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The primary cause of death (COD) provides important information in many studies of hematopoietic stem cell transplantation (HSCT). A panel of experts critically assessed the CODs submitted by 15 transplantation centers for 281 patients who died in a randomized multicenter trial of unrelated HSCT. The panel reviewed the CODs reported by the transplantation centers, which used the Center for International Blood and Marrow Transplant Research and National Marrow Donor Program COD reporting form. The panel determined that the existing criteria for primary and contributing CODs lacked sufficient stringency for uniform interpretation. A hierarchy was developed and applied to the T cell depletion project. Using its scheme, the panel reclassified 157 CODs (56%) reported by the transplantation centers. The changes resulted in increased recognition of graft-versus-host disease as the primary COD and a concomitant decrease in attribution of the primary COD to infection. This algorithm promotes consistent assignment of primary and contributing CODs for patients with leukemia or lymphoma who expire after myeloablative allogeneic HSCT.

Serious infections are a major obstacle limiting the usefulness of unrelated donor marrow transplantation. Graft-versus-host disease (GVHD) and its therapy are associated with a high risk of opportunistic infection. In this study, patients were randomized to receive 1 of 2 GVHD prophylaxis strategies, marrow T cell depletion, and cyclosporine (TCD) or methotrexate/cyclosporine (M/C) after transplantation. The patients underwent transplantation between March 1995 and October 2000 as part of a multicenter randomized trial. As a secondary analysis, we analyzed infections in this study cohort. Among the 404 patients who underwent transplantation, a total of 1598 infections were reported. The rates of serious and fatal infections did not differ between the TCD and M/C groups. Bacterial infections accounted for 1/3 of serious infections in each treatment arm. A significantly higher incidence of severe cytomegalovirus (CMV) and life-threatening or fatal aspergillus infections was observed in the patients receiving TCD (CMV, 28% vs 17% [P = .02]; aspergillosis, 16% vs 7% [P < .01]). The only independent risk factor for serious infection was the development of grade III-IV acute GVHD (aGVHD; hazard ratio = 1.41; 95% confidence interval = 1.03-1.91). Strategies to speed immune recovery, even in the absence of GVHD, are needed to overcome the risk of infection after unrelated donor transplantation.

A carcinogen-transformed rat hepatoma cell line (Reuber H-35) was utilized as a model system for investigation of the biochemical factors which may limit the effectiveness of chemotherapy in intrinsically resistant tumors such as hepatocellular carcinoma. Northern blotting demonstrated expression of mRNA coding for the P-170 membrane-glycoprotein associated with the multi-drug resistance phenotype, while Western blotting identified the P-170 glycoprotein in the hepatoma cell membrane. Consistent with these observations, tumor cell sensitivity to the vinca alkaloids, vincristine and vinblastine, to the anthracycline antibiotics, Adriamycin ® and daunorubicin, and to the demethyl-epipodophyllotoxin derivative, VM-26, was enhanced by continuous incubation in the presence of the calcium channel antagonist, verapamil. Verapamil produced a minimal change in cell sensitivity to the demethylepipodophyllotoxin derivative, VP-16, and to the aminoacridine, m -AMSA. Relatively high detoxification potential via the glutathione metabolic pathway was also observed in the hepatoma cell. The capacity of topoisomerase II in nuclear extracts from the hepatoma cell to mediate cleavable complex formation stimulated by VM-26, VP-16 and m -AMSA appeared to be at least comparable to, if not greater than that from drug-sensitive HL-60 cells, suggesting that drug resistance may not occur at the level of this enzyme. Consistent with findings in a number of tumor cell lines resistant to antineoplastic drugs, the antiproliferative activity of the topoisomerase II inhibitors VM-26, VP-16 and m -AMSA appeared to be dissociable from the induction of DNA strand breaks, suggesting that such lesions in DNA may fail to fully account for the antiproliferative activity of these agents in the hepatoma cell.

Advanced atherosclerotic lesions are characterized by lipid accumulation, chronic inflammation, and defective efferocytosis; an ideal therapy should address all aspects of this multi-factorial disease. Ixmyelocel-T, an expanded autologous multicellular therapy showing clinical promise in the treatment of severe diseases associated with atherosclerosis, includes a novel population of M2-like macrophages. We examined the properties of these macrophages to determine their potential mechanisms of action in atherosclerotic states. Flow cytometry revealed that ixmyelocel-T macrophages express surface receptors of alternative activation (CD206 and CD163) and scavenger receptors involved in lipid and apoptotic cell uptake (CD36, LDLR, CD91, MSR1, and MerTK). ELISA analysis revealed ixmyelocel-T macrophages secrete substantial levels of IL-10 (1060 278 vs. 1978 313 pg/ml, p < 0.05) and IL-1ra (12673 1242 vs. 37576 3650 pg/ml, p < 0.001) before and after overnight LPS stimulation. Baseline secretion of the pro-inflammatory cytokines IL-1b, TNFa, and IL-12 is minimal and remains low after LPS stimulation. Fluorescent microscopy and flow cytometry revealed that ixmyelocel-T readily phagocytosed apoptotic cells. Apoptosis analyzed by a caspase 3/7 assay demonstrated that ixmyelocel-T isn’t sensitive to the lipotoxic effects of modified cholesterol (87 10.78 vs. 100 14.58% of control). Real time PCR revealed that the cholesterol transporter genes ABAC1 (1.49 0.32 vs. 0.42 0.11 fold change, p < 0.01) and ABCG1 (0.41 0.13 vs. 0.07 0.03 fold change, p < 0.05) are both significantly upregulated when ixmyelocel-T macrophages are loaded with cholesterol. Ixmyelocel-T also exhibits enhanced ApoAI mediated cholesterol efflux (13.91 1.90 vs. 3.42 0.31%, p < 0.001 compared to THP-1). In addition, ixmyelocel-T effluxed cholesterol in vivo in using a mouse model for reverse cholesterol transport. These biological properties of ixmyelocel-T macrophages suggest that this cellular therapy may exert beneficial effects on atherosclerotic disease by providing macrophages that potentially limit atheroma development through secretion of anti-inflammatory cytokines, removal of apoptotic cells, and promotion of cholesterol efflux.

Purified populations of T and B cells were obtained from individuals with chronic lymphocytic leukemia (CLL) by the use of anti-F(ab′) 2 affinity column chromatography techniques in which twice the amount of column material used for normal separations was used for the separation of Ig − and Ig + cells from CLL patients. Furthermore, the flow rate was reduced in order to decrease the possibility that some B cells from CLL patients, containing a low density of surface Ig, would pass through without binding to the coupled Sephadex G-200. Examination of surface Ig, P23,30 antigens, and T-cell antigens in the separated populations indicated that both the Ig − and Ig + populations were highly enriched. These T cells were also tested for their response to mitogenic stimulation as well as their ability to cooperate with leukemic B cells, normal B cells, or B cells from a transformed B-cell line. T cells from leukemic patients were found to be significantly deficient in both the response to mitogens and ability to cooperate with B cells in the synthesis and secretion of immunoglobulin.