Mutational Spectrum and Prognosis Analysis of Young Patients with Diffuse Large B-Cell Lymphoma Based on Next-Generation Sequencing / 中国实验血液学杂志

OBJECTIVE@#To investigate the mutational spectrum in young patients with diffuse large B-cell lymphoma (DLBCL) based on next generation sequencing (NGS), and to provide a basis for in-depth understanding of the molecular biological characteristics and accurate prognosis of young DLBCL.@*METHODS@#From March 2009 to March 2021, 68 young DLBCL patients with complete initial diagnosis data from the Department of Hematology, The People's Hospital Xinjiang Uygur Autonomous Region were retrospectively analyzed, and their paraffin-embedded tissues were subjected to targeted sequencing analysis by NGS technology (including 475 Target genes), and the differences in gene mutation profiles and signaling pathways between high-risk patients with aaIPI ≥2 and low-intermediate risk patients with aaIPI <2 were compared.@*RESULTS@#A total of 44 high-frequency mutation genes were detected in 68 young DLBCL patients. By comparing the high-frequency mutation genes in aaIPI high-risk group and low-intermediate risk group, it was found that CARD11 mutation in aaIPI high-risk group was significantly higher than that in low-intermediate risk group (P =0.002), while MGA mutation (P =0.037) only appeared in the aaIPI high-risk group, and SPEN mutation (P =0.004) only appeared in the aaIPI low-intermediate risk group. The high-frequency mutation genes and clinical indicators of the aaIPI high-risk group were included in the survival analysis, and the results showed that TP53 (P =0.009, P =0.027), POU2AF1 (P =0.003, P =0.006) and CCND3 (P =0.040, P =0.014) genes mutations were associated with worse PFS and OS, while B2M was associated with better PFS (P =0.014) and OS (P =0.013). Multivariate COX regression analysis showed that the TP53, POU2AF1 and CCND3 were independent risk factors for PFS（P ＝0.021，P =0.005，P =0.020） and OS（P ＝0.042，P =0.010，P =0.013）.@*CONCLUSION@#The aaIPI staging combination with molecular biology markers is more conducive to accurately judging the prognosis of young DLBCL patients. TP53, POU2AF1 and CCND3 mutations predict worse survival in the patients with the aaIPI high-risk group.

The Expression and Correlation of miR-195, miR-125 and Calreticulin in Diffuse Large B-Cell Lymphoma / 中国实验血液学杂志

OBJECTIVE@#To analyze the expression and correlation of microRNA-195 (miR-195), miR-125 and calreticulin in diffuse large B-cell lymphoma (DLBCL).@*METHODS@#From April 2020 to April 2021, 80 DLBCL patients with complete data archived by the Pathology Department of Handan First Hospital and The Second Hospital of Hebei Medical University were selected as the study group, and 70 patients with reactive lymph node hyperplasia were selected as the control group. The expressions of miR-195 and miR-125 were detected by real-time fluorescence quantitative PCR, and the expression of calreticulin was detected by Western blot. Pearson correlation was used to analyze the correlation between miR-195, miR-125, calreticulin and DLBCL, and ROC curve was used to analyze the predictive value of miR-195, miR-125 and calreticulin for DLBCL.@*RESULTS@#Compared with the control group, the expression of miR-195 decreased but miR-125 and calreticulin increased in the study group (P<0.001). The expression levels of miR-195, miR-125 and calreticulin were not related to sex, age, primary site and B symptoms of patients with DLBCL, but related to immunophenotype, Ann Arbor stage, lactate dehydrogenase, IPI score, nodule involvement and Ki-67 index. The expression of miR-195 decreased and the expression of miR-125 and calreticulin increased in DLBCL paitents with non-germinal center source, Ann Arbor stage III-IV, lactate dehydrogenase > 245 U/L, IPI score 3-5, nodule involvement≥2 and Ki-67 index≥75% (P<0.05). Pearson correlation analysis showed that miR-195 and miR-125 were negatively correlated (r=-0.536, P=0.001), miR-195 and calreticulin were negatively correlated (r=-0.545, P=0.001), while miR-125 and calreticulin were positively correlated (r=0.523, P=0.001). ROC curve showed that compared with the single diagnosis of miR-195, miR-125 and calreticulin, the combination of the three items had higher predictive value for DLBCL (P<0.001).@*CONCLUSION@#The expression of miR-195 decreases and the expression of miR-125 and calreticulin increase in patients with DLBCL. Along with the increase of disease stage and IPI score, the decrease of miR-195 and the increase of miR-125 and calreticulin aggravate gradually. The three items may participate in the occurrence and progress of DLBCL.

Correlation between miR-21, miR-191 and Clinical Stage of Patients with Diffuse Large B-Cell Lymphoma / 中国实验血液学杂志

OBJECTIVE@#To analyze the relationship between microRNA (miR)-21, miR-191 and clinical stage of patients with diffuse large B-cell lymphoma (DLBCL).@*METHODS@#100 patients with DLBCL treated in Shanxi Fenyang Hospital from January 2019 to January 2021 were selected as the research subjects. All patients was divided into stage I, stage II, stage III and stage IV according to Ann-Arbor (Cotswolds) staging system at admission. The baseline data of patients at different clinical stages were counted and compared in detail. The relationship between the levels of miR-21 and miR-191 and the clinical stage of DLBCL patients was mainly analyzed.@*RESULTS@#Among the 100 patients with DLBCL, there were 15 patients at stage I, 25 patients at stage II, 37 patients at stage III and 23 patients at stage IV. The levels of miR-21 and miR-191 in patients at stage Ⅰ, Ⅱ, Ⅲ and Ⅳ were increased gradually, which showed statistically significant differences (P<0.05). According to Kendall's tau-b correlation analysis, it was found that the levels of miR-21 and miR-191 were positively correlated with the clinical stage of DLBCL patients (r=0.566, 0.636). Multiple logistic regression analysis showed that the overexpression of serum miR-21 and miR-191 was a risk factor for high clinical stage in patients with DLBCL (OR>1, P<0.05). Bivariate Pearson correlation analysis showed that there was a positive correlation between miR-21 and miR-191 levels in patients with DLBCL (r=0.339).@*CONCLUSION@#The overexpression of miR-21 and miR-191 in patients with DLBCL is related to high clinical stage.

Clinicopathological features and prognosis of high-grade B-cell lymphoma with MYC and bcl-2 and/or bcl-6 rearrangements / 中华病理学杂志

Objective: To investigate the clinicopathological characteristics and prognosis of high-grade B-cell lymphoma (HGBL) involving combined rearrangements of MYC, bcl-2 and bcl-6. Methods: A total of 1 138 cases of large B cell lymphoma (LBL) that were treated at the Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine from January 2017 to September 2020 were analyzed using fluorescence in situ hybridization (FISH) with probes against MYC, bcl-2 and bcl-6. The clinical and pathological data of the 45 patients with HGBL that had rearrangements of MYC and bcl-2 and/or bcl-6 were collected and retrospectively analyzed. Results: Among the 1 138 LBL, 45 (4.0%) cases had combined rearrangements of MYC, bcl-2 and/or bcl-6 that included 6 HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, 14 HGBL cases with MYC and bcl-2 rearrangements, and 25 HGBL cases with MYC and bcl-6 rearrangements. Of these 45 patients, 29 patients were male, and 16 patients were female, aged 29 to 83 years. HGBL with MYC, bcl-2 and bcl-6 rearrangements and HGBL with MYC and bcl-2 rearrangement were reclassified as the germinal center B-cell (GCB) subtype using the Hans algorithm. HGBL with MYC and bcl-6 rearrangement were reclassified as the GCB subtype (68.0%) and the non-GCB subtype (32.0%). The vast majority of HGBL cases had a high Ki-67 proliferation index. Most HGBL patients had advanced stage disease with a high IPI score and an increased LDH level. Also, some patients had clinical features including elevated plasma β2-microglobulin levels, B symptoms, and bone marrow involvement. The IPI scores and LDH levels were significantly different between the HGBL cases with MYC, bcl-2 and bcl-6 rearrangements and the HGBL cases with MYC and bcl-6 rearrangements (P<0.05). Compared with the HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, the HGBL cases with MYC and bcl-2 or bcl-6 rearrangements had a lower incidence of bone marrow involvement (P<0.05). There were no significant differences in the prognosis among HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, the cases with MYC and bcl-2 rearrangements, and the cases with MYC and bcl-6 rearrangements (P>0.05). Conclusions: HGBL with MYC, bcl-2 and/or bcl-6 rearrangements are rare types of B-cell lymphoma with high degree of malignancy and have a short overall survival. To reduce misdiagnosis and improve diagnostic accuracy, it is necessary to assess the patients' clinical features and conduct histopathological, immunohistochemical and FISH analyses.

Correlation between Serum miR-34a Level and Thrombocytopenia after Chemotherapy in Patients with Diffuse Large B-Cell Lymphoma / 中国实验血液学杂志

OBJECTIVE@#To analyze the relationship between serum miR-34a level and thrombocytopenia after chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL).@*METHODS@#A total of 69 eligible DLBCL patients who received chemotherapy in our hospital from January 2018 to January 2020 were prospectively included as the research subjects, all patients received R-CHOP 21 regimen (rituximab + cyclophosphamide + adriamycin + vincristine + prednisone) for chemotherapy, 3 weeks was 1 cycle, and 2 cycles of chemotherapy were used. The patients were divided into a reduction group and a non reduction group according to whether there was thrombocytopenia after chemotherapy, the general data and laboratory indexes of the two groups were investigated and compared, the relationship between serum miR-34a before chemotherapy and thrombocytopenia after chemotherapy in patients was analyzed.@*RESULTS@#Among the 69 DLBCL patients, 36 patients developed thrombocytopenia after 2 cycles of R-CHOP 21 regimen for chemotherapy, the incidence was 52.17%; the level of serum IL-11 and the relative expression of miR-34a mRNA in the reduction group were significantly lower than the non reduction group (P<0.05), compared other data between groups, there was no statistical significant difference (P>0.05); after Logistic regression analysis, the results showed that the level of serum IL-11 and the relative expression of miR-34a mRNA were related to thrombocytopenia after chemotherapy in DLBCL patients, low expression of each index may be a risk factor of thrombocytopenia after chemotherapy in DLBCL patients (OR>1, P<0.05); ROC curve was drawn, and the results showed that the AUC of serum IL-11 level and miR-34a mRNA relative expression before chemotherapy alone and in combination predicted the risk of thrombocytopenia after chemotherapy in DLBCL patients were all >0.80, and the predictive value was ideal, when the cut-off value of serum IL-11 level before chemotherapy was 42.094 pg/ml, and the cut-off value of miR-34a mRNA relative expression was 3.894, the combined prediction value was the best.@*CONCLUSION@#The relative expression of miR-34a mRNA is associated with thrombocytopenia after chemotherapy in DLBCL patients, which may be a risk factor for thrombocytopenia in patients after chemotherapy, has certain value in predicting the risk of thrombocytopenia of patients after chemotherapy.

Relationship between Polymorphism of miR-155 and Its Target Gene MyD88 and Clinicopathological Features of Diffuse Large B-cell Lymphoma / 中国实验血液学杂志

OBJECTIVE@#To investigate the relationship between the polymorphism of miR-155 and its target gene MyD88 and clinicopathological features of diffuse large B-cell lymphoma (DLBCL).@*METHODS@#135 cases of DLBCL patients in our hospital from March 2015 to August 2017 were selected, and 90 cases of reactive hyperplasia of lymph nodes were selected as the control group. The relative expression of miR-155 and MyD88 gene polymorphism were detected in the two groups, and the relationship between miR-155 and MyD88 gene polymorphism and clinicopathological characteristics of DLBCL was analyzed.@*RESULTS@#The relative expression of miR-155 in DLBCL patients was significantly higher than that in the control group (P<0.05). The mutation rate of MyD88 L265P in DLBCL group was significantly higher than that in control group (P<0.05). The relative expression of miR-155 in patients with MyD88 L265P mutation was significantly higher than that in patients with wild-type DLBCL (P<0.05). The relative expression of miR-155 and the polymorphism of MyD88 L265P were associated with lesion location, stage, BCL-2 protein expression and MyD88 protein expression in DLBCL patients (t=7.461、8.804、6.487、10.812； χ@*CONCLUSION@#The abnormal expression of miR-155 and the mutation rate of MyD88 gene in DLBCL patients are increased, and the expression of miR-155 and the mutation of MyD88 gene affect the disease progression and prognosis of patients, which may be potential biological indicators for the diagnosis, treatment and prognosis of DLBCL.

Clinical Application of Circulating Tumor DNA in Diffuse Large B-Cell Lymphoma--Review / 中国实验血液学杂志

Diffuse large B-cell lymphoma (DLBCL) as an aggressive lymphoma, there has not a good molecular marker to assess the therapeutic efficacy and prognosis of the disease. As compared with the traditional deteation method, it was found that the circulating tumor DNA (ctDNA) can be used as a non-invasive specific biomarker which can dynamically provide the information about the lymphoma. ctDNA in DLBCL can be obtained by dideoxy chain termination method combined with PCR, so as to detect genetic markers, targeted sequences of gene which is related to lymphoma; the digital PCR (dPCR) for lymphoma somatic mutations and the detection of abnormal methylation; ctDNA is closely related to the diagncsis, therapeutic efficiency and prognosis of DLBCL, thus ctDNA can be used for the early detection, mid-term and prognostic monitoring in DLBCL, which makes ctDNA have a broad clinical applied prospect.

R-CHOP resistance in diffuse large B-cell lymphoma: biological and molecular mechanisms / 中华医学杂志(英文版)

Although the first-line rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone regimen (R-CHOP) substantially improved outcomes for patients with diffuse large B-cell lymphoma (DLBCL), 40% of the patients suffered from relapsed/refractory disease and had poor survival outcomes. The detailed mechanism underlying R-CHOP resistance has not been well defined. For this review, we conducted a thorough search for literature and clinical trials involving DLBCL resistance. We discussed DLBCL biology, epigenetics, and aberrant signaling of the B-cell receptor (BCR), phosphatidylinositol 3-kinase (PI3K)/Akt, nuclear factor kappa light chain enhancer of activated B-cells (NF-κB), and the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathways as defining mechanisms of DLBCL heterogeneity and R-CHOP resistance. The cell of origin, double- or triple-hit lymphoma and double-protein-expression, clonal evolution, tumor microenvironment, and multi-drug resistance help to contextualize DLBCL resistance in an (epi)genetically and biologically comparative manner. With better understanding of the biological and molecular landscape of DLBCL, a more detailed classification system and tailored treatments will ideally become available to further improve the prognosis of DLBCL patients.

Evolución de un linfoma no Hodgkin "triple expresor" en un paciente trasplantado renal con quimioterapia DA-R-EPOCH. Caso clínico / Triple expressor lymphoma in a kidney transplant patient

Patients transplanted from solid organs have an increased risk of cancer, especially lymphomas. Lymphomas correspond to 4 to 5% of malignant neoplasms in the general population and in solid organ transplant patients it reaches an incidence of 21%. The incidence of non-Hodgkin lymphomas is 10 times higher than in the non-transplanted population. We report the case of a 68-year-old man with a kidney transplant who 6 years after transplantation, developed a non-Hodgkin diffuse large cells B lymphoma with lymph node and pulmonary involvement, with markers of very poor prognosis (triple MYC expressor, BCL2 and BCL6). and its evolution with chemotherapy with DA R EPOCH.

Hipercalcemia, peak monoclonal y leucemización como presentación de un linfoma de células B de alto grado, con reordenamiento de MYC, BCL-2 y BCL-6 (Triple Hit). Caso clínico / Hypercalcemia, monoclonal peak and leukemic presentation of a High-grade B-cell lymphoma with MYC, BCL-2 and BCL-6 translocations (triple hit). Report of one case

High-grade B-cell lymphomas with rearrangement of MYC, BCL-2 and/or BCL-6 were introduced by the update of the WHO classification of lymphoid neoplasms. They usually present unique morphological and molecular characteristics, with an aggressive clinical outcome and worse prognosis. We report a 48 year-old female patient presenting with B symptoms and enlarged lymph nodes. Blood count showed pancytopenia and peripheral blood smears showed large lymphoid cells, some with nuclei and vacuoles. LDH was 3524 g/L and serum calcium was 11.5 mg/dL. Flow cytometry immunophenotyping showed pathological mature B lymphocytes. Protein electrophoresis showed a slight monoclonal peak. The biopsy disclosed a triple expressor diffuse large B-cell lymphoma, arising from germinal center. FISH was positive for MYC, BCL-2 and BCL-6 (triple hit) with a clonal evolution. Conventional cytogenetics showed a complex karyotype. Chemotherapy was started with R-CHOP (Rituximab/cyclophosphamide/doxorubicin/vincristine/prednisone). She developed impaired consciousness; the brain CT scan showed a large brain mass. The patient died within 3 weeks.

Interleukin 10 gene promoter polymorphism and risk of diffuse large B cell lymphoma [DLBCL]

Given the importance of understanding the genetic variations involved in the pathogenesis of non-Hodgkin's lymphoma [NHL], this work was designed to study the impact of IL-10 [-1082 G/A; rs!800896 and -819 C/T; rs!800871] gene promoter polymorphism on susceptibility of Egyptians to diffuse large B cell lymphoma [DLBCL]; the major type of NHL. To the best of our knowledge, this study is the first one that examines IL-10 promoter polymorphism in DLBCL in Egyptians. Genotyping polymorphism is performed using sequence-specific primers polymerase chain reaction [SSP-PCR] in 100 Egyptian DLBCL patients and 119 normal controls. Circulating plasma levels of IL-10 were measured using Enzyme-linked immunosorbent assay [ELISA]. Insignificant change in IL-10 [-1082 and -819] genotypes was recorded. Although A allele is slightly decreased in DLBCL patients, it did not reach statistical significance. GT haplotype was significantly elevated [P < 0.05] in NHL patients. A significant linkage disequilibrium between the -1082 and 819 SNPs with D' = 0.596 and r[2] = 0.1032 [P < 0.001] was demonstrated. Significantly increased plasma IL-10 [P < 0.01] was found which is positively correlated [r = 0.307; P < 0.01] with the disease Taken together, our findings demonstrated that IL-10 promoter gene polymorphism [-1082 and -819] may not have an influence on the clinical outcome of DLBCL, especially in terms of overall secretion level. Further investigations of other cytokine gene polymorphisms will lead to a better understanding of the disease's biological background

Bcl-2 protein frequency in patients with high-risk diffuse large B-cell lymphoma / Frequência da proteína Bcl-2 em pacientes com linfoma difuso de grandes células B de alto risco

CONTEXT AND OBJECTIVE: Gene expression and immunohistochemical profiling of diffuse large B-cell lymphoma (DLBCL) have revealed important prognostic subgroups: germinal center B-cell-like (GCB-like) DLBCL and activated B cell-like (ABC-like) DLBCL. Although few reports on high-risk DLBCL are available, the prognosis for the GCB-like subgroup has been shown to be better than that of the ABC-like subgroup. The role of Bcl-2 as a predictor of survival in DLBCL cases is unclear and its expression varies between the two subgroups of DLBCL. In this study, we analyzed the frequency and prognostic impact of Bcl-2 protein expression in high-risk DLBCL cases. DESIGN AND SETTING: Retrospective cohort study among DLBCL patients treated at Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP). METHODS: The prognostic impact of the expression of the proteins CD10, Bcl-6, MUM1 (multiple myeloma oncogene-1) and Bcl-2 on high-risk DLBCL cases was evaluated by means of immunohistochemistry. Seventy-three patients aged 18-60 years were evaluated for all these markers. RESULTS: Twenty-four cases (32.9 percent) were GCB-like and 49 (67.1 percent) were ABC-like, with no difference regarding complete remission, disease-free survival or overall survival rates. Twenty-seven patients (37 percent) showed Bcl-2 expression, which was the only independent factor predicting a worse prognosis for overall survival according to multivariate analysis. CONCLUSION: Bcl-2 protein was expressed in 37 percent of the high-risk DLBCL patients, without any difference between the ABC-like DLBCL and GCB-like DLBCL cases.

CONTEXTO E OBJETIVO: A expressão gênica e imunoistoquímica do linfoma difuso de grandes células B (LDGCB) vem permitindo a identificação de importantes subgrupos prognósticos: LDGCB do centro germinativo (CG) e LDGCB de células B ativadas (CBA). Entretanto, existem poucos dados disponíveis com LDGCB de alto risco, sendo o prognóstico dos LDGCB do CG melhor que os LDGCB de CBA. A participação do Bcl-2 como preditor de sobrevida nos LDGCB não é clara e sua expressão é variável entre os dois subgrupos de LDGCB. Neste estudo é avaliada a frequência e o prognóstico da expressão da proteína Bcl-2 em LDGCB de alto risco. TIPO DE ESTUDO E LOCAL: Estudo de coorte retrospectivo realizado entre portadores de LDGCB tratados no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. MÉTODOS: Foi avaliado o impacto prognóstico da expressão das proteínas CD10, Bcl-6, MUM1 (multiple myeloma oncogene-1) e Bcl-2 por imunoistoquímica em LDGCB de alto risco. Foram avaliados, para todos os marcadores, 73 pacientes com idade de 18 a 60 anos. RESULTADOS: Vinte e quatro (32,9 por cento) pacientes foram classificados como LDGCB do CG e 49 (67,1 por cento) como LDGCB de CBA, sem diferença nas taxas de remissão completa, sobrevida livre de doença e sobrevida global. Vinte e sete (37 por cento) apresentaram expressão de Bcl-2, o qual foi o único fator preditivo independente de pior prognóstico de sobrevida global à análise multivariada. CONCLUSÃO: A expressão da proteína Bcl-2 ocorreu em 37 por cento dos portadores de LDGCB de alto risco, sem diferença entre os subgrupos de LDGCB do CG ou de CBA.

Cytomorphology and Molecular Characterization of CLTC-ALK Rearrangement in 2 Cases of ALK-Positive Diffuse Large B-cell Lymphoma with Extensive Bone Marrow Involvement / 대한진단검사의학회지

Aanaplastic lymphoma kinase (ALK)-positive diffuse large B-cell lymphoma (DLBCL) is an unusual disease entity first reported in 1997 as DLBCL with expression of full-length ALK protein. The World Health Organization classification enlists the disease as a rare variant of DLBCL. Herein we describe two cases of ALK-positive DLBCL with cytomorphologic and molecular characteristics for the first time in Korea. The patients were 35-yr-old and 24-yr-old male patients. Immunohistochemical studies on the lymph nodes revealed large sized neoplastic cells with plasmablastic differentiation, which were negative for CD30 and positive for ALK with the characteristic granular staining in the cytoplasmic region. Extensive involvement of bone marrow was observed in both cases showing large, extremely atypical cells. Fluorescence in situ hybridization and molecular studies on the bone marrow aspirate specimens led to the detection of a clathrin (CLTC)/ALK rearrangement. Despite aggressive chemotherapy, the patients died 15 and 17 months after the diagnosis, indicating poor prognosis of the disease entity. This is the first report demonstrating the cytomorphologic findings of ALK-positive DLBCL cells on bone marrow aspirates.

nm23-H1 Protein Expression and Gene Mutation in 150 Patients with Non-Hodgkin's Lymphomas

The metastasis-suppressing role of the nm23 gene in the metastatic spread of malignant tumor is still debated. We examined the nm23-H1 protein expression and gene mutation in non-Hodgkin's lymphomas to compare with the clinicopathologic parameters. The expression of nm23-H1 protein was immunohistochemically examined in 150 cases of non-Hodgkin's lymphomas; 85 diffuse large B cell lymphomas (DL-BCL), 18 marginal zone B cell lymphomas (MZL), 3 mantle cell lymphomas, 25 peripheral T cell lymphomas, not otherwise specified (TCLNOS), and 19 NK/T cell lymphomas (NK/T). Eighty-one cases (58 DLBCL, 6 MZL, 4 TCLNOS, and 13 NK/T) were studied for nm23-H1 gene mutation in exon 1 to 5. The high expression of nm23-H1 protein was associated with the high IPI score (p=0.019) and the low survival rate of the patients (p=0.0039). The gene mutation of nm23-H1 was detected in 10.3% of DLBCL and 30.7% of NK/T; but none in MZL and TCLNOS. The mutation was found in exon 1 in 5 cases, exon 2 in two cases, exon 4 in one case and both exon 1 and 2 in two cases. Our results suggest that the expression of nm23-H1 protein can be used as a poor prognostic marker in non-Hodgkin's lymphomas, and the mutational change of gene may operate in the lymphomagenesis.

Bcl-2 gene rearrangement in Jordanian follicular and diffuse large B-cell lymphomas

Follicular lymphoma [FL], a common subtype of non-Hodgkin's lymphoma [NHL] in the West, represents a rare subtype in Jordan. Bcl-2 gene rearrangement plays a crucial role in the biology of the vast majority of FL and a substantial number of diffuse large B-cell lymphoma [DLBCL] in the West; but its presence has not been studied in Jordan. Our aims are to document if bcl-2 gene rearrangement exists in Jordanian FL and DLBCL, and if present to determine whether its frequency among these lymphomas is different from the West and therefore may be responsible for some of the epidemiological differences seen between Jordan and the West. The study was conducted in the year 2001 using polymerase chain reaction [PCR], to detect bcl-2 gene rearrangement in paraffin sections in 5 FL and 23 DLBCL cases diagnosed at the Department of Pathology at Jordan University of Science and Technology, Irbid, Jordan. Two sets of primers including the major breakpoint region [MBR] and the minor cluster region [MCR] were used. Amplifiable DNA was extracted from all cases. Bcl-2 gene rearrangement was seen among 4 [80%] of 5 FL cases, and 8 [35%] of 23 DLBCL cases. The majority of the rearrangements involved the MBR; however, one fourth of cases [one of 4 FL; 2 of 8 DLBCL] with bcl-2 rearrangement involved the MCR. Bcl-2 gene rearrangement was seen in the vast majority of Jordanian FL cases and approximately one third of all DLBCL cases. These figures are similar to those reported in the West, and therefore bcl-2 gene rearrangement does not help in explaining the epidemiological differences of NHL between Jordan and the West. The presence of bcl-2 gene rearrangement in DLBCL may define a subset of lymphomas that may be biologically and clinically unique and different from the rest of DLBCL