New perspectives in experimental and clinical research for cutaneous T cell lymphomas

Oral bexarotene in a therapy-resistant Sezary syndrome patient: observations on Sezary cell compartmentalization

BACKGROUND

A 63-year-old man with therapy-resistant Sézary syndrome was enrolled in a multicenter trial of oral bexarotene for advanced-stage cutaneous T-cell lymphoma (CTCL).

METHODS

Monthly evaluations for efficacy and side-effects were conducted and documented.

RESULTS

Gradual improvement in erythema, pruritus, and scale was noted during the initial 16-week trial period and treatment was extended to 40 weeks. From week 20 to week 40, the erythroderma continued to improve and the lymph node burden decreased, but the absolute Sézary cell count inversely increased. By week 40, intractable pruritus and erythroderma abruptly recurred, and bexarotene was discontinued.

CONCLUSIONS

Bexarotene is well tolerated and can be efficacious in patients with Sézary syndrome. Shifting of Sézary cells between different compartments was noted. Further studies on the interaction between the skin, lymph nodes, and peripheral blood compartments during bexarotene treatment in this subset of patients with CTCL are needed.

Multilineage progression of genetically unstable tumor subclones in cutaneous T-cell lymphoma

Molecular analysis of solid malignant tumors has suggested multilineage progression of genetically unstable subclones during early stages of tumorigenesis as a common mechanism of tumor cell evolution. We have investigated whether multilineage progression is a feature of cutaneous T-cell lymphoma (CTCL). To identify individual tumor cell subclones, we determined the pattern of mutations within microsatellite DNA obtained from multiple histomorphologically confined tumor cell nests of mycosis fungoides (MF) and lymphomatoid papulosis (LyP) lesions. Tumor cells were isolated by laser microdissection, and allelotypes were determined at microsatellite markers D6S260, D9S162, D9S171, D10S215, TP53.PCR15, and D18S65. Nine cases of MF and one patient with anaplastic large cell lymphoma (ALCL) originating from LyP were analyzed at 277 different microdissected areas obtained from 31 individual lesions. Three specimens of cutaneous lichen planus microdissected at 26 areas served as the control tissue. Microsatellite instability in microdissected tissue [MSI(md-tissue)] was detected in tumor tissues of all CTCL patients. One hundred and fifty-seven of 469 analyzed polymerase chain reaction (PCR) amplifications contained mutated microsatellite alleles (34%). In lichen planus, MSI(md-tissue) was seen in only four of 76 PCR products (5%) (P < 0.0001). The distribution of allelotypes in tumor cells from different disease stages was consistent with multilineage progression in five MF cases, as well as in the LyP/ALCL patient. Our results suggest that CTCL may evolve by multilineage progression and that tumor subclones in MF can be detected in early disease stages by mutation analysis of microsatellite DNA obtained from multiple microdissected areas.

Complete molecular remission during biologic response modifier therapy for Sézary syndrome is associated with enhanced helper T type 1 cytokine production and natural killer cell activity

BACKGROUND

Cutaneous T-cell lymphoma (CTCL) is a clonally derived, skin-invasive malignancy of CD4(+) T lymphocytes with the phenotype of mature helper T cells. Advancing stages of CTCL are associated with depressed cell-mediated immunity, increased production of T helper type 2 cytokines and decreased levels of T helper type 1 cytokines.

OBJECTIVE

Our purpose was to evaluate the cytokine secretion pattern and cell-mediated cytotoxicity in peripheral blood mononuclear cells of patients with Sézary syndrome in relation to the presence of the malignant clone.

METHODS

Serial polymerase chain reaction for the T-cell receptor-beta or T-cell receptor-gamma gene rearrangement was used to determine the presence of the malignant clone. Enzyme-linked immunosorbent assays were used to determine the levels of interleukin 4 and interferon gamma produced by the peripheral blood mononuclear cells from the patients with Sézary syndrome.

RESULTS

We demonstrate 3 cases of Sézary syndrome with typically suppressed cell-mediated cytotoxicity, elevated production of interleukin 4, and depressed production of interferon gamma by their peripheral blood mononuclear cells before institution of therapy with biologic response modifier therapy. In all 3 cases after clinical and molecular remission, we observed striking immunologic changes, including an increase in levels of natural killer cell activity and interferon gamma production and decreased production of interleukin 4.

CONCLUSIONS

The observation that the cytokine secretion pattern by peripheral blood mononuclear cells from 3 patients with Sézary syndrome normalized with the disappearance of the malignant clone from the peripheral blood suggests that the malignant T cells account for the aberrant cytokine production. Moreover, the aberrant cytokine production may be the cause for suppression of cell-mediated immunity seen in advancing stages of CTCL.

Cytokines and cutaneous T-cell lymphomas

Cytokines are considered to be of major importance for the pathogenesis of cutaneous T-cell lymphomas (CTCL). Their impact may result from autocrine, paracrine or endocrine effects. Several investigations demonstrated the overexpression of different cytokines in different CTCL entities. Interestingly, stage-dependent shifts in the cytokine pattern have been observed in mycosis fungoides (MF). There is evidence that the abnormal cytokine expression in CTCL might be responsible for tumor progression, resulting from an enhanced proliferation of the malignant cells and/or the depression of the anti-tumor immune response. Moreover, cytokine loops might explain phenomena like the epidermotropism of malignant cells or eosinophilia and increased plasma levels of IgE, which are present in advanced stages of CTCL. Analysis of the cytokine pattern in CTCL might give the basis for direct therapeutic intervention into the cytokine network as a new therapeutic approach. In this review, the current knowledge regarding cytokines in CTCL is summarized.

Progression of mycosis fungoides is associated with increasing cutaneous expression of interleukin-10 mRNA

Cytokines are believed to play an important role in the pathogenesis of cutaneous T cell lymphoma. Data regarding the local cytokine pattern in mycosis fungoides (MF) are partly conflicting. Recent studies have suggested a shift from type 1 to type 2 cytokine pattern because IL-4 and IL-5 mRNA have been more frequently detected in lesions of advanced stages. Another study has described a type 1 cytokine pattern in MF lesions. None of the previous studies of cytokine mRNA expression in MF, however, used quantitative methods, and therefore only the presence of a cytokine, but not the level of expression, could be determined. To gain better insight into the development of cytokine pattern during tumor progression we used semiquantitative reverse transcriptase-polymerase chain reaction to analyze cytokine mRNA expression in MF skin lesions at different stages. Biopsies from patients with patch (n = 11), plaque (n = 6), and tumor (n = 3) stage MF were compared with biopsies from patients with pleomorphic T cell lymphoma (n = 5), psoriasis (n = 7), atopic dermatitis (n = 5), and nonlesional skin (n = 8). MF progression was associated with significantly higher IL-10 and lower interferon-gamma mRNA expression. Moreover, the stage-dependent increase in IL-10 mRNA expression was also found in paired samples from individual patients. Unlike in pleomorphic T cell lymphoma, however, typical T helper 2 cells did not seem to be the source of increasing IL-10 in advanced MF, because stage-independent IL-4 mRNA was rarely detected, suggesting contribution of nonlymphoid cells to local IL-10 production. The overexpression of IL-10 in MF may be of importance for tumor progression, because this immunosuppressive cytokine might be involved in downregulation of immunologic tumor surveillance.