| 1. |
- Bena, Frederique, et al.
(författare)
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Molecular and clinical characterization of 25 individuals with exonic deletions of NRXN1 and comprehensive review of the literature
- 2013
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Ingår i: American Journal of Medical Genetics Part B. - : Wiley. - 1552-4841 .- 1552-485X. ; 162B:4, s. 388-403
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to elucidate the observed variable phenotypic expressivity associated with NRXN1 (Neurexin 1) haploinsufficiency by analyses of the largest cohort of patients with NRXN1 exonic deletions described to date and by comprehensively reviewing all comparable copy number variants in all disease cohorts that have been published in the peer reviewed literature (30 separate papers in all). Assessment of the clinical details in 25 previously undescribed individuals with NRXN1 exonic deletions demonstrated recurrent phenotypic features consisting of moderate to severe intellectual disability (91%), severe language delay (81%), autism spectrum disorder (65%), seizures (43%), and hypotonia (38%). These showed considerable overlap with previously reported NRXN1-deletion associated phenotypes in terms of both spectrum and frequency. However, we did not find evidence for an association between deletions involving the -isoform of neurexin-1 and increased head size, as was recently published in four cases with a deletion involving the C-terminus of NRXN1. We identified additional rare copy number variants in 20% of cases. This study supports a pathogenic role for heterozygous exonic deletions of NRXN1 in neurodevelopmental disorders. The additional rare copy number variants identified may act as possible phenotypic modifiers as suggested in a recent digenic model of neurodevelopmental disorders.
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| 2. |
- Hellberg, Åsa, et al.
(författare)
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P1PK: the blood group system that changed its name and expanded.
- 2013
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Ingår i: Immunohematology. - 0894-203X. ; 29:1, s. 25-33
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Tidskriftsartikel (refereegranskat)abstract
- The antigens in the P1PK blood group system are carried on glycosphingolipids. The system currently includes three different antigens, P1, Pk, and NOR. The P1 antigen was disovered in 1927 by Landsteiner and Levine, and Pk and NOR were described in 1951 and 1982, respectively. As in the ABO system, naturally occurring antibodies of the immunoglobulin (Ig) M or IgG class, against the missing carbohydrate structures, can be present in the sera of people lacking the corresponding antigen. Anti-P1 is generally a weak and cold-reactive antibody not implicated in hemolytic transfusion reaction (HTR) or hemolytic disease of the fetus and newborn while Pk antibodies can cause HTR, and anti-NOR is regarded as a polyagglutinin. A higher frequency of miscarriage is seen in women with the rare phenotypes p, P1k, and P2k. Furthermore, the Pk and P1 antigens have wide tissue distributions and can act as host receptors for various pathogens and toxins. Why p individuals lack not only Pk and P expression but also P1 has been a longstanding enigma. Recently, it was shown that the same A4GALT-encoded galactosyltransferase synthesizes both the P1 and Pk antigens and that a polymorphism in a new exon in this gene predicts the P1 and P2 phenotypes.
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| 3. |
- Irshaid, N M, et al.
(författare)
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Genomic typing of the Kidd blood group locus by a single-tube allele-specific primer PCR technique
- 1998
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 102:4, s. 1010-1014
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Tidskriftsartikel (refereegranskat)abstract
- The Kidd (JK) blood group system is clinically important in transfusion medicine. Alloantibodies to antigens in this system may be produced following blood transfusion or during pregnancy and can result in serious haemolytic transfusion reactions and haemolytic disease of the newborn (HDN). JK antigens on erythrocytes are carried by glycoproteins with the capacity to transport urea through cell membranes. cDNA complementary to mRNA transcribed at the JK locus was cloned in 1994. The molecular basis of the Jk(a)/Jk(b) blood group polymorphism was recently shown to be a single nucleotide substitution predicting an amino acid change (Asp280Asn) in an extracellular loop of the JK glycoprotein. After confirmation of the JK gene polymorphism we developed a rapid and robust technique for JK genotyping with allele-specific primers in a single-tube PCR. In addition, a 217 bp intron located at nucleotides 811-812 in the JK gene was found and sequenced. The genotyping test was validated with samples from 106 Caucasian Swedish and 13 Black South African random blood donors. Complete phenotype-genotype correlations were obtained. However, four Jk(a-b-) samples of Polynesian and Finnish origin typed as Jk(b)Jk(b). Potential use of the presented method can be predicted in clinical transfusion medicine including prenatal determination of the JK genotype in a fetus at risk for HDN caused by JK antibodies.
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| 4. |
- Olsson, Martin L, et al.
(författare)
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An Ael allele-specific nucleotide insertion at the blood group ABO locus and its detection using a sequence-specific polymerase chain reaction
- 1995
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 216:2, s. 642-647
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Tidskriftsartikel (refereegranskat)abstract
- Genomic DNA from each of four Acl individuals (genotypes AO1, AO1var, AO2) and one AclB individual was used as a template for amplifying exons 6 and 7 of the ABO genes, which were subsequently sequenced. In all the Ael alleles a single nucleotide insertion, compared to the A consensus sequence, was observed that would alter the amino acid sequence of the glycosyltransferase immediately after its postulated nucleotide sugar binding site and furthermore extend the translated protein by 37 amino acids (16 more than the A2 enzyme). A sequence-specific primer PCR assay was developed to detect the nucleotide insertion. It was possible to differentiate all 20 serologically defined Acl/AclB individuals available from 145 blood donors with normal ABO phenotypes and genotypes and 26 individuals with various A subgroups other than A1, A2 and Acl. This mutation explains the Acl phenotype and forms the basis of a method for detecting the Ael allele.
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| 5. |
- Rajnavolgyi, E, et al.
(författare)
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A repetitive sequence of Epstein-Barr virus nuclear antigen 6 comprises overlapping T cell epitopes which induce HLA-DR-restricted CD4(+) T lymphocytes
- 2000
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Ingår i: International Immunology. - : Oxford University Press (OUP). - 1460-2377 .- 0953-8178. ; 12:3, s. 281-293
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Tidskriftsartikel (refereegranskat)abstract
- Most human adults carry the Epstein-Barr virus (EBV) and develop immunological memory against the structural and the virus-encoded cellular proteins. The EBV nuclear antigen 6 (EBNA6) elicits cytotoxic T cell responses and it also maintains a persistent antibody response. The majority of sera from EBV-seropositive individuals reacts with a synthetic peptide, p63, comprising 21 amino acids of a repetitive region of EBNA6. CD4(+) T lymphocytes, with specificity for p63, could be recalled from the T cell repertoire of EBV carriers that expressed certain HLA-DR allotypes which were identified as good binders of p63 by an in vitro flow cytometric assay. Analysis of the HLA-DR/p63 interaction by molecular mechanics calculations indicated the presence of multiple overlapping epitopes which were predicted to bind in a HLA-DRB1 allo- and subtype-specific manner. Specific activation of p63-selected long-term CD4(+) T cell cultures resulted in a proliferative response, in the production of IL-2 and in the secretion of high levels of tumor necrosis factor as measured by bioassays. Proliferation and cytokine production of p63-specific T cells could be induced by p63-loaded HLA-DR-matched antigen-presenting cells and by B cells co-expressing relevant HLA-DR molecules and EBNA6. Our results show that peptides of an EBNA6 repeat region induce CD4(+) T cells which can react with EBNA6-carrying cells in many individuals. We suggest that these T(h) cells may be important in conditioning dendritic cells for initiation potent virus-specific immune responses, provide help for EBV-specific B cells, drive IgG isotype switch and support the sustained effector function of memory cytotoxic T lymphocytes.
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| 6. |
- Schoumans, Jacqueline, et al.
(författare)
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Comprehensive mutational analysis of a cohort of Swedish Cornelia de Lange syndrome patients
- 2007
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 15:2, s. 143-149
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Tidskriftsartikel (refereegranskat)abstract
- Cornelia de Lange syndrome (CdLS; OMIM 122470) is a rare multiple congenital anomaly/mental retardation syndrome characterized by distinctive dysmorphic facial features, severe growth and developmental delay and abnormalities of the upper limbs. About 50% of CdLS patients have been found to have heterozygous mutations in the NIPBL gene and a few cases were recently found to be caused by mutations in the X-linked SMC1L1 gene. We performed a mutation screening of all NIPBL coding exons by direct sequencing in 11 patients (nine sporadic and two familial cases) diagnosed with CdLS in Sweden and detected mutations in seven of the cases. All were de novo, and six of the mutations have not been previously described. Four patients without identifiable NIPBL mutations were subsequently subjected to multiplex ligation-dependent probe amplification analysis to exclude whole exon deletions/duplications of NIPBL. In addition, mutation analysis of the 5' untranslated region (5' UTR) of NIPBL was performed. Tiling resolution array comparative genomic hybridization analysis was carried out on these four patients to detect cryptic chromosome imbalances and in addition the boys were screened for SMC1L1 mutations. We found a de novo 9p duplication with a size of 0.6 Mb in one of the patients with a CdLS-like phenotype but no mutations were detected in SMC1L1. So far, two genes (NIPBL and SMC1L1) have been identified causing CdLS or CdLS-like phenotypes. However, in a considerable proportion of individuals demonstrating the CdLS phenotype, mutations in any of these two genes are not found and other potential loci harboring additional CdLS-causing genes should be considered.
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| 7. |
- Storry, Jill, et al.
(författare)
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Homozygosity for a null allele of SMIM1 defines the Vel-negative blood group phenotype
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:5, s. 537-U109
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Tidskriftsartikel (refereegranskat)abstract
- The Vel antigen is present on red blood cells (RBCs) from all humans except rare Vel-negative individuals who can form antibodies to Vel in response to transfusion or pregnancy. These antibodies may cause severe hemolytic reactions in blood recipients. We combined SNP profiling and transcriptional network modeling to link the Vel-negative phenotype to SMIM1, located in a 97-kb haplotype block on chromosome 1p36. This gene encodes a previously undiscovered, evolutionarily conserved transmembrane protein expressed on RBCs. Notably, 35 of 35 Vel-negative individuals were homozygous for a frameshift deletion of 17 bp in exon 3. Functional studies using antibodies raised against SMIM1 peptides confirmed a null phenotype in RBC membranes, and SMIM1 overexpression induced Vel expression. Genotype screening estimated that similar to 1 of 17 Swedish blood donors is a heterozygous deletion carrier and similar to 1 of 1,200 is a homozygous deletion knockout and enabled identification of Vel-negative donors. Our results establish SMIM1 as a new erythroid gene and Vel as a new blood group system.
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| 8. |
- Swedin, Agneta, et al.
(författare)
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Clinical utility of immunoglobulin heavy chain gene rearrangement identification for tumour cell detection in multiple myeloma
- 1998
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048. ; 103:4, s. 1145-1151
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Tidskriftsartikel (refereegranskat)abstract
- In an attempt to define the clinical utility of immunoglobulin heavy chain (IgH) gene rearrangement identification for tumour cell detection in multiple myeloma, we investigated 36 consecutive newly diagnosed patients intended for high-dose chemotherapy in a study protocol. After identification of the IgH rearrangement, an allele specific oligonucleotide (ASO) was constructed and used in a semiquantative PCR for minimal residual disease (MRD) evaluation. The myeloma-specific IgH gene rearrangement could be identified and an ASO primer constructed in 24 (67%) of the patients. All of these patients underwent transplantation; 22 were autologous, of whom three had PCR-negative stem cell harvests, and two were allogeneic. 10 patients achieved a clinical complete response (CR) and five were PCR negative in sequential bone marrow analyses. In patients not achieving CR, PCR negativity was occasionally found, but in general the PCR results reflected the clinical status of the patients. No consistent relationship between the bone marrow MRD status and the clinical course was found, and early relapses occurred also in PCR-negative patients.
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| 9. |
- Thuresson, Britt, et al.
(författare)
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A novel B(weak) hybrid allele lacks three enhancer repeats but generates normal ABO transcript levels.
- 2012
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Ingår i: Vox Sanguinis. - : Wiley. - 1423-0410 .- 0042-9007. ; 102:1, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives Weak expression of A/B histo-blood group antigens is often explained by single nucleotide substitutions at the ABO locus. However, hybrid alleles containing segments from different ABO alleles can result in unexpected phenotypes and may complicate genotype analysis. We investigated the basis of weak B phenotype in a referred sample. Materials and Methods A healthy young woman was serologically phenotyped as AB(weak) and RBCs were characterized by flow cytometry. All seven ABO exons, five introns plus the 5'-region including the CCAAT-binding factor/Nuclear Factor Y (CBF/NF-Y) binding enhancer were sequenced. ABO transcript levels were measured in fresh peripheral blood samples. Expression of B antigen was semiquantified following transfection of HeLa cells. Results A new B(weak) allele with 53G>T resulted in a characteristic pattern of moderately weakened B antigen expression on RBCs. Its sequence revealed a novel hybrid between O(2) [O03] and B [B101] alleles with a crossingover region in intron 4 as defined by allele-specific polymorphisms. B transcript levels were similar to normal controls despite the O(2) -related single CBF/NF-Y-binding 43-bp motif in the enhancer region. Expression of the glycosyltransferase including the O(2) -specific Arg18Leu substitution resulted in a slight decrease in B-antigen-positive cells. Conclusion We describe here the first hybrid between an O(2) and a B allele and characterized the associated decrease in B antigen expression. Although it lacks three enhancer repeat units compared to common B alleles, the resulting transcript level was unaltered. This study challenges previous suggestions that the number of 43-bp motifs in the ABO enhancer determines transcription rates in erythroid cells.
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| 10. |
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| 11. |
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| 12. |
- Thuresson, Britt, et al.
(författare)
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ABO transcript levels in peripheral blood and erythropoietic culture show different allele-related patterns independent of the CBF/NF-Y enhancer motif and multiple novel allele-specific variations in the 5'- and 3'-noncoding regions.
- 2008
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 48:3, s. 493-504
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Mechanisms regulating the ABO gene are unclear, especially in the hematopoietic compartment. The number of 43-bp repeats in the CBF/NF-Y-binding enhancer region is considered to have a major influence on transcription. STUDY DESIGN AND METHODS: Transcript levels in peripheral blood and in erythropoietic culture of CD34+ cells from marrow donors were measured with TaqMan assays. The 5'-regulatory region and 3'-downstream sequences were investigated to determine if allelic variations occur. RESULTS: Surprisingly, transcripts from A(1) and A(2) alleles could not be detected in peripheral blood, although transcripts from B/O(1)/O(1v)/O(2) alleles were readily observed. Sequencing of approximately 4 kb upstream and 1.8 kb downstream of the coding region showed multiple novel allele-specific and allele-related motifs. No correlation between these sequence variations and transcript levels was found, however. Contradictory to the results with peripheral blood, in erythropoietic culture of CD34+ cells from healthy marrow donors transcripts from A(1) and A(2) alleles were found at higher levels than transcripts from B/O(1)/O(1v) alleles. CONCLUSION: These data do not support previous suggestions that nonsense-mutated O(1)/O(1v) transcripts are eliminated first. Furthermore, our results contradict the notion that the number of repeats in the upstream CBF/NF-Y-binding enhancer region, which contains four 43-bp repeats in A(2)/B/O(1)/O(1v) but only one 43-bp unit in A(1)/O(2) alleles, determines the transcription rate. The reason for the remarkable discrepancy between blood and marrow remains to be elucidated.
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| 13. |
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| 14. |
- Thuresson, Britt, et al.
(författare)
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Identification of a novel A4GALT exon reveals the genetic basis of the P1/P2 histo-blood groups.
- 2011
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 117:2, s. 678-687
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Tidskriftsartikel (refereegranskat)abstract
- The A4GALT locus encodes a glycosyltransferase that synthesizes the terminal Galα1-4Gal of the P(k)(Gb3/CD77) glycosphingolipid, important in transfusion medicine, obstetrics and pathogen susceptibility. Critical nucleotide changes in A4GALT not only abolish P(k) formation but also another Galα1-4Gal-defined antigen, P1, which belongs to the only blood group system for which the responsible locus remains undefined. Since known A4GALT polymorphisms do not explain the P1-P(k)+ phenotype, P(2), we set out to elucidate the genetic basis of P(1)/P(2). Despite marked differences (P(1)>P(2)) in A4GALT transcript levels in blood, luciferase experiments showed no difference between P(1)/P(2)-related promoter sequences. Investigation of A4GALT-mRNA in cultured human bone marrow cells revealed novel transcripts containing only the non-coding exon 1 and a sequence (here termed exon 2a) from intron 1. These 5'-capped transcripts include poly-A tails and 3 polymorphic sites, one of which was P(1)/P(2)-specific among >200 donors and opens a short reading frame in P(2) alleles. We exploited these data to devise the first genotyping assays to predict P1 status. P(1)/P(2) genotypes correlated with both transcript levels and P1/P(k) expression on red cells. Thus, P(1) zygosity partially explains the well-known interindividual variation in P1 strength. Future investigations need to focus on regulatory mechanisms underlying P1 synthesis.
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| 15. |
- Thuresson, Britt
(författare)
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Studies on the Polymorphism and Transcriptional Regulation of the ABO and P1PK Histo-blood Group Genes
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Antigens of the clinically important ABO and P1PK blood group systems are carbohydrate structures. Thus the underlying genes do not encode antigens directly but glycosyltransferases that add specific sugar molecules to selected precursor chains. The aim of this study was to investigate the transcriptional regulation of ABO and A4GALT, with an emphasis on interindividual differences. The up-and downstream regions of the major ABO alleles were sequenced to identify allele-specific motifs. Transcript levels were evaluated in both peripheral blood and bone marrow samples. Considerable allelic variation was observed between the common ABO alleles although this did not appear to influence transcript levels. Strikingly, however transcripts from the two major A alleles, A1 and A2 were undetectable in peripheral blood while, B/O transcripts were readily found. Consequently all alleles were transcribed in bone marrow cells undergoing erythroid culture. In a second study, a novel ABO hybrid allele with an anomalous enhancer region was characterized in a A1Bweak sample. Contrary to current beliefs, the number minisatellite 43-bp elements in the enhancer region did not correlate with ABO transcript levels in these two studies. A4GALT gene transcripts were measured in P1 and P2 phenotypes samples. Regarding transcript levels and RBC surface antigen expression. Through the discovery of a novel A4GALT transcript containing a previously unrecognized and polymorphic A4GALT exon, the long-suspected link between the P1 and Pk antigens was established. A P1/P2 polymorphism was confirmed useful for genotyping in >200 donors. The P2 allele was shown to lower A4GALT transcript levels as well as P1 and Pk antigen expression. Accordingly P1/P2 zygosity appears to explain the well-known but poorly understood variability in P1 strength on erythrocytes. Based on these studies, the Pk antigen has now joined P1 in the former P blood group system, appropriately re-designated P1PK. In summary, these studies of ABO and A4GALT transcriptional have resulted in significant discoveries towards increased understanding of two clinically important blood group systems. The mechanisms underlying 1) the apparent absence of A transcripts in peripheral blood, and 2) how the P2-specific polymorphism down-regulates A4GALT transcripts remains to be explained.
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| 16. |
- Thörn, Ingrid, 1957-, et al.
(författare)
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Analysis of IG/TCR gene rearrangements in Swedish childhood acute lymphoblastic leukemia diagnosed 2002-2006: a multi-centre study supporting the applicability of real-time-PCR for minimal residual disease assessment
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Minimal residual disease (MRD) detection during the early treatment phase has become an important stratification parameter in many childhood acute lymphoblastic leukemia (ALL) treatment protocols. Here we aimed to address the applicability of real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged antigen receptor genes as an MRD method in a multi-centre setting. From a Swedish population-based cohort of 334 ALL cases diagnosed during 2002-2006, we analysed 279 diagnostic samples (84%) by screening for rearranged immunoglobulin (IG) and T-cell receptor (TCR) genes. Allele-specific oligonucleotides were designed for each patient rearrangement, and the sensitivity and quantitative level was determined for each target. The analyses were performed at five different centres while interpretation of the results was performed at consensus meetings. Overall, clonal IG/TCR rearrangements were detected in 97% (236/244) of B-cell precursor ALL (BCP ALL) and 94% (33/35) of T-ALL. A sensitive RQ-PCR analysis (≤ 10-4) was obtained in 89% (216/244) of BCP ALL and in 74% (26/35) of T-ALL. With the stratification threshold of ≥10-3 for identification of high-risk patients, 93% of BCP ALL and 86% of T-ALL reached this quantitative range by at least one target gene. Taken together, this national multi-centre study supports the use of RQ-PCR analysis as a robust method for MRD detection in the majority of childhood ALL cases.
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| 17. |
- Thörn, Ingrid, et al.
(författare)
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Applicability of IG/TCR gene rearrangements as targets for minimal residual disease assessment in a population-based cohort of Swedish childhood acute lymphoblastic leukaemia diagnosed 2002-2006.
- 2010
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Ingår i: European journal of haematology. - : Wiley. - 1600-0609 .- 0902-4441. ; 84:2, s. 117-27
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Tidskriftsartikel (refereegranskat)abstract
- Minimal residual disease (MRD) detection during the early treatment phase has become an important stratification parameter in many childhood acute lymphoblastic leukaemia (ALL) treatment protocols. Here, we aimed to address the applicability of rearranged antigen-receptor genes as potential MRD markers using real-time quantitative polymerase chain reaction (RQ-PCR) in a Swedish population-based cohort. From 334 childhood ALL cases diagnosed during 2002-2006, we analysed 279 diagnostic samples (84%) by screening for rearranged immunoglobulin (IG) and T-cell receptor (TCR) genes. Allele-specific oligonucleotides were designed, and the sensitivity and quantitative level was determined for each target. Overall, clonal IG/TCR rearrangements were detected in 97% (236/244) of B-cell precursor ALL (BCP ALL) and 94% (33/35) of T-ALL. A sensitive RQ-PCR analysis (< or = 10(-4)) was obtained in 89% (216/244) of BCP ALL and in 74% (26/35) of T-ALL, whereas two sensitive targets were only available in 47% (115/244) of BCP ALL and 29% (10/35) of T-ALL cases. With the stratification threshold of > or = 10(-3), which is applied in the current Nordic treatment protocol (NOPHO-ALL 2008) for the identification of high-risk patients, 93% of BCP ALL and 86% of T-ALL reached this quantitative range by at least one target gene. Taken together, this national retrospective study demonstrates that an IG/TCR target for MRD monitoring can be identified in the majority of childhood ALL cases, whereas identification of a second sensitive target gene needs to be improved.
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| 18. |
- Thörn, Ingrid, 1957-, et al.
(författare)
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Minimal residual disease assessment in childhood acute lymphoblastic leukemia : Results of a Swedish multi-centre study comparing real-time PCR and multi-colour flow cytometry
- 2009
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this Swedish multi-center study of early treatment response in childhood acute lymphoblastic leukemia (ALL), we evaluated the concordance between multicolour flow cytometry (FCM) and real-time quantitative polymerase chain reaction (RQ-PCR) for assessment of minimal residual disease (MRD). Multiple time points (i.e. day 15, 29, 50 and 106) were evaluated with the NOPHO (Nordic Society of Pediatric Hematology and Oncology) ALL 2000 treatment protocol as backbone. During 2002-2006, 334 children were diagnosed with ALL, where 228 had paired samples taken at any of the four time points. With the detection level of 0.1%, the concordance between RQ-PCR and FCM was 90% in the 726 paired samples analyzed. At day 29, the correlation between the methods was greater with MRD levels >0.1% (rs=0.7, p<0.001) than below (rs=0.2, p=0.024). MRD levels higher than 0.1% at day 29 was a significant predictor of higher risk of having a bone marrow relapse. This was true both for BCP ALL and T-ALL analysed with either FCM or RQ-PCR, although RQ-PCR was a better discriminator than FCM in T-ALL. However, using the NOPHO ALL 2000 protocol, our data indicate that a higher cut-off value (0.2%) should be applied in BCP ALL when using RQ-PCR as MRD method. In contrast, MRD levels ≥ 0.1%, analysed with either method late during induction therapy, was not a predictor of isolated extramedullary relapse. We therefore conclude that MRD assessment by RQ-PCR based IG/TCR rearrangement and multicolour FCM monitoring can be used as a clinical tool if the aim is to find childhood ALL cases with increased risk of having bone marrow relapses.
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| 19. |
- Thörnerup, Ingrid, et al.
(författare)
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Minimal residual disease assessment in childhood acute lymphoblastic leukaemia: a Swedish multi-centre study comparing real-time polymerase chain reaction and multicolour flow cytometry.
- 2011
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 152:6, s. 743-753
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Tidskriftsartikel (refereegranskat)abstract
- Minimal residual disease (MRD) assessment is a powerful prognostic factor for determining the risk of relapse in childhood acute lymphoblastic leukaemia (ALL). In this Swedish multi-centre study of childhood ALL diagnosed between 2002 and 2006, the MRD levels were analysed in 726 follow-up samples in 228 children using real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes and multicolour flow cytometry (FCM). Using an MRD threshold of 0·1%, which was the sensitivity level reached in all analyses, the concordance between RQ-PCR and FCM MRD values at day 29 was 84%. In B-cell precursor ALL, an MRD level of ≥0·1% at day 29 predicted a higher risk of bone marrow relapse (BMR) with both methods, although FCM was a better discriminator. However, considering the higher median MRD values achieved with RQ-PCR, a higher MRD cut-off (≥0·2%) improved the predictive capacity of RQ-PCR. In T-ALL, RQ-PCR was notably superior to FCM in predicting risk of BMR. That notwithstanding, MRD levels of ≥0·1%, detected by either method at day 29, could not predict isolated extramedullary relapse. In conclusion, the concordance between RQ-PCR and FCM was high and hence both methods are valuable clinical tools for identifying childhood ALL cases with increased risk of BMR.
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| 20. |
- Truedsson, Lennart, et al.
(författare)
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Sharing of MHC haplotypes among patients with systemic lupus erythematosus from unrelated Caucasian multicase families: disease association with the extended haplotype [HLA-B8, SC01, DR17]
- 1995
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Ingår i: Journal of Rheumatology. - 0315-162X. ; 22:10, s. 1852-1861
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease often clustered in families. We investigated the association between MHC haplotypes and SLE in multicase Caucasian families. METHODS: Ten consecutive families with 2 or more patients with SLE, in total 27 patients among 66 individuals, were studied. MHC haplotypes were determined by typing for HLA-A, B, C, DR, and DQ by serological and DNA methods. Complotypes were determined by protein typing and C4 gene polymorphism by DNA analysis. RESULTS: Fifty-four independent MHC haplotypes were found. Ten of the 31 haplotypes in the patients with SLE were examples of the extended haplotype [HLA-B8,SC01,DR17]. Six of these were found in 2 or more patients with SLE within the same family. All the 14 SLE sib-pairs in the families shared at least one haplotype and in 9 of the sib-pairs the shared haplotype was [HLA-B8,SCO1,DR17]. Three SLE associated haplotypes were [HLA-B7,SC31,DR15]. Four of the 27 patients with SLE were C4A deficient. Two C2 deficient siblings were homozygous for the haplotype [HLA-B18,S042,DR15]. CONCLUSION: We demonstrate that a very limited number of MHC haplotypes are associated with familial SLE. The haplotype [HLA-B8,SCO1,DR17] was closely related with the disease. There was no evidence suggesting familial SLE constitutes a disease subset. Determination of MHC haplotypes in multicase families is of value for assessment of disease susceptibility.
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| 21. |
- Vidovic, Karina, et al.
(författare)
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Wilms' tumor gene 1 protein represses the expression of the tumor suppressor interferon regulatory factor 8 in human hematopoietic progenitors and in leukemic cells.
- 2010
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 24:5, s. 992-1000
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Tidskriftsartikel (refereegranskat)abstract
- Wilms' tumor gene 1 (WT1) is a transcription factor involved in developmental processes. In adult hematopoiesis, only a small portion of early progenitor cells express WT1, whereas most leukemias show persistently high levels, suggesting an oncogenic role. We have previously characterized oncogenic BCR/ABL1 tyrosine kinase signaling pathways for increased WT1 expression. In this study, we show that overexpression of BCR/ABL1 in CD34+ progenitor cells leads to reduced expression of interferon regulatory factor 8 (IRF8), in addition to increased WT1 expression. Interestingly, IRF8 is known as a tumor suppressor in some leukemias and we investigated whether WT1 might repress IRF8 expression. When analyzed in four leukemia mRNA expression data sets, WT1 and IRF8 were anticorrelated. Upon overexpression in CD34+ progenitors, as well as in U937 cells, WT1 strongly downregulated IRF8 expression. All four major WT1 splice variants induced repression, but not the zinc-finger-deleted WT1 mutant, indicating dependence on DNA binding. A reporter construct with the IRF8 promoter was repressed by WT1, dependent on a putative WT1-response element. Binding of WT1 to the IRF8 promoter was demonstrated by chromatin immunoprecipitation. Our results identify IRF8 as a direct target gene for WT1 and provide a possible mechanism for oncogenic effects of WT1 in leukemia.Leukemia advance online publication, 18 March 2010; doi:10.1038/leu.2010.33.
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| 22. |
- Westman, Julia, et al.
(författare)
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Large deletions involving the regulatory upstream regions of A4GALT give rise to principally novel P1PK-null alleles.
- 2014
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 54:7, s. 1831-1835
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Tidskriftsartikel (refereegranskat)abstract
- Cells of the clinically important p histo-blood group phenotype lack P1, P(k) , and P glycosphingolipid antigens. All cases investigated so far are due to alterations in the 4-α-galactosyltransferase-encoding Exon 3 of A4GALT. Repetitive elements in the genome can mediate DNA rearrangements, the most abundant being the Alu family of repeats.
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| 23. |
- Westman, Julia, et al.
(författare)
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P1/P2 genotyping of known and novel null alleles in the P1PK and GLOB histo-blood group systems.
- 2013
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Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 53:11, s. 2928-2939
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Tidskriftsartikel (refereegranskat)abstract
- The rare but clinically important null phenotypes of the P1PK and GLOB blood group systems are due to alterations in A4GALT and B3GALNT1, respectively. A recently identified single-nucleotide polymorphism in Exon 2a of A4GALT predicts the common P1 and P2 phenotypes but rare variants have not been tested.
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