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Biomedical subjects

E Delabesse

Publications and source records attributed to E Delabesse.

At least 37 records · Page 2Linked to original sources
PubMed2000

Refractory sprue, coeliac disease, and enteropathy-associated T-cell lymphoma. French Coeliac Disease Study Group.

BACKGROUND: Adult refractory sprue is a poorly defined disorder. We did a multicentre national study of patients with refractory sprue to characterise their clinical and pathological profile and outcome, and to assess the frequency and prognostic significance of phenotypic and molecular abnormalities in the intraepithelial T-cell population. METHODS: Patients with severe symptomatic villous atrophy mimicking coeliac disease but refractory to a strict gluten-free diet, and with no initial evidence of overt lymphoma, were diagnosed at gastrointestinal referral centres between 1974 and 1998. Fixed and/or frozen duodenojejunal biopsy samples were reanalysed and immunostained with CD3 and CD8 monoclonal antibodies to find out the phenotype of intraepithelial lymphocytes (IEL). TCRgamma gene rearrangements were assessed on frozen biopsy samples by multiplex fluorescent PCR. FINDINGS: There were 21 patients with refractory sprue and 20 controls with coeliacs disease. 16 (84%) of 19 assessed patients had an aberrant intraepithelial lymphoid intestinal population expressing intracytoplasmic CD3 but not surface CD8. Clonal intestinal TCRgamma gene rearrangements were found in 13 (76%) of 17 patients assessed; four (out of 12 assessed) had clonal dissemination to the blood. The 16 patients with an aberrant phenotype all had uncontrolled malabsorption; three subsequently developed overt T-cell lymphoma, and eight died. The three (16%) patients without aberrant clonal IEL made a complete clinical and histological recovery with steroid therapy plus a gluten-free diet. INTERPRETATION: An immunophenotypically aberrant clonal intraepithelial T-cell population (similar to that of most cases of enteropathy-associated T-cell lymphoma) can be found in up to 75% of patients with refractory coeliac sprue; its identification by simple diagnostic techniques represents a marker of poor outcome (including occurrence of overt T-cell lymphoma). We suggest that refractory sprue associated with an aberrant clonal IEL may be the missing link between coeliac disease and T-cell lymphoma and may be classified as cryptic enteropathy-associated T-cell lymphoma.

Adult↗
PubMed2000

Association of a duodenal follicular lymphoma and hereditary nonpolyposis colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is an inherited predisposition to colorectal and endometrial cancers caused by germline mutation of mismatch repair genes, with hMLH1 and hMSH2 underlying the majority of the cases. Although lymphoid tumors are the most common tumors in mouse models for HNPCC, lymphomas are almost never encountered in patients who have HNPCC, except in rare families with germline homozygous deletion of hMLH1. We report the case of a 53-year-old man who had a history of colon cancers related to constitutional hMLH1 mutation and who was diagnosed as having a duodenal follicular lymphoma This diagnosis was supported by IgH-BCL2 rearrangement and BCL2 immunoreactivity in tumor cells. The association of both of these possibly related rare diseases has never been reported. To clarify this relationship, we searched for hMLH1 expression and mismatch repair deficiency in the duodenal lymphoma. hMLH1 immunostaining was positive in lymphoid tumor cells, and no microsatellite instability was detected. In agreement with mouse models for HNPCC, these results suggest the involvement of alternative mechanisms to complete mismatch repair deficiency for lymphomagenesis in HNPCC syndrome.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Rapid, multifluorescent TCRG Vgamma and Jgamma typing: application to T cell acute lymphoblastic leukemia and to the detection of minor clonal populations.

Detection of clonal T cell receptor gamma (TCRG) gene rearrangements by PCR is widely used in both the diagnostic assessment of lymphoproliferative disorders and the follow-up of acute lymphoblastic leukaemia (ALL), when residual positivity in excess of 10(-3) at morphological complete remission is increasingly recognised to be an independent marker of poor prognosis. This is largely based on specific detection of V-J rearrangements from childhood cases. We describe rapid, multifluorescent Vgamma and Jgamma PCR typing of multiplex amplified diagnostic samples, as applied to 46 T-ALL. These strategies allow selected analysis of appropriate cases, immediate identification of Vgamma and Jgamma segments in over 95% of alleles, improved resolution and precision sizing and a sensitivity of detection at the 10(-2)-10(-3) level. We demonstrate preferential V-J combinations but no difference in V-J usage between children and adults, nor between SIL-TAL1-negative and -positive cases. A combination of fluorescent multiplex and Vgamma-Jgamma-specific monoplex follow-up, as described here, will allow detection of both significant clonal evolution and of the diagnostic clone at a level of prognostic significance, by techniques which can readily be applied to large-scale prospective studies for which real-time analysis is required.

Adolescent↗
PubMed2000

Distinction between coeliac disease and refractory sprue: a simple immunohistochemical method.

AIMS: We recently showed that refractory sprue is distinct from coeliac disease, the former being characterized by abnormal intraepithelial T-lymphocytes expressing a cytoplasmic CD3 chain (CD3c), lacking CD3 and CD8 surface expression, and showing TCRgamma gene rearrangements. To take advantage of the abnormal phenotype of CD3c + CD8 - intraepithelial lymphocytes (IEL) in refractory sprue we developed a simple method to distinguish coeliac disease from refractory sprue. METHODS AND RESULTS: Comparative immunohistochemical studies using anti-CD3 and anti-CD8 antibodies were applied on paraffin-embedded and frozen biopsy specimens in refractory sprue (n = 6), coeliac disease (n = 10), healthy controls (n = 5) and suspected refractory sprue (n = 6). Comparable results were obtained on fixed and frozen biopsy specimens. In four of the six patients with suspected refractory sprue, abnormal CD3c + CD8 - IEL and TCRgamma gene rearrangements were found, as in refractory sprue; the remaining two patients had normal (CD3 + CD8 +) IEL and no TCRgamma gene rearrangements. Both patients had coeliac disease, as one failed to comply with a gluten-free diet, while the other was a slow responder. CONCLUSION: This simplified immunostaining method using anti-CD3 and anti-CD8 antibodies on paraffin sections can distinguish active coeliac disease from refractory sprue and should prove useful in clinical practice.

Adult↗
PubMed2000

Virological and molecular characterisation of a new B lymphoid cell line, established from an AIDS patient with primary effusion lymphoma, harbouring both KSHV/HHV8 and EBV viruses.

We report here a new case of primary effusion lymphoma (PEL), occurring in a French homosexual HIV-1 infected male with a pericardial, pleural and mesenteric tumour dissemination, and the establishment from his pleural effusion of a new cell line, Cra-BCBL, dually infected by EBV and KSHV/HHV8. Cra-BCBL cells are of B-cell origin as judged by their clonal immunoglobulin heavy chain (IgH) gene rearrangement, identical to that of the parental tumour. Both the cell line and the lymphoma cells expressed CD38 and CD45 antigens but no classical B-cell or T-cell lineage-restricted antigens. Cra-BCBL harbours a type I EBV virus, expressing a latency type II. Expression of KSHV/HHV8 ORF72 and ORF75 was detected by RT/PCR. In addition, KSHV lytic replication could be induced by treatment by n-butyrate. An equivalent and high copy number of KSHV genomes (20 to 200 copies by cell) was detected both in the primary tumour cells and in the cell line. Southern blot (SB) analysis of EBV terminal repeats (TR) displayed the same unique band in the cell line DNA and in the original tumour cells, consistent with a monoclonal infection of EBV. Furthermore, SB analysis of KSHV/HHV8 TR revealed the same hybridisation pattern between Cra-BCBL and the effusion cells, with a common band at around 30-40 kb corresponding to the fused termini of the viral episomes and a 5 Kb rearranged fragment. The new cell line characterised here could be a useful model to study interactions between two human herpes viruses and their contribution to lymphomagenesis.

Adult↗
PubMed1999

Standardized RT-PCR analysis of fusion gene transcripts from chromosome aberrations in acute leukemia for detection of minimal residual disease. Report of the BIOMED-1 Concerted Action: investigation of minimal residual disease in acute leukemia.

Prospective studies on the detection of minimal residual disease (MRD) in acute leukemia patients have shown that large-scale MRD studies are feasible and that clinically relevant MRD-based risk group classification can be achieved and can now be used for designing new treatment protocols. However, multicenter international treatment protocols with MRD-based stratification of treatment need careful standardization and quality control of the MRD techniques. This was the aim of the European BIOMED-1 Concerted Action 'Investigation of minimal residual disease in acute leukemia: international standardization and clinical evaluation' with participants of 14 laboratories in eight European countries (ES, NL, PT, IT, DE, FR, SE and AT). Standardization and quality control was performed for the three main types of MRD techniques, ie flow cytometric immunophenotyping, PCR analysis of antigen receptor genes, and RT-PCR analysis of well-defined chromosomal aberrations. This study focussed on the latter MRD technique. A total of nine well-defined chromosome aberrations with fusion gene transcripts were selected: t(1;19) with E2A-PBX1, t(4;11) with MLL-AF4, t(8;21) with AML1-ETO, t(9;22) with BCR-ABL p190 and BCR-ABL p210, t(12;21) with TEL-AML1, t(15;17) with PML-RARA, inv (16) with CBFB-MYH11, and microdeletion 1p32 with SIL-TAL1. PCR primers were designed according to predefined criteria for single PCR (external primers A <--> B) and nested PCR (internal primers C <--> D) as well as for 'shifted' PCR with a primer upstream (E5' primer) or downstream (E3' primer) of the external A <--> B primers. The 'shifted' E primers were designed for performing an independent PCR together with one of the internal primers for confirmation (or exclusion) of positive results. Various local RT and PCR protocols were compared and subsequently a common protocol was designed, tested and adapted, resulting in a standardized RT-PCR protocol. After initial testing (with adaptations whenever necessary) and approval by two or three laboratories, the primers were tested by all participating laboratories, using 17 cell lines and patient samples as positive controls. This testing included comparison with local protocols and primers as well as sensitivity testing via dilution experiments. The collaborative efforts resulted in standardized primer sets with a minimal target sensitivity of 10-2 for virtually all single PCR analyses, whereas the nested PCR analyses generally reached the minimal target sensitivity of 10-4. The standardized RT-PCR protocol and primer sets can now be used for molecular classification of acute leukemia at diagnosis and for MRD detection during follow-up to evaluate treatment effectiveness.

Acute Disease↗
PubMed1999

NG2 expression in MLL rearranged acute myeloid leukaemia is restricted to monoblastic cases.

Expression of NG2 has been reported in the majority of paediatric acute leukaemia (AL) cases with MLL rearrangement. We demonstrated 7. 1 positivity in 2/3 paediatric and 4/11 adult MLL rearranged acute myeloid leukaemia (AML) but in 0/28 adult AML without MLL rearrangement, thus extending the 100% specificity to adult cases. Positivity correlated with stage of maturation arrest since it was found in 0/6 immature AML but in 6/8 monoblastic cases. These data demonstrate that, if NG2 expression in AL is the (in)direct result of MLL rearrangement, such activation is restricted to a monoblastic population in AML. They also have practical implications for NG2 diagnostic screening strategies.

Acute Disease↗
PubMed1999

Molecular approaches to the diagnosis and evaluation of lymphoid malignancies.

The processes of somatic immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangement that occur in lymphoid precursors provide insights into the pathogenesis and molecular analysis of lymphoid malignancies, in addition to the more universal molecular oncogenic mechanisms. Detection of lymphoid clonality can help distinguish polyclonal reactive disorders from clonal, predominantly, but not exclusively, malignant proliferations. Ig/TCR V-(D)-J polymerase chain reaction (PCR) amplification has largely replaced Southern blotting, and the techniques of PCR product analysis are evolving rapidly. V-(D)-J errors are often involved in genetic abnormalities leading to lymphoid malignancies, with consequent deregulated expression of the associated proto-oncogenes. Genetic abnormalities producing fusion transcripts and chimeric proteins are also frequent, particularly in acute lymphoblastic leukemia (ALL). A variety of molecular techniques, including reverse-transcriptase (RT)-PCR, Southern blotting, and fluorescence in situ hybridization (FISH) are finding an increasingly established place in the diagnosis, prognostic evaluation, therapeutic stratification, and follow-up of lymphoblastic leukemias, and it is likely that the same methods will be applied to non-Hodgkin's lymphoma (NHL) and to chronic leukemias.

Cytogenetic Analysis↗
PubMed1998

Antiapoptotic effect of ectopic TAL1/SCL expression in a human leukemic T-cell line.

Aberrant expression of TAL1 occurs frequently in human T-cell acute lymphoblastic leukemia. The effect of TAL1 expression in the T-cell lymphoid precursor, however, remains unclear. In the current study, we have developed TAL1 stable transfectants in a human immature T-cell lymphoid cell line. Whereas no effect on proliferation, cell culture density, or cell cycle was detected, the transfectants were more resistant than the parental cell line to apoptosis induced by chemotherapeutic agents including etoposide, daunorubicin, doxorubicin, cytosine arabinoside, methotrexate and vincristine and also to apoptosis induced by Fas/CD95 cross-linking. This effect was independent of the cytostatic effects of the drugs. The basic domain-deleted transfectants did not demonstrate altered sensitivity, suggesting that DNA binding was necessary for resistance to apoptosis. The ability to alter the response to a wide range of cell death-inducing stimuli suggests that TAL1 acts at a late stage of the apoptotic cascade. These data therefore provide direct evidence of an antiapoptotic effect of ectopic TAL1 expression in response to cytotoxic agents, thus providing insight into its oncogenic function in T-cell acute lymphoblastic leukemia and a novel experimental model to further investigate the underlying mechanisms. These data also have potential practical significance for cytotoxic therapy of this disorder.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Deregulated expression of the TAL1 gene by t(1;5)(p32;31) in patient with T-cell acute lymphoblastic leukemia.

TAL1 gene deregulation is frequent in T-cell acute lymphoblastic leukemia (T-ALL) and can result from translocations involving 1p32 or, more frequently, from a cytogenetically undetectable interstitial deletion of chromosome 1. This study presents a case of T-ALL with a t(1;5)(p32;q31) involving TAL1, in which the breakpoint occurs approximately 10kbp 5' to the gene and leads to transcriptional activation and synthesis of a TAL1 protein, and extends the spectrum of recognized TAL1 gene translocations associated with T-ALL.

Adult↗
PubMed1998

Abnormal intestinal intraepithelial lymphocytes in refractory sprue.

BACKGROUND & AIMS: The etiology of refractory sprue is unclear. To gain insight into its pathogenesis, the phenotype and T-cell receptor (TCR) gene rearrangement status of intestinal lymphocytes were analyzed in a group of patients with clinical or biological features of celiac disease but either initially or subsequently refractory to a gluten-free diet. METHODS: Intestinal biopsy specimens were obtained from 26 adults: 6 patients with refractory sprue, 7 patients with active celiac disease, and 13 normal controls. The phenotype of intestinal lymphocytes was studied by immunohistochemistry and, in 3 patients with refractory sprue, by cytometry of lymphocytes purified from intestinal biopsy specimens. TCR rearrangements were assessed by studying TCRgammaV-J junctional regions from DNA extracted from intestinal biopsy specimens and purified intestinal lymphocytes. RESULTS: In the 6 patients with refractory sprue, but not in normal controls or patients with active celiac disease, the intestinal epithelium was massively infiltrated by small lymphocytes that lacked CD8, CD4, and TCR, contained intracytoplasmic but not surface CD3epsilon chains, and exhibited restricted TCRgamma gene rearrangements. CONCLUSIONS: Refractory sprue is associated with an abnormal subset of intraepithelial lymphocytes containing CD3epsilon and restricted rearrangements of the TCRgamma chain but lacking surface expression of T-cell receptors.

Adult↗
PubMed1998

TAL1 expression does not occur in the majority of T-ALL blasts.

The TAL1 gene is disrupted by translocation or deletion (tal(d)) in up to 30% of T-cell acute lymphoblastic leukaemia (T-ALL), leading to aberrant transcriptional activation, as a SIL-TAL1 fused transcript in tal(d). It has been suggested that TAL1 transcription occurs in approximately 50% of a T-ALLs without apparent rearrangement. SIL-TAL1 was positive in 15/60 (25%) of T-ALL, whereas wild-type TAL1 transcripts were detected in all 13 SIL-TAL1 and in 19/43 (44%) T-ALL without SIL-TAL1. To investigate the cellular origin of TAL1 we exploited the fact that GATA1 and TAL1 are co-ordinately expressed in non-lymphoid haemopoietic cells, whereas only the latter is found in T-ALL. GATA1 was detected in 10/23 (43%) TAL1-negative T-ALLs but in 17/19 (89%) 'unexplained' TAL1-positive cases, suggesting a common non-lymphoid cellular origin. Immunocytochemical analysis with a TAL1-specific monoclonal antibody showed nuclear expression in the blasts of 10/34 (29%) cases, including 8/10 SIL-TAL1+ and two RT-PCR TAL1+, SIL-TAL1- cases. In the remaining cases TAL1 expression was restricted to a minor population (< 5%) of larger, strongly TAL1-positive cells which comprised erythroid cells, CD34+ CD3- precursors and an unidentified TAL1+ CD45- population which morphologically resembled monocytes/macrophages. We therefore suggest that appropriate diagnostic evaluation of T-ALL should include molecular detection of SIL-TAL1 transcripts and in situ immunocytochemical detection of TAL1 protein expression by leukaemic blasts. This approach will enable accurate analysis of the prognostic significance of TAL1 deregulation in T-ALL.

Adolescent↗
PubMed1998

Helix-loop-helix (E2-5, HEB, TAL1 and Id1) protein interaction with the TCRalphadelta enhancers.

In order to dissect the correlation between aberrant TAL1 basic-helix-loop-helix (b-HLH) expression and the exclusive development of T cell acute lymphoblastic leukemias (T-ALL) of the TCRalphabeta lineage, we have assessed the ability of class A b-HLH proteins to regulate the TCRalpha and delta enhancers. We demonstrate that E47S binds to TCRalpha but not to TCRdelta E-boxes in vitro. Despite this, neither E2-5 nor HEB transactivate the TCRalpha enhancer in NIH 3T3, nor did Id1 modify endogenously driven TCRalpha [alphaE1-4] activity in a TCRalphabeta cell line. We also demonstrate that TAL1 inhibits both binding of E47S to aE3 and aE4 and endogenous transactivation of the TCRalpha enhancer. Comparison of the activity of the minimal [alphaE1-2] fragment, which contains no E-boxes, with the accessory [aE3-4] fragment, which contains two, suggested some contribution from the latter to TCRalpha enhancer activity in HPB-ALL. TCR [alphaE1-2] activity was partially (40%) inhibited by TAL1 but not at all by Id1. In contrast, [alphaE3-4] activity was almost completely inhibited by TAL1 (80%) and slightly reduced by Id1 (15%). These data demonstrate that class A b-HLH regulation of the TCRalpha enhancer E-boxes differs from their B lymphoid Igmicro counterparts and suggest a novel mechanism of transcriptional inhibition by TAL1, which may be, at least partly, independent of E-box-mediated activation, as we currently recognize it. They also clearly demonstrate that the restriction of TAL1 deregulation to T-ALL of the TCRalphabeta lineage is not due to induction of TCRalpha enhancer activity by the TAL1 protein.

3T3 Cells↗
PubMed1998

Microsatellite markers for typing Aspergillus fumigatus isolates.

The use of microsatellites as highly polymorphic DNA markers for the typing of isolates of Aspergillus fumigatus was investigated. Four CA repeats were selected by screening an A. fumigatus DNA library with a (CA)10 oligonucleotide. Primers flanking these CA repeats were designed to amplify each locus. One primer of each pair was labeled with a fluorophore, and the PCR products were analyzed with an automatic sequencer and the GeneScan software. For each primer set and for a given isolate, one band was detected and was assigned to an allele because A. fumigatus is haploid. With 50 clinical isolates, 50 environmental isolates, and 2 reference strains we obtained 12, 11, 10, and 23 different alleles for the four CA microsatellites, respectively (discriminatory power, 0.994). The results were identical by whatever DNA extraction technique was used. Interestingly, no clustering between environmental and clinical isolates was observed, suggesting that every isolate is potentially pathogenic. Microsatellite markers appear suitable for use in large epidemiological studies of invasive aspergillosis.

Aspergillosis↗
PubMed1998

Simultaneous detection of MYC, BVR1, and PVT1 translocations in lymphoid malignancies by fluorescence in situ hybridization.

The rapid detection of chromosome band 8q24 rearrangements, including classical translocations involving MYC and variant 3' translocations, is important for the accurate diagnosis and appropriate treatment of lymphoid malignancies. We have identified and characterized a CEPH YAC, 934e1, which extends from at least 190 kbp upstream to over 280 kbp downstream to MYC, allowing detection of classical t(8; 14)(q24;q32) and variant t(8;22)(q24;q11) and t(8;14)(q24;q11), extending distal to PVT1 and therefore, by extrapolation, to BVR1. This YAC also allowed clarification of complex chromosome 8 abnormalities and the identification of translocations in interphase nuclei. A second CEPH YAC, 904c3, previously shown to contain the PVT1 locus but not MYC, allowed distinction between translocations occurring centromeric and telomeric to MYC. Use of the 934e1 YAC will aid classification of a variety of lymphoid proliferations and further characterization of rearranged cases with the 904c3 YAC will simplify mapping of their diverse breakpoints.

Chromosomes, Artificial, Yeast↗
PubMed1997

Simultaneous SIL-TAL1 RT-PCR detection of all tal(d) deletions and identification of novel tal(d) variants.

Site-specific deletions of the 5' part of the TAL1 gene (tal(d)) are among the most frequent non-random genetic abnormalities in T-cell acute lymphoblastic leukaemia (T-ALL). They are usually detected by PCR from DNA with several primer pairs or by Southern blot analysis. Since tal(d) lead to expression of a SIL-TAL1 fusion transcript, irrespective of the genomic breakpoint, we have used a single monoplex RT-PCR reaction to screen 55 T-ALL patients at diagnosis. SIL-TAL1 transcripts were demonstrated in 12 (22%) cases, including 7/27 (26%) children <15 years of age, 2/8 (25%) adolescents and 2/17 (12%) adults aged >20 years. SIL-TAL1 RT-PCR was preferrable to tal(d) DNA PCR since it allowed the simultaneous detection of tal(d), tal(d2) and two previously undescribed tal(d) variants. SIL-TAL1 RT-PCR screening should therefore increase the detection rate of tal(d) by approximately 15-20%, with an at least comparable sensitivity to tal(d) genomic PCR, and represents a more practical and economic alternative to multiple DNA PCRs or Southern blotting when incorporated into molecular screening for multiple transcripts at diagnosis.

Adolescent↗
PubMed1997

Molecular analysis of clonality in Kaposi's sarcoma.

BACKGROUND: Kaposi's sarcoma is considered to be an angioproliferative disease associated with a novel herpesvirus (KSHV/HHV8), but the precise pathophysiology of the lesion remains unclear. The study of clonality in Kaposi's sarcoma using X linked DNA polymorphism has been difficult so far, because of a very strong prevalence of the disease in males. AIMS: To study the clonality of Kaposi's sarcoma lesions. METHODS: An assay based on a methyl sensitive restriction digest followed by polymerase chain reaction (PCR) amplification of the highly polymorphic human androgen receptor (HUMARA) gene was used. Tissues from Kaposi's sarcoma lesions and control tissues from the same patients were obtained from seven females, four with classic Kaposi's sarcoma and three with AIDS associated Kaposi's sarcoma. A cutaneous angiosarcoma was also analysed, for comparative purposes, and showed evidence of clonality after HpaII digestion. RESULTS: All patients were heterozygous for the HUMARA polymorphism and informative for analysis. In all patients, including four with a nodular form of Kaposi's sarcoma and more than 70% spindle cells in the lesion, a polyclonal pattern of inactivation could be demonstrated. CONCLUSIONS: The Kaposi's sarcoma lesion is first of all a polyclonal cell proliferation.

Acquired Immunodeficiency Syndrome↗