Diagnostic role of tests for T cell receptor (TCR) genes

Pattern of immunoglobulin and T-cell receptor-δ/γ gene rearrangements in Iranian children with B-precursor acute lymphoblastic leukemia

INTRODUCTION

Acute lymphoblastic leukemia (ALL) cells have unique rearranged immunoglobulin heavy chain (IgH), immunoglobulin light chain (IgK), and T-cell receptor (TCR) genes, which can be used as markers for clonality assay and evaluation of minimal residual disease. In this study, we have evaluated the pattern of IgH, IgK chains, and TCRG/D gene rearrangements in precursor-B ALL.

MATERIALS AND METHODS

In our prospective study, hyper-variable regions (CDRI and III) of IgH, TCRD (Vδ2-Dδ3 and Dδ2-Dδ3), TCRG (Vγ, VγI, and VγII), and IgK (Vκ-Kde) were studied in 126 cases with diagnosis of B-precursor ALL.

RESULTS

One hundred and fourteen (90.5%) out of 126 patients had clonal rearrangements of IgH using consensus primers for CDRI and/or CDRIII regions. Monoclonal, biclonal, and oligoclonal patterns were observed in 63 (57.8%), 38 (34.9%), and 6 (5.5%) patients with IgH (CDRIII) rearrangements, respectively. Clonal rearrangements of TCRG (Vγ) and VγI/II were present in 79.3 and 64.9% of patients, respectively, and only 5% of cases showed biclonal pattern. The VγII rearrangement was the most common (46.8%) type in TCRG. Vδ2-Dδ3 and Dδ2-Dδ3 partial gene rearrangements were observed in 47 (45.2%; n = 104) and 11 (16.6%; n = 66) patients, respectively. Biclonal/oligoclonal patterns were present in 13 (27.7%) and 2 (4.3%) cases with Vδ2-Dδ3 rearrangement, respectively. Only one patient had biclonal Dδ2-Dδ3 rearrangement. Clonal pattern of IgK-Kde was detected in 59 cases (67%; n = 88).

CONCLUSION

Our findings showed that clonal rearrangements of IgH and TCRD (Vδ2-Dδ3 and Dδ2-Dδ3) genes had similar patterns to other studies. Frequency of TCRG (VγI and VγII) and IgK rearrangements was found to be slightly higher than previous reports. Among the IgK rearrangements, VKI (25%) was the most common.

The important role of T cells and receptor expression in Sjögren's syndrome

Sjögren's syndrome (SjS), an autoimmune disease characterized by exocrine gland dysfunction leading to dry mouth and dry eye diseases, is typified by progressive leucocyte infiltrations of the salivary and lacrimal glands. Histologically, these leucocyte infiltrations generally establish periductal aggregates, referred to as lymphocytic foci (LF), which occasionally appear as germinal centre (GC)-like structures. The formation and organization of these LF suggest an important and dynamic role for helper T cells (TH), specifically TH1, TH2 and the recently discovered TH17, in development and onset of clinical SjS, considered a B cell-mediated hypersensitivity type 2 disease. Despite an ever-increasing focus on identifying the underlying aetiology of SjS, defining factors that initiate this autoimmune disease remain a mystery. Thus, determining interactions between infiltrating TH cells and exocrine gland tissue (auto-)antigens represents a fertile research endeavour. This review discusses pathological functions of TH cells in SjS, the current status of TH cell receptor gene rearrangements associated with human and mouse models of SjS and potential future prospects for identifying receptor-autoantigen interactions.

T-large granular lymphocyte leukemia: current molecular concepts

T-large granular lymphocyte (T-LGL) leukemia is a chronic and often indolent T cell lymphoproliferation characterized by extreme expansion of a semi-autonomous cytotoxic T lymphocyte (CTL) clone. Clinically, T-LGL can be associated with various cytopenias; neutropenia constitutes the most frequent manifestation. LGL clone represents a pathologic counterpart of the cytotoxic effector T cell but an abnormal memory CD8 cell seems to provide the supply of the matured LGL population. Analysis of clonal T cell receptor (TCR) rearrangement and complementarity determining region 3 (CDR3) of the TCR beta-chain is a useful tool to investigate clonal expansions, track the frequency of expanded clones and also clinically useful to monitor the response to therapy. The lessons learned from molecular analysis of clonal repertoire support a clinically-derived conclusion that the LGL clone arises in the context of an initially polyclonal immune response or an autoimmune process. Consequently, specific manifestations of T-LGL may be a result of the recognition spectrum of the transformed clone and the cytokines it produces. Due to the often monoclonal manifestation, T-LGL constitutes a suitable model to investigate polyclonal CTL-mediated processes. Application of new technologies, including TCR repertoire analysis by sequencing, clonotypic quantitative PCR and VB flow cytometry facilitate clinical diagnosis and may allow insights into the regulation of TCR repertoire and consequences resulting from the contraction of clonal diversity.

Diagnostic Impact of Molecular Lineage Analysis on Paraffin-Embedded Tissue in Hematolymphoid Neoplasia Reclassified by Current WHO Criteria

BACKGROUND AND OBJECTIVE

By current WHO criteria, most - though not all - cases of hematolymphoid neoplasm can be diagnosed immunomorphologically, diminishing the role of molecular tests for lymphoid antigen receptor clonality in lymphoma diagnosis. Hence, our objective was to glean immunomorphological and molecular correlates from hematolymphoid neoplasms that had remained unresolvable without diagnostic molecular input.

METHODS

Thirty-five such cases were reviewed histologically and with standard immunoperoxidases. In situ hybridization for Epstein-Barr virus (EBV)-encoded RNAs (EBER) was performed on selected cases. PCR amplification of genes encoding T-cell receptors (TcR) and immunoglobulin heavy chains (IgH) [TR and IGH genes, respectively] was performed on whole tissue in all cases, and on microdissected cells in two cases.

RESULTS

Twenty-five cases (71%) requiring diagnostic molecular genotyping had some form of peripheral T-cell lymphoma (PTCL). Twenty (80%) of these were complicated by a proliferation of B-lineage cells, either within the same tissue ('syntopic') as large B cells (LBC) or Reed-Sternberg (RS)-like cells (17 cases), florid lymphoid hyperplasia (two cases, one also with syntopic LBC) or monotypic plasma cells (one case), or at a separate ('metatopic') site as a B-cell lymphoma (two cases, one of which also had syntopic LBC) or Hodgkin lymphoma (HL; one case, also showing syntopic LBC). Fifteen (75%) of these 20 PTCLs with B-lineage proliferation yielded monoclonal TR gene rearrangements, and only two (10%) showed IGH monoclonality, which was transient in one case. Three (18%) of the PTCLs with LBC had originally been misinterpreted as some form of HL. Conversely, of the remaining cases, three of four (75%) that had been diagnosed initially as some form of large cell non-HL (NHL), including two of three that were called 'anaplastic', had to be revised to grade II/syncytial nodular sclerosing (NS) HL, yielding polyclonal TcRgamma gene (TRG) rearrangements, with one case, in addition, disclosing a biallelic clonal IGH gene rearrangement that excluded anaplastic large cell lymphoma.

DISCUSSION/CONCLUSION

Paradoxically, monoclonality of TR rather than IGH gene rearrangement may more often be detectable in a predominantly dispersed ('hodgkinoid'), large B-lineage cell proliferation, consistent with release from immune regulation in the milieu of impaired immunosurveillance within a PTCL. This is compounded by the difficulty in ascertaining clonal IGH gene rearrangements resulting from (1) poor consensus primer hybridization due to somatic hypermutations, and (2) 'dilution' in a T-cell-rich milieu. These same difficulties also account for the long-elusive identification of the RS cell lineage. Conversely, anaplastic lymphoma, which is of non-B lineage, may be mimicked by NSHL, which is of B lineage.

Diagnostic significance of TCR gene clonal rearrangement analysis in early mycosis fungoides

Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, has various unspecific clinical and histological characteristics. Its early diagnosis is challenging. The application of T-cell receptor (TCR) gene clonal rearrangement to the diagnosis of MF has been widely studied. In this study, we used polymerase chain reaction (PCR) to investigate the diagnostic significance of detecting TCR-γ and -β gene clonal rearrangement in the early diagnosis of mycosis fungoides. PCR for TCR-γ and TCR-β gene rearrangement was performed on 19 patients with suspected early MF, 6 with typical MF, and 6 with chronic dermatitis. Of the 19 patients with suspected early MF, 13 had TCR-γ gene clonal rearrangement, whereas none had TCR-β gene clonal rearrangement. All patients with typical MF had TCR gene clonal rearrangement, in which 4 showed TCR-γ clonal rearrangement, 1 showed TCR-β gene clonal rearrangements, and 1 showed both. No patients with chronic dermatitis had TCR gene clonal rearrangement. These results indicate that TCR gene clonal rearrangement analysis is a useful tool in diagnosing early MF. TCR-γ gene is recommended to the routine analysis, whereas TCR-β gene has potential in combination toward intractable cases.

Analysis of T-cell receptor-γ gene rearrangements using heteroduplex analysis by high-resolution microcapillary electrophoresis

Determination of T-cell clonality has an important additional value for diagnosis of T-cell lymphomas. Various molecular methods have been developed, including polymerase chain reaction (PCR) of T-cell receptor γ (TCRγ). The detection of PCR products usually relies commonly on either GeneScan (GS) analysis or heteroduplex (HD) analysis by polyacrylamide gel electrophoresis (PAGE). These techniques have their disadvantages, being relatively time-consuming and laborious or requiring expensive equipment. Here, we propose an alternative method that combines multiplex PCR and HD analysis by microcapillary electrophoresis (ME) on the Agilent 2100 Bioanalyzer. The sensitivity of the method was determined with clonal PEER T-cell line DNA dilution in polyclonal DNA and was evaluated as 1-5%. Fifty-three samples from patients with T-cell lymphoproliferative disorders were analyzed by HD analysis using ME and GS analyses. Comparison of the two techniques showed them to be highly concordant (93% similarity). The rate of clonality detection by GS analysis was higher than HD analysis by ME, but none of the discordant patients (n=5) has yet developed lymphoma. HD analysis by ME to reveal TCRγ gene rearrangements in clinical specimens was consistent with clinical data and the outcome of patients. Detection of T-cell clonality by HD analysis with ME is sensitive, practical, safe and represents a potential alternative to PAGE and GS analysis.

Asymptomatic T-cell large granular lymphocyte leukemia with an unusual immunophenotype

T-cell large granular lymphocyte (T-LGL) leukemia represents a clonal proliferation of cytotoxic T-cells which etiology has not been entirely elucidated. However, CD4⁺, CD4⁻, CD8⁻, CD4⁺, CD8⁺ cases have been described. The disease is usually characterized by cytopenias and a modest lymphocytosis. The majority of patients with T-LGL leukemia remains asymptomatic for a long period and will require treatment later during the course of their disease. Hereby we describe a case of T-LGL leukemia diagnosed by flow cytometry, which presented indolent course and required no treatment so far.

The role of immunohistochemical analysis in the diagnosis of parapsoriasis

Parapsoriasis is a chronic dermatosis whose biological distinction from early mycosis fungoides, the most frequent form of cutaneous T-cell lymphoma, is still not clearly defined. Two types of parapsoriasis have been delineated: large-plaque parapsoriasis and small-plaque parapsoriasis. The lack of clinical and histological features, which may allow distinguishing parapsoriasis from early mycosis fungoides has prompted several investigations to assess the role of immunohistochemistry in establishing a conclusive diagnosis of these conditions. However, the additional data obtained by immunohistochemical analysis concerning the CD4/CD8 ratio, the aberrant expression of T-cell antigens and the expression of proliferation markers has not generally helped establish a more definitive diagnosis. This review critically discusses these immunohistochemical markers and their use in diagnosis of parapsoriasis.

Nfe2l3 (Nrf3) deficiency predisposes mice to T-cell lymphoblastic lymphoma

We have previously generated mice deficient for Nfe213 (NF-E2 p45 related factor 3 or Nrf3), a member of the cap 'n' collar family of basic-leucine zipper transcription factors. To examine whether Nrf3 is involved in chemical-induced carcinogenesis, we exposed the mice to benzo[a]pyrene (B[a]P), a carcinogen found in cigarette smoke. Contrary to wild-type mice, Nrf3-null animals are highly susceptible to B[a]P, exhibiting significantly increased mortality. Pathology analysis of affected tissue sections revealed a high incidence of T-cell lymphoblastic lymphoma in B[a]P-treated Nrf3(-/-) mice. Lymphoblastic lymphoma occasionally metastasized into the lung as demonstrated by perivascular malignant lymphocytic infiltration. Together, our studies show that the absence of Nrf3 predisposes mice to lymphoma development, suggesting a protective role of this transcription factor in hematopoietic malignancies. Our data demonstrate the first in vivo function of Nrf3 and its link to tumor development. Nrf3-deficient mice may serve as a preclinical mouse model to study carcinogen-induced lymphomagenesis.

Copy number variation and association over T-cell receptor genes--influence of DNA source

Genomic copy number variants (CNVs) are a common, heritable source of inter-individual differences in genomic sequence. Their influence on phenotypic variability and their involvement in the pathogenesis of several common diseases is well established and the object of many current studies. In the course of examining CNV association to various quantitative traits in a general population, we have detected a strong association of CNVs over the four TCR genes to lymphocyte and neutrophil numbers in blood. In a small replication series, we have further characterized the nature of these CNVs and found them not to be germline, but dependent on the origin of analysed DNA. Germline deletion and rearrangement around the T-cell receptor (TCR) genes naturally occurs in white blood cells. Blood DNA derived from persons with high lymphocyte counts generates variable intensity signals which behave like germline CNVs over these genes. As DNA containing a relative high proportion of these CNV-like events involving the TCR genes has the ability to influence genotype counts of SNPs in the regions of these genes, care should be taken in interpreting and replicating association signals on variants within these genes when blood-derived DNA is the only source of data.

The role of fluorescence in situ hybridization and polymerase chain reaction in the diagnosis and classification of lymphoproliferative disorders on fine-needle aspiration

BACKGROUND

Fine-needle aspiration (FNA) has been used in the evaluation of lymphadenopathy for a long time and is highly reliable in the identification of metastatic malignancies. However, the role of FNA in the assessment of new lymphoproliferative disorders continues to be a subject of debate. The objective of the current study was to evaluate the role of molecular cytogenetic studies in FNA diagnoses of lymphoproliferative disorders.

METHODS

A retrospective, computer-based search for lymph node FNAs from 2006 to 2007 was performed. Cases with either fluorescence in situ hybridization (FISH) and/or polymerase chain reaction (PCR) studies were subjected to further analysis.

RESULTS

In total, 243 lymph node FNAs were performed during the period, including 104 that were positive/suspicious for metastatic malignancies, 16 that were positive/suspicious for lymphomas, 15 that demonstrated atypical lymphoid proliferation, 73 that were reactive, 14 that were deemed granulomas, and 21 that were determined to be nondiagnostic. Molecular analysis included combined FISH/PCR in 4 cases, FISH only in 7 cases, and PCR only in 4 cases. By using multiplex PCR, 6 cases with atypical/negative flow cytometry results were diagnosed as 4 B-cell lymphomas, 1 T-cell lymphoma, and 1 reactive lymph node; and 4 cases that had atypical T cells determined by flow cytometry were diagnosed as reactive. One CD10-negative follicular lymphoma and 2 cases with suspicious flow cytometry results were positive for t(14;18)(q32;q21) by FISH. Forty-five cases had follow-up histology with 3 false-negative findings and no false-positive results.

CONCLUSIONS

In this study, multiplex PCR studies for immunoglobulin heavy-chain or T-cell receptor gene rearrangements were useful for demonstrating clonality, and FISH studies were able to detect translocations or gene rearrangements that allowed for the subclassification of B-cell non-Hodgkin lymphomas.

T-cell abnormalities are present at high frequencies in patients with hypereosinophilic syndrome

BACKGROUND

A T-cell clone, thought to be the source of eosinophilopoietic cytokines, identified by clonal rearrangement of the T-cell receptor and by the presence of aberrant T-cell immunophenotype in peripheral blood defines lymphocytic variant of hypereosinophilic syndrome (L-HES).

DESIGN AND METHODS

Peripheral blood samples from 42 patients who satisfied the diagnostic criteria for HES were studied for T-cell receptor clonal rearrangement by polymerase chain reaction according to BIOMED-2. The T-cell immunophenotype population was assessed in peripheral blood by flow cytometry. The FIP1L1-PDGFRA fusion gene was detected by nested polymerase chain reaction.

RESULTS

Forty-two HES patients (18 males and 24 females) with a median age at diagnosis of 56 years (range 17-84) were examined in this study. Their median white blood cell count was 12.9 x 10(9)/L (range 5.3-121), with an absolute eosinophil count of 4.5 x 10(9)/L (range 1.5-99) and a median eosinophilic bone marrow infiltration of 30% (range 11-64). Among the 42 patients, clonal T-cell receptor rearrangements were detected in 18 patients (42.8%). Patients with T-cell receptor clonality included: T-cell receptor beta in 15 patients (35%), T-cell receptor gamma in 9 (21%) and T-cell receptor delta in 9 (21%) patients, respectively. Clonality was detected in all three T-cell receptor loci in 4 cases, in two loci in 7 patients and in one T-cell receptor locus in the remaining 7 patients. The FIP1L1-PDGFRA fusion transcript was absent in all but 2 patients with T-cell receptor clonality. Three patients out of 42 revealed an aberrant T-cell immunophenotype. In some patients, an abnormal CD4:CD8 ratio was demonstrated.

CONCLUSIONS

T-cell abnormalities are present at high frequencies in patients with HES.

Primer sets for cloning the human repertoire of T cell Receptor Variable regions

Background

Amplification and cloning of naïve T cell Receptor (TR) repertoires or antigen-specific TR is crucial to shape immune response and to develop immuno-based therapies. TR variable (V) regions are encoded by several genes that recombine during T cell development. The cloning of expressed genes as large diverse libraries from natural sources relies upon the availability of primers able to amplify as many V genes as possible.

Results

Here, we present a list of primers computationally designed on all functional TR V and J genes listed in the IMGT^®, the ImMunoGeneTics information system^®. The list consists of unambiguous or degenerate primers suitable to theoretically amplify and clone the entire TR repertoire. We show that it is possible to selectively amplify and clone expressed TR V genes in one single RT-PCR step and from as little as 1000 cells.

Conclusion

This new primer set will facilitate the creation of more diverse TR libraries than has been possible using currently available primer sets.

T cell receptor Vbeta repertoire of T lymphocytes and T regulatory cells by flow cytometric analysis in healthy children

Evaluation of the T cell receptor (TCR) Vbeta repertoire by flow cytometric analysis has been used for studying the T cell compartments for diseases in which T cells are implicated in the pathogenesis. For the interpretation of these studies information is needed about Vbeta usage in healthy individuals and there are few data for normal usage in paediatric populations. We examined the T lymphocyte (sub)populations in 47 healthy controls (age range: 3 months-16 years). We found non-random Vbeta usage with skewed reactivity of some families towards CD4+ or CD4- T cells. Importantly, there appeared to be no significant change in Vbeta usage according to age group. Some controls showed expansions in some Vbeta families, although incidence of such expansions was low. We went on to examine the repertoire of CD4+CD25(Bright) T regulatory cells in 25 healthy controls. We found overlapping quantitative usage for each of the Vbeta families between CD4+CD25- and CD4+CD25(Bright) T cells. However, there was a significant preferential usage for five Vbeta families and decreased usage of two Vbeta families in the CD4+CD25(Bright) T cells, suggesting that although they overlap there may be subtle but important differences in the TCR repertoire of T regulatory cells.

Molecular genetic analysis of haematological malignancies II: mature lymphoid neoplasms

Molecular genetic techniques have become an integral part of the diagnostic assessment for many lymphomas and other chronic lymphoid neoplasms. The demonstration of a clonal immunoglobulin or T cell receptor gene rearrangement offers a useful diagnostic tool in cases where the diagnosis is equivocal. Molecular genetic detection of other genomic rearrangements may not only assist with the diagnosis but can also provide important prognostic information. Many of these rearrangements can act as molecular markers for the detection of low levels of residual disease. In this review, we discuss the applications of molecular genetic analysis to the chronic lymphoid malignancies. The review concentrates on those disorders for which molecular genetic analysis can offer diagnostic and/or prognostic information.

Are clonal T-cell large granular lymphocytes to blame for unexplained haematological abnormalities?

Abnormalities diagnosed on routine blood work, such as mild neutropenia, anaemia, thrombocytopenia and relative lymphocytosis, often have obscure aetiologies. A series of 30 patients were evaluated for various unexplained haematological abnormalities between 1997 and 2005, and found to have circulating monoclonal T-cell large granular lymphocytes (T-LGL). These patients fit the diagnosis of T-cell clonopathy of unknown significance (TCUS), which may represent a clinical spectrum of clonal T-LGL proliferation. Our patients were characterised by a complete absence of severe neutropenia (<0.5 x 10(9)/l), absence of recurrent neutropenic infection (0%), negative rheumatoid serology (0%) and a low incidence of constitutional symptoms (20%). This overall asymptomatic clinical presentation appeared to be different from other previously reported series of TCUS or T-LGL leukaemia who typically had symptomatology and required treatment. Our series of 30 patients represented the benign end of the spectrum of clonal T-LGL proliferation, and might reflect diagnosis at earlier stages of the condition relative to other reported series. TCUS may be a heterogeneous and under-diagnosed condition. This study further broadens our understanding of the clinical and laboratory manifestations of indolent clonal T-cell proliferation, and raises our awareness of this condition. We suggest that TCUS should be considered in the diagnostic evaluation of unexplained haematological problems.

Powerful strategy for polymerase chain reaction-based clonality assessment in T-cell malignancies Report of the BIOMED-2 Concerted Action BHM4 CT98-3936

Polymerase chain reaction (PCR) assessment of clonal T-cell receptor (TCR) and immunoglobulin (Ig) gene rearrangements is an important diagnostic tool in mature T-cell neoplasms. However, lack of standardized primers and PCR protocols has hampered comparability of data in previous clonality studies. To obtain reference values for Ig/TCR rearrangement patterns, 19 European laboratories investigated 188 T-cell malignancies belonging to five World Health Organization-defined entities. The TCR/Ig spectrum of each sample was analyzed in duplicate in two different laboratories using the standardized BIOMED-2 PCR multiplex tubes accompanied by international pathology panel review. TCR clonality was detected in 99% (143/145) of all definite cases of T-cell prolymphocytic leukemia, T-cell large granular lymphocytic leukemia, peripheral T-cell lymphoma (unspecified) and angioimmunoblastic T-cell lymphoma (AILT), whereas nine of 43 anaplastic large cell lymphomas did not show clonal TCR rearrangements. Combined use of TCRB and TCRG genes revealed two or more clonal signals in 95% of all TCR clonal cases. Ig clonality was mostly restricted to AILT. Our study indicates that the BIOMED-2 multiplex PCR tubes provide a powerful strategy for clonality assessment in T-cell malignancies assisting the firm diagnosis of T-cell neoplasms. The detected TCR gene rearrangements can also be used as PCR targets for monitoring of minimal residual disease.

Clonal T-Large Granular Lymphocyte Proliferation in Solid Organ Transplant Recipients

Large granular lymphocytic (LGL) leukemia is a rare disorder, usually caused by clonal proliferation of CD3+ CD57+ T-LGL cells. T-cell clonality is confirmed by rearrangements of the T-cell receptor (TCR) gene. Characteristic features of T-LGL leukemia include neutropenia, anemia, and constitutional symptoms such as fatigue. Many solid organ transplant recipients experience similar symptoms and have neutropenia and anemia often attributed to immunosuppressive therapy. The purpose of this study was to determine the prevalence of T-LGL proliferation in solid organ transplant recipients and demonstrate its association with leukopenia and anemia. Twenty-three cardiac and renal transplant patients were evaluated by peripheral smear examination, flow cytometry, and TCR gene rearrangement study by polymerase chain reaction. Ten of 14 (71%) cardiac transplant patients and 4 of 9 (44%) renal transplant patients, without evidence of either allograft rejection or a viral syndrome, were found to have clonal expansion of T-LGL cells. Constitutional symptoms were present in 30% of these patients. Anemia of <10 g/dL was seen in 75% of renal transplant and 10% of cardiac transplant patients. None of these patients had significant neutropenia defined as absolute neutrophil count of 1500 mu/L. Most of the patients did not require any specific therapeutic intervention. Although TCR gene rearrangement is considered a hallmark of T-LGL leukemia, we believe that this monoclonality is not a true form of posttransplant lymphoproliferative disorder. Constant antigenic stimulus from the allograft may be the underlying etiology of clonal expansion and may contribute to cytopenias and fatigue seen in transplant patients.

A patient with paroxysmal nocturnal hemoglobinuria, T cell large granular lymphocyte clonal expansion, and monoclonal gammopathy of undetermined significance

Paroxysmal nocturnal hemoglobinuria (PNH) has been described in association separately with T cell large granular lymphocyte (LGL) clonal expansions and plasma cell dyscrasias. We describe a patient with anemia related to hemolytic PNH, with concurrent T cell LGL oligoclonal expansion and IgG lambda monoclonal gammopathy of undetermined significance. Peripheral blood flow cytometry revealed decreased expression of CD55 and CD59 on erythrocytes and decreased expression of CD55 and CD66 on neutrophils. An LGL population was present in the peripheral blood and was characterized as oligoclonal by polymerase chain reaction-based analysis of the T cell receptor gamma-chain variable region. Serum protein electrophoresis with immunofixation showed a low level IgG lambda monoclonal protein. We describe the diagnostic evaluation of this patient and provide a brief review of the reported associations among PNH, LGL clonal expansion, and monoclonal gammopathy.

CD7/CD19 double-positive T-cell acute lymphoblastic leukemia

We report a rare case of T-cell acute lymphoblastic leukemia (T-ALL) with an aberrant phenotype. A 52-year-old man was admitted to our hospital because of lymph node (LN) swelling in the bilateral neck. A computed tomographic scan showed LN swelling in the mediastinum and a right pleural effusion. The tumor cells in the neck LN showed positivity for cytoplasmic CD3, CD7, CD19, and CD79a, whereas the tumor cells in the bone marrow (BM) showed positivity for CD10 and CD13 in addition to the former 4 antigens. The chromosomes in the BM were normal. Neither T-cell receptor gamma nor immunoglobulin heavy chain rearrangement was detected in the neck LN. We diagnosed this case as T-ALL with an aberrant phenotype and started the standard chemotherapy for ALL. The response was so effective that complete remission (CR) was easily attained. The patient is now under maintenance therapy in the first CR without hematopoietic cell transplantation.

Minimal Disease Detection and Confirmation in Hematologic Malignancies: Combining Cell Sorting with Clonality Profiling

Background: In this study we demonstrate the technical application of flow cytometry and cell sorting combined with gene-rearrangement clonality profiling to detect and confirm minimal disease in 2 leukemia and 2 lymphoma cases.

Methods: Specimens with low percentages (0.05%–5%) of abnormal lymphoid populations were identified by flow cytometry. The abnormal lymphoid populations were sorted by flow cytometry, and the purified tumor populations along with unsorted fractions were subsequently analyzed for the presence of clonal gene rearrangements by PCR and fluorescence-based capillary electrophoresis fragment analysis.

Results: In 3 cases, distinct clonality profiles could be detected in the purified tumor cell fraction, and suspicious amplicons of identical sizes were detected among the polyclonal backgrounds in the unsorted specimens. For 1 patient, a monoclonal signal was detected in the sorted tumor cell fraction but not in the unseparated bone marrow specimen containing 0.05% abnormal lymphoblasts. A subsequent bone marrow specimen containing 4.8% recurring leukemia cells tested positive with a clonality profile that matched the previous profile in the sorted cell population.

Conclusions: The described method integrating 2 technologies allows genotypic confirmation of an aberrant population detected by immunophenotype to increase diagnostic certainty. This strategy provides a sensitive tool for disease monitoring without the need for patient-specific primer design and assay optimization required for quantitative PCR analysis.

BIOMED-2 multiplex immunoglobulin/T-cell receptor polymerase chain reaction protocols can reliably replace Southern blot analysis in routine clonality diagnostics

To establish the most sensitive and efficient strategy of clonality diagnostics via immunoglobulin and T-cell receptor gene rearrangement studies in suspected lymphoproliferative disorders, we evaluated 300 samples (from 218 patients) submitted consecutively for routine diagnostics. All samples were studied using the BIOMED-2 multiplex polymerase chain reaction (PCR) protocol. In 176 samples, Southern blot (SB) data were also available, and the two types of molecular results were compared. Results of PCR and SB analysis of both T-cell receptor and immunoglobulin loci were concordant in 85% of samples. For discordant results, PCR results were more consistent with the final diagnosis in 73% of samples. No false-negative results were obtained by PCR analysis. In contrast, SB analysis failed to detect clonality in a relatively high number of samples, mainly in cases of low tumor burden. We conclude that the novel BIOMED-2 multiplex PCR strategy is of great value in diagnosing patients with suspected B- and T-cell proliferations. Because of its higher speed, efficiency, and sensitivity, it can reliably replace SB analysis in clonality diagnostics in a routine laboratory setting. Just as with SB results, PCR results should always be interpreted in the context of clinical, immunophenotypical, and histopathological data.

Chronic lymphoid leukemias other than chronic lymphocytic leukemia: diagnosis and treatment

The World Health Organization classification divides lymphoid malignancies into precursor B-cell and T-cell neoplasms as well as mature B-cell and T-cell neoplasms. Mature B-cell neoplasms comprise more than 85% of non-Hodgkin lymphomas worldwide and can be further subclassified according to the postulated cell of origin by using specific morphologic, immunophenotypic, and molecular characteristics. Similarly, the more uncommon mature T-cell neoplasms have been better characterized to include numerous distinct entities with widely varying natural histories. The distinction between lymphoma and leukemia is somewhat arbitrary and is based on variable involvement of the bone marrow, peripheral blood, and lymphatic system. In this article, we review the diagnostic and clinical features of mature B-cell and T-cell lymphoproliferative disorders that commonly have a leukemic presentation.

Age-related loss of naïve T cells and dysregulation of T-cell/B-cell interactions in human lymph nodes

In this study we analysed the effects of age on T and B lymphocytes in human lymph nodes by comparing lymphocyte subsets in paraffin sections from lymph node tissue taken from healthy young and elderly people. We demonstrate that the relative number of CD8(+) T cells decreases with age but that the relative number of CD4(+) T cells does not. There is also a very pronounced age-dependent loss of CD45RA(+) naive T cells. The number and size of follicles and the relative number of CD20(+) B cells are similar in young and elderly donors. For polymerase chain reaction analysis of the T-cell receptor (TCR) repertoire the TCR-gamma gene rearrangements were used as a marker of clonality. This is a reliable tool to detect not only clonal TCR-gammadelta populations but also TCR-alphabeta populations. Young donors with clonal T-cell expansions in their lymph node tissue do, however, have a higher number of CD20(+) B cells, a higher relative size of germinal centres compared to the follicle mantles and a higher number of immunoglobulin M-expressing cells than young donors without evidence of clonal T-cell expansions. Corresponding changes are not observed in elderly donors with clonal T-cell expansions in their lymph node tissue. In summary our findings demonstrate characteristic effects of aging on human lymph node tissue, the most striking feature being the depletion of naive T cells and the apparent dysregulation of T-cell/B-cell interactions in old age.

Acute lymphoblastic leukemia with the phenotype of a putative B-cell/T-cell bipotential precursor

Biphenotypic acute leukemias (BALs) are uncommon. Most are of myeloid-B-cell or myeloid-T-cell lineage. We report herein a 70-year-old man with an unusual acute leukemia where the blasts expressed both B- and T-lymphoid markers. He presented to us with an enlarging cutaneous tumor. The presenting peripheral blood and bone marrow aspirate showed 40% and 90% blasts, respectively, which were negative for the usual cytochemical stains. The flow cytometric analysis revealed that the blasts were positive for CD19, CD20, CD22, cytoplasmic (Cyt) CD79a, CD10, Cyt CD3, CD5, CD7, CD4, HLA-DR, TdT, and were negative for myeloid markers. According to the scoring system from the European Group for the Immunological Characterization of Acute Leukaemias (EGIL), this case was an unequivocal B-cell/T-cell BAL. Conventional cytogenetic analysis revealed 46XY [t(4;11)(q31;q13), add(8)(q24), der(9)del(9)(p21)del(9)(q32q34), -13, +mar] in all 25 metaphases analyzed. Fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) for 11q23 rearrangements as well as t(9;22) were negative. PCR for both TCR-gamma and IgH gene analyses revealed polyclonal rearrangements. We postulate that this case of BAL might have arisen from the putative common lymphoid progenitor cell.

Early TCR-beta and TCR-gamma PCR detection of T-cell clonality indicates minimal tumor disease in lymph nodes of cutaneous T-cell lymphoma: diagnostic and prognostic implications

The lymph nodes are generally the first extracutaneous manifestation in patients with cutaneous T-cell lymphoma (CTCL); however, their early involvement is difficult to assess. The aim of our study was to define the diagnostic and prognostic value of T-cell clonality analysis for a more precise assessment of lymph node involvement in CTCL. T-cell clonality was determined by 2 independent polymerase chain reaction (PCR) assays, namely a recently developed T-cell receptor-beta (TCR-beta) PCR technique as well as an established TCR-gamma PCR. T-cell clonality was found in 22 of 22 lymph nodes with histologically detectable CTCL involvement as well as in 7 of 14 histologically noninvolved dermatopathic lymph nodes. The clonal T-cell populations in the lymph nodes were in all cases identical to those detected in the corresponding skin lesions, identifying them as the tumor cell population. T-cell clonality was not found in any of the 12 dermatopathic lymph nodes from 12 patients with inflammatory skin diseases. Clonal T-cell detection in 7 of 14 dermatopathic lymph nodes of patients with CTCL was associated with limited survival (74 months; confidence interval [CI], 66-82 months) as in patients with histologically confirmed lymph node involvement (41 months; CI, 35-47 months), whereas all patients without T-cell clonality in the lymph nodes (7 patients) were alive at the last follow-up. Thus, T-cell clonality analysis is an important adjunct in differentiating benign dermatopathic lymphadenitis from early CTCL involvement.

T-cell large granular lymphocyte leukemia and related disorders

T-cell large granular lymphocyte (LGL) leukemia is a clonal proliferation of cytotoxic T cells, which causes neutropenia, anemia, and/or thrombocytopenia. This condition is often associated with autoimmune disorders, especially rheumatoid arthritis, and other lymphoproliferative disorders. The diagnosis is suggested by flow cytometry demonstrating an expansion of CD8(+)CD57(+) T cells and is confirmed by T-cell receptor gene rearrangement studies. Mounting evidence suggests that LGL leukemia is a disorder of dysregulation of apoptosis through abnormalities in the Fas/Fas ligand pathway. In most patients, this is an indolent disorder, and significant improvement of cytopenias can be achieved with immunosuppressive agents such as steroids, methotrexate, cyclophosphamide, and cyclosporin A. This review provides a concise, up-to-date summary of LGL leukemia and the related, more aggressive, malignancies of cytotoxic T cells and natural killer cells.

Molecular diagnosis in lymphoma

The evolution of our ability to diagnose and classify lymphomas in an increasingly refined manner has paralleled the development of novel technologic approaches, with contemporary practice dependent upon the harnessing of a plethora of data that include microscopic, immunophenotypic, and genetic information. Although each of these components is currently indispensable, there is a purported progressive improvement in biologic objectivity as one maneuvers through these respective technologies. Accordingly, and in particular given the rapid pace at which key insights into lymphoma biology are emerging with microarray and other cutting-edge technologies, the role of molecular genetic testing is assuming even greater relevance. The ability to diagnose and classify lymphomas more accurately, precisely, and rationally by incorporating molecular data ought to lead to the development of more appropriate directed therapies.

Effect of Hejie decoction on T cell immune state of chronic hepatitis B patients

AIM: To explore the effect of Hejie decoction (HJD) (mediation decoction) on T cellular immune state of chronic hepatitis B patients.

METHODS: Sixty-five patients with chronic hepatitis B were randomly divided into 2 groups. Forty patients in the treatment group were treated by HJD, and 25 patients in the control group were treated by routine Western medicine. The TCRVβ₇ gene expression, T lymphocyte subsets (CD₃⁺, CD₄⁺, CD₈⁺, CD₄⁺/CD₈⁺) levels were observed before and after treatment.

RESULTS: The level of CD₄⁺ cells was lower whereas the level of CD₈⁺ cells was higher in patients than in the normal group. There was no significant difference between the levels of CD₃⁺ cells in patients and normal persons. After 6 months of treatment, ALT, AST, TB levels of the 2 groups were obviously decreased, and the level of CD₄⁺ cells was increased whereas the level of CD₈⁺ cells was decreased in the treatment group. However, the level of CD₄⁺ cells and CD₈⁺ cells had no significant difference in the control group. TCRVβ₇ expressions were detected in 6 patients of the treatment group, whose HBV-DNA and HBeAg turned negative and ALT became normal. HBeAg in another 3 patients turned negative while HBV-DNA did not, and TCRVβ₇ expressions were not detectable. TCRVβ₇ expression could not be detected in the control group, HBV-DNA of the control group did not turn negative. HBeAg in 1 patient turned negative while HBV-DNA did not, and TCRVβ₇ expressions were not detectable. The total effective rate was not significantly different between the 2 groups and the markedly effective rate was significantly different (P < 0.01).

CONCLUSION: HJD is effective for treating chronic hepatitis B, and its effect seems to relate with the improvement of the TCRVβ₇ expression of chronic hepatitis B patients, thus activating T cells and eliminating HBV. T cellular immune function plays an important role in HBV infection and virus elimination.

Investigation of T-cell receptor-γ gene rearrangement in gastrointestinal lymphomas by PCR-SSCP analysis

AIM: To analyze the characterization of T-cell receptor-γ (TCR-γ) gene rearrangement in the gastrointestinal lymphomas and evaluate the value of PCR-SSCP analysis in gastrointestinal lymphomas investigation.

METHODS: TCR-γ gene rearrangement segments of gastrointestinal lymphomas were cloned and sequenced. Single clone plasmid and mixed clone plsamids were subsequently submitted to PCR-SSCP analysis to investigate the relationship between the number of amplified clones and band patterns of the amplified products. The PCR products of TCR-γ gene rearrangement of 40 gastrointestinal lymphomas were electrophoresed on agarose gels and the positive cases on agarose gels were studied by SSCP analysis.

RESULTS: The sequencing showed that TCR-γ gene rearrangement of the gastrointestinal lymphomas included functional gene and pseudogene with extensive variety in the junctional regions. In SSCP analysis, the number of the single-stranded bands was about two times of the number of amplified clones, and double-stranded band became broad with the increased number of the amplified clones. Thirteen of the 25 B- cell gastrointestinal lymphomas and 14 of the 15 gastrointestinal T-cell lymphomas were positive detected on agarose gel electrophoresis. Of the positive cases detected by SSCP analysis, 3 B-cell lymphomas and 13 T-cell lymphomas showed positive bands. The other cases showed only smears. The rearranged pattern included 13 monoallelic gene rearrangements and 3 biallelic or oligoclonal gene rearrangements.

CONCLUSION: The pattern of TCR-γ gene rearrangement in gastrointestinal lymphomas are similar to that of the nodular lymphomas. PCR-SSCP analysis for TCR-γ gene rearrangement can be applied both for adjuvant diagnosis of gastrointestinal lymphomas and analysis of the gene rearrangement pattern. The ratio of TCR-γ gene rearrangements occurred in T-cell gastrointestinal lymphomas is significantly higher than that in B-cell gastrointestinal lymphomas. The gene rearrangement pattern involves monoallelic and biallelic (or oligoclonal) gene rearrangement.