Impact of red blood cell transfusion dose density on progression-free survival in patients with lower-risk myelodysplastic syndromes.

Progression-free survival (PFS) of patients with lower-risk myelodysplastic syndromes (MDS) treated with red blood cell transfusions is usually reduced, but it is unclear whether transfusion dose density is an independent prognostic factor. The European MDS Registry collects prospective data at 6-monthly intervals from newly diagnosed lower-risk myelodysplastic syndromes patients in 16 European countries and Israel. Data on the transfusion dose density - the cumulative dose received at the end of each interval divided by the time since the beginning of the interval in which the first transfusion was received - were analyzed using proportional hazards regression with time-varying co-variates, with death and progression to higher-risk MDS/acute myeloid leukemia as events. Of the 1,267 patients included in the analyses, 317 died without progression; in 162 patients the disease had progressed. PFS was significantly associated with age, EQ-5D index, baseline World Health Organization classification, bone marrow blast count, cytogenetic risk category, number of cytopenias, and country. Transfusion dose density was inversely associated with PFS (P<1×10-4): dose density had an increasing effect on hazard until a dose density of 3 units/16 weeks. The transfusion dose density effect continued to increase beyond 8 units/16 weeks after correction for the impact of treatment with erythropoiesis-stimulating agents, lenalidomide and/or iron chelators. In conclusion, the negative effect of transfusion treatment on PFS already occurs at transfusion densities below 3 units/16 weeks. This indicates that transfusion dependency, even at relatively low dose densities, may be considered as an indicator of inferior PFS. This trial was registered at www.clinicaltrials.gov as #NCT00600860.

[Diagnostic and prognostic significance of CD45 cell surface antigen expression in hematologic malignancies with main focus on acute leukemias]. / Dijagnosticko i prognosticko znacenje izrazaja biljega CD45 u hematoloskim zlocudnim bolestima s posebnim osvrtom na akutne leukemije.

CD45 cell surface antigen is a transmembrane protein with tyrosine phosphatase activity, expressed by all nucleated cells of hematopoietic origin, except erythrocytes and platelets. Monoclonal antibodies directed against CD45 represent irreplaceable tool in differential diagnosis of hematologic and other, non-hematologic low differentiated malignancies, primarily in cases of: extranodal lymphomas, non-hematologic malignancies with nodal or bone marrow localization or their metastases in mentioned sites. As cell surface immunophenotype marker, CD45 is of great value in differentiation of lymphoproliferative diseases subtypes. By flow cytometry, based on CD45 expression, the malignant cell population is being identified and that fact is used in, not only diagnosis, but also in detection of minimal residual disease, especially in cases of CD45 negative acute leukemias. Incidence of childhood CD45 negative acute lymphoblastic leukemias (ALL) is about 10%. Children diagnosed with low CD45 expression ALL generally have better prognosis than those with high CD45 expression, especially when cut-off value for CD45 expression is set on 90%. We have analyzed CD45 expression by flow cytometry in 28 consecutive patients diagnosed with ALL in our institution during a 5-year period. Among these patients 7.1% were CD45 negative. A positive correlation between CD45 and CD20 expression was found, and a negative correlation between CD45 and CD34. In our group of patients, CD45 expression did not have any influence on survival.

[Association of CD34 cell surface antigen expression with cytomorphological characteristics of acute promyelocytic leukemia blasts and clinical characteristics of patients: one center experience]. / Povezanost izrazaja biljega CD34 s morfoloskim znacajkama blasta u akutnoj promijelocitnoj leukemiji i klinickim znacajkama oboljelih: iskustvo jednog centra.

The aims of the study were to investigate the association between cytomorphology and immunophenotypic expression of CD34 cell surface antigen of blasts and their relationship with clinical and laboratory characteristics of patients with acute promyelocytic leukemia (APL). Sixteen consecutive patients (male 69% and female 31%) diagnosed with APL at Department of Hematology, Merkur University Hospital between August 1998 and December 2010 were included in the study. The mean age of patients was 43.9 (range: 18-78, SD 14.9). The patients' clinical and laboratory features, cytomorphological characteristics of APL-blasts and their immunophenotype determined by flow cytometry were analyzed. Patients were divided into two groups, CD34- and CD34+, and were then compared according to clinical and laboratory characteristics. There was no difference according to age, sex or white blood cell count between two groups. The mean value of hypogranular/agranular APL-blasts was markedly higher in CD34+ group than CD34- group (34%, range 9-60, SD 24.4 vs. 11.5%, range 0-38, SD 13.7), with borderline statistical significance (P=0.055). CD34- patients had significantly better overall survival than CD34+ ones (P=0.02). Patients without Auer rods detected in APL-blasts had higher CD34 expression (69.4% +/- 33.8) compared to patients with detected Auer rods (7.3% +/- 24.8), but statistical significance was not reached (p=0.053). Our results are consistent with the results of other published studies and point to the fact that higher CD34 expression and lower cytoplasmic granularity of APL-blasts are factors that seem to define a specific subgroup of APL patients. Together with other diagnostic tools currently available, they could be of value in planning treatment of APL patients.

[Isolated myeloid sarcoma involving the mediastinum]. / Izolirani mijeloidni sarkom medijastinuma.

Myeloid sarcoma is a rare extramedullary solid tumor consisting of immature myeloid cells and most commonly involving the bone, skin, lymph nodes, soft tissue, gastrointestinal tract and testis. Mediastinal myeloid sarcoma is very rare. There are two major types of myeloid sarcoma: granulocytic sarcoma and monoblastic sarcoma, according to immature cell type. Myeloid sarcoma is found in 2%-8% of patients with acute myeloid leukemia (AML). Myeloid sarcoma may develop before or concurrently with AML, or may be the initial manifestation of AML relapse in previously treated patients. Blast transformation of some form of myeloproliferative neoplasm or myelodysplastic syndrome may also manifest as myeloid sarcoma. A major differential diagnostic problem is isolated primary myeloid sarcoma without bone marrow and peripheral blood involvement, which may precede leukemic stage for months or years, and which is frequently misdiagnosed, mostly as malignant lymphoma. A case is presented of a 56-year-old female patient complaining of weakness, vertigo, dry cough and breathing difficulties. Clinical examination revealed enhanced vascular pattern on the right chest and right arm edema. Computed tomography (CT) of the thorax showed an expansive growth measuring 11 cm craniocaudally in the anterior mediastinum. Fine needle aspiration cytology of tumor mass yielded a scarcely cellular sample with individual atypical immature cells, fine chromatin structure and scarce cytoplasm with occasional granules and Auer rods. Considering the morphological, cytochemical and immunocytochemical characteristics of immature cells, the diagnosis of myeloid sarcoma was made and verified by histopathology of tumor biopsy sample. Immature cells were not found by analysis of bone marrow puncture sample, immunophenotyping of bone marrow cells and bone biopsy analysis. As immature cell proliferation was not detected in bone marrow and peripheral blood, while spread of the disease beyond the mediastinum was ruled out by imaging methods (CT, ultrasonography), it was decided to be a primary non-leukemic form of mediastinal myeloid sarcoma. Myeloid sarcoma should be taken in consideration on differential diagnosis of solid tumors because making an accurate diagnosis is necessary for timely initiation of appropriate therapy. Weakly expressed or lacking clear signs of myeloid differentiation may hamper morphological diagnosis. As isolated myeloid sarcoma is a very rare entity frequently resembling lymphoma in clinical presentation, it poses a major diagnostic challenge for both morphologists and clinicians.