Primary Mediastinal (Thymic) Large B-Cell Lymphoma: Diagnostics of Extramediastinal Lesions and Treatment Opportunities

Background. Current diagnostic methods and the introduction of molecular investigations into clinical practice allow to improve the understanding of classical primary mediastinal (thymic) large B-cell lymphoma (PMBCL). Aim. To investigate clinical characteristics of PMBCL patients with extramediastinal lesions. Materials & Methods. The study was performed from 2007 to 2017 in the National Medical Hematology Research Center and included 157 PMBCL patients. The data of 16 (10.2 %; 4 men and 12 women) patients with extramediastinal lesions were analyzed; the median age was 27 years (range 23–69). Results. The extramediastinal lesions were found in pancreas (6; 37.5 %), kidneys (5; 31.2 %), ovaries (3; 18.7 %), liver (3; 18.7 %), bone marrow (3; 18.7 %), and breasts (2; 12 %); the lesions in stomach, bones, soft tissues, spleen, adrenals, and small pelvis were observed each in a single case. In 15 of 16 cases extramediastinal lesions were accompanied by involvement of superior mediastinum, and only 1 patient had an isolated lesion in thoracic soft tissues without mediastinal involvement. The samples of 8 out of 16 patients were analyzed using PCR. In all samples overexpression of 2 or more genes (JAK2, TRAF1, MAL, PDL1, PDL2) was determined which allowed to confirm, and in some cases to revise the diagnosis of PMBCL. Overall 5-year survival (93 %) of patients with classical PMBCL with thoracic involvement was similar to the cohort with extramediastinal lesions. All unfavourable events (progression/relapse) were identified at an early stage, i.e. within a year after the completion of therapy. Conclusion. PMBCL patients can have not only superior mediastinum involvement, but extramediastinal lesions as well, including bone marrow. The spreading of the disease beyond superior mediastinum should be differentiated from diffuse large B-cell lymphoma using standard evaluation methods, and molecular analysis in some cases

Expression of the BCR-ABL1 Gene in Patients with Chronic Myeloproliferative Diseases with Signs of Progression

Background. The V617F mutation of JAK2 is known to manifest in Ph-negative chronic myeloproliferative diseases (cMPD), such as polycythemia vera, thrombocythemia, and myelofibrosis. These diseases not infrequently advance into more aggressive forms up to acute leukemia. As the progression mechanism is still unknown, its study retains a high priority. JAK2 carrying the V617F mutation is believed to cause constant activation of V(D)J recombinase in myeloid tumor cells in cMPD patients. Aberrant activation of V(D)J recombinase in tumor cells in cMPD patients can lead to t(9;22)(q34;q11) chromosomal rearrangement. Aim. To study the expression of BCR-ABL1 resulting from translocation t(9;22)(q34;q11) in cMPD patients at the progression stage in order to test the suggested hypothesis. Materials & Methods. The BCR–ABL1 expression was assessed in peripheral blood granulocytes in cMPD patients by real-time PCR. The JAK2 V617F mutation was identified by quantitative allele-specific PCR. The JAK2 exon 12 mutations were determined using Sanger direct sequencing of PCR products. Results. The BCR-ABL1 expression was discovered in 29 % of patients with cMPD progression. The BCR-ABL1 expression in these patients correlated with hepatosplenomegaly and hyperleukocytosis. Conclusion. In a significant proportion of cMPD patients the disease progression can be associated with activation of the BCR-ABL expression

The Comparison of De Novo Grade 3 Follicular Lymphoma and Transformed Grade 3 Follicular Lymphoma: Own Data

Background. Grade 3 follicular lymphoma (FL) is a heterogenetic group of tumors. The selections of patients with similar characteristics of the tumor process is important for classification 3 grade forms of FL and risk stratification, as well as for the development of new therapeutic approaches. Different morphological, immunohistochemical and cytogenetical characteristics of the tumor result in different clinical forms of the disease. Aim. To describe the clinical, morphological, immunohistochemical and cytogenetical characteristics of grade 3 FL and evaluate their prognostic value for R-CHOP-21 chemotherapy. Materials & Methods. We performed retrospective and prospective analysis of morphological, immunohistochemical and genetical characteristics of 93 primary patients with grade 3 FL (21–78 years, median 53 years, women to men — 1:1.4) admitted to National Medical Hematology Research Center from years 2001 to 2016. Morphological and immunohistochemical assessment of the affected lymph nodes and bone marrow biopsy material was performed. Data obtained from the standard cytogenetic and FISH assessment were compared to identify the BCL2 rearrangement. Results. We proposed an algorithm for differential diagnosis of the 2 types of grade 3 FL: de novo FL (n = 22) and transformed FL (n = 21). De novo grade 3 FL had the immunophenotype of CD10– in 19 (86 %) cases, MUM1++ (monomorphically) in 19 (90 %), and BCL-2 in 5 (22 %). It was characterized by the absence of the BCL2 rearrangement (n = 22, 100 %) and bone marrow involvement (n = 14, 67 %) and/or bone marrow involvement (n = 7, 100 %). Third grade FL transformed from grades 1 or 2 had was CD10+ (n = 19, 90 %), MUM1+ (heterogeneously, n = 16, 76 %) or MUM1– (n = 4, 19 %), BCL-2+ (n = 20, 95 %) and had BCL2 rearrangement (n = 19, 90 %). Small cell bone marrow involvement was observed in 71 % of cases, whereas large cell involvement was seen predominantly in de novo FL (p = 0.06). The analysis showed that 5-year relapse-free survival in patients with grade 3 de novo FL after R-CHOP-21 therapy was 87 % compared to 16 % with transformed FL (p = 0.06) for the median 41 months of follow up. Conclusion. We described the morphological, immunohistochemical and cytogenetical characteristics of grade 3 de novo FL and grade 3 FL, transformed from grades 1 or 2. The described variants show different sensitivity to immunochemotherapy

Prognostic Value of the PRAME Gene Expression in T-Cell Lymphoproliferative Disorders

Background. T-cell lymphomas (T-CL) represent a heterogeneous group of malignant lymphoproliferative disorders characterized by unfavorable prognosis. The cancer-testis PRAME gene is notable for its spontaneous expression in transformed cells as observed in solid tumors, B-cell lymphoproliferative and chronic myeloproliferative diseases. Activity and clinical significance of PRAME in T-CL was not studied before, which determines the relevance and provides ground for the present trial. Aim. To assess the clinical significance of the PRAME gene expression in T-CL. Materials & Methods. PRAME gene expression level was measured in samples of lymph nodes, blood, and bone marrow from 35 T-CL patients. Among them 3 patients received allogeneic hematopoietic stem cell transplantation, and 6 patients received autologous hematopoietic stem cell transplantation. A correlation was established between the PRAME expression in bone marrow and peripheral blood with morphological markers of disseminated disease with bone marrow lesions and leukemic blood. PRAME expression level was correlated with survival parameters and tumor proliferative activity (Ki-67). Results. PRAME activity was observed in 21 (60 %) patients. PRAME hyperexpression is associated with advanced stages of disease (p = 0.0734), bone marrow lesions (p = 0.0289), leukemic blood (p = 0.0187), worsening of the overall survival (OS) (p = 0.0787) and event-free survival (EFS) (p = 0.7185), also after hematopoietic stem cell transplantation (p = 0.2661 for OS and p = 0.0452 for EFS), and with a high Ki-67 expression level (p = 0.0155). Conclusion. PRAME expression in T-CL is often observed and related with unfavorable clinical prognosis

Whole-genome analysis of diverse Chlamydia trachomatis strains identifies phylogenetic relationships masked by current clinical typing

Chlamydia trachomatis is responsible for both trachoma and sexually transmitted infections, causing substantial morbidity and economic cost globally. Despite this, our knowledge of its population and evolutionary genetics is limited. Here we present a detailed phylogeny based on whole-genome sequencing of representative strains of C. trachomatis from both trachoma and lymphogranuloma venereum (LGV) biovars from temporally and geographically diverse sources. Our analysis shows that predicting phylogenetic structure using ompA, which is traditionally used to classify Chlamydia, is misleading because extensive recombination in this region masks any true relationships present. We show that in many instances, ompA is a chimera that can be exchanged in part or as a whole both within and between biovars. We also provide evidence for exchange of, and recombination within, the cryptic plasmid, which is another key diagnostic target. We used our phylogenetic framework to show how genetic exchange has manifested itself in ocular, urogenital and LGV C. trachomatis strains, including the epidemic LGV serotype L2b