Long-term treatment with rituximab is feasible in selected patients with B-CLL: response-adjusted low-dose maintenance treatment with rituximab in patients with relapsed B-CLL, who achieved a partial or minimal response to prior rituximab therapy.

The feasibility and efficacy of flexible, response-adjusted rituximab maintenance therapy in B-cell chronic lymphocytic leukemia (B-CLL) was investigated in 12 patients with an at least minor response to four weekly cycles of 375 mg/m(2) of rituximab induction therapy. Rituximab maintenance therapy consisted of infusions of 100 mg rituximab every 4 weeks. If disease progression occurred, either the rituximab dose was increased or the time between infusions was shortened. Treatment-related side effects led to discontinuation of rituximab maintenance therapy in three cases. Maintenance therapy was successfully conducted for > or =6 months in seven cases; three of these individuals have been on maintenance therapy for >1 year to 3.5 years so far. Long-term toxicity, as determined based on hematological and immunological parameters, was mild.

Differential gene expression in peripheral blood lymphocytes of cancer patients treated with whole body hyperthermia and chemotherapy: a pilot study.

PURPOSE: The effect of whole body hyperthermia (WBH) at 41.8-42 degrees C on the cellular immune system is still poorly investigated. The aim of this study was to identify genes that become upregulated in peripheral blood lymphocytes (PBLs) of cancer patients during a combined treatment with WBH and chemotherapy by generating complex arrays of cDNA. METHODS: PBLs were obtained from four patients with different malignancies treated with WBH and varying cytostatic schedules before treatment and immediately thereafter. After constructing subtracted cDNA libraries, clones were screened for cDNA induction by dot-blot and semi-quantitative RT-PCR (sq-RT-PCR). RESULTS: Among 192 clones, 39 cDNAs were significantly upregulated. Sequencing revealed three groups of genes for which upregulation of mRNA was confirmed by sq-RT-PCR. The first group consisted of genes encoding for various heat shock proteins (HSP 60, 90a, 90b, 105). Further sq-RT-PCR demonstrated differential expression of HSP27 and HSP70 as well. The second group (calcyclin-binding-protein, haemoglobin-beta-chain) comprised genes without pre-specified association to hyperthermia. The cDNA encoding macrophage-inflammatory-protein-1-beta was also observed and may be associated with the pre-described activation of lymphocyte sub-populations during WBH. CONCLUSION: Treatment with WBH and chemotherapy elicits significant short-term effects on the expression of a variety of genes responsible for cellular integrity, stimulation and migration of immune effector cells. Further investigation is warranted to more clearly define the role of those genes for the clinical effect of WBH.

Clinical relevance of CD95 (Fas/Apo-1) on T cells of patients with B-cell chronic lymphocytic leukemia.

OBJECTIVE: Apoptosis mediated via CD95 (Fas/Apo-1) is a key regulator for the biology of normal and malignant lymphocytes. Although the function of CD95 on B-cell chronic lymphocytic leukemia cells (B-CLL cells) has been studied intensively, the clinical importance of CD95 expression on normal T cells in B-CLL has not been clarified. This study aimed to investigate whether expression of CD95 on peripheral blood T cells correlates with clinically relevant parameters of B-CLL disease. MATERIALS AND METHODS: Expression of CD95 (Fas/Apo-1) on peripheral blood T lymphocytes of patients with B-CLL was determined using flow cytometry and was correlated with expression of activation markers, sensitivity to apoptosis by anti-CD95, and clinical data, such as blood count, Binet stage, therapy, progression-free probability, and survival probability. RESULTS: Differential CD95 expression did not correlate with activation markers or with levels of apoptosis through anti-CD95. However, high levels of CD95 on T cells from B-CLL patients correlated significantly with low lymphocyte doubling time, increased Binet stages, and requirement for chemotherapeutic treatment. Furthermore, increased cell-surface CD95 on T cells was associated with reduced progression-free probability and poorer survival. CONCLUSIONS: CD95 levels on T cells correlate with the clinical course of B-CLL. Prospective studies appear warranted to investigate whether CD95 on T cells has a direct influence on B-CLL disease progression.

New directions in the diagnosis and treatment of chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) is the most common leukaemia of adults in Western countries. It is a systemic haematological malignancy that originates from B cells (B-CLL) in 95% of patients, while only a minority are derived through malignant transformation of T cells (T-CLL). Although B-CLL is classified as a non-Hodgkin's lymphoma, several issues make this leukaemia a unique entity among malignant lymphoma. Inhibition of the programmed cell death (apoptosis) and upregulation of the anti-apoptotic protein Bcl-2 are key elements of the pathophysiology of B-CLL cells and define clinical prognosis. Furthermore, B-CLL cells are arrested in G0/G1 phase of the cell cycle. Dysfunctional apoptosis and cell cycle are the main reasons for the clinical enigma, that CLL can not yet be cured with conventional chemotherapy. However, the molecular pathways that are responsible for this characteristic feature of the B-CLL cells still need further definition.Recently, considerable progress has been made in defining the molecular basis for the pathogenesis of CLL and in finding new therapeutic options. Recent studies indicate that B-CLL cells may be delineated from two main groups of normal B cells, i.e. pre- and postgerminal B cells, and can be distinguished through lack of or existence of mutations of the V heavy chain gene. This differential mutational status of the Ig V gene has significant impact on patient survival. Modern cytogenetic methods such as fluorescence in situ hybridisation (FISH) have opened a new era in the molecular analysis of CLL cells. Determining the chromosomal aberration of the leukaemic cells has become a standard scientific programme for each clinical trial. The cytogenetic profile may soon help to define a clinical risk profile and guide the various treatment strategies. Further progress has been made in the therapy of CLL. Purine analogues such as fludarabine were able to induce significant improvement in remission rates; however, they did not lead to improved survival. Chimera of murine or rat monoclonal antibodies and human antibodies were designed to treat CLL. Antibodies such as rituximab and alemtuzumab (Campath-1H), directed against CD20 and CD52, respectively, appear as attractive alternatives to conventional chemotherapy because of their lack of significant myelotoxicity. Studies using myeloablative chemotherapy followed by autologous or allogeneic stem cell transplantation were initiated with the hope of finding a cure for CLL. In contrast to autologous stem cell transplantation, allogeneic transplants appear to display a plateau of relapse rates. In conclusion, for many years CLL was considered as a chronic haematological malignancy that required only few diagnostic tools and for whom no hope of cure could be offered. The current review focuses on recent improvements in diagnosis and treatment of CLL that have opened a new era in the management of patients with this systemic malignancy.

Selective internalization of monoclonal antibodies by B-cell chronic lymphocytic leukaemia cells.

B-cell chronic lymphocytic leukaemia (B-CLL) cannot be cured by conventional chemotherapy, therefore, toxin-linked therapeutic monoclonal antibodies (mAbs) are increasingly examined for their potential to improve clinical outcome. The current study aimed to identify mAbs that were internalized by the B-CLL cells of 14 patients, using both flow cytometry and confocal laser scanning microscopy. Anti-CD5, CD22 and CD40 mAbs were effectively taken up by B-CLL cells, whereas mAbs against CD19, CD20, CD23 and CD45 were not. This study may form a basis for further research to identify antibodies that may serve as carriers for toxins to treat B-CLL.

Increased expression of CD40 ligand on activated T cells of patients with colon cancer.

PURPOSE: Proper function of T lymphocytes is crucial for an effective destruction of cancer cells in vivo. Identifying the cell surface molecules on the T cells that may be involved in this antitumor response may help to elucidate immunological factors influencing the biology of human tumors. EXPERIMENTAL DESIGN: Differences in the antigen expression profile of unstimulated and stimulated peripheral blood T-lymphocytes from patients with colon cancer and from normal controls were determined using flow cytometry. RESULTS: Freshly isolated peripheral blood T cells of patients with colon cancer did not differ in their phenotype significantly from those of patients with nonmalignant diseases. In contrast, in vitro stimulated T cells of patients with colon cancer had a significantly increased expression of CD40 ligand (CD40L, CD154) compared with activated T cells of the control group; increased CD40L expression was also found in the CD4(+)- and CD8(+)-T-cell subpopulations. CONCLUSIONS: The data presented support additional studies investigating the role of CD40L in the immune response against colon carcinoma.