CD23 Antigen Density is Related to Serum Gamma Globulin Level, Bone Marrow Reticulin Pattern, and Treatment in B Chronic Lymphocytic Leukemia

The CD23 antigen density was evaluated by a cytofluorometric technique in 55 patients with chronic lymphocytic leukemia. The quantification method was based on the use of biological standards in indirect immunofluorescence. The CD23 antigen density was correlated with the percentage of CD23 positive cells, but antigen density appeared to be a more informative parameter. CD23 antigen density was lower in stage B than in stages A or C patients, and higher in patients undergoing chemotherapy or previously treated than in untreated patients. There was a significant negative correlation between CD23 antigen density and serum gamma globulin and IgG levels, that existed only in patients in an advanced stage of the disease. CD23 antigen density was higher in patients with abnormal bone marrow reticulin pattern. Serum gamma globulin level was lower in these patients, as well as in patients with prognostically unfavorable histologic bone marrow infiltration pattern. These data emphasize the interest of antigen density as an additional parameter and the complex relationship between CD23 expression, hypogammaglobulinemia, bone marrow histologic findings, and treatment in chronic lymphocytic leukemia.     

Expression of inducible nitric oxide synthase in tumors in relation with their regression induced by lipid A in rats.

It is well documented that nitric oxide (NO) is an effector molecule of macrophage-mediated tumor cell toxicity in vitro; however, little is known about the role of NO in the antitumor immune response in vivo. We have developed a treatment protocol using lipid A. We have investigated the effects of lipid A on inducible NO synthase (NOS II) expression and evolution inside tumors during the course of treatment. Lipid A (OM-174) treatment induced tumor regression in rats bearing established colon tumors. Furthermore, NO was synthesized and secreted inside the tumors of lipid A-treated rats, as demonstrated by the increase of NOS II mRNA and NOS II content in the tumors, as well as of NOS II activity and NO production. During treatment, NOS II was localized in tumor cells only. Lipid A had no direct effect on tumor cells in vitro, while the combination of interferon gamma (IFN-gamma) plus interleukin-1 beta (IL-1beta) induced production of NO by tumor cells which was cytostatic. The content of IFN-gamma and IL-1beta in tumors was enhanced during lipid A treatment; this is in agreement with an indirect effect of lipid A in vivo via the IFN-gamma and IL-1beta pathways.     

An image analysis method for the study of cell adhesion to biomaterials.

This fluorescence image analysis method for the quantitative determination of cell adhesion on biomaterials allows bone cells labelled with propidium iodide to be counted automatically, directly on their support. The reliability of the estimation by fluorescence image analysis was validated by comparison with visual counting and with results obtained by an electronic particle counter. In this way it was possible to demonstrate that the adhesive properties of bone cells are dependent on the type of substrate--enstatite (MgO, SiO2, CaO-P2O5-Al2O3), Thermanox (modified polyethyleneterephthalate), or glass. In contrast, the spread of the cell cytoplasm, labelled with fluorescein isothiocyanate and measured by image analysis, does not vary significantly according to the substrate. The characterisation by SKIZ tessellation of the spatial cell arrangement shows that the bone cells have a random organisation on Thermanox and glass, whereas they form aggregates on enstatite.     

Reduced intensity conditioning: enhanced graft-versus-tumor effect following dose-reduced conditioning and allogeneic transplantation for refractory lymphoid malignancies after high-dose therapy

Non-myeloablative regimens have been proven to allow engraftment following allogeneic stem cells transplantation (allo-SCT) with minimal procedure-related toxicity. Conventional allo-SCT may produce remissions in patients with relapsed and refractory lymphoid malignancies (LM) but these good results may be achieved at the cost of high treatment-related morbidity and mortality. Application of allo-SCT using less intensive regimens may temper the frequency of these complications, allowing a potent graft-versus-tumor effect (GVT). We present our data on 11 patients with LM receiving allo-SCT with a reduced regimen. Ten patients had received previous high-dose therapy, and were at high risk for toxicity, thus precluding the use of allo-SCT. A fludarabine and low-dose busulfan combination facilitated engraftment while exerting GVT. Hematological recovery was quick, and full donor T cell chimerism preceded acute GVHD. GVHD and infections were the major problems. Spontaneous acute GVHD occurred in eight patients (72%). Five patients (45%) achieved complete remission, and the GVT effect was closely associated with GVHD. These results support the concept that GVT is effective against LM in patients who have been heavily pretreated. Further studies are needed to investigate strategies to generate more specific alloreactive effects providing optimal GVT and an acceptable risk of GVHD and infections.