Next generation sequencing-based clonality assessment of immunoglobulin gene rearrangements: a multicenter validation study by EuroClonality-NGS

AbstractClonality analysis in classic Hodgkin lymphoma (cHL) is of added value for correctly diagnosing patients with atypical presentation or histology reminiscent of T cell lymphoma, and for establishing the clonal relationship in patients with recurrent disease. However, such analysis has been hampered by the sparsity of malignant Hodgkin and Reed-Sternberg (HRS) cells in a background of reactive immune cells. Recently, the EuroClonality-NGS Working Group developed a novel next-generation sequencing (NGS)-based assay and bioinformatics platform (ARResT/Interrogate) to detect immunoglobulin (IG) gene rearrangements for clonality testing in B-cell lymphoproliferations. Here, we demonstrate the improved performance of IG-NGS compared to conventional BIOMED-2/EuroClonality analysis to detect clonal gene rearrangements in 16 well-characterized primary cHL cases within the IG heavy chain (IGH) and kappa light chain (IGK) loci. This was most obvious in formalin-fixed paraffin-embedded (FFPE) tissue specimens, where three times more clonal cases were detected with IG-NGS (9 cases) compared to BIOMED-2 (3 cases). In total, almost four times more clonal rearrangements were detected in FFPE with IG-NGS (N = 23) as compared to BIOMED-2/EuroClonality (N = 6) as judged on identical IGH and IGK targets. The same clonal rearrangements were also identified in paired fresh frozen cHL samples. To validate the neoplastic origin of the detected clonotypes, IG-NGS clonality analysis was performed on isolated HRS cells, demonstrating identical clonotypes as detected in cHL whole-tissue specimens. Interestingly, IG-NGS and HRS single-cell analysis after DEPArray™ digital sorting revealed rearrangement patterns and copy number variation profiles indicating clonal diversity and intratumoral heterogeneity in cHL. Our data demonstrate improved performance of NGS-based detection of IG gene rearrangements in cHL whole-tissue specimens, providing a sensitive molecular diagnostic assay for clonality assessment in Hodgkin lymphoma.

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Immunoglobulin gene rearrangement in Koreans with multiple myeloma: Clonality assessment and repertoire analysis using next-generation sequencing

PLoS ONE ◽

10.1371/journal.pone.0253541 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0253541

Author(s):

Miyoung Kim ◽

Kibum Jeon ◽

Kasey Hutt ◽

Alyssa M. Zlotnicki ◽

Hyo Jung Kim ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Next Generation Sequencing ◽

Light Chain ◽

Gene Rearrangement ◽

Lymphoid Cells ◽

Immunoglobulin Gene ◽

Next Generation ◽

Korean Patients ◽

Generation Sequencing

Introduction We assessed the applicability of next-generation sequencing (NGS)-based IGH/IGK clonality testing and analyzed the repertoire of immunoglobulin heavy chain (IGH) or immunoglobulin kappa light chain (IGK) gene usage in Korean patients with multiple myeloma (MM) for the first time. Methods Fifty-nine bone marrow samples from 57 Korean patients with MM were analyzed, and NGS-based clonality testing that targeted the IGH and IGK genes was performed using IGH FR1 and IGK primer sets. Results Clonal IGH and IGK rearrangements were observed in 74.2% and 67.7% of samples from Korean patients with kappa-restricted MM, respectively (90.3% had one or both), and in 60.7% and 95.5% of samples from those with lambda-restricted MM, respectively (85.7% had one or both). In total, 88.1% of samples from Koreans with MM had clonal IGH and/or IGK rearrangement. Clonal rearrangement was not significantly associated with the bone marrow plasma cells as a proportion of all BM lymphoid cells. IGHV3-9 (11.63%) and IGHV4-31 (9.30%) were the most frequently reported IGHV genes and were more common in Koreans with MM than in Western counterparts. IGHD3-10 and IGHD3-3 (13.95% each) were the most frequent IGHD genes; IGHD3-3 was more common in Koreans with MM. No IGK rearrangement was particularly prevalent, but single IGKV-J rearrangements were less common in Koreans with kappa-restricted MM than in Western counterparts. IGKV4-1 was less frequent in Koreans regardless of light chain type. Otherwise, the usages of the IGH V, D, and J genes and of the IGK gene were like those observed in previous Western studies. Conclusion NGS-based IGH/IGK clonality testing ought to be applicable to most Koreans with MM. The overrepresentation of IGHV3-9, IGHV4-31, and IGHD3-3 along with the underrepresentation of IGKV4-1 and the differences in IGK gene rearrangement types suggest the existence of ethnicity-specific variations in this disease.

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Clinical utility of clonality testing by next generation sequencing in the monitoring of B-cell and T-cell malignancies.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.7_suppl.72 ◽

2017 ◽

Vol 35 (7_suppl) ◽

pp. 72-72

Author(s):

Mustafa H. Syed ◽

Caleb Ho ◽

Kseniya Petrova-Drus ◽

JinJuan Yao ◽

Wayne Yu ◽

...

Keyword(s):

Next Generation Sequencing ◽

T Cell ◽

B Cell ◽

Response To Therapy ◽

Next Generation ◽

Assay Sensitivity ◽

T Cell Malignancies ◽

Generation Sequencing ◽

Clonality Assessment

72 Background: Clonality testing is an integral part of the initial assessment of B and T cell malignancies. The further use of conventional clonality assays for monitoring of disease post treatment is limited by low assay sensitivity and inability to track clones based on their unique sequences. Clonality assessment by next generation sequencing (NGS) provides increased diagnostic capabilities, allowing the tracking of disease specific clones as well as the full spectrum of clonal sequences that arise in response to therapy. Here we describe our initial experience using an NGS based assay for monitoring and our comparison to conventional clonality assays and flow cytometry. Methods: DNA was extracted from hematologic samples received for routine clonality assessment including diagnostic (DS) and follow-up post therapy (PT) samples. Clonality testing was performed by conventional PCR-based assays using biomed II primers and by NGS utilizing Lymphotrack IGH FR1 and TRG kits (Invivoscribe). The amplified products were sequenced on Illumina MiSeq. For MRD assessment, we created dedicated laboratory protocols as well as in-house developed software, MSK-LymphoClone (LC), containing a data analysis pipeline, analytical tools for clonality assessment and a signout portal for easy search and retrieval of pertinent clones. Results: Samples from 48 patients were included (48 DS and 60 PT) encompassing 12 plasma cell neoplasms, 11 acute lymphoblastic leukemias, 16 mature B-cell and 9 T-cell lymphomas. All diagnostic samples showed clonal rearrangement with 100% concordance between conventional and NGS assays. Residual disease was detected in 27/60 (45%) PT samples using conventional fragment size based assays, 27/57 (47%) using flow and 38/60 (63%) using NGS. Diagnostic clonal sequences were detected in as low as 0.0019% of total reads in PT samples tested by NGS. 18/60 (30.0%) PT samples (17 patients) were disease negative by all assays; 16 patients remained disease-free (median follow-up - 2.4 months). Conclusions: NGS clonality testing is a valuable tool for monitoring patients with B and T cell neoplasms showing higher sensitivity and specificity than conventional assays.

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