Dragana Stamatovic

Stem cells in the arrangement of bone marrow repopulation and regenerative medicine.

Hematopoiesis is a permanent and complex event in which a spectrum of different mature blood cells from a small population of toti/pluri/multipotent stem cells (SCs) are produced through a variety of proliferative and differentiative processes. Hematopoietic SCs are defined as the cells with extensive self–renewal and proliferative potential, together with their ability to differentiate into all blood–cell lineages. Many studies have demonstrated that a multifactorious network of interactive cytokines and other blood–derived mediators regulate the survival, maturation, and proliferation of SCs .

Autologous transplant in the treatment of severe aplastic anemia – A case report

The initial use of immunosuppressive therapy (IST) in severe aplastic anemia (sAA) or reapplication of IST-centered methods following disease relapse is successful only in well-selected patients. The potential treatment by autologous stem cell (SC) transplant in sAA is still an innovative/pioneering therapeutic approach. To our best knowledge, this is the second published case of autologous SC transplant in sAA. The aim of this work was to optimize mobilization and timing for SC harvesting - using our own controlled-rate cryopreservation - with higher CD34(+)/CD90(+) subset yield and recovery in order to obtain complete and long-term hematopoietic reconstitution following autologous SC transplant. We report a 35 year-old sAA male patient who initially underwent IST using rabbit ATG and Cyclosporine A (CsA). He was supportive transfusion dependent for the whole period of IST-phase. After the second IST-cycle, polymorphonuclear (PMN) cell count increase (>2.0 × 10(9)/L) was observed, when SC mobilization, two large volume leukapheresis procedures and following autologous transplant were performed. The yields of harvested CD34(+) and CD34(+)/CD90(+) cells were 5.75 × 10(6)/kgbm and 1.7 × 10(6)/kgbm, respectively. The quantity of applied CD34(+) and CD34(+)/CD90(+) cells in autologous SC transplant were 5.45 × 10(6)/kgbm (7-AAD(CD34)(+)(viability)=95.42%) and 1.63 × 10(6)/kgbm (7-AAD(CD34)(+)(/CD90)(+)(viability)=95.42%), respectively. Hematopoietic reconstitution registered due to second month after autologous SC transplant and he is 24 months in complete medullar, hematological and clinical remission, with normal cytogenetic status - applying only continuous CsA therapy. The results obtained strongly confirm that in sAA, with no allogeneic SC donor, autologous transplant can result in a successful clinical outcome. We suggest that CD34(+)/CD90(+) subset count in peripheral blood and/or cell-harvest could be more valuable predictive factor than total CD34(+) quantity of optimized collection-timing and superior treatment efficacy of autologous SC transplant in sAA.

Multiple myeloma invasion of the central nervous system

INTRODUCTION Multiple myeloma (MM) is characterized by the presence of neoplastic proliferating plasma cells. The tumor is generally restricted to the bone marrow. The most common complications include renal insufficiency, hypercalcemia, anemia and reccurent infections. The spectrum of MM neurological complications is diverse, however, involvement of MM in the cerebrospinal fluid (CSF) and leptomeningeal infiltration are rare considered. In about 1% of the cases, the disease affects the central nervous system (CNS) and presents itself in the form of localized intraparenchymal lesions, solitary cerebral plasmocytoma or CNS myelomatosis (LMM). CASE REPORT We presented the clinical course of a 55-year-old man with MM and LMM proven by malignant plasma cells in the CSF, hospitalized with the pain in the thoracic spine. His medical history was uneventful. There had been no evidence of mental or neurological impairment prior to the seizures. Physical examination showed no abnormalities. After a complete staging, the diagnosis of MM type biclonal gammopathia IgG lambda and free lambda light chains in the stage III was confirmed. The treatment started with systemic chemotherapy (with vincristine, doxorubicin plus high-dose dexamethasone--VAD protocol), radiotherapy and bisphosphonate. The patient developed weakness, nausea, febrility, dispnea, bilateral bronchopneumonia, acute renal insufficiency, confusions, headaches and soon thereafter sensomotor aphasias and right hemiparesis. The patient was treated with the adequate therapy including one hemodyalisis. His neurological status was deteriorated, so Multislice Computed Tomography (MSCT) of the head was performed and the findings were normal. Analysis of CSF showed pleocytosis, 26 elements/mL and increased concentrations of proteins. Cytological analysis revealed an increased number of plasma cells (29%). Electrophoretic analysis of proteins disclosed the existance of monoclonal components in the serum, urine and CSF. Immunofixation electrophoretic and quantitative nephelometric tests confirmed Biclonal multiple myeloma of IgG lambda and light chain lambda isotypes. Analysis of neurothropic viruses with ELISA methods was negative. Once the presence of LMM was confirmed, the patient received intrathecal chemotherapy with methotrexate, cytosine arabinoside, dexamethasone three times a week, and systemic high doses of dexamethasone iv like a single agent without craniospinale irradiations. Despite the treatment, the patient died one month after the diagnosis. Autopsy was not performed. CONCLUSION Presented patient, as well as most other patients with MM progressing to CN Sinfiltration was in the stage III. In addition to the detailed clinical examination, and all investigations required for MM diagnosis and staging of the disease, we introduced the additional CSF examination and calculation of kappa lambda ratio, that helped us make an early diagnosis and prognosis of MM with LMM. Although LMM had a low prevalence, it could be more frequent than expected especially in patients with high risk. CSF examination with positive plasma cells and abnormal morphology remains the hallmark for diag nosing CNS infiltration.

[Expression of Bcl-2 protein and the amplification of c-myc gene in patients with chronic myeloid leukemia].

BACKGROUND/AIM Chronic myeloid leukemia (CML) represents a malignant myeloproliferative disease developed out of pluripotent hematopoietic stem cell that contains the fusion bcr-abl gene. Disorders that occur in the process of apoptosis represent one of the possible molecular mechanisms that bring about the disease progress. The aim of our study was to carry out the analysis of the presence of the amplification of the c-myc oncogene, as well as the analysis of the changes in the expression of Bcl-2 in the patients with CML. METHODS Our study included 25 patients with CML (18 in chronic phase, 7 in blast transformation). Using an immunohistochemical alkaline phosphatase-anti-alkaline phosphatase (APAAP) method, we analyzed the expression of cell death protein in the mononuclear bone marrow cells of 25 CML patients. By a differential PCR (polymerase chain reaction) method, we followed the presence of amplified c-myc gene in mononuclear peripheral blood cells. RESULTS The level of the expression of Bcl-2 protein was considerably higher in the bone marrow samples of the patients undergoing blast transformation of the disease. The amplification of c-myc gene was detected in 30% of the patients in blast transformation of the disease. CONCLUSION The expression of Bcl-2 protein and the amplification of c-myc gene are in correlation with the disease progression.

Genetic alterations in B-cell non-Hodgkin's lymphoma

BACKGROUND Although the patients with diagnosed B-NHL are classified into the same disease stage on the basis of clinical, histopathological, and immunological parameters, they respond significantly different to the applied treatment. This points out the possibility that within the same group of lymphoma there are different diseases at molecular level. For that reason many studies deal with the detection of gene alterations in lymphomas to provide a better framework for diagnosis and treatment of these hematological malignancies. AIM To define genetic alterations in the B-NHL with highest possibilites for diagnostic purposes and molecular detection of MRD. METHODS Formalin fixed and paraffin embedded lymph node tissues from 45 patients were examined by different PCR techniques for the presence of IgH and TCR gamma gene rearrangement; K-ras and H-ras mutations; c-myc amplification and bcl-2 translocation. There were 34 cases of B-cell non-Hodgkins lymphoma (B-NHL), 5 cases of T-cell non-Hodgkins lymphoma (T-NHL) and 6 cases of chronic lymphadenitis (CL). The mononuclear cell fraction of the peripheral blood of 12 patients with B-NHL was analyzed for the presence of monoclonality at the time of diagnosis and in 3 to 6 months time intervals after an autologous bone marrow transplantation (BMT). RESULTS The monoclonality of B-lymphocytes, as evidenced by DNA fragment length homogeneity, was detected in 88 % (30/34) of B-NHL, but never in CL, T-NHL, or in normal PBL. Bcl-2 translocation was detected in 7/31 (22.6%) B-NHL specimens, c-myc amplification 9/31 (29%, all were more than doubled), K-ras mutations in 1/31 (3.23%) and H-ras mutations in 2/31 (6.45%) of the examined B-NHL samples. In the case of LC and normal PBL, however, these gene alterations were not detected. All the patients (12) with B-NHL had dominant clone of B-lymphocyte in the peripheral blood at the time of diagnosis while only in 2 of 12 patients MRD was detected 3 or 6 months after BMT. CONCLUSION Because it is quic and simple, PCR analysis of clonal IgH rearrangements is very useful when diagnostic assistance is required. This technique is also very effecient for tracking minimal residual disease in lymphomas and leukemias and for monitoring clonal evolution in acute and chronic lymphoblastic leukemias and lymphomas. The presence of other genetic alterations, which we detected, should serve as an additional prognostic or predictive factor in the patients with B-NHL.

PCR-based clonality assessment in patients with lymphocytic leukaemias: a single-institution experience

PCR-based clonality testing can be performed in all lymphoproliferations by analysing gene rearrangements of antigen receptors, rearrangements that are unique for each kind of lymphocyte. Reactive lymphoproliferations have polyclonally rearranged Ig/TCR genes, whereas malignant proliferations (leukaemias and lymphomas) show clonal rearrangements. The aim of this study was to assess the clinical benefits of clonality testing with previously evaluated consensus primers in leukaemia patients. The study included peripheral blood and bone marrow samples of 67 leukaemia patients (32 B-CLL, 24 B-ALL and 11 T-ALL). Clonality testing was based on PCR amplification of rearranged IgH and TCR genes. During diagnosis, monoclonal pattern was found in all analysed B-CLL and T-ALL samples. Testing in B-ALL patients showed positive results in all bone marrow and one peripheral blood samples. Results of clonality testing in B-CLL patients during follow-up were concordant between peripheral blood and bone marrow. Obtained results corresponded to clinical course in all but one patient. In B-ALL group, results of molecular testing in peripheral blood and bone marrow confirmed remission estimated according to clinical criteria in all except one patient. Before any clinical sign of relapse, monoclonal pattern was found in six/seven patients by bone marrow and in three/seven patients by peripheral blood analysis, respectively. Results of molecular monitoring in T-ALL patients did not confirme clinical evaluation in two patients. Obtained results indicate high accuracy of re-evaluated primers for clonality assessment in ALL and CLL patients at the time of diagnosis. Results of clonality testing in B-ALL patients indicate that bone marrow analysis has higher sensitivity compared to analysis of peripheral blood.