Immunoglobulin Heavy Chain Gene Rearrangement Research Articles

Primary hepatic extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), is one of the specific type of low-grade B-cell lymphoma not infrequently found worldwide. It typically involves mucosal sites such as stomach and conjunctiva; however, primary hepatic MALT lymphoma has been extremely rarely reported. We describe a case of hepatic MALT lymphoma in a 70-year-old male patient who underwent left hepatectomy due to the incidentally detected liver masses at a medical checkup. The resected specimen revealed multinodular masses consisting of small-to-intermediate-sized lymphoid cells with serpentine pattern and focal lymphoepithelial lesions. The tumor cells were diffusely positive for CD20 and Bcl-2 but negative for CD3, CD10, CD5, CD23, CD43, and cyclinD1. The Ki-67 labeling index was 10% and immunoglobulin heavy chain gene rearrangement study confirmed monoclonal proliferation. In this paper, we discuss several unique clinicopathologic characteristics which will be helpful to the differential diagnosis of hepatic MALT lymphoma.

Localised pulmonary crystal-storing histiocytosis with underlying extranodal marginal zone lymphoma: A case report

Crystal-storing histiocytosis (CSH) is a rare entity, composed of a proliferation of non-neoplastic histiocytes with an accumulation of intracytoplasmic crystalline material. It is often associated with an underlying lymphoproliferative disorder, most often those that express monoclonal immunoglobulins, such as multiple myeloma and lymphoplasmacytic lymphoma. Here we report a case of localised pulmonary CSH in an asymptomatic 54-year-old man, found to have an incidental solid lesion in the right lung on computed tomography (CT). The lesion was composed of sheets of CD68 positive histiocytes that contained refractile eosinophilic crystalline inclusions, scattered lymphoid follicles of CD20 positive B lymphocytes, and occasional plasma cells. PCR for immunoglobulin heavy chain gene rearrangement confirmed the presence of a monoclonal population of B cells. These findings were supportive of a diagnosis of CSH with an underlying B cell/ plasma cell lymphoproliferative disorder, which was favoured to be an extranodal marginal zone lymphoma after clinical and radiological workup. Recognition of this rare entity is important as it may obscure an underlying lymphoproliferative disorder. A diagnosis of CSH should prompt careful exclusion of neoplasia, including clinical workup for systemic disease. In this case report we also discuss clinical features and diagnostic pitfalls.

Diffuse Large B-Cell Lymphoma during Complete Remission of Acute Myeloid Leukemia (M4Eo) Exhibiting Immunoglobulin Heavy Chain Gene Rearrangement and Inv(16)

In previous studies, it has been reported that 10-20% of acute myeloid leukemia (AML) cases showed immunoglobulin heavy chain gene (IGH) rearrangements, a genetic hallmark of B-cell differentiation. However, the clinical significance of this is uncertain. Here, we report a case of diffuse large B-cell lymphoma (DLBCL) after complete remission (CR) from AML that exhibited an IGH rearrangement.

Molecular diagnosis of bovine B-cell lymphoma using polymerase chain reaction for immunoglobulin heavy chain gene.

We performed a clonality analysis using polymerase chain reaction (PCR) for immunoglobulin heavy chain (IgH) gene rearrangement, specifically with regard to its utility as a method to diagnose bovine B-cell lymphoma. PCR for IgH gene rearrangement indicated monoclonal proliferation of B-cells in 24 of 35 cattle with B-cell lymphoma. In contrast, PCR for IgH gene rearrangement in lymph nodes and tumor tissues from 65 cattle diagnosed with tumors other than B-cell lymphoma and non-tumors revealed polyclonal population of B-cells. Sensitivity, specificity, positive predictive value, and negative predictive value for PCR for IgH gene rearrangement for bovine B-cell lymphoma were 68.6%, 100%, 100%, and 85.5%, respectively. Clonality analysis using PCR for IgH gene rearrangement may be useful for adjunctive diagnosis of bovine B-cell lymphoma.

Introduction of Chromosomal Translocation t(11; 14) and a p53 Deletion into Normal B Cell-Derived iPSCs to Elucidate the Cellular Origin of Myeloma Cells

The cellular origin of multiple myeloma (MM) has not ben identified. Based on the results of transplantation experiments using bone marrow samples from MM patients in immunodeficient mice, so-called myeloma stem cells have been inferred to be present in CD19-/CD38++/CD138+ or CD138- plasma cells populations; however, it is possible that the results indicated the presence of plasma cell populations with cell proliferation ability rather than the cellular origin of myeloma cells. On the other hand, based on immunoglobulin heavy chain (IgH) gene analysis, myeloma cells are derived from mature B cells. Chromosomal aberrations such as trisomy and chromosomal translocation play a critical role in early tumorigenesis of MM. We hypothesize that the reprograming of mature B cells, in which IgH gene rearrangements have maintained, are the origin of MM. We propose that mature B cells gain potential by reprograming, and then chromosomal aberrations cause the development of abnormal B cells as a myeloma-initiating cell during B cell redifferentiation. To identify myeloma-initiating cells, we established normal B cell-derived induced pluripotent stem cells (BiPSCs; BiPSC13 and MIB2-6). These BiPSCs maintain VDJ rearrangement of the IgH gene, and they can be induced by the tet-off system to express activation-induced cytidine deaminase (AID; BiPSC13-AID and MIB2-6-AID) and differentiate into hematopoietic progenitor cells (HPCs) (Scientific Rep, 2017). Subsequently, we used the CRISPR/Cas9 system (Oncology Letters, 2019) to establish two BiPSCs with chromosomal translocation t(11;14); the cleavage site were located in the IgH Eμ region of the VDJ non-rearranged allele of the IgH gene and the CCND1 5'-upsteam region of the CCND1 gene (BiPSC13 with t(11;14) and MIB2-6 with t(11;14)). Furthermore, p53 was deleted using the CRISPR/Cas9 system (Ota A, J Cell Sci, 2017) in BiPSC13 with t(11;14) and BiPSC13-AID with t(11;14). These BiPSCs differentiated into CD34+/CD38-/CD45+/-/CD43- HPCs in co-culture with stromal cell, AGM-S3, and their ability to subsequently differentiate into granulocytes, macrophages, and erythroblasts was confirmed by colony-formation assay. Until now, the co-culture of BiPSC13, MIB2-6, and MIB2-6 with t(11;14) with AGM-S3 followed by co-culture with stromal cell, MS-5, showed the appearance of CD34-/CD45+ and CD34-/CD10+ cell population. Also of interest, by RT-PCR, the expression levels of E2F, EBF, GATA3 and CD10 were higher in CD34+ HPCs differentiated by the co-culture of BiPSC13 and MIB2-6 with AGM-S3 when compared to the levels in cord blood-derived CD34+ cells. Overall, the results suggest that these BiPSCs have the ability to differentiate into HPCs, and that they may further differentiate into B cells. If these BiPSCs could be differentiated into mature B cells, they may be useful for the elucidation and study of myeloma-initiating cells derived from mature B cells. Disclosures Hanamura: Mundi: Honoraria; Yamada Yohojo: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Nihon Shinyaku: Honoraria, Research Funding; Fukuyu Hospital: Research Funding; Fujimoto: Research Funding; Taiho: Research Funding; Ono: Consultancy, Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Chugai: Research Funding; Eisai: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Eli Lilly: Research Funding; Asai Clinic: Research Funding; AbbVie: Honoraria; MSD: Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Zenyaku: Research Funding; Sanofi: Research Funding; Shionogi: Honoraria, Research Funding; Kyowa Kirin: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Astellas: Research Funding; Pfizer: Honoraria, Research Funding.

R-m-NHL-BFM-90/R-EPOCH Protocol in the Treatment of Patients with Primary Mediastinal Lymphoma: First Results

Background. Response to the induction chemotherapy is an important predictor of favorable outcome in aggressive lymphomas. As it was shown recently (Kurtz et al.2018) combination of interim PET/CT (iPET/CT) negativity and early molecular response detected by cell-free DNA (cfDNA) analysis, robustly stratify EFS and OS in patients (pts) with diffuse large B-cell lymphoma. There is no consensus on the most optimal program for primary mediastinal lymphoma (PML) treatment. Both R-CHOP+\-RT and R-DA-EPOCH are highly effective frontline options for PML, but about 10-15% of pts develop relapse/progression mainly within 2 years from diagnosis. We hypothesize that intensification of induction with 2 courses of modified R-NHL-BFM-90 program (R-m-NHL-BFM-90), followed by 4 courses of R-EPOCH without dose escalation might improve treatment outcome in PML. Aim. To assess the efficacy of R-m-NHL-BFM-90/R-EPOCH regimen for untreated PML pts by means of PET/CT and cfDNA evaluation. Methods. Overall, 18 pts were enrolled in prospective study between 2015 and 2019 years; median age 34 (19-50); M/F=4/14; Ann Arbor stage >I in 18 (100%); adverse factors in 12 pts (bulky disease>10 cm in 11 pts, involvement of the soft tissues in 9 pts and breast in 4 pts, pleural effusion in 6 pts, elevated lactate dehydrogenase level in 10 pts). The treatment plan consisted of: (i) induction of remission (blocks A and B of R-mNHL-BFM-90 program); (ii) consolidation with 4 courses of R-EPOCH. PET/CT was performed in all pts before therapy, after 2 courses of induction and after the end of therapy. B-cell clonality was assessed detecting immunoglobulin heavy chain gene rearrangements IGH (VH-JH FR2) and immunoglobulin light kappa chain gene rearrangement (IGK), by the use of multiplex Biomed-2 primer system for PCR and Gene-Scan analysis. cfDNA was obtained before the start of the treatment, after the induction and after the end of therapy in 4 pts. DNA concentration was measured by real time PCR with beta-globin primers. Results. All 18 pts completed induction phase. After 2 courses of R-mNHL-BFM-90 PET/CT Deauville score (DS) were DS1-3 in 9 pts (50%) and DS4 in 9 pts (50%). 16 pts completed treatment; from these 12 pts received all 4 courses of R-EPOCH. 2 pts received 2 courses and 2 pts only 1 course due to hematologic toxicity grade 3-4 and infectious complications. After the end of therapy PET/CT were DS1-3 in 15 out of 16 (94%) pts. Only 1 patient response was assessed as DS4; after she received autologous HSCT PET/CT negativity was achieved. cfDNA assessment at all stages of treatment was available in 4 patients (Table 1). In all cases before treatment there were no clonal rearrangements in blood samples. Clonal rearrangements in cfDNA before treatment and in tumor samples were the same in all cases. After induction treatment in one case B-cell clonality persisted in cfDNA, but after the end of the treatment there was no amplification of cfDNA from all pts. Overall, with a median follow-up of 14 months (range 1-40) 16/16 pts (100%) are alive in complete remission. Of note, all 4 pts who received only 1-2 courses of R-EPOCH are in complete remission for 4, 13, 16 and 17 months. Conclusions. Our results suggest that R-m-NHL-BFM-90/R-EPOCH protocol is highly effective for treatment of patients with PML. Given our results, we consider the possibility of reducing the number of cycles of chemotherapy. We suggest that detection of the tumor markers in cfDNA could be used as a biomarker to adapt treatment strategies in the future. Disclosures No relevant conflicts of interest to declare.

Preliminary Minimal Residual Disease Analysis of the Australasian Leukaemia & Lymphoma Group (ALLG) ALL8 Study of Front-Line Blinatumomab with Chemotherapy in Adults with Ph Negative B-Cell Acute Lymphoblastic Leukaemia

Preliminary Minimal Residual Disease Analysis of the Australasian Leukaemia & Lymphoma Group (ALLG) ALL8 Study of Front-Line Blinatumomab with Chemotherapy in Adults with Ph Negative B-Cell Acute Lymphoblastic Leukaemia

Clinical Utility of B- and T-Cell Gene Rearrangement Studies in Blood and Bone Marrow Samples

In the evaluation of bone marrow (BM) and peripheral blood (PB) for hematologic malignancy, positive immunoglobulin heavy chain (IG) or T-cell receptor (TCR) gene rearrangement results may be detected despite unrevealing results from morphologic, flow cytometric, immunohistochemical (IHC), and/or cytogenetic studies. The significance of positive rearrangement studies in the context of otherwise normal ancillary findings is unknown, and as such, we hypothesized that gene rearrangement studies may be predictive of an emerging B- or T-cell clone in the absence of other abnormal laboratory tests. Data from all patients who underwent IG or TCR gene rearrangement testing at the authors' affiliated VA Hospital between January 1, 2013 and July 6, 2018 were extracted from the electronic medical record. Date of testing; specimen source; and morphologic, flow cytometric, IHC, and cytogenetic characterization of the tissue source were recorded from pathology reports. Gene rearrangement results were categorized as true positive, false positive, false negative, or true negative. Lastly, patient records were reviewed for subsequent diagnosis of hematologic malignancy in patients with positive gene rearrangement results with negative ancillary testing. A total of 136 patients, who had 203 gene rearrangement studies (50 PB and 153 BM), were analyzed. In TCR studies, there were 2 false positives and 1 false negative in 47 PB assays, as well as 7 false positives and 1 false negative in 54 BM assays. Regarding IG studies, 3 false positives and 12 false negatives in 99 BM studies were identified. Sensitivity and specificity, respectively, were calculated for PB TCR studies (94% and 93%), BM IG studies (71% and 95%), and BM TCR studies (92% and 83%). Analysis of PB IG gene rearrangement studies was not performed due to the small number of tests (3; all true negative). None of the 12 patients with false positive IG/TCR gene rearrangement studies later developed a lymphoproliferative disorder, although two patients were later diagnosed with acute myeloid leukemia. Of the 14 false negatives, 10 (71%) were related to a diagnosis of plasma cell neoplasms. Results from the present study suggest that positive IG/TCR gene rearrangement studies are not predictive of lymphoproliferative disorders in the context of otherwise negative BM or PB findings. As such, when faced with equivocal pathology reports, clinicians can be practically advised that isolated positive IG/TCR gene rearrangement results may not indicate the need for closer surveillance. Disclosures No relevant conflicts of interest to declare.

Comprehensive Profiling of Disease-Relevant Copy Number Aberrations Improves Risk Assessment and Unveils the Clonal Origin of Relapse in Pediatric Acute Lymphoblastic Leukemia

Introduction: Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy characterized by a heterogeneous genomic landscape. Copy number aberrations (CNA) emerge during the development, progression and treatment resistance of ALL, and can serve as genomic markers for prognostic classification of patients or for scrutinizing clonal evolution associated with relapse. While identification of distinct CNAs with well-characterized prognostic significance has its own value, uncovering the co-segregation of driver aberrations in individual patient samples could allow for a more personalized risk assessment and treatment response prediction. Methods: Disease-relevant CNAs were profiled in children with B- or T-cell precursor ALL using a next-generation sequencing based digital multiplex ligation-dependent probe amplification (digitalMLPA) assay containing 598 probes specific for 54 genes with key relevance in ALL. Besides the diagnostic samples of 91 patients treated according to the BFM protocols, 14 matching samples drawn at the time of first or second relapse were comparatively analyzed. Clonal relationship between B-cell precursor cell populations prevailing at different time points during the disease course was also investigated by screening immunoglobulin heavy-chain gene rearrangements in matching diagnostic and relapse samples using Illumina deep-sequencing with >20,000x coverage. Results: Whole chromosome gains and losses, subchromosomal CNAs as well as alterations conferring intrachromosomal gene fusions were simultaneously identified by digitalMLPA with results available within 36 hours. Aberrations were observed in 96% of diagnostic patient samples and increased numbers of CNAs were detected in individual samples at the time of relapse as compared to diagnosis. DigitalMLPA results were successfully validated by conventional MLPA, FISH and PCR data. Comparative scrutiny of 24 matching diagnostic and relapse samples from 11 patients harboring CNAs revealed three different patterns of clonal relationships with (i) one patient displaying identical CNA profiles at diagnosis and relapse, (ii) six patients showing clonal evolution with all lesions detected at diagnosis being present at relapse and (iii) four patients displaying conserved as well as lost or gained CNAs at the time of relapse, suggestive of the presence of a common ancestral cell compartment giving rise to clinically manifest leukemia at different time points during the disease course. Time between diagnosis and first relapse of T-ALL patients displaying altered CNA profiles suggested a prolonged time requirement of clonal evolution, and of the development of manifest leukemia from an ancestral clone compared to the quick return of an identical clone at the time of relapse. Comparison of the IGH gene rearrangements identified at diagnoses and relapse revealed identical compositions of the most abundant clonotypes in all but one B-ALL patients analyzed; hence, IGH repertoire did not reveal an additional depth of clonal history in our cohort, e.g. by demonstrating the presence of an ancestral clone as the major source of clonal expansion at disease progression in a patient with altered CNA profiles suggesting direct clonal evolution between diagnosis and relapse. Copy number profiles acquired by digitalMLPA were used for determining CNA-based risk groups (Table 1) which were combined with karyotyping and molecular cytogenetic data in order to establish an extended prognostic classifier for patients with B-cell precursor ALL. This novel classifier distinguished four combined genetic risk groups showing significantly different 5-year survival rates (GR: 97%, IR: 84%, IHR: 63% and PR: 13%). Conclusions: DigitalMLPA allows for a rapid, scalable and highly optimized copy number profiling of genomic regions recurrently altered by driver aberrations in pediatric ALL. Based on the comparison of CNA profiles at diagnosis and relapse, clonal evolution and emergence of relapse from an ancestral clone are the predominant driving mechanisms of disease progression. Comprehensive copy number profiling by digitalMLPA identifies distinct prognostic groups for risk assessment in B-cell precursor ALL. Supporting grants : LP95021, K_16 #119950, NVKP_16-1-2016-0004, KH17-126718, BO/00320/18/5, FK_19 #131476, ÚNKP-19-4-SE-77 Disclosures Benard-Slagter: MRC Holland: Employment. de Groot:MRC Holland: Employment. Savola:MRC Holland: Employment.

3142 Atypical Presentation of an Upper Gastrointestinal (GI) Bleed Manifesting as Extranodal Involvement of Diffuse Large B-Cell Lymphoma (DLBCL) Diagnosed in a Community Setting

INTRODUCTION: Diffuse large B-cell lymphoma (DLBCL) is the most common type of Non-Hodgkin's Lymphoma (NHL), with 5.4 new cases diagnosed per 100,000 persons as of 2016. There is a male predominance, with an average age of 64.2. One extranodal site involves the GI tract, predominantly the stomach. Commonly seen are mucosa associated lymphoid tissue lymphomas and DLBCL. The majority of cases present at stage III/IV, with 40% presenting as local involvement. Here we present an unusual case of extranodal DLBCL in a patient presenting with dysphagia and an upper GI bleed. CASE DESCRIPTION/METHODS: An 85 year-old female presented for evaluation of dysphonia, ongoing for several months. The patient complained of bilateral submandibular adenopathy, dysphagia, trouble breathing, and a 15 pound weight loss over two weeks. Computed tomography of the neck revealed a nasopharyngeal mass in the left (L) nasopharynx extending into the nasal cavity, right (R) nasopharynx, and eroding into the skull. Additionally, bilateral necrotic cervical lymph nodes and L supraclavicular adenopathy were also seen. Histologic sample was consistent with DLBCL, non-germinal center type. Fluorescence in-situ hybridization was negative for MYC rearrangement, t(8:14), t(4:18), and Epstein Barr Virus, but indeterminate for BCL6 rearrangement. She was staged IIA and underwent radiation therapy without chemotherapy. During treatment, the patient was admitted for evaluation of an upper GI bleed associated with dysphagia, fatigue, and progressive weakness. She underwent an esophagogastroduodenoscopy with findings showing Los Angeles class A esophagitis, large, inflammatory nodular tissue within the lesser curvature of the stomach with associated linear ulcerations, multiple punctate ulcers throughout the gastric body and antrum, duodenitis, and a small, clean-based ulcer in the duodenal sweep. Histology of the gastric mass revealed an atypical clonal lymphoid infiltrate involving the gastric mucosa, suggestive of DLBCL, with clonal immunoglobulin heavy chain gene rearrangement. DISCUSSION: This case represents an atypical presentation of an upper GI bleed that is the result of extranodal involvement of DLBCL. An atypical presentation like this should have lymphoma in the differential for those with a history. Treatment is dependent upon the extent of disease, usually starting with the regimen of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone therapy. If left untreated, this disease can progress rapidly and prove fatal.

Evaluation of Positive T- and B-Cell Gene Rearrangement Studies Among Patients Without a Definitive Diagnosis by Other Assays

Abstract In the evaluation of bone marrow (BM) and peripheral blood (PB) for hematologic malignancy, positive immunoglobulin heavy chain (IG) or T-cell receptor (TCR) gene rearrangement results may be detected despite unrevealing results from morphologic, flow cytometric, immunohistochemical (IHC), and/or cytogenetic studies. The significance of positive rearrangement studies in the context of otherwise normal ancillary findings is unknown, and as such, we hypothesized that gene rearrangement studies may be predictive of an emerging B- or T-cell clone in the absence of other abnormal laboratory tests. Data from all patients who underwent IG or TCR gene rearrangement testing at the authors’ affiliated VA hospital between January 1, 2013, and July 6, 2018, were extracted from the electronic medical record. Date of testing; specimen source; and morphologic, flow cytometric, IHC, and cytogenetic characterization of the tissue source were recorded from pathology reports. Gene rearrangement results were categorized as true positive, false positive, false negative, or true negative. Lastly, patient records were reviewed for subsequent diagnosis of hematologic malignancy in patients with positive gene rearrangement results with negative ancillary testing. A total of 136 patients, who had 203 gene rearrangement studies (50 PB and 153 BM), were analyzed. In TCR studies, there were 2 false positives and 1 false negative in 47 PB assays, as well as 7 false positives and 1 false negative in 54 BM assays. Regarding IG studies, 3 false positives and 12 false negatives in 99 BM studies were identified. Sensitivity and specificity, respectively, were calculated for PB TCR studies (94% and 93%), BM IG studies (71% and 95%), and BM TCR studies (92% and 83%). Analysis of PB IG gene rearrangement studies was not performed due to the small number of tests (3; all true negative). None of the 12 patients with false-positive IG/TCR gene rearrangement studies later developed a lymphoproliferative disorder, although 2 patients were later diagnosed with acute myeloid leukemia. Of the 14 false negatives, 10 (71%) were related to a diagnosis of plasma cell neoplasms. Results from the present study suggest that positive IG/TCR gene rearrangement studies are not predictive of lymphoproliferative disorders in the context of otherwise negative BM or PB findings. As such, when faced with equivocal pathology reports, clinicians can be practically advised that isolated positive IG/TCR gene rearrangement results may not indicate the need for closer surveillance.

Molecular diagnosis angioimmunoblastic T-cell lymphoma

to determine molecular diagnostics routine for different tissue samples in angioimmunoblastic T-cell lymphoma. Molecular studies were performed for 84 primary AITL patients. The median age was 61 year (29-81); the male to female ratio was 48/36. T-cell and B-cell clonality was assessed by GeneScan analysis of rearranged T-cell receptor (TCRG, TCRB) and immunoglobulin heavy chain genes. For the quantitative determination of cells with RHOA G17V mutation real - time polymerase chain reaction (PCR) with allele - specific LNA modified primers was used. In lymph nodes rearrangements of T-cell receptor genes were determined in 76 (90.5%) of 84 patients and were absent in 8 (9.5%) cases. Identification of the same clonal products of the TCRG and TCRB genes in the lymph node and in peripheral blood and/or bone marrow indicated the prevalence of the tumor process and was observed in 64.7% of patients. Clonal products in peripheral blood and/or bone marrow different from those in the lymph node indicated reactive cytotoxic lymphocyte population and were noted in 58.8% of AITL cases. Simultaneous detection of T- and B-cell clonality in the lymph node was observed in 20 (24.7%) of 81 patients. Cells with RHOA G17V mutation were detected in lymph node in 45 (54.9%) of 82 patients. The use of allele - specific PCR with LNA modified primers revealed presence of the tumor cells in peripheral blood in 100% and in bone marrow in 93.9% of patients with G17V RHOA mutation in the lymph nodes. The validity of different molecular assays performed on certain tissue samples for the diagnosis of angioimmunoblastic T-cell lymphoma has been evaluated. Quantitative allele - specific PCR assay for RHOA G17V mutation based on LNA modified primers possesses sufficient sensitivity for tumor process prevalence evaluation and minimal residual disease monitoring.

Prognostic markers for immunodeficiency-associated primary central nervous system lymphoma

Immunodeficiency is a major risk factor for primary central nervous system lymphoma (PCNSL), but data on the disease in immunocompromised hosts are scarce. We aimed to define clinical and imaging features and determine prognostic factors for immunodeficiency-associated PCNSL. All PCNSL cases seen at Yale-New Haven Hospital between 2002 and 2017 were retrospectively screened for immunodeficiency. For patients with immunosuppression, biopsies were evaluated and clinical data were collected. Predictors of survival were identified using Kaplan-Meier survival analysis and log-rank test. p values < 0.05 were considered significant. 23 patients with immunodeficiencies were identified: eleven on immunosuppressants after solid organ transplantation, seven with human immunodeficiency virus infection, and five on immunosuppressive treatment due to various autoimmune disorders. PCNSL cases were largely Epstein-Barr-Virus positive (78%), histologically classified as diffuse large B cell lymphomas (87%), and showed peripheral contrast enhancement (81%) and corresponding heterogeneous diffusion-weighted imaging patterns (DWI) on magnetic resonance imaging (MRI) (71%). Median overall survival was 31months. Age > 60years at diagnosis (p < 0.01), peripheral enhancement of the mass on MRI (p = 0.04), heterogeneous DWI patterns (p = 0.04), and clonal immunoglobulin heavy chain gene rearrangement (IgHR) (p = 0.03) were found to be negative prognostic markers. Immunodeficiency-associated PCNSL presents with similar clinical, pathological and imaging features. Age > 60years, clonal IgHR, heterogeneous DWI pattern and peripheral enhancement on MRI may serve as predictors of less favorable outcome.

Generalized crystal-storing histiocytosis with diffuse large B-cell lymphoma and monoclonal gammopathy in a Chinese elderly woman: a case report

BackgroundCrystal-storing histiocytosis (CSH) is a rare lesion characterized by sheets of crystal-laden non-neoplastic histiocytes. CSH shows a prominent association with lymphoproliferative disorders that express monoclonal immunoglobulins, mainly multiple myeloma (MM), lymphoplasmacytic lymphoma (LPL) and monoclonal gammopathy of undetermined significance (MGUS). However, no aggressive B cell lymphoma has been reported to be associated with CSH.Case presentationA 74-year-old Chinese woman presented with multiple subcutaneous masses, abdominal pain, and fever. An IgM kappa type of monoclonal gammopathy (MG) was noted by immunofixation performed on the patient’s serum. Computed tomographic (CT) scan revealed subcutaneous masses on the left upper arm and at the waist and multiple low-density lesions in the spleen. Microscopically, sections of subcutaneous masses revealed sheets of large polygonal and spindle cells with abundant eosinophilic cytoplasm, round to ovoid eccentric nuclei, reticulate chromatin, and median nucleoli. Massive needle-shaped crystals were confined to the cytoplasm. Immunohistochemically, these crystal-containing cells were positive for CD68/PGM1, CD163, IgM, and Igκ. Meanwhile, the splenic tumour was diagnosed as diffuse large B-cell lymphoma (DLBCL), non-germinal-centre B (non-GCB) subtype (Hans algorithm). Immunohistochemistry for IgM was positive in the cytoplasm of some neoplastic cells. Immunoglobulin heavy chain (IgH) gene rearrangement was detected by PCR analysis of the subcutaneous mass and the splenic tumour.ConclusionTo the best of our knowledge, this is the first case of generalized CSH with DLBCL and MG. Although the rarity of CSH and separate locations of CSH and lymphoma led to a diagnostic dilemma, the presence of MG was a clue to appreciate the relation between CSH and DLBCL. This case stressed a full investigation into the underlying lymphoproliferative disorder for integrated diagnosis and correct treatments.

Clinical Characteristics and Prognosis of MAF Deletion in Chinese Patients With Multiple Myeloma

BackgroundIn this study, we analyzed the frequency, clinical characteristics, and prognosis of MAF deletion in Chinese patients with multiple myeloma (MM). Patients and MethodsTwo hundred consecutive patients with newly diagnosed MM were analyzed. Patient samples were evaluated using a fluorescence in situ hybridization probe set, including 13q deletion, 17p deletion, and 1q21 gain, as well as immunoglobulin heavy chain gene (IgH) rearrangement, IgH/cyclin D1, IgH/fibroblast growth factor receptor 3 (FGFR3), and IgH/MAF. The frequency of MAF deletion and the clinical characteristics and overall survival of patients with MAF deletion were analyzed. ResultsThe incidence rate of MAF deletion was 15.0% (30/200) in newly diagnosed patients and all of them were monoallelic of MAF deletion. MAF deletion was associated with sex (P = .008), lactate dehydrogenase level (P = .026), 13q deletion (P = .028), FGFR3 deletion (P = .006), and IgH deletion (P = .018). Additionally, in an analysis of the overall survival rates of patients with MAF deletion who received a bortezomib-based regimen treatment, no significant differences were found in overall survival between positive and negative groups (P = .365). ConclusionMAF deletion was more frequent than MAF translocation with IgH in patients with MM and was more commonly observed in women. Moreover, MAF deletion was often combined with 13q, FGFR3, and IgH deletion. MAF deletion did not influence prognosis in patients with MM who were given a bortezomib-based chemotherapy regimen.

Biclonal splenic marginal zone lymphoma with T cell-rich background and aggressive transformation to large cell lymphoma

Marginal zone B cell lymphomas (MZL) are biologically heterogeneous, rarely demonstrating biclonality, complex cytogenetic abnormalities, or T cell predominance. We report a case of biclonal splenic MZL, T cell-rich variant with an abnormal karyotype that progressed to large B cell lymphoma. A 74-year-old female presented with pancytopenia, weight loss, fever, and splenomegaly. Microscopically, the spleen revealed an extensive, vaguely nodular lymphoid proliferation, composed of small lymphocytes, majority of which were reactive T cells. B cells were mostly small and < 5% of total lymphocytes. Focal follicular dendritic cell networks were present, but germinal centers were absent. Flow cytometric analysis revealed two distinct CD5 and CD10 negative B cell clones, one kappa positive and one lambda positive. Conventional cytogenetic analysis revealed the following abnormal karyotype: 47,XX,add(7)(q36),del(7)(q22),add(21)(p11.2),+mar[10]/46,XX[10]. Immunoglobulin heavy chain gene rearrangement showed two monoclonal peaks of different magnitude, consistent with biclonality. Overall, these features favored a low-grade splenic MZL. The staging bone marrow biopsy was normocellular with few interstitial lymphoid aggregates, composed of small lymphocytes, consistent with minimal involvement by low-grade B cell lymphoma. The patient improved without adjuvant chemotherapy; however, 12 months later, she developed anemia and lymphocytosis. Subsequent bone marrow biopsy showed extensive involvement by a large B cell lymphoma and complex karyotype with the previously identified abnormalities, as well as additional numerical and structural aberrations, consistent with cytogenetic evolution and biclonal gene rearrangement. These findings were consistent with transformation. This case demonstrates a unique pathological presentation of splenic MZL with disease progression, highlighting the importance of an integrated approach for lymphoma classification and the difficulties in diagnosing such cases.

MRD Detection in B-Cell Non-Hodgkin Lymphomas Using Ig Gene Rearrangements and Chromosomal Translocations as Targets for Real-Time Quantitative PCR.

Minimal residual disease (MRD) diagnostics is of high clinical relevance in patients with indolent B-cell non-Hodgkin lymphomas (B-NHL) and serves as a surrogate parameter to evaluate treatment effectiveness and long-term prognosis. MRD diagnostics performed by real-time quantitative PCR (RQ-PCR) is still the gold standard and currently the most sensitive and the most broadly applied method in follicular lymphoma (FL) and mantle cell lymphoma (MCL). Alternatively, droplet digital PCR (ddPCR) can be used for MRD monitoring in multiple myeloma, mantle cell lymphoma, and follicular lymphoma with comparable sensitivity, accuracy, and reproducibility.The most broadly applicable MRD target in B-NHL is the junctional regions of the rearranged immunoglobulin heavy chain gene (IGHV). Chromosomal translocations like the t(14;18) translocation in FL and t(11;14) translocation in MCL can be used as MRD target in selected lymphoma subtypes. In patients with B-cell chronic lymphocytic leukemia, both flow-cytometry and RQ-PCR are equally suited for MRD assessment as long as a sensitivity of 10-4 shall be achieved.MRD diagnostics targeting the IGHV gene is complex and requires extensive knowledge and experience because the junctional regions of each lymphoma have to be identified before the patient-specific RQ-PCR assays can be designed for MRD monitoring. In addition, the presence and load of somatic hypermutation (SHM) within the rearranged IG heavy variable (IGHV) gene occurring as during B-cell development of germinal center and post-germinal center lymphomas may hamper appropriate primer binding leading to false-negative results. The translocations mentioned above have the advantage that consensus forward primers and probes, both placed in the breakpoint regions of chromosome 18 in FL and chromosome 11 in MCL, can be used in combination with a reverse primer placed in the IGH joining region of chromosome 14. RQ-PCR-based methods can reach a good sensitivity (≤10-4). This chapter provides all relevant background information and technical aspects for the complete laboratory process from detection of the clonal IGHV gene rearrangement and the chromosomal translocations at diagnosis to the actual MRD measurements in clinical follow-up samples of B-NHL. However, it should be noted that MRD diagnostics for clinical treatment protocols has to be accompanied by regular international quality control rounds to ensure the reproducibility and reliability of the MRD results.

Simple deep sequencing-based post-remission MRD surveillance predicts clinical relapse in B-ALL

BackgroundNext-generation sequencing (NGS) of the rearranged immunoglobulin heavy-chain gene has emerged as a highly sensitive method to detect minimal residual disease (MRD) in B acute lymphoblastic leukemia/lymphoma (B-ALL). However, a sensitive and easily implemented NGS methodology for routine clinical laboratories is lacking and clinical utility of NGS-MRD surveillance in a post-remission setting to predict clinical relapse has not been determined.MethodsHere we described a simple and quantitative NGS platform and assessed its performance characteristics, quantified NGS-MRD levels in 122 B-ALL samples from 30 B-ALL patients, and explored the clinical merit of NGS-based MRD surveillance.ResultsThe current NGS platform has an analytic sensitivity of 0.0001% with excellent specificity and reproducibility. Overall, it performs better than routine multi-color flow cytometry (MCF) in detecting MRD. Utilizing this assay in MRD surveillance in a post-remission setting showed that it detected conversion to positive MRD (CPMRD) in patients with NGS-based molecular remission much earlier than MCF, and that positive MRD conversion could be detected as early as 25.6 weeks prior to clinical relapse in closely surveilled patients. Post-remission CPMRD, but not NGS-based MRD positivity at end of induction, can accurately predict clinical relapse in our limited cohort of B-ALL patients.ConclusionsThis pilot proof-of-concept study illustrates the clinical utility of a simple, sensitive, and clinically feasible MRD detection platform in post-remission NGS-based MRD surveillance and early relapse detection in B-ALL patients.

Monitoring immunoglobulin heavy chain and T‑cell receptor gene rearrangement in cfDNA as minimal residual disease detection for patients with acute myeloid leukemia

The present study aimed to examine whether monoclonal immunoglobulin heavy chain (IGH) or T-cell receptor (TCR) gene rearrangement in cell-free DNA (cfDNA) may be used for minimal residual disease (MRD) monitoring in patients with acute myeloid leukemia (AML). Monoclonal IGH and TCR rearrangement in cfDNA were monitored in patients with AML. A total of 94 (40%) patients had monoclonal IGH or TCR rearrangements in cfDNA at diagnosis; 84% of these patients (79 cases) achieved complete remission following 1–3 courses of induction chemotherapy. Among these cases, 89.9% were negative for monoclonal IGH or TCR rearrangement in cfDNA following consolidation chemotherapies. A total of 8 patients with consistently positive monoclonal IGH or TCR rearrangement in cfDNA relapsed within 6–10 months. During follow up, 39 patients demonstrated positive monoclonal IGH or TCR rearrangement in cfDNA and relapsed. Recurrence of monoclonal IGH or TCR rearrangement in cfDNA was observed 1–3 months earlier than bone marrow relapse and 11 patients with solitary extramedullary relapse demonstrated positive monoclonal IGH or TCR rearrangement recurrence in cfDNA. In conclusion, the detection of monoclonal IGH and TCR rearrangement in cfDNA may represent a useful tool for MRD monitoring in patients with AML.

A BTB-ZF protein, ZNF131, is required for early B cell development

Members of the BTB-ZF transcription factor family play important roles in lymphocyte development. During T cell development, ZNF131, a BTB-ZF protein, is critical for the double-negative (DN) to double-positive (DP) transition and is also involved in cell proliferation. Here, we report that knockout of Znf131 at the pre-pro-B cell stage in mb1-Cre knock-in mouse resulted in defect of pro-B to pre-B cell transition. ZNF131 was shown to be required for efficient pro-B cell proliferation as well as for immunoglobulin heavy chain gene rearrangement that occurs in the proliferating pro-B cells. We speculate that inefficient gene rearrangement may be due to loss of cell proliferation, since cell cycle progression and immunoglobulin gene rearrangement, which would occur in a mutually exclusive manner, may be interconnected or coupled to avoid occurrence of genomic instability. ZNF131 suppresses expression of Cdk inhibitor, p21cip1, and that of pro-apoptotic factors, Bax and Puma, targets of p53, to facilitate cell cycle progression and suppress unnecessary apoptosis, respectively, of pro-B cells. There results demonstrate the essential roles of ZNF131 in coordinating the B cell differentiation and proliferation.