Analysis of immunoglobulin and T cell receptor gene rearrangement in the bone marrow of lymphoid neoplasia using BIOMED-2 multiplex polymerase chain reaction

Primary Nodal Unclassifiable CD20 Negative Diffuse Large B-cell Lymphoma With Dual IgK and TCR Gene Rearrangement: A Diagnostic Challenge

Non-Hodgkin lymphomas are most frequently classified based on the lineage marker expression. However, lymphomas with aberrant marker expression as well as monoclonal IgH/IgΚ and TCR gene rearrangements may co-exist which can be misleading and confusing. Primary CD20 negative diffuse large B-cell lymphomas (DLBCL) represent a rare entity, and they account for 1% to 3% of cases. However, some CD20 negative DLBCLs could not be classified into known variants, creating both diagnostic and therapeutic dilemma's. Primary CD20 negative DLBCL are more likely to have a non-germinal centre subtype, a higher proliferation index, more frequent extra-nodal involvement, a poorer response, and poorer prognosis to conventional treatment compared to CD20 positive DLBCL. A 66- year-old postmenopausal lady, presented with palpable, bilateral neck lymphadenopathy and difficulty swallowing. She also had left leg lymphoedema, poor appetited, fatigue and weight loss. Her symptoms lasted approximately 1 month. After histological, immunohistochemical and clonality analysis of the lymph node the patient was diagnosed with primary nodal CD20 and PAX-5 negative DLBCL with dual immunoglobulin light-chain kappa (IgK) and T-cell receptor (TCR) gene rearrangement. This unusual and unique case presented a diagnostic challenge because it was CD20 and PAX-5 negative, had dual IgK and TCR gene rearrangement and, it could not be classified within the known and well established CD20 negative DLBCL variants. Describing such cases emphasises the fact that lymphomas unclassifiable within known variants of CD20 negative DLBCL do exist and that range and heterogeneity of CD20 negative DLBCL continues to evolve, and pathologist should be aware of these uncommon, atypical mature B-cell neoplasms.

T-cell clones of uncertain significance are highly prevalent and show close resemblance to T-cell large granular lymphocytic leukemia. Implications for laboratory diagnostics

Benign clonal T-cell expansions in reactive immune responses often complicate the laboratory diagnosis T-cell neoplasia. We recently introduced a novel flow cytometry assay to detect T-cell clones in blood and bone marrow, based on the identification of a monophasic T-cell receptor (TCR) β chain constant region-1 (TRBC1) expression pattern within a phenotypically distinct TCRαβ T-cell subset. In routine laboratory practice, T-cell clones of uncertain significance (T-CUS) were detected in 42 of 159 (26%) patients without T-cell malignancy, and in 3 of 24 (13%) healthy donors. Their phenotype (CD8⁺/CD4^-: 78%, CD4^-/CD8^-: 12%, CD4⁺/CD8⁺: 9%, or CD4⁺/CD8^-: 2%) closely resembled that of 26 cases of T-cell large granular lymphocytic leukemia (T-LGLL) studied similarly, except for a much smaller clone size (p < 0.0001), slightly brighter CD2 and CD7, and slightly dimmer CD3 expression (p < 0.05). T-CUS was not associated with age, gender, comorbidities, or peripheral blood counts. TCR-Vβ repertoire analysis confirmed the clonality of T-CUS, and identified additional clonotypic CD8-positive subsets when combined with TRBC1 analysis. We hereby report the phenotypic features and incidence of clonal T-cell subsets in patients with no demonstrable T-cell neoplasia, providing a framework for the differential interpretation of T-cell clones based on their size and phenotypic properties.

The application of antigen receptor gene rearrangement of BIOMED-2 in the pathologic diagnosis of 348 cases with non-Hodgkin lymphoma in a single institution in Southwest of China

OBJECTIVE

To explore the clinical value of immunoglobulin (Ig) and T cell receptor (TCR) gene rearrangement in the diagnosis of non-Hodgkin lymphoma.

METHODS

Using the standardized BIOMED-2 multiplex PCR strategy to detect IgH, IgK and TCR in 272 cases of mature B-cell lymphoma, 55 cases of mature T-cell lymphoma, 21 cases of extranodal NK/ T-cell lymphoma, nasal type, and 20 cases of lymphoid tissue reactive hyperplasia.

RESULTS

Among all mature B-cell lymphomas, the sensitivity of Ig gene rearrangement was 91.18% (248/272), IgH and IgK gene rearrangement was 76.47% (208/272) and 75.00% (204/272), respectively, meanwhile the sensitivity of TCRγ rearrangement was 3.68% (10/272). In the 55 cases of mature T-cell lymphoma, the sensitivity of the detection of TCRγ was 76.36% (44/55), at the same time the sensitivity of Ig gene rearrangement was 14.55% (8/55), IgH and IgK gene rearrangement was 7.27% (4/55) and 12.73% (7/55), respectively. In 21 cases of extranodal NK/T cell lymphoma, nasal type, and 20 cases of reactive lymphoid hyperplasia, no gene rearrangement was found in the samples of IgH, IgK and TCR. The sensitivity of gene rearrangement in Ig/TCR in B and T-cell lymphoma was significantly different from that in the control group (P < 0.05).

CONCLUSION

The Ig/TCR gene rearrangement of BIOMED-2 multiplex PCR strategy has important auxiliary value in the diagnosis of B/T-cell non-Hodgkin lymphoma respectively, however, a few B-cell lymphomas may company TCR gene rearrangement as well as a few T-cell lymphomas may accompany Ig gene rearrangement, it must be comprehensively judged with the combination of morphology, immunohistochemistry and clinical features.

Diagnostic Utility of Isolated Tube C Positivity in T-Cell Receptor β Testing Using BIOMED-2 Primers

OBJECTIVES

T-cell receptor (TCR) gene rearrangement studies are widely used for assessing T-cell clonality. The frequency and significance of clonal peaks restricted to TCR β (TCRB) tube C are uncertain. We retrospectively reviewed 80 TCR studies performed on bone marrow/peripheral blood.

METHODS

TCRB and TCR γ (TCRG) analyses were performed using BIOMED-2 primers. A peak was considered clonal or atypical if it was reproducible and 5× or more or 3× to 5× polyclonal background, respectively.

RESULTS

TCRB analysis demonstrated 12 (15%) of 80 cases with one to four isolated peaks in tube C (>3×) with polyclonal pattern in tubes A and B. TCRG analysis was monoclonal in two cases (both definite T-cell neoplasms), polyclonal in four, and oligoclonal in six. Of the 10 cases without clone in TCRG, six had autoimmune disorder and none had T-cell neoplasm.

CONCLUSIONS

Peaks restricted to TCRB tube C in the TCR analysis may be misleading, as it is often not indicative of an overt T-cell neoplasm.

Laboratory Test Utilization Management: General Principles and Applications in Hematopathology

As the cost of health care continues to rise and reimbursement rates decrease, there is a growing demand and need to cut overall costs, enhance quality of services, and maintain as a top priority the needs and safety of the patient. In this article, we provide an introduction to test utilization and outline a general approach to creating an efficient, cost-effective test utilization strategy. We also present and discuss 2 test utilization algorithms that are evidence-based and may be of clinical utility as we move toward the future of doing the necessary tests at the right time.

Two cases of concurrent development of essential thrombocythemia with chronic lymphocytic leukemia, one related to clonal B-cell lymphocytosis, tested by array comparative genomic hybridization

We present two cases of concurrent development of essential thrombocythemia (ET) with chronic lymphocytic leukemia (CLL) and one related to clonal B-cell lymphocytosis (CBL). Both patients were referred for lymphocytosis and thrombocytosis. A bone marrow biopsy revealed infiltration of small, mature lymphocytes and megakaryocytic hyperplasia. Flow cytometric immunophenotyping and immunoglobulin (IG) gene clonality tests revealed clonal B lymphocytes. Both patients were positive for the JAK2 V617F mutation in whole bone marrow aspirate. The JAK2 V617F mutation was present in isolated B lymphocytes of patient 1, but not patient 2. Cytogenetics were normal in both patients. An array comparative genomic hybridization (CGH) analyses of B cells revealed a gain of 4q28.3, which is reported in non-Hodgkin's lymphoma, in patient 1, and deletion 22q11.22, which is associated with CLL, and a gain of Xp22.31 in patient 2. In both patients, B cells showed no myeloproliferative neoplasm (MPN)-specific genetic abnormalities. These results suggest that different oncogenic mechanisms in each cell lineage may underlie the concurrent development of ET and CLL (or CBL). Array CGH may be helpful in identifying the pathogenic mechanism in cases of concurrent development of lymphoid neoplasm and MPN.

Evaluation diagnostic usefulness of immunoglobulin light chains (Igκ, Igλ) and incomplete IGH D-J clonal gene rearrangements in patients with B-cell non-Hodgkin lymphomas using BIOMED-2 protocol

PURPOSE

Evaluation diagnostic usefulness of immunoglobulin light chains (Igκ, Igλ) and incomplete IGH D-J clonal gene rearrangements in formalin-fixed, paraffin-embedded (FFPE) tissue of patients with B-cell non-Hodgkin lymphomas (B-NHL).

MATERIALS AND METHODS

This study was performed on samples from 70 patients with B-NHL, including two cases of follicular lymphoma (FL), 20 cases of diffuse large B-cell lymphoma (DLBCL), one case of mantle cell lymphoma (MCL), and 47 cases of B-cell neoplasm (non-classified), which had been previously assessed for complete IGH clonality, and failure to clarify gene rearrangements. We used a gold standard multiplex PCR protocol provided by European Biomedicine and Health (BIOMED-2) Concerted Action Project BMH4-CT98-3936 for improvement of diagnosis and analysis of clonality gene rearrangement in lymphoma malignancies.

RESULTS

Our results revealed a total positive monoclonality of 89 % (62/70) in Igκ, Igλ, and 11.4 % (8/70) polyclonality in gene rearrangements assay. The samples with positive clonality consisting (Igκ: 45 %, Igλ: 55 %) in DLBCL, (Igκ: 100 %) in FL, (Igλ: 100 %) in MCL, and (Igκ: 47 %, Igλ: 36 %) in B-cell neoplasm non-classified. None of the incomplete IGH D-J immunoglobulin gene families (0 %) showed monoclonality, and all samples demonstrated polyclonality pattern.

CONCLUSIONS

Our findings on FFPE tissue revealed that immunoglobulin light chains clonality gene rearrangements assays using BIOMED-2 protocol, could be considered a valuable and reliable method for clonality detection, particularly in cases of failure of complete IGH gene rearrangements analysis. Clonal Ig gene rearrangements assay is applicable for routine diagnostic testing of lymphoproliferative disorders and as a reliable method for differentiating between malignant and benign lymphoma disorders.