Human and mouse DOCK10 splicing isoforms with alternative first coding exon usage are differentially expressed in T and B lymphocytes.

DOCK10 is a member of the dedicator of cytokinesis (DOCK) family of Rho GTPase activators preferentially expressed in lymphocytes. In this paper, we analyzed DOCK10 mRNA diversity produced because of alternative splicing. Alternative first coding exon usage led to 2 main protein-coding transcripts, DOCK10.1 and DOCK10.2. Full-length cDNA clones of both isoforms were obtained from both normal human peripheral blood mononuclear cells and mouse spleen for the first time for human DOCK10.1, mouse DOCK10.1, and mouse DOCK10.2. Human and mouse DOCK10.1 clones corresponded to the protein coding assemblies provided by the National Center for Biotechnology Information as Reference Sequences for DOCK10. Our analysis especially focused on human cDNA clones, of which 63% were alternatively spliced forms involving diverse exons and introns. DOCK10.1 expression was enriched in normal T cells, and DOCK10.2 expression was enriched in normal B cells and chronic lymphocytic leukemia (CLL) B cells. Both isoforms were upregulated in response to interleukin-4 in B cells, both normal and CLL, but not in T cells. Our data suggest that cell-specific mechanisms regulate expression of the alternative first exon variants of DOCK10 in vertebrates.

Cryopreservation impact on blood progenitor cells: influence of diagnoses, mobilization treatments, and cell concentration.

BACKGROUND: The aim of this study was to analyze the impact of cryopreservation in series of peripheral blood progenitor cells stratified by diagnosis, mobilization treatments, and cell concentration, as well as the accuracy of the control aliquots. STUDY DESIGN AND METHODS: Viability and colony-forming unit-granulocyte-macrophage (CFU-GM), CD34+ cell, lymphocyte, monocyte, and granulocyte counts and recovery were analyzed in 397 leukapheresis procedures before freezing and after thawing. Data from control cryotubes were compared to those from infusing bags. RESULTS: Cell viability decreased after thawing. Viability recovery was lower in cryotubes than in bags in non-Hodgkin's lymphoma (NHL), in cyclophosphamide plus granulocyte-colony-stimulating factor (Cy+G-CSF) mobilization, and in cell concentration of median or greater. Viability recovery in cryotube was higher in NHL (92.1%) than in Hodgkin's disease (HD; 87.3%) and in G-CSF (95.9%) than Cy+G-CSF mobilization (91.3%). The number of CD34+ cells decreased after thawing in total group, Cy+G-CSF mobilization, and cell concentration less than median subgroups. CD34+ cell recovery was higher in cryotubes (111.3%) than in bags (99.6%) in multiple myeloma (MM; p = 0.015). CFU-GM decreased after thawing in all groups. CFU-GM recovery was lower in cryotubes than in bags in MM (26.0% vs. 59.3%) and in Cy+G-CSF mobilization (49.8% vs. 76.3%). CFU-GM recovery in cryotubes was lower in MM compared with NHL (61.5%), HD (45.1%), and breast cancer (84.0%). Lymphocytes, monocytes, and granulocytes showed differences in the subgroups. CONCLUSION: Cryopreservation negatively impacts in cell viability, CD34+ cell recovery, granulocytes, and CFU-GM, although slight differences between the groups were observed. Cryotubes satisfactorily reflected the quality of the infused cells.

Splenic rupture in a plasma cell leukemia, mobilized with G-CSF for autologous stem cell transplant.

Splenic rupture (SR) is a rare adverse event observed in patients treated with G-CSF as a peripheral hematopoietic stem cell (PHSC) mobilizing agent, mostly in myeloma multiple and amiloidosis; to date, to our knowledge, it has not been previously described in plasma-cell leukemia (PCL). We report a case of a woman with PCL, who presented a SR after PHSC mobilization with Cyclophosphamide+G-CSF. The spleen removed showed hematopoietic foci and amiloid material. In the course of a second mobilization, 2 months after, the patient died from sepsis. We considered it important to report this case, in order to keep in mind the possibility of SR in patients with malignant gammopathy.

Large-volume-apheresis facilitates autologous transplantation of hematopoietic progenitors in poor mobilizer patients.

Given that pre-apheresis CD34(+) cell count (PA-CD34) predicts the apheresis' yield, a minimum of 5 to 20 PA-CD34/microl is required in many institutions to initiate cell collection. The aim of this study was to clarify whether large-volume-apheresis (LVA) could facilitate progenitor cell transplantation in patients with low PA-CD34. Apheresis was initiated in 226 patients, disregarding PA-CD34, at days: +5 in G-CSF, +10 in cyclophosphamide+G-CSF, and +15 to +20 in other chemotherapy+G-CSF mobilization, when leucocytes >2.5 x 10(9)/L. Four times the blood volume was processed. Patients were grouped according to their PA-CD34: >or=10/microl (group-A, n = 143); <10/microl but >or=5/microl (group-B, n = 40) and <5/microl (group-C, n = 43). No differences were found in diagnoses, gender, age, previous treatments or mobilization regimen between groups. Enough CD34(+) cells (>1.9 x 10(6)/kg) were obtained in 31 patients (72%) from group-C, although in this group two mobilizations were needed in 20 patients (46.5%), compared to 5 (3.5%) and 1 (2.5%) in groups A and B, respectively (P < 0.01). Evenly three apheresis or more were required in 28 patients (65.1%) from group-C, compared to 8 (5.6%) and 6 (15.0%) in groups A and B, respectively (P < 0.01). In conclusion LVA can facilitate autologous transplantation in poor-mobilizer-patients, low PA-CD34 should not be an inflexible exclusion factor.