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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.Цель: определить показания и последовательность проведения молекулярных исследований при ангиоиммунобластной Т-клеточной лимфоме (АИТЛ) в различном биологическом материале. Материалы и методы. Молекулярные исследования проведены у 84 первичных больных АИТЛ. Медиана возраста составила 61 (29-81) год, соотношение мужчины/женщины - 48/36. Оценку T-клеточной и В-клеточной клональности проводили по реаранжировкам генов цепей T-клеточного рецептора и тяжелых цепей иммуноглобулинов. Для количественного определения клеток с мутацией G17V гена RHOA применяли полимеразную цепную реакцию (ПЦР) в реальном времени с аллель - специфичными LNA модифицированными праймерами. Результаты. В биоптатах лимфатических узлов реаранжировки генов цепей Т-клеточных рецепторов определены у 76 (90,5%) из 84 больных и отсутствовали в 8 (9,5%) случаях. Выявление одинаковых клональных продуктов амплификации генов TCRG и TCRB в биоптате лимфатического узла и в образцах периферической крови и/или костного мозга свидетельствовало о лейкемизации опухолевого процесса и наблюдалось у 64,7% больных. Определение в образцах периферической крови и/или костного мозга клональных продуктов, отсутствующих в лимфатическом узле, обусловлено реактивной цитотоксической популяцией лимфоцитов и наблюдалось в 58,8% случаев АИТЛ. Одновременное выявление Т- и В-клеточной клональности в биоптате лимфатического узла отмечалось у 20 (24,7%) из 81 больного. Клетки с мутацией G17V гена RHOA выявлены в биоптатах лимфоузлов у 45 (54,9%) из 82 пациентов. Применение метода аллель - специфичной ПЦР с LNA модифицированными праймерами позволило выявить лейкемизацию опухолевого процесса у 100% и поражение костного мозга - у 93,9% пациентов с выявленной мутацией в лимфоузлах. Заключение. В результате выполненной работы определены показания и последовательность проведения молекулярных исследований при АИТЛ в различном биологическом материале. Количественная аллель - специфичная ПЦР с LNA модифицированными праймерами для определения мутации G17V гена RHOA обладает высокой чувствительностью, позволяет верифицировать лейкемизацию опухолевого процесса и проводить мониторинг минимальной резидуальной болезни во время терапии.

Angioimmunoblastic T-cell lymphoma is a rare T-cell lymphoproliferative disease with generalized lymphadenopathy, hepatosplenomegaly, intoxication and polyclonal hypergammaglobulinemia. The persistence of plasma cells in peripheral blood can be a manifestation of both tumor and reactive processes. In our article, we described the case of angioimmunoblastic T-cell lymphoma with an increase in the number of peripheral blood plasma cells to 28 %, and in bone marrow to 9 %. The complex diagnostics, including plasma cells immunophenotyping, morphology of the lymph node biopsy and bone marrow samples, made it possible to verify the diagnosis of angioimmunoblastic T-cell lymphoma with polyclonal plasmacytosis.

Introduction. Аngioimmunoblastic T-cell lymphoma (AITL) is a T-cell lymphoma, characterized by abundant polymorphocellular infiltrate of lymph nodes with the small number of tumor CD4 + T-cells. AITL could often be misdiagnosed as reactive processes and other lymphomas, including Hodgkin’s lymphoma. Molecular methods of determining clonality are used to confirm the diagnosis. TCR gene rearrangements detected in the lymph nodes may not coincide with those detected in the bone marrow (BM), blood or skin, that makes their interpretation difficult. Recently discovered point somatic RHOA (Ras homolog gene family, member A) Gly17Val mutation is present in 53–71 % of angioimmunoblastic T-cell lymphomas. The aim of the study was to evaluate the number of RHOA Gly17Val mutated cells in different tissues of AITL patients and to correlate it with corresponding T-cell clonality results. Materials and methods . TCRG and TCRB gene rearrangements were PCR-amplified according to BIOMED-2 standardized protocol and analyzed by capillary electrophoresis on ABI Prism 3130. Gly17Val mutation was analyzed by quantitative allele-specific (qAS) TaqMan Real-Time PCR assay. Lymph nodes (LN) and skin biopsies, blood and BM samples were studied for 40 patients with AITL. Results. The clonal TCR gene rearrangements were found in 37 (92 %) of 40 patients in LN and in 26 (96 %) of 28 patients in BM, but they were not matched in length in LN and BM in 12 (46 %) of 26 patients. RHOA (Gly17Val) mutation in LN was revealed in 60 % (24 of 40) patients. Number of cells with RHOA mutation was highest in the LN (in average 26.7 % of the total cells), while in the BM RHOA mutation were undetectable (in 7 patients), or detected in 10 patients in a low quantity (in average 2 % of the total cells). Skin, blood and BM samples with the T-cell clonality peaks that differ from those found in the LN were also negative for the presence of cells having RHOA Gly17Val mutation. Also, in four patients we showed that clonal products in BM and blood that do not coincide with LN refer to CD8+ lymphocytes. Conclusions. The results of the study demonstrate that the quantitative determination of cells with the mutation of RHOA Gly17Val must be taken into account in staging the disease and interpreting the results of T-cell clonality assay. Clonal cells with rearrangements not matching those identified for the LN should be considered reactive.

Extranodal NK/T-cell lymphoma – a rare lymphoproliferative disease characterized predominantly by extranodal localization, aggressive course and low efficiency of conventional chemotherapy. Clinical presentation is diverse and depends on tumor lesion localization. In this article, a literature review and case report of patient with generalized extranodal NK/T-cell lymphoma with bone marrow involvement, unusual intracranial tumor localization, tumor leukemization and central nervous system-leukemia were presented. Adequate treatment strategy made it possible to achieve long-term complete remission in a patient with poor prognosis.

An immunofluorescence assay that enables the quantitative detection of the level and intensity of the expression of multidrug resistance marker Pgp in human solid tumors using flow cytometry and monoclonal antibody (clone 17F9, BD Pharmingen) was developed and adapted for clinical assessment. The analysis includes the following relevant task-specific stages. Single-cell suspension can be prepared from both surgical biopsy native tumor tissues and tumor specimens fixed in 4% formaldehyde. The assay allows one to verify results, even after the tumor material has been stored for 2 years. The cost of analysis can be decreased by increasing the period of cell incubation with antibodies and reducing the antibody concentration. The possibility of analyzing minimal tumor samples, e.g., endoscopic biopsy specimens, by decreasing the concentration of cells incubated with antibodies to 100000 cells/mL and the number of cells used in the flow cytometer to 1000 has also been shown. Despite its continuance, the developed assay does not require any changes in the investigator’s work schedule.

Molecular mechanisms underlying the formation of B-cell lymphomas in connection with processes associated with the maturation of B-lymphocytes are reviewed. The currently used diagnostic methods do not always distinguish lymphomas from reactive changes of the lymphoid tissue. The principle of the molecular genetic method of clonality detection in lymphocyte populations, technical problems, and the strategy of its application in clinical diagnostics of lymphomas are described in detail.