Follow-up of the T-cell clonality in Sezary patients treated by extracorporeal photopheresis using a new assay: the immunoscope technique

Down-regulating constitutive activation of the NF-κB canonical pathway overcomes the resistance of cutaneous T-cell lymphoma to apoptosis

Constitutive activation of the nuclear factor-kappaB (NF-κB) pathway has been shown to be involved in the resistance of tumor cells to apoptosis in several human malignancies of the hematopoietic lineage. By using electrophoretic mobility shift assay (EMSA) and confocal microscopic analysis, we demonstrate that NF-κB is constitutively activated in cutaneous T-cell lymphoma (CTCL) cell lines HuT-78, MyLa, and SeAx and in peripheral blood lymphocytes (PBLs) from patients with Sézary syndrome (SS) presenting a high ratio of tumor cells, with evidence of p50 and RelA/p65 in DNA-linked complexes. Transfection of SeAx line with a κB/luciferase reporter plasmid showed that translocated NF-κB complexes were functional. Selective inhibition of NF-κB, by transfecting CTCL cell lines with a super-repressor form of IκBα, led to apoptosis. We evidenced down-regulation of NF-κB activation and induction of CTCL cell apoptosis in the presence of proteasome 26S inhibitors ALLN, MG132, and bortezomib. Bortezomib at nanomolar concentrations inhibited constitutive activation of NF-κB and induced apoptosis of CTCL cells, with evidence of an upregulation of Bax expression. These results demonstrate the key role played by NF-κB in the resistance of CTCL to apoptosis and suggest that bortezomib might be useful for the treatment of patients with advanced stages of CTCL refractory to standard antineoplastic chemotherapy.

Quo vadis haemapheresis. Current developments in haemapheresis

The techniques of haemapheresis originated in the development of centrifugal devices separating cells from plasma and later on plasma from cells. Subsequently membrane filtration was developed allowing for plasma-cell separation. The unspecificity of therapeutic plasma exchange led to the development of secondary plasma separation technologies being specific, semi-selective or selective such as adsorption, filtration or precipitation. In contrast on-line differential separation of cells is still under development. Whereas erythrocytapheresis, granulocytapheresis, lymphocytapheresis and stem cell apheresis are technically advanced, monocytapheresis may need further improvement. Also, indications such as erythrocytapheresis for the treatment of polycythaemia vera or photopheresis though being clinically effective and of considerable importance for an appropriate disease control are to some extent under debate as being either too costly or without sufficient understanding of the mechanism. Other forms of cell therapy are under development. Rheohaemapheresis as the most advanced technology of extracorporeal haemorheotherapy is a rapidly developing approach contributing to the treatment of microcirculatory diseases and tissue repair. Whereas the control of a considerable number of (auto-) antibody mediated diseases is beyond discussion, the indication of apheresis therapy for immune complex mediated diseases is quite often still under debate. Detoxification for artificial liver support advanced considerably during the last years, whereas conclusions on the efficacy of septicaemia treatment are debatable indeed. LDL-apheresis initiated in 1981 as immune apheresis is well established since 24 years, other semi-selective or unspecific procedures, allowing for the elimination of LDL-cholesterol among other plasma components are also being used. Correspondingly Lp(a) apheresis is available as a specific, highly efficient elimination procedure superior to techniques which also eliminate Lp(a). Quality control systems, more economical technologies as for instance by increasing automation, influencing the over-interpretation of evidence based medicine especially in patients with rare diseases without treatment alternative, more insight into the need of controlled clinical trials or alternatively improved diagnostic procedures are among others tools ways to expand the application of haemapheresis so far applied in cardiology, dermatology, haematology, immunology, nephrology, neurology, ophthalmology, otology, paediatrics, rheumatology, surgery and transfusion medicine.

Small-scale extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma: A report of 3 cases

Extracorporeal photopheresis is an accepted method for the treatment of cutaneous T-cell lymphoma and much progress has recently been achieved in therapy and understanding of its mechanism. In general large numbers of white blood cells are collected by a cell separator and irradiated in the presence of 8-MOP. In contrast to this practice, data from an animal model showed that as few as 0.2% of the body's blood volume irradiated are sufficient to achieve an immune response after photopheresis. Based on these data we developed a small-scale photopheresis procedure and applied the method in 3 end-stage T-cell lymphoma patients who were not eligible for apheresis. The mononuclear cells from 50 ml of blood were separated by density gradient centrifugation, irradiated with UV-light in the presence of 8-Methoxy-Psoralen (MOP) with 2J/cm(2) and reinjected. 2-3 treatments per week were conducted. The three patients-2 male and 1 female, age 63-86, Sezary syndrome (1x) and mycosis fungoides in tumour stage (2x)-showed no side effects on cell injection. The two patients with mycosis fungoides showed a prompt regression and softening of the tumours. The patient with Sezary syndrome developed numerous necrotic spots on the skin after 6 weeks of therapy that turned normal within a few days. Patient 1 died of pneumonia 4 weeks after the start of therapy and patient 3 died of heart failure 8 weeks after start of therapy, both during regression of the tumours. Patient 2 was treated over a period of 11 months, with an initial regression in the first weeks followed by a slow progression of the tumours after she rejected any form of further treatment. The small-scale extracorporeal photopheresis therapy presented is effective in cutaneous T-cell lymphoma. But questions regarding the optimal number of cells irradiated per treatment, the conditions of cell incubation after irradiation and the number of treatment cycles are still open. Therefore further studies are required to establish a method that is effective and circumvents the use of apheresis technology.

Mycosis fungoides and the Sézary syndrome

PURPOSE OF REVIEW

Mycosis fungoides and the Sézary syndrome represent a heterogeneous group of good-to-intermediate-risk non-Hodgkin lymphomas that have recently been identified as distinct histopathologic and clinical entities by the World Health Organization and European Organization for Research on the Treatment of Cancer lymphoma classification systems. Significant progress has been made in identifying and categorizing patients based on clinical prognostic factors, but there is little information regarding the etiology, molecular biology, and molecular genetics of these diseases. This review outlines recent advances in clinical diagnosis and prognosis as well as novel therapeutic approaches.

RECENT FINDINGS

A number of reports have further defined clinical prognostic subgroups among early-stage patients and those with circulating Sézary cells. The recent availability and demonstrated efficacy of the oral RXR retinoid, bexarotene, has altered the treatment paradigm of early-stage patients who would not otherwise be exposed to systemic therapies. Novel targeted agents and receptor-directed therapies, including the fusion toxin, denileukin diftitox, histone deacetylase inhibitors, and novel nucleoside analog therapies, have demonstrated promising activity and are undergoing further clinical evaluation. The evolution of immunotherapy has been augmented by studies demonstrating the efficacy of peptide-loaded dendritic cells as well as the use of photopheresis to generate an anti-idiotype cytotoxic T-cell response.

SUMMARY

This review will enumerate the most recent findings with respect to clinical staging, prognosis, and treatment of patients with mycosis fungoides and the Sézary syndrome. Novel treatment options will be reviewed and treatment paradigms will be outlined.

Selective immmunotherapy through extracorporeal photochemotherapy: yesterday, today, and tomorrow

ECP's extensive clinical record, as well as a considerable improvement in the understanding of the mechanism that underlies its efficacy, opens potential novel strategies for the treatment of cancer, GVHD, transplant rejection, and autoimmunity. The low side effect profile of this therapy has made it a more attractive treatment consideration than current conventional chemotherapeutic and immunosuppressive medications. As the mechanism of action of ECP is more fully elucidated and clinical studies are completed, the role of ECP in modern therapeutics of CTCL and other malignancies, as well as in the treatment of other T-cell mediated diseases, will be become clearer.