum supplement of the culture medium were seen with foetal calf serum and to a lesser extent with pooled human sera. This could be avoided by the use of autologous serum. We were unable to ensure satisfactory culture conditions in serum-free medium. The reproducibility of the HTLp frequency determinations was tested for intra- and inter-assay variation. The coefficients of variation were estimated as 24% and 35%, respectively. This was acceptable considering the range of the HTLp frequencies (1:10(2) to 1:10(7)). The influence of the extent of autoreactivity of the bone marrow donors was investigated in 28 HLA-identical sibling transplantations. We found no correlation between the autoreactivity of the donors and the HTLp frequencies. The extent of autoreactivity of the donor did not correlate with the clinical outcome in terms of acute graft-versus-host disease, treatment-related mortality, risk of relapse and overall survival. In spite of methodological difficulties and interference from autoreactivity and backstimulation, reproducible quantification of clinically significant alloreactivity can be attained.
Autoimmunity↗
Acute respiratory tract infections and mannose-binding lectin insufficiency during early childhood.
CONTEXT: Hospital-based studies have found that increased susceptibility to certain infections is associated with low serum levels of mannose-binding lectin (MBL) due to MBL variant alleles. However, the contribution of MBL insufficiency to incidence of common childhood infections at a population level is unknown. OBJECTIVE: To investigate the effect of MBL insufficiency on risk for acute respiratory tract infection (ARI) in unselected children younger than 2 years. DESIGN AND SETTING: Population-based, prospective, cohort study conducted in Sisimiut, Greenland. PARTICIPANTS: Two hundred fifty-two children younger than 2 years who were followed up weekly between August 1996 and August 1998 for morbidity surveillance. MAIN OUTCOME MEASURE: Risk of ARI, based on medical history and clinical examination, compared by MBL genotype, determined from blood samples based on presence of structural and promoter alleles. RESULTS: A 2.08-fold (95% confidence interval [CI], 1.41-3.06) increased relative risk (RR) of ARI was found in MBL-insufficient children (n = 13) compared with MBL-sufficient children (n = 239; P<.001). The risk association was largely restricted to children aged 6 to 17 months (RR, 2.92; 95% CI, 1.78-4.79) while less effect (RR, 1.47; 95% CI, 0.45-4.82) and no effect (RR, 1.00; 95% CI, 0.42-2.37) was shown among children aged 0 to 5 months and 18 to 23 months, respectively. CONCLUSION: These data suggest that genetic factors such as MBL insufficiency play an important role in host defense, particularly during the vulnerable period of childhood from age 6 through 17 months, when the adaptive immune system is immature.
Acute Disease↗
The predictive value of helper T lymphocyte precursor frequencies for graft-versus-host disease and graft-versus-leukaemia effects in allogeneic bone marrow transplantation.
Helper T lymphocyte precursor (HTLp) frequencies determined by limiting dilution analysis were studied in the graft-versus-host direction to assess the predictive value for outcome in allogeneic BMT. The HTLp frequencies correlated with the degree of HLA disparity. HTLp frequencies from 28 HLA-identical sibling BMT pairs had a median of 1:557 362 (range 1:9511 to <1:2 500 000). The HTLp frequencies from 20 HLA-matched unrelated and partially HLA-matched related BMT pairs had a median of 1:88 110 (range 1:4139-1:736 123). The HLA-identical sibling BMT pairs were split evenly into high and low HTLp frequency groups above and below 1:500 000. There was a trend towards a higher risk for acute GVHD > or =grade II (P = 0.075) in the high frequency group. There was no difference in TRM. The high HTLp frequency group had a significantly higher risk for chronic GVHD (P = 0.04), a significantly lower risk for relapse (P = 0.01), as well as a significantly better overall survival (P = 0.045) and leukaemia-free survival (P = 0.008). The HLA-matched unrelated and partially HLA-matched related BMT pairs were split evenly into high and low HTLp frequency groups above and below 1:90 000. There was a significantly higher risk for acute GVHD > or = grade II (P = 0.007) in the high HTLp frequency group. There was a trend towards a higher TRM in the high HTLp frequency group (P = 0.05). There were no differences in chronic GVHD, risk of relapse, overall survival and leukaemia-free survival. Analyzing all 48 patients the risk of acute GVHD > or = grade II and TRM was significantly higher (P = 0.012 and 0.021, respectively) with HTLp frequencies >1:100 000 and there was a trend towards a higher risk of relapse (P = 0.058) with low HTLp frequencies <1:400 000. Patients in the intermediate HTLp frequency group 1:100 000-1:400 000 had a trend towards improved survival (P = 0.059). The HTLp frequency seems to detect clinically significant differences in alloreactivity, that can be useful in donor selection and graft engineering.
Adolescent↗
Association of mannose-binding lectin gene variation with disease severity and infections in a population-based cohort of systemic lupus erythematosus patients.
This study describes the importance of mannose-binding lectin (MBL) variant alleles for systemic lupus erythematosus (SLE) and accompanying infections in a population-based cohort. MBL alleles were determined in 99 SLE patients recruited from a representative Danish region. Patients were classified according to the 1982 revised ACR criteria as definite SLE (D-SLE) (n = 77) fulfilling > or =4 criteria and incomplete SLE (I-SLE) (n = 22) with 0.99, respectively). A meta-analysis of eight previously published studies suggested that the presence of MBL variant alleles confer a 1.6 times overall increased risk for D-SLE (P < 0.00001). MBL variant allele carriers had higher disease activity (SLEDAI-index) in a 2-year follow-up period (P = 0.02) and had an increased risk of acquiring complicating infections in general (P = 0.03) and respiratory infections in particular (P = 0.0006). Only in SLE patients fulfilling > or =4 ACR criteria an increased frequency of MBL variant alleles was found. MBL variant alleles were also associated with increased risk of disease activity and of complicating infections indicating that the MBL gene is an SLE disease modifier locus.
Adolescent↗
Characterization of t(12;21) breakpoint junctions in acute lymphoblastic leukemia.
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Base Sequence↗
Post-induction residual leukemia in childhood acute lymphoblastic leukemia quantified by PCR correlates with in vitro prednisolone resistance.
Most prognostic factors in childhood acute lymphoblastic leukemia (ALL) are informative for groups of patients, whereas new approaches are needed to predict the efficacy of chemotherapy for the individual patient. The residual leukemia following 4 weeks of induction therapy with prednisolone, vincristine, doxorubicin and i.t. methotrexate and the in vitro resistance to prednisolone, vincristine, and doxorubicin were measured in 30 boys and 12 girls with B (n = 34) or T lineage (n = 8) ALL. The residual leukemia was quantified after 2 (MRD-D15, n = 29) and 4 weeks (MRD-PI, n = 42) of induction therapy with a precise and reproducible clone-specific PCR technique. The median MRD-D15 and MRD-PI were 0.50% (75% range 0.0088.1%) and 0.014% (75% range 0.001-2.0%), respectively, and these levels correlated significantly (n = 29, rs = 0.75, P < 0.001). Both the MRD-D15 and the MRD-PI were related to the age of the patient (MRD-D15: rs= 0.48, P= 0.009; MRD-PI: rs = 0.45, P = 0.003). Patients with T lineage ALL had higher MRD-PI than those with B lineage ALL (median MRD-PI: 0.5% vs 0.01%, P = 0.05). The median LC50 (concentration lethal to 50% of cells) for prednisolone was 2.3 microg/ml (75% range 0.05-668). Both MRD-D15 and MRD-PI correlated significantly with the in vitro resistance to prednisolone (MRD-D15: rs = 0.41, P = 0.03; MRD-PI: rs = 0.39, P = 0.01); but not to in vitro vincristine or doxorubicin resistance. The correlations between MRD and in vitro prednisolone resistance were even more pronounced when B cell precursor and T cell leukemia were analyzed separately (B cell precursor ALL: MRD-PI vs prednisolone LC50: n = 33, rs = 0.47, P = 0.006; T cell ALL: MRD-PI vs prednisolone resistance: n = 8, rs = 0.84, P = 0.009). After a median follow-up of 5.0 years (75% range 3.2-6.9) eight patients have relapsed. All of the 21 patients with a MRD-PI < or =0.5% and a prednisolone LC50 < or =10 microg/ml have remained in remission whereas the 7 year event-free survival for the remaining 20 patients was 0.45 +/- 0.16 (P= 0.002) Prospective studies in childhood ALL are needed to clarify whether combined monitoring of in vitro drug resistance and residual leukemia early during chemotherapy could offer new ways to classify patients and stratify the intensity of therapy.
Adolescent↗
Transient pancytopenia preceding acute lymphoblastic leukaemia (pre-ALL) precipitated by parvovirus B19.
A preleukaemic phase, typified by pancytopenia and bone marrow (BM) hypoplasia, is an uncommon but well-documented prelude to acute lymphoblastic leukaemia (pre-ALL) in children. Parvovirus B19 (B19) exhibits a marked tropism to human BM and replicates only in erythroid progenitor cells acting as a confounding, but treatable agent in immunocompromised patients. We present the first case of B19-associated pre-ALL characterized by severe and recurring transient pancytopenia in a child who developed ALL 5 months later. The advent of B19-specific IgG at the time of infection and the subsequent disappearance 1.5 years later has not previously been described. In this patient the observed cytopenias were probably the result of B19 acting in concert with the failing BM and B19 is possibly one of several factors capable of triggering the onset of pre-ALL.
Bone Marrow Cells↗
Lack of FasL expression in cultured human retinal pigment epithelial cells.
Retinal pigment epithelial (RPE) cells have been proposed to play a part in maintaining the eye as an immune privileged organ. However, our knowledge of the implicated mechanism is still sparse. Fas ligand (FasL) expression of RPE cells is generally recognized to be essential for the immune privilege of the eye, but due to contradictory published results, it is unclear whether RPE cells express this molecule. The purpose of this study was to investigate the expression of FasL in RPE cells in vitro and in vivo. Cultured human fetal and adult RPE cells were examined by flow cytometry, Western blotting, RT-PCR and RNase Protection assay for FasL expression. Additionally, sections of ocular tissue were stained for FasL by immunohistochemistry. None of the used methods indicated FasL expression in cultured fetal or adult RPE cells of various passages. However, RPE cells in vivo, as judged from tissue sections, were positive for FasL, indicating a discrepancy between RPE cells in vitro and in vivo with regard to this molecule.
Adult↗
The influence of mannose binding lectin polymorphisms on disease outcome in early polyarthritis. TIRA Group.
OBJECTIVE: To determine whether variant alleles of the mannose binding lectin (MBL) gene causing low serum concentrations of MBL are associated with increased susceptibility to rheumatoid arthritis (RA) and erosive outcome in an inception cohort of patients with early polyarthritis. METHODS: MBL and HLA-DRB1 alleles were determined by polymerase chain reaction in 68 Danish patients with incident early polyarthritis observed for one year. The associations between MBL and specific HLA-DRB1 genotypes and disease outcomes were analyzed. RESULTS: Among the patients with early polyarthritis 7.4% (5/68) and 41.2% (28/68) were homozygous and heterozygous for MBL variant alleles, compared with 2.8% (7/250) and 34.4% (86/250) of healthy controls (p = 0.09), while the corresponding figures in the patients with RA were 10% (5/50) and 42% (21/50) (p = 0.03), and in the patients with erosive RA 18.8% (3/16) and 35.3% (6/16), respectively (p = 0.004). Patients with early polyarthritis homozygous for MBL variant alleles had an increased risk of having erosive RA at inclusion by a factor of 4.7 (p = 0.02) and after one year by a factor of 3.6 (p = 0.04). MBL deficiency was associated with increased levels of C-reactive protein (CRP) and IgM rheumatoid factor (RF) at inclusion (p < 0.05). HLA-DRB1 alleles were not found to be associated with disease outcome. CONCLUSION: MBL variant alleles appear to be weak susceptibility markers for RA, and patients with early polyarthritis and homozygous for MBL structural variant alleles have a higher risk of developing early erosive RA. These findings, together with the positive association between MBL variant alleles and the increased serum levels of IgM RF and CRP, point at the MBL gene as a relevant locus in the pathophysiology of RA.
Adult↗