Extracorporeal photopheresis as a curative treatment strategy in non epidermotropic T-cell lymphoma and large granular lymphocyte leukemia

The Value of Flow Cytometry Clonality in Large Granular Lymphocyte Leukemia

Simple Summary

Large granular lymphocyte (LGL) leukemia, a lymphoproliferative disease, is characterized by an increased frequency of large-sized lymphocytes with typical expression of T-cell receptor (TCR) αβ, CD3, CD8, CD16, CD45RA, and CD57, and with the expansion of one to three subfamilies of the TCR variable β chain reflecting gene rearrangements. Molecular analysis remains the gold standard for confirmation of TCR clonality; however, flow cytometry is time and labor saving, and can be associated with simultaneous investigation of other surface markers. Moreover, Vβ usage by flow cytometry can be employed for monitoring clonal kinetics during treatment and follow-up of LGL leukemia patients.

Abstract

Large granular lymphocyte (LGL) leukemia is a lymphoproliferative disorder of mature T or NK cells frequently associated with autoimmune disorders and other hematological conditions, such as myelodysplastic syndromes. Immunophenotype of LGL cells is similar to that of effector memory CD8⁺ T cells with T-cell receptor (TCR) clonality defined by molecular and/or flow cytometric analysis. Vβ usage by flow cytometry can identify clonal TCR rearrangements at the protein level, and is fast, sensitive, and almost always available in every Hematology Center. Moreover, Vβ usage can be associated with immunophenotypic characterization of LGL clone in a multiparametric staining, and clonal kinetics can be easily monitored during treatment and follow-up. Finally, Vβ usage by flow cytometry might identify LGL clones silently underlying other hematological conditions, and routine characterization of Vβ skewing might identify recurrent TCR rearrangements that might trigger aberrant immune responses during hematological or autoimmune conditions.

Modification of Hemodialysis Membranes for Efficient Circulating Tumor Cell Capture for Cancer Therapy

Background: It is well known that more than 90% of cancer deaths are due to metastases. However, the entire tumorigenesis process is not fully understood, and it is evident that cells spreading from the primary tumor play a key role in initiating the metastatic process. Tumor proliferation and invasion also elevate the concentration of regular and irregular metabolites in the serum, which may alter the normal function of the entire human homeostasis and possibly causes cancer metabolism syndrome, also referred to as cachexia. Methods: We report on the modification of commercially available hemodialysis membranes to selectively capture circulating tumor cells from the blood stream by means of immobilized human anti-EpCAM antibodies on the inner surface of the fibers. All critical steps are described that required in situ addition of the immuno-affinity feature to hemodialyzer cartridges in order to capture EpCAM positive circulating tumor cells, which represents ~80% of cancer cell types. Results: The cell capture efficiency of the suggested technology was demonstrated by spiking HCT116 cancer cells both into buffer solution and whole blood and run through on the modified cartridge. Flow cytometry was used to quantitatively evaluate the cell clearance performance of the approach. Conclusions: The suggested modification has no significant effect on the porous structure of the hemodialysis membranes; it keeps its cytokine removal capability, addressing cachexia simultaneously with CTC removal.

LGL leukemia: from pathogenesis to treatment

Large granular lymphocyte (LGL) leukemia has been recognized by the World Health Organization classifications amongst mature T-cell and natural killer (NK) cell neoplasms. There are 3 categories: chronic T-cell leukemia and NK-cell lymphocytosis, which are similarly indolent diseases characterized by cytopenias and autoimmune conditions as opposed to aggressive NK-cell LGL leukemia. Clonal LGL expansion arise from chronic antigenic stimulation, which promotes dysregulation of apoptosis, mainly due to constitutive activation of survival pathways including Jak/Stat, MapK, phosphatidylinositol 3-kinase-Akt, Ras-Raf-1, MEK1/extracellular signal-regulated kinase, sphingolipid, and nuclear factor-κB. Socs3 downregulation may also contribute to Stat3 activation. Interleukin 15 plays a key role in activation of leukemic LGL. Several somatic mutations including Stat3, Stat5b, and tumor necrosis factor alpha-induced protein 3 have been demonstrated recently in LGL leukemia. Because these mutations are present in less than half of the patients, they cannot completely explain LGL leukemogenesis. A better mechanistic understanding of leukemic LGL survival will allow future consideration of a more targeted therapeutic approach than the current practice of immunosuppressive therapy.

Extracorporeal photopheresis promotes IL-1β production

Extracorporeal photopheresis (ECP) is a widely used clinical cell-based therapy exhibiting efficacy in heterogenous immune-mediated diseases such as cutaneous T cell lymphoma, graft-versus-host disease, and organ allograft rejection. Despite its documented efficacy in cancer immunotherapy, little is known regarding the induction of immunostimulatory mediators by ECP. In this article, we show that ECP promotes marked release of the prototypic immunostimulatory cytokine IL-1β. ECP primes IL-1β production and activates IL-1β maturation and release in the context of caspase-1 activation in monocytes and myeloid dendritic cells. Of interest, IL-1β maturation by ECP was fully intact in murine cells deficient in caspase-1, suggesting the predominance of an inflammasome-independent pathway for ECP-dependent IL-1β maturation. Clinically, patient analysis revealed significantly increased IL-1β production in stimulated leukapheresis concentrates and peripheral blood samples after ECP. Collectively, these results provide evidence for promotion of IL-1β production by ECP and offer new insight into the immunostimulatory capacity of ECP.

Systematic review and meta-analysis of prospective studies for ECP treatment in patients with steroid-refractory acute GVHD

PURPOSE

The aim of this systematic review was to evaluate the efficacy and safety of extracorporeal photopheresis (ECP) treatment in patients with steroid-refractory acute graft-versus-host disease (SR-aGVHD).

METHODS

An electronic search was carried out on the MEDLINE, EMBASE, Science Citation Index (SCI), and Cochrane Library databases. We included prospective clinical trials in SR-aGVHD treated by ECP. The main endpoints consisted of mortality, exacerbation, or response.

RESULTS

Only seven studies involving 121 patients met the inclusion criteria for further review. Our analysis showed positive results of ECP for aGVHD. The overall response rate (ORR) was 0.71 and the complete response rate (CRR) was 0.71. The efficacy of ECP for skin aGVHD, liver aGVHD, and gut aGVHD were 0.86, 0.60, and 0.68, respectively. However, no sufficient evidence verifies the exact benefit in this review, because the number of patients enrolled in trials is limited and publish bias exists.

CONCLUSION

ECP is an effective therapy for skin, liver, and gut aGVHD, and large double-blind clinical trials are required to prove the outcome of this meta-analysis.

Extracorporeal photopheresis (photochemotherapy) in the treatment of acute and chronic graft versus host disease: immunological mechanisms and the results from clinical studies

Extracorporeal photopheresis (ECP) is an immunomodulatory alternative for treatment of graft versus host disease (GVHD). The blood is then separated into its various components through apheresis; buffy coat cells are thereafter treated with 8-methoxypsoralen before exposure to ultraviolet light and finally reinfused into the patient. There is a general agreement that this treatment has an anti-GVHD effect, but the mechanisms of action behind this effect are only partly understood. However, altered maturation of dendritic cells (DC) and thereby indirect modulation of T-cell reactivity seems to be one important mechanism together with DC-presentation of antigens derived from apoptotic donor T cells and induction of regulatory T cells. The treatment has been best studied in patients with chronic GVHD (both pediatric and adult patients), but most studies are not randomized and it is difficult to know whether the treatment is more effective than the alternatives. The clinical studies of ECP in adults with acute GVHD are few and not randomized; it is not possible to judge whether this treatment should be a preferred second- or third-line treatment. There is no evidence for increased risk of leukemia relapse or suppression of specific graft versus leukemia reactivity by this treatment, so specific antileukemic immunotherapy may still be possible. Thus, even though the treatment seems effective in patients with GVHD, further clinical (especially randomized) as well as biological studies with careful standardization of the treatment are needed before it is possible to conclude how ECP should be used in acute and chronic GVHD.

Results From a Prospective, Open-Label, Phase II Trial of Bendamustine in Refractory or Relapsed T-Cell Lymphomas: The BENTLY Trial

Purpose

To determine the efficacy and safety of bendamustine as a single agent in refractory or relapsed T-cell lymphomas.

Patients and Methods

Patients with histologically confirmed peripheral T-cell lymphoma (PTCL) or cutaneous T-cell lymphoma who progressed after one or more lines of prior chemotherapy received bendamustine at 120 mg/m2 per day on days 1 through 2 every 3 weeks for six cycles. The primary end point was overall response rate (ORR). Secondary end points were duration of response (DOR), progression-free survival (PFS), and overall survival (OS).

Results

Of the 60 patients included, 27 (45%) were refractory to their last prior chemotherapy, and the median duration of the best previous response was 6.6 months. Histology was predominantly angioimmunoblastic lymphadenopathy and PTCL not otherwise specified. The disease was disseminated in the majority of patients (87%). The median number of previous lines of chemotherapy was one (range, one to three). Twenty patients (33%) received fewer than three cycles of bendamustine, mostly because of disease progression. In the intent-to-treat population, the ORR was 50%, including complete response in 17 patients (28%) and partial response in 13 patients (22%). Bendamustine showed consistent efficacy independent of major disease characteristics. The median values for DoR, PFS, and OS were 3.5, 3.6, and 6.2 months, respectively. The most frequent grade 3 to 4 adverse events were neutropenia (30%), thrombocytopenia (24%), and infections (20%).

Conclusion

Bendamustine showed an encouraging high response rate across the two major PTCL subtypes, independent of age and prior treatment, with acceptable toxicity in refractory or relapsed T-cell lymphoma.

Large granular lymphocytic leukemia: molecular pathogenesis, clinical manifestations, and treatment

Large granular lymphocyte (LGL) leukemia represents a spectrum of rare lymphoproliferative diseases defined by clonal amplification of either CD3+ cytotoxic T-lymphocytes or CD3− natural killer cells. This chapter focuses on the T-cell form of LGL leukemia. Clinical features include neutropenia, anemia, and rheumatoid arthritis. LGL leukemia is thought to arise from chronic antigenic stimulation, with the long-term survival of LGL being promoted by constitutive activation of multiple survival signaling pathways, such as the JAK/STAT3, sphingolipid, and Ras/MEK/ERK pathways. Therefore, these lead to global deregulation of apoptosis and resistance to normal pathways of activation-induced cell death. The majority of LGL leukemia patients eventually need treatment. Treatment of leukemic LGL is based on immunosuppressive therapy, primarily using low doses of methotrexate or cyclophosphamide. However, no standard therapy has been established because of the lack of large, prospective trials. In addition, because some patients are refractory to currently available treatments and none of these therapeutic modalities can cure LGL leukemia, new therapeutic options are needed. Understanding the current state of the pathogenesis of LGL leukemia may provide insights into novel therapeutic options.