Humoral Effect of a B-Cell Tumor on the Bone Marrow Multipotent Mesenchymal Stromal Cells.

The properties of bone marrow (BM)-derived multipotent mesenchymal stromal cells (MSCs) are altered in the patients with the diffuse large B cell lymphoma (DLBCL) without BM involvement. It was suggested that plasma from the patients contains soluble factors that affect MSCs. Plasma and BM-derived MSCs from the DLBCL patients at the onset of the disease and one month after the end of treatment were studied. Concentration of the plasma cytokines and gene expression in the MSCs were evaluated by the Bio-Plex Pro Human Cytokine Panel kit to measure 27 analytes and real-time PCR. Plasma and MSCs from the healthy donors were used as controls. Analysis of cytokines in the plasma from healthy donors and patients before and one month after the end of treatment revealed significant differences in the concentration of 14 out of 27 cytokines. Correlations between the levels of secreted cytokines were altered in the plasma from patients indicating that the immune response regulation was disturbed. Cultivation of the MSCs from the healthy donors in the medium supplemented with the plasma from patients led to the changes in the MSC properties, similar to those observed in the MSCs from patients. The BM-derived MSCs were shown to participate in the humoral changes occurring in the DLBCL patients. For the first time, it was shown that the precursors of the stromal microenvironment - multipotent mesenchymal stromal cells - are altered in the patients with DLBCL without bone marrow involvement due to the humoral effect of the tumor and the response of organism to it. Comprehensive analysis of the results shows that, when remission is achieved in the patients with DLBCL, composition of the plasma cytokines normalizes, but does not reach the level observed in the healthy donors. The discovery of a new aspect of the effect of the tumor B-cells on the organism could help to reveal general regularities of the humoral effect of various tumors on the bone marrow stromal cells.

Diagnostic significance of flow cytometry scales in diagnostics of myelodysplastic syndromes.

BACKGROUND: Myelodysplastic syndromes (MDS) can present a challenge for clinicians. Multicolor flow cytometry (MFC) can aid in establishing a diagnosis. The aim of this study was to determine the optimal MFC approach for MDS. METHODS: The study included 102 MDS (39 low-grade MDS), 83 cytopenic patients without myeloid neoplastic disorders (control group), and 35 healthy donors. Bone marrow was analyzed using a six-color MFC. Analysis was conducted according to the "Ogata score," "Wells score," and the integrated flow cytometry (iFC) score. RESULTS: The respective sensitivity and specificity values were 77.5% and 90.4% for the Ogata score, 79.4% and 81.9% for the Wells score, and 87.3% and 87.6% for the iFC score. Specificity was not 100% due to deviations of MFC parameters in the control group. Patients with paroxysmal nocturnal hemoglobinuria (PNH) had higher levels of CD34+ CD7+ myeloid cells than donors. Aplastic anemia and PNH were characterized by a high proportion of CD56+ cells among CD34+ precursors and neutrophils. The proportion of MDS-related features increased with the progression of MDS. The highest number of CD34+ blasts was found in MDS with excess blasts. MDS with isolated del(5q) was characterized by a high proportion of CD34+ CD7+ cells and low granularity of neutrophils. In 39 low-grade MDS, the sensitivities were 53.8%, 61.5%, and 71.8% for Ogata score, Wells score, and iFC, respectively. CONCLUSION: The results support iFC as a useful diagnostic tool in MDS.

Human Herpesvirus Type 8-positive Multicentric Castleman Disease.

Castleman disease (CD) is rare lymphoproliferative disorder with local lesionsor with multiple lessions (multicentric CD [MCD]-usually with plasma cell or mix cell morphology). Patients with human herpesvirus (HHV) type 8-positive MCD were included in a separate group owing to its extremely aggressive course and the high risk of transformation into HHV8(+) plasmablastic lymphoma. At our hematologic center, from 1996 to the present, the clinical and morphologic features of 87 patients with CD were analyzed. Immunohistochemical examination revealed DNA HHV8(+) lymph node tissue in patients with plasma cell and mixed cell morphology. In 45 patients, plasma cell or mixed cell variant CD was diagnosed. In 21 patients (8%), the manifestation of CD was local and in 29 (9%), it was multicentric. HHV8 was identified in only 6 cases (23.1%) of MCD (5 men and 1 woman, with a median age of 48.2 years; range, 36-77 years). The median follow-up point was 39.2 months. In 4 patients, the mixed cell variant was diagnosed and in 2, the plasma cell variant was diagnosed. In all the patients, constitutional symptoms, generalized lymphadenopathy, and hepatosplenomegaly were detected. Various laboratory changes were observed, but the most significant were anemia, thrombocytopenia, hypergammaglobulinemia, M-component, increased erythrocyte sedimentation rate, and circulating immune complexes. In 2 cases of HHV8(+) CD, MCD was combined with autoimmune hemolytic anemia and in 2 cases with non-Hodgkin lymphoma. At the last follow-up point, 2 patients were still alive after CHOP (cyclophosphamide, prednisone, Adriamycin, vincristine) and R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate [Oncovin], prednisone) therapy with rituximab maintenance. HHV8(+) MCD results in aggressive multiorgan lesions and pronounced changes in laboratory test results. It is characterized by an unfavorable prognosis with a high risk of transformation to plasmablastic lymphoma and a lethal outcome. Timely chemotherapy for patients with HHV8(+) MCD can result in remission and prolong life.