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Biomedical subjects

E Macintyre

Publications and source records attributed to E Macintyre.

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

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

Fluorescence in situ hybridization analysis of masked (8;21)(q22;q22) translocations.

The translocation (8;21)(q22;q22) is associated with acute myeloblastic leukemia (AML M2). The accurate detection of this chromosomal rearrangement is vital due to its association with a favorable prognosis. Variant translocations exist; these may be hidden within an unusual or complex karyotype. In such cases, it is often difficult to confirm the presence of t(8;21)(q22;q22) by conventional cytogenetic analysis alone. The molecular detection of the AML1/ETO fusion gene is possible by reverse transcriptase polymerase chain reaction (RT-PCR) or dual-color fluorescence in situ hybridization (FISH) using probes specific for AML1 and ETO. Four cases of AML M2, with unusual or complex structural chromosomal abnormalities, without cytogenetic evidence of the classical t(8;21)(q22;q22), were studied by FISH. Two were AML1/ETO positive by RT-PCR, one showed a rearrangement by AML1 by Southern analysis, and the fourth had morphological features characteristic of t(8;21). The FISH results showed a co-localization of one AML1 and one ETO signal in interphase and metaphase nuclei in all four cases, demonstrating the presence of variant t(8;21)(q22;q22) rearrangements. Therefore, FISH analysis with the AML1 and ETO probes is extremely valuable, in cases of AML M2, because of its ability to reveal masked t(8;21)(q22;q22) translocations and thus quickly confirm the diagnosis, allowing patients to be assigned to the correct risk group in terms of treatment.

Adult↗
PubMed1999

Variability of polymerase chain reaction detection of the bcl-2-IgH translocation in an international multicentre study.

BACKGROUND: The capacity of the polymerase chain reaction (PCR) to detect very low numbers of cells bearing a t(14;18) translocation has led to its application in assessment of the results of treatment for follicular lymphoma, and suggestions that therapy might be guided by molecular studies. To test the reliability of PCR a collaborative study was undertaken to compare results from different laboratories in Europe and North America. METHODS: Twenty laboratories with records of publication in molecular diagnostics were sent blood from normal donors with varying numbers of t(14;18)-bearing cells added from a cell line with a translocation in the major breakpoint region (MBR) of the bcl-2 gene. Samples contained 1000, 100, 10, 1 or 0 cells per ml of whole blood and were sent blinded in duplicate. PCR methodology varied widely, with the total number of amplification cycles between 30 and 70, and 13 different primers used for the MBR region. Twelve laboratories used nested PCR and eight single round amplification. RESULTS: The sensitivity of nested and single round PCR was similar at 100 cells/ml but below this the nested method proved significantly more sensitive. The false positive rate was 28%, with 11 samples from 9 laboratories reported as positive when no t(14;18) cells were added. PCR product size and sequence analysis showed that false positives were due to contamination from cell-line DNA rather than background translocations in the donors. There was no significant difference in false positive rates between nested and single round techniques. CONCLUSION: The polymerase chain reaction to detect bcl-2-IgH rearrangements is presently carried out with widely disparate results. Further effort is required to bring forward a standard PCR protocol which can be re-tested in different laboratories to improve accuracy and reproducibility. The application of quantitative techniques such as real-time PCR may resolve many of the problems presently encountered.

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

Cutaneous T cell lymphomas: mycosis fungoides, Sezary syndrome and HTLV-I-associated adult T cell leukemia (ATL) in Mali, West Africa: a clinical, pathological and immunovirological study of 14 cases and a review of the African ATL cases.

Cutaneous T cell lymphomas (CTCL) are rare lymphoproliferative diseases, which are frequently suspected to be of viral origin. As very few data were available concerning cutaneous T cell lymphomas in tropical Africa, we undertook a clinical, histopathological, immunological and viro-molecular study of patients with a clinical diagnosis of cutaneous lymphoma, in Bamako, Mali. While prior to this study, no case of CTCL had been reported in this country, 14 patients (five women, nine men; mean age 58 years) with a diagnosis of cutaneous lymphoma were seen over a period of 30 months (1992-1994) in the only dermatological department in Mali. Clinically, the most frequent pattern was an infiltrated erythrodermia similar to Sezary syndrome. Nodular lesions and/or plaques were rarely observed. All these cutaneous tumors were T cell lymphoproliferations, only one expressing the CD8+ antigen. A comprehensive analysis of all the available data permitted characterization of three cases of adult T cell leukemia/lymphoma (ATL) associated with HTLV-I (one definitive case, of leukemic type, with demonstration of clonal integration of HTLV-I proviral genome and two probable ATL cases), three cases of Sezary syndrome (SS), two cases of mycosis fungoides (MF) and five cases of pleomorphic cutaneous lymphoma. In one case, the differentiation between MF and pleomorphic cutaneous lymphoma could not be established. HTLV-I serological and/or molecular markers were restricted to the three ATL cases. From the unique definitive ATL case, a T cell line was established from culture of peripheral blood mononuclear cells and sequence analysis of the env gene and the U3-LTR region demonstrated that the virus present in this patient belonged to the cosmopolitan subtype A. Thus, we report here the first evidence of HTLV-I infection and associated ATL in Mali. This is the second ATL case described for the whole Sahelian region (one ATL of the lymphoma type was reported previously in a Mauritanian patient). Furthermore, we demonstrate that the main types of CTCL described in Europe and North America are also present in this African area and that the prevalence of these diseases is greatly underestimated in such regions. Furthermore, no association was observed between HTLV-I/II infection and SS, MF or pleomorphic cutaneous lymphoma in Mali in contrast to other studies.

Adult↗
PubMed1998

t(3;17)(q21;q25) in Epstein-Barr virus associated peripheral T-cell lymphoma: a paediatric case.

We describe an immunocompetent 8-year-old boy with a serological profile indicating chronic infection by Epstein-Barr virus (EBV) who developed subcutaneous and pulmonary lesions related to a peripheral T-cell proliferation. No clonal rearrangement of T-cell receptor or immunoglobulin genes was seen. However, the finding of a t(3;17)(q21;q25) in 44 metaphases from one skin lesion demonstrated a clonal origin. We also showed that the proliferative T cells contained EBV genome leading to the diagnosis of EBV-associated peripheral T-cell lymphoma. Further cytogenetic and molecular studies are needed to identify genes implicated in the pathogenesis of this haematological malignancy.

Child↗
PubMed1997

[Molecular anomalies in malignant hemopathies].

Much of our understanding of the molecular anomalies involved in the process of oncogenesis has resulted from research into malignant hematologic diseases, facilitated by the accessibility of hematopoietic cells. For example, in lymphoid tumors, rearrangement of the genomic DNA can lead to the juxtaposition of proto-oncogenes and the highly active sequences regulating synthesis of immunoglobulins or T-cell receptors. The subsequent malignancy results from an uncontrolled overexpression of a normal protein. This type of "quantitative" anomaly occurs in follicular lymphomas where B-cells overexpress the normal BCL2 protein which inhibits apoptosis, contributing to immortalization of the B done. The same type of rearrangement process can approach gene fragments which fusion and lead to production of a highly oncogenic chimerical or truncated abnormal protein. Such "qualitative" anomalies occur in myeloid hemopathies. Both types of anomalies involve genes controlling the cell cycle, cell differentiation or cell death (apoptosis), in particular transcription factors (for example, E2A, RARA, MYC) and molecules involved in signal transduction (for example RAS, ABL, LCK). A molecular anomaly can be detected in approximately 30% of all cases of acute leukemia and in up to 75% of the non-Hodgkin lymphomas. Analysis of the junction fragments of the different heavy chains of the immunoglobulins produced in these cases provides a specific marker for detecting the B or T-cell clone in digestive or skin biopsies. For example, detection of a BCR-ABL transcript in a patient with primary thrombocythemia or an atypical myeloproliferative syndrome can be diagnostic and detection of the donal immunoglobulin or T-cell receptor rearrangement can confirm the malignant nature of the lymphoid proliferation. Molecular markers also have prognostic value allowing patient stratification and more adapted therapy. Molecular anomalies detected in malignant hematologic diseases are thus examples of nearly perfect "tumor-specific" markers.

Hematologic Neoplasms↗
PubMed1997

Translocation t(4;11)(q21;q23) and MLL gene rearrangement in acute lymphoblastic leukemia secondary to anti topoisomerase II anticancer agents.

Secondary therapy-related, acute lymphoblastic leukemia (S-ALL) is less common than its myeloblastic counterpart. S-ALL with MLL gene rearrangements have only been reported on six previous occasions. Only three of these had t(4;11)(q21;23) S-ALL with MLL-AF4 fusion transcript has only been reported in one earlier case. In this report a rare case of S-ALL with MLL-AF4 transcript is described in a 36 year old woman treated for breast carcinoma with chemotherapy which included the topoisomerase II inhibitor, VP-16. The precise incidence of MLL gene rearrangement in S-ALL still remains to be clarified.

Adult↗
PubMed1996

High frequency of somatic mutations in the VH genes expressed in prolymphocytic leukemia.

Prolymphocytic leukemia (PLL) is a chronic lymphoproliferative disorder, characterized by prominent splenomegaly, prolymphocytes accounting for more than 55% of circulating lymphocytes, and short-term survival. To better characterize the nature of the cellular origin in this disease, we analyzed lg heavy chain variable region (VH) genes in eleven cases of de novo PLL Leukemic cells expressed a skewed repertoire characterized by predominant use of the V3 family members (73%), with preferential use of the V3-23 gene (50% of the VH3 genes). All sequences from expressed VH genes diverged from their putative germline counterpart, and in eight cases the divergence was greater than 5%. In seven cases, which expressed the V3-23 gene and VH4 family members, nucleotide substitutions could be confidently attributed to somatic mutations. The type and distribution of these mutations clearly indicated that in three cases the cells had been subjected to an antigen selection process. Taken together, these results suggest that B-PLL cells display a skewed repertoire of lg VH regions and probably represent, at least in some instances, expansion of postgerminal center cells that have undergone antigen driven selection.

Adult↗
PubMed1996

Incidence and characterization of MLL gene (11q23) rearrangements in acute myeloid leukemia M1 and M5.

To determine the incidence of MLL rearrangement in acute myeloid leukemia (AML) French-American-British (FAB) type M1 and to evaluate optimal screening strategies for the characterization of such abnormalities, we analyzed specimens from 41 patients with AML by Southern blotting with two MLL genomic probes and compared the capacities of reverse transcription-polymerase chain reaction (RT-PCR) and fluorescent in situ hybridization (FISH) to identify the types of rearrangement found in AML M1 with those observed in AML M5. MLL rearrangement was found in 6 of 29 (20%) AML M1 and 6 of 10 AML M5 cases. RT-PCR characterization of 11 cases showed four MLL self-fusions, four MLL-AF6, two MLL-AF9, including a novel AF9 breakpoint, and one uncharacterized t(11:19). Only 5 of 10 MLL-rearranged cases tested demonstrated karyotypic 11q23 abnormalities. FISH analysis of nine cases with an MLL-specific yeast artificial chromosome (YAC) confirmed the cytogenetic abnormalities in two cases, clarified them in one, and did not detect six cases, including three MLL self-fusions, one case with a probable MLL-rearranged subclone not represented karyotypically, and twoMLL-AF6. A whole chromosome 11 paint detected one of these MLL-AF6, and an AF6 cosmid demonstrated that the other was probably due to insertion of a submicroscopic portion of chromosome 6, including part of AF6, into an apparently normal chromosome 11. We conclude that MLL rearrangements are common in adult AML M1, that MLL self-fusion and MLL-AF6 are the most frequent types of abnormalities, and that RT-PCR is preferable to 11q23 FISH analysis for their characterization.

Adult↗
PubMed1996

Molecular detection of t(8;21)/AML1-ETO in AML M1/M2: correlation with cytogenetics, morphology and immunophenotype.

The t(8;21) identifies a subgroup of acute myeloid leukaemia (AML) with a relatively good prognosis which may merit different treatment. It is associated predominantly, but not exclusively, with AML M2, and corresponds to rearrangements involving the AML1 and ETO genes. AML1-ETO positive, t(8;21) negative cases are well recognized but their incidence is unknown. In order to determine optimal prospective AML1-ETO RT-PCR screening strategies, we analysed 64 unselected AML M1 and M2 cases and correlated the results with other biological parameters. Molecular screening increased the overall detection rate from 8% to 14%. AML1-ETO was found in 3% (1/32) of AML M1 and 25% (8/32) of M2, including three patients without a classic (8;21) but with chromosome 8 abnormalities. It was more common in younger patients. Correlation with morphology enabled development of a scoring system which detected all nine AML1-ETO-positive cases with a false positive rate of 7% (4/55). Although certain AML1-ETO-positive cases demonstrated characteristic immunological features (CD19 and CD34 expression, CD33 negativity), each of these markers was insufficiently specific to permit prediction in an individual case. We conclude that initial routine prospective molecular screening for AML1-ETO in all AMLs, combined with standardized morphological and immunological analysis, is desirable in order to produce improved prognostic stratification and to determine whether screening can ultimately be restricted to appropriate subgroups.

Adolescent↗
PubMed1996

Sustained complete cytologic and molecular remission induced by donor leucocyte infusions alone in an acute myeloblastic leukaemia in relapse after bone marrow transplantation.

Therapeutic options for treatment of recurrence of leukaemia after allogeneic bone marrow transplantation (BMT) are limited. A beneficial effect of donor lymphocyte infusions (DLI) has not previously been described in acute myeloid leukaemia (AML) relapse. We report a case of AML with t(8;21), relapsing 3 months after BMT, who received DLI without adjuvant chemotherapy or growth factors. The patient developed acute GVHD and achieved a rapid complete remission of his AML by both cytologic and molecular criteria of at least 14 months duration, thereby showing that DLI for AML in relapse after BMT is an alternative therapeutic option.

Adult↗