Biomedical subjects

T C Diss

Publications and source records attributed to T C Diss.

At least 37 records · Page 2Linked to original sources

PubMed1997

Clonality analysis in tumours of women by PCR amplification of X-linked genes.

Modifications have been made to two polymerase chain reaction (PCR) methods for clonality analysis based on the inactivation patterns of two highly polymorphic X-linked genes encoding the androgen receptor (AR) and monoamine oxidase A (MAOA). These methods have been used to examine the clonal nature of frozen tissues from 42 tumours and 25 non-tumour controls from female subjects. Unbalanced inactivation patterns of the genes, which indicate monoclonality, were frequently observed in tumours of heterozygous (informative) cases (18/35 = 51.4 per cent for the AR gene, 9/30 = 30 per cent for the MAOA gene, and 21/38 = 55.2 per cent for both). Among 23 informative non-tumour controls, only one (4.3 per cent), a reactive lymph node, showed skewing in the AR gene. Successful detection of monoclonality was found to depend on the proportion of tumour cells in the tissues examined. None of the AR or MAOA informative cases containing less than 50 per cent of tumour cells showed imbalance in inactivation patterns. With more than 50 per cent of tumour cells in the samples, 66.6 per cent (18/27) of AR and 39.1 per cent (9/23) of MAOA informative cases showed allelic imbalance, with a combined frequency of 72.4 per cent (21/29) of both genes. Our results demonstrate that the methods described are useful for clonal analysis of tissue samples from female patients.

Breast Neoplasms↗

PubMed1997

Epstein-Barr virus in B-cell lymphomas associated with chronic suppurative inflammation.

Chronic antigenic stimulation is considered to play an important role in neoplastic lymphoid transformation. This paper describes three cases of non-Hodgkin lymphomas (NHLs) associated with long-standing chronic suppuration. Two were primary bone lymphomas associated with long-standing chronic osteomyelitis and one was a primary skin lymphoma associated with chronic venous ulcers with a latent period of 13 years. All were diffuse large B-cell lymphomas, with plasmacytoid differentiation in two cases. Epstein-Barr virus (EBV)-encoded RNAs were demonstrated in virtually all tumour cells in all cases by in situ hybridization. Immunohistochemistry revealed EBV-encoded latent membrane protein (LMP)-1 expression in one case and BZLF1 protein expression in all three cases, whilst the EBV-encoded nuclear antigen (EBNA)-2 was not detected. Kaposi's sarcoma-associated herpesvirus (KSHV) sequences were absent in two cases studied. Our cases show similarities with pyothorax-associated pleural lymphomas reported mainly from Japan and recently from France, which are invariably associated with EBV. These findings suggest a causal effect of EBV in the development of this type of lymphoma complicating long-standing chronic suppuration. Localized immunodepression induced by chronic inflammation or immunosuppressive cytokines may favour the clonal proliferation of EBV-infected B cells.

Aged↗

PubMed1997

Composite mantle-cell lymphoma and plasmacytoma.

We report a case of a composite lymphoma comprising both mande cell lymphoma and a plasmacytoma. The two components were morphologically and immunohistochemically quite distinct. These properties, coupled with both direct and indirect molecular genetic evidence, suggest that these were two separate tumours occurring together by chance or by unknown oncogenic mechanisms, rather than clonally linked lymphomas.

Biomarkers↗

PubMed1997

Ongoing immunoglobulin gene mutations in mantle cell lymphomas.

Mantle cell lymphomas (MCL) frequently show a vaguely follicular growth pattern. This phenomenon is thought to result from the colonization of reactive B-cell follicles by tumour cells. In view of the unique property of the germinal centre environment, antigen stimulation may play a role in the expansion of the tumour. To assess this, we have examined ongoing Ig mutations, which are genetic markers of B cells in persistent response to antigen stimulation, in five MCLs including two cases derived from the gastrointestinal tract known as lymphomatous polyposis (LP). We have specifically analysed Ig ongoing mutations in tumour cells from multiple lesions in one case and in tumour cells microdissected from colonized follicles in two cases. The consensus Ig VB sequences in four MCLs were identical, or almost identical (three cases 100%, one case 99% homology), to the published germlines, which in each case were those frequently employed by autoantibodies. The consensus Ig VH sequence in the remaining case displayed 95.5% homology to the closest published germline. This may represent derivation from an unknown VH germline or a rare instance of somatic mutations. Extensive sequencing of the rearranged Ig genes revealed ongoing mutations within the tumour clone in two cases: one was a LP with multiple lesions of the gastrointestinal tract and the other was a nodal MCL in which tumour cells from colonized follicles were analysed. Our results indicate that MCLs are derived from pre-germinal centre B cells, possibly autoreactive B-cell clones. The ongoing mutations identified suggest a possible involvement of antigen stimulation in the clonal expansion of a proportion of MCLs.

Base Sequence↗

PubMed1997

Genetic evidence for a clonal link between low and high-grade components in gastric MALT B-cell lymphoma.

High-grade MALT lymphomas often contain low-grade tumour components; both cell populations have been shown to express the same immunoglobulin light chain previously. However, the clonal link between the low and high-grade components has not been established at the genetic level. To investigate this link, we have examined low- and high-grade components micro-dissected from tissue sections of four high-grade gastric MALT lymphomas. PCR and sequence analyses were performed to identify clone-specific rearranged immunoglobulin heavy chain gene sequences. In each of these cases, the PCR products from the two components were identical in size by electrophoresis. Direct sequencing revealed common clone-specific immunoglobulin heavy chain gene rearrangements in both lesions of each case, providing genetic evidence for a clonal link. These results support the proposal that high-grade MALT lymphomas generally evolve from low-grade clones.

Base Sequence↗

PubMed1997

The value of the polymerase chain reaction in the diagnosis of cutaneous T-cell infiltrates.

The distinction between reactive and neoplastic cutaneous T-cell infiltrates is difficult and requires good clinicopathologic correlation. Many cases manifest changes that are at the borderline between the two. The polymerase chain reaction (PCR) has been reported to detect monoclonality in 52-90% of cutaneous T-cell lymphomas and may be of use in the diagnosis of histologically borderline lesions. We have investigated the use of PCR in a series of borderline lesions including borderline biopsy samples from patients who subsequently developed cutaneous lymphoma. PCR amplification of T-cell receptor (TCR)-gamma chain gene was performed on formalin-fixed, paraffin-embedded tissue from 27 cases of clinically and histologically typical mycosis fungoides (MF), 22 borderline biopsy samples from 10 patients who subsequently developed MF (pre-MF), 32 clinically suspicious, histologically borderline lesions, and 31 cases of chronic dermatitis. Monoclonality was demonstrated in 16 of 27 (59%) cases of MF, 10 of 22 (50%) pre-MF biopsy samples (six of 10 patients), and six of 32 (19%) borderline biopsy samples. The same size monoclonal band was detected in pre-MF biopsy samples from six of seven patients in which a band was demonstrated in the diagnostic MF biopsy. Sequencing confirmed that the MF biopsy sample and the pre-MF biopsy sample contained the same clone. The 31 dermatitis cases gave rise to polyclonal PCR products. Monoclonality can be demonstrated using PCR in 59% of MF cases, which is comparable with other T-cell lymphomas and in up to 50% of borderline biopsy samples in patients who later develop lymphoma. Detection of T-cell monoclonality by PCR is strong evidence of an established or evolving cutaneous T-cell lymphoma.

Base Sequence↗

PubMed1997

Absence of Helicobacter pylori DNA in salivary lymphoepithelial lesions.

Helicobacter pylori is a common cause of chronic gastritis and has been implicated as the main agent responsible for the development of lymphomas of mucosa associated lymphoid tissue (MALT) in the stomach. An uncommon cause of salivary gland swelling is salivary lymphoepithelial lesion (SLEL), which shows histological features of acquired MALT and is associated with the development of MALT-type lymphomas. Since H. pylori has been identified in the oral cavity, we hypothesised that this organism might act as a potential antigen for the development of MALT in salivary glands. Routinely processed biopsies of 20 SLEL were screened for H. pylori DNA using a sensitive two-stage PCR technique to amplify the 16S ribosomal RNA gene. Immunoglobulin heavy chain gene monoclonality was determined by amplifying the VDJ gene using a nested PCR technique. All SLEL had histological features of organised MALT and 14 cases showed Ig heavy chain gene monoclonality consistent with MALT lymphoma. None of the SLEL contained H. pylori DNA. In contrast to the putative role of H. pylori as an antigenic stimulus in gastric MALT lymphomas, it appears not to play a role locally in the development of MALT or MALT lymphomas of the salivary gland.

Adult↗

PubMed1997

Cryptogenic fibrosing alveolitis: lack of association with Epstein-Barr virus infection.

BACKGROUND: Cryptogenic fibrosing alveolitis (CFA) is a well defined clinical entity of unknown aetiology. An association between CFA and the presence of protein indicating Epstein-Barr virus (EBV) replication within epithelial cells of the respiratory tract has recently been suggested, leading to speculation for a role for EBV in the pathogenesis of CFA. METHODS: Lung tissue was obtained from patients in three groups: those with cryptogenic fibrosing alveolitis, either lone or associated with systemic sclerosis; patients with other pulmonary disorders; and patients with normal lung. Paraffin blocks were stained using three antibodies raised against well defined EBV antigens. In addition, EBER-1 and EBER-2 anti-sense nucleotide probes were used in an attempt to identify EBV RNA. DNA was also extracted from the tissue sections and evaluated for evidence of EBV DNA using the polymerase chain reaction. RESULTS: Immunohistochemistry showed inconsistent focal positive staining with anti-EBV antibodies in all three groups, but there was no evidence of EBV RNA using in situ hybridisation. None of the samples from patients with pulmonary fibrotic disorders was found to contain EBV DNA following gene amplification. CONCLUSION: Contrary to an earlier report, these results do not support the hypothesis that EBV has a role in the pathogenesis of CFA.

DNA, Viral↗

PubMed1997

Histologic, molecular, and radiologic characterization of resolving cerebral posttransplant lymphoproliferative disorder.

Lymphoproliferative disorders (LPDs) are commoner in pediatric versus adult immunosuppressed transplant recipients, and frequently involve the central nervous system. In these circumstances, the justification for biopsy is heavily influenced by the likely diagnostic yield. The present study centers on a 12-y-old renal transplant patient who developed multifocal cerebral LPD and had serial magnetic resonance (MR) examinations during the course of her illness from which she has completely recovered upon reduction of immunosuppression. She underwent stereotaxic biopsy, which was analyzed by both immunocytochemistry and polymerase chain reaction to examine the general question of how to release the maximum amount of information contained within, as well as to obtain a tissue diagnosis in this particular case. We show that a combination of these methods permits identification of the immunophenotype, lineage, clonality, viral involvement, and origin of abnormal cellular infiltrates. The biopsy also showed a novel histologic pattern of LPD, comprising numerous benign T cells obscuring a tiny clone of B cells. The MR examinations documented, for the first time, the differences in signal that accompany clinical resolution at both biopsied and nonbiopsied sites, showing that the latter may be associated with reduction, but not elimination, of MR signal abnormality. We conclude: 1) a combination of conventional and polymerase chain reaction analysis offers the greatest diagnostic yield from stereotaxic biopsies, even when the available tissue is minimal; 2) a focal polyclonal T cell infiltrate should prompt further investigation to exclude an underlying B cell lesion.

Adult↗

PubMed1997

Immersion-histo polymerase chain reaction: a practical tool for visualization of single-copy genes in tissue sections.

A method, immersion-histo polymerase chain reaction (IH-PCR), was developed for visualization of single-copy DNA sequences in cells in paraffin-embedded tissue sections. Sections were mounted on coverslips, cut into small pieces, and immersed in reaction mixtures in micro-tubes for specific DNA amplification using a conventional thermal cycler. This was followed by in situ hybridization, in micro-tubes, with PCR-generated, digoxigenin-labeled probes. Epstein-Barr virus, chromosomal translocations, and rearranged immunoglobulin genes were clearly demonstrated in individual cells in human lymphomas. The use of a standard thermal cycler, the ease of probe preparation, and the high specificity and sensitivity of target localization make IH-PCR a practical and powerful tool for the study of genetic events within individual cells.

DNA Primers↗

PubMed1997

Molecular analysis of T-cell clonality in ulcerative jejunitis and enteropathy-associated T-cell lymphoma.

Ulcerative jejunitis (UJ) and enteropathy-associated T-cell lymphoma (EATL) are closely related conditions both associated with celiac disease. Benign-appearing inflammatory ulcers are seen in both, which has led to the suggestion that UJ is a manifestation of EATL. The aim of this study was to investigate this relationship using the polymerase chain reaction (PCR) to detect T-cell gene rearrangement. PCR amplification of the T-cell receptor gamma-chain gene was performed on DNA extracted from lymphoma, associated inflammatory ulcers, and intervening mucosa in six EATL cases and from ulcers and intervening mucosa of seven cases of UJ. In two of these cases, DNA from a subsequent lymphoma was also studied. The PCR products from the tumor and an ulcer from one EATL case, two ulcers from one case of UJ, and one ulcer and subsequent cutaneous lymphoma from one UJ case were sequenced. Twenty-five ulcers from twelve cases of Crohn's disease, twenty sections of normal bowel, and nine celiac biopsies were included as controls. A monoclonal T-cell population defined by a dominant band equal in size to that amplified from the lymphoma was identified in at least one ulcer from four informative EATL cases and from intervening mucosa in three. Monoclonality was demonstrated in at least one, and up to thirteen, ulcers from all seven cases of UJ, in intervening mucosa in five, and in the two subsequent lymphomas. Sequencing showed the same clone was present in the tumor and the ulcer in the EATL case, in two of three ulcers from the UJ case, and in an ulcer and subsequent cutaneous lymphoma in one UJ case. All Crohn's disease ulcers and all sections of normal bowel were polyclonal. One of nine celiac biopsies showed a dominant band. In conclusion, we have shown that T-cell monoclonality is a feature of the ulcers in both UJ and EATL and that the same clone is present in EATL and its associated inflammatory ulcers and in UJ and subsequently developing lymphoma.

Celiac Disease↗

PubMed1997

Polymerase chain reaction in the assessment of lymphomas.

The polymerase chain reaction (PCR) offers a practical means of studying the molecular genetic features of lymphomas. The method is rapid and, as formalin-fixed, paraffin processed samples can be used, does not require special tissue handling procedures. PCR amplified immunoglobulin and T cell receptor gene rearrangements can be exploited as markers of clonality and lineage and genetic abnormalities such as chromosome translocations and mutations of oncogenes and tumour suppressor genes can be used to identify specific lymphoma types. Polymorphic X linked loci may also be used as markers of clonality in females. Direct sequencing of PCR amplified IGH variable regions has provided insights into the developmental stages, susceptibility to antigen drive and dissemination patterns of lymphomas. The role of oncogenes and tumour suppressor genes such as MYC and TP53 in lymphomas can be studied by PCR amplification of mutation hotspots and direct sequencing of products. Known viral and bacterial DNA can readily be identified using PCR and unknown organisms sought using conserved primers to amplify polymorphic sequences. PCR analysis of the lymphomas and related disorders has accelerated our understanding of their molecular biology and provides a practical tool with diagnostic and prognostic applications. Future development of in situ PCR methods will provide cellular localization of genetic defects and infectious agents.

Gene Rearrangement↗

PubMed1996

Intestinal dissemination of gastric mucosa-associated lymphoid tissue lymphoma.

Despite increasing identification of concurrent gastric and intestinal lymphomas of mucosa-associated lymphoid tissue (MALT), the clonal relationship between the two tumors and their sequential development are poorly understood. It is also unknown whether the development of these concurrent tumors is closely associated with direct antigen stimulation, which is thought to play an important role in the clonal expansion of low-grade MALT lymphomas. To investigate these, we have studied six cases of concurrent gastric and intestinal MALT lymphomas by polymerase chain reaction (PCR) amplification, cloning, and sequencing of the rearranged Ig gene, a strategy that has been widely used for analysis of clonality and antigen-driven properties of B-cell malignancies. In each case, an identical or nearly identical complementarity determining region (CDR) 3 sequence was observed between the dominant clones of concurrent gastric and intestinal MALT lymphomas. In four of six cases examined, sufficient Ig variable region sequence information was obtained to permit analysis of somatic mutations. The mutation patterns in one case suggest that the intestinal lesion is secondary to the gastric tumor, and the mutation patterns in two cases indicate that the gastric and intestinal lesions are derived from different tumour subclones, which emerge after expansion of a common early tumor clone. Furthermore, three of four cases showed ongoing Ig mutations among different PCR clones at each site. These results show that concurrent gastric and intestinal MALT lymphomas are derived from the same clone and suggest that the intestinal lesions result from dissemination of gastric tumours. Antigen stimulation may play a role in tumor evolution, particularly at an early stage.

Amino Acid Sequence↗

PubMed1996

Nodular lymphocyte predominance Hodgkin's disease: a monoclonal or polyclonal B-cell disorder?

Nodular lymphocyte predominance Hodgkin's disease (NLPHD) is characterized by the presence of atypical putatively neoplastic cells (L & H cells) with a B-cell phenotype. A proportion of patients with NLPHD develop a simultaneous or subsequent large cell B lymphoma (LCL) that is thought to evolve directly from the L & H cells of NLPHD. However, the clonal nature of L & H cells remains controversial, and the relationship between NLPHD and complicating LCL has not been fully established. In an attempt to determine the clonality of L & H cells and to clarify the link between NLPHD and complicating LCL, we used polymerase chain reaction (PCR) to analyze 33 cases of NLPHD, including 15 cases with simultaneous or subsequent LCL, for clonal immunoglobulin (lg) heavy chain variable region (VH) gene rearrangements. PCR amplifications with consensus primers covering framework 2 or framework 3 to joining region were performed on paraffin-embedded tissue sections and, in 12 cases, on microdissection-enriched L & H cells. No clonal Ig rearrangements were detected. In eight of the 15 LCL, monoclonal IgVH regions were amplified, four of which were cloned and sequenced. Clone specific primers were designed based on the unique N region sequences. These allowed detection of LCL clones at a sensitivity up to 1,000 times greater than the consensus primers, as determined by dilution assays. However, no LCL clones were detected in the preceding NLPHD, including microdissection-enriched L & H cells. Our results suggest that populations of L & H cells do not carry monoclonal Ig rearrangements and provide no evidence for a clonal link between NLPHD and complicating LCL.

Antibodies, Monoclonal↗

PubMed1996

Diagnosis and posttreatment follow-up of Helicobacter pylori-positive gastric lymphoma of mucosa-associated lymphoid tissue: histology, polymerase chain reaction, or both?

The differential diagnosis between Helicobacter pylori (H pylori-associated chronic gastritis and low-grade B-cell gastric lymphoma of mucosa-associated lymphoid tissue (MALT) and the assessment of endoscopic biopsy specimens after treatment of lymphoma can be problematic. Although immunocytochemistry can be used to identify clonal B-cell populations, which are characteristic of MALT lymphoma, its application to small biopsy specimens and the subsequent interpretation can be difficult. The polymerase chain reaction (PCR) can detect clonal B-cell populations by analysis of the Ig heavy chain gene in routinely fixed paraffin-embedded material and might provide a useful tool in the assessment of these specimens. We have investigated the value of histology and PCR in the diagnosis of lymphoma and its followup in formalin-fixed paraffin-embedded gastric endoscopy biopsy specimens from 69 sequential patients selected on the basis of a dense mucosal lymphoid infiltrate associated with H pylori infection. Histologic evidence of MALT lymphoma was identified in 13 cases, 9 of which showed PCR-detected monoclonality. In 12 of 13 cases, H pylori was eradicated, and in 11 of 12 cases, histologic regression of the lymphoma followed. PCR evidence of monoclonality disappeared in 6 of 9 originally monoclonal cases. This was synchronous with histologic remission in 1 case, but lagged in the remaining 5 cases by up to 28 months. Two of the 3 of the 9 cases originally monoclonal by PCR that have not shown molecular regression have monoclonal-amplified products 17 and 24 months after negative histology. In 3 cases, the histology of the biopsies was considered indeterminate or discordant. In 1 of these cases, the histologic features were obscured by crush artefact. In a second case, there was molecular evidence of monoclonality in the absence of histologic features suggestive of lymphoma; this persisted after H pylori eradication. An additional single case originally diagnosed as reactive developed a PCR detectable clonal population 29 months after original evaluation in the absence of histologic features of lymphoma but in the presence of persistent H pylori infection. These findings suggest that the histologic assessment of gastric biopsies remains the method of choice for the diagnosis of lymphoma in gastric endoscopic biopsies with a dense mucosal lymphoid infiltrate. PCR provides a useful technique to support the diagnosis if clonal amplification products are found. The significance of PCR detected clonality in the absence of histologic evidence of lymphoma in uncertain but may represent a stage of tumor progression/regression when the clonal population is insufficient to be detected by conventional histology. This is supported by the evidence that PCR-detectable monoclonality can persist after treatment and the disappearance of histologically detectable lymphoma.

Adolescent↗

PubMed1996

Low grade gastric B-cell lymphoma of mucosa associated lymphoid tissue in immunocompromised patients.

An increased incidence of non-Hodgkin's lymphoma is seen in patients with immunodeficiency from any cause. The majority of these are high grade B-cell lymphoma and most are associated with the Epstein-Barr virus (EBV). In post-transplant lymphoma/lymphoproliferative disorders the tumour may regress following reduction of immuno-suppression but in AIDS the lymphomas show a characteristic aggressive course and poor prognosis. We describe low grade B-cell gastric lymphoma of mucosa associated lymphoid tissue (MALT) in three immunocompromised patients (two post-transplant, one HIV positive). In each case, the tumour showed classical morphological features of gastric MALT lymphoma and was not associated with EBV. Helicobacter pylori was identified in each case. Clinical follow-up suggests that the behaviour in these tumours is similar to that seen in MALT lymphomas in immunocompetent patients and not typical of the lymphomas usually associated with immunosuppression. Although the finding of MALT lymphoma in immunosuppressed patients might be coincidental, the association of some MALT lymphomas with autoimmune disease suggests that dysregulation of the immune system might play a role in the pathogenesis of these tumours.

Aged↗

PubMed1996

Monocytoid/marginal zone B-cell differentiation in follicle centre cell lymphoma.

We report on two cases of low grade follicle centre cell lymphoma with a pronounced parafollicular monocytoid/ marginal zone B-cell component. One patient had a history of preceeding follicular high grade B-cell lymphoma of centroblastic type showing the same light chain restriction and identical immunoglobulin heavy chain gene rearrangement as the low grade lymphoma diagnosed 15 months later. Morphologically, in both cases the two constituents of the low grade tumours were clearly distinguishable. Immunohistochemically, the follicular component strongly expressed bcl-2 protein in contrast to a weak staining of the marginal zone B-cell component. Performing PCR, a rearrangement of the major breakpoint region of bcl-2 was not found. Identical light chain restriction of the follicular and the monocytoid B-cell/marginal zone components strongly indicates a clonal relationship between them. A monocytoid/marginal zone B-cell component in follicular lymphoma probably results from differentiation of the follicle centre cells and does not indicate a composite lymphoma.

Antigens, CD20↗

PubMed1996

Lymphomatoid granulomatosis: evidence that some cases represent Epstein-Barr virus-associated B-cell lymphoma.

Lymphomatoid granulomatosis is currently classified as part of a spectrum of angiocentric immunoproliferative lesions. These were initially thought to be of T-cell phenotype, but recent papers have shown that some cases are B-cell proliferations, sometimes associated with Epstein-Barr virus infection. We reviewed the clinicopathological features of 16 patients with pulmonary lymphomatoid granulomatosis, using immunohistochemistry to assess the phenotype of the infiltrate, the polymerase chain reaction to look for immunoglobulin heavy chain and T-cell receptor gene rearrangements, and in-situ-hybridization to look for Epstein-Barr virus infection. In seven of seven cases the atypical lymphoid population was of B-cell phenotype, with four cases showing evidence of either monoclonality or oligoclonality. All seven cases, including those that lacked unequivocal proof of malignancy, behaved aggressively. Epstein-Barr virus RNA was detected in four cases. We conclude that some cases of lymphomatoid granulomatosis are B-cell lymphomas, sometimes associated with Epstein-Barr virus infection.

Adult↗