Demonstration of Frequent Occurrence of Clonal T Cells in the Peripheral Blood of Patients With Primary Cutaneous T-Cell Lymphoma

Interleukin-13 is overexpressed in cutaneous T-cell lymphoma cells and regulates their proliferation

Cutaneous T-cell lymphomas (CTCLs) primarily affect skin and are characterized by proliferation of mature CD4(+) T-helper cells. The pattern of cytokine production in the skin and blood is considered to be of major importance for the pathogenesis of CTCLs. Abnormal cytokine expression in CTCLs may be responsible for enhanced proliferation of the malignant cells and/or depression of the antitumor immune response. Here we show that interleukin-13 (IL-13) and its receptors IL-13Rα1 and IL-13Rα2 are highly expressed in the clinically involved skin of CTCL patients. We also show that malignant lymphoma cells, identified by the coexpression of CD4 and TOX (thymus high-mobility group box), in the skin and blood of CTCL patients produce IL-13 and express both receptors. IL-13 induces CTCL cell growth in vitro and signaling through the IL-13Rα1. Furthermore, antibody-mediated neutralization of IL-13 or soluble IL-13Rα2 molecules can lead to inhibition of tumor-cell proliferation, implicating IL-13 as an autocrine factor in CTCL. Importantly, we established that IL-13 synergizes with IL-4 in inhibiting CTCL cell growth and that blocking the IL-4/IL-13 signaling pathway completely reverses tumor-cell proliferation. We conclude that IL-13 and its signaling mediators are novel markers of CTCL malignancy and potential therapeutic targets for intervention.

Current approaches to diagnostics of mycosis fungoides

The authors describe strong and weak sides of current methods for diagnostics of mycosis fungoides. Diagnostics of mycosis fungoides is mainly based on the clinical presentation of this disease, which is a significant problem for a dermatovenerologist, especially at early stages of the disease when rashes are of different types. Laboratory methods used to confirm the diagnosis are microscopic examination and immunophenotypic analysis of skin biopsy samples from the affected region as well as determination of clonality of T-lymphocytes in the skin using the PCR method.

Immunophenotypic correlation between skin biopsy and peripheral blood findings in mycosis fungoides

In mycosis fungoides (MF) with blood involvement, T-cell immunophenotypes in skin and blood have not been compared. Our aim was to evaluate T-cell immunophenotypes in skin by immunohistochemical analysis and compare results with flow cytometric (FC) findings in blood. Of 20 patients with MF with blood involvement, the immunophenotype was discrepant in 11 (55%). Compared with FC findings in blood, immunohistochemical analysis of skin samples failed to detect partial deletion of CD2 (5/11 [45%]), CD3 (3/11 [27%]), and CD5 (3/11 [27%]) and overrepresented deletion of CD7 in 2 (18%) of 11 patients. In addition, CD8+ MF was missed by immunohistochemical analysis in 2 (18%) of 11 patients. Identical T-cell populations were demonstrated by T-cell gene polymerase chain reaction in skin and blood in 8 of the 11 patients who had a discrepant immunophenotype. Awareness of the limitations of immunohistochemical analysis of skin samples is of practical value for pathologists interpreting skin biopsies in MF patients. In addition, our findings suggest CD8+ MF to be more common than previously reported.

A Comparative Study of Polymerase Chain Reaction Detection of Clonal T-cell Receptor Gamma Chain Gene Rearrangements Using Polyacrylamide Gel Electrophoresis versus Fluorescence Capillary Electrophoresis

Introduction: Polymerase chain reaction (PCR)-based molecular techniques are useful adjunctive tools in the diagnosis of cutaneous T-cell lymphomas (CTCL). This study compares the sensitivity of PCR analysis of the T-cell receptor-γ (TCR-γ) gene rearrangements using conventional polyacrylamide gel electrophoresis (PCR-PAGE) and fluorescent capillary electro-phoresis (PCR-FCE). Materials and Methods: A total of 22 paraffin blocks were analysed using PCR-PAGE and PCR-FCE. There were 17 cases of mycosis fungoides (MF), 4 cases of non-MF CTCL and 1 case of lymphoblastic leukaemia. Results: Complete agreement was obtained between PCR-PAGE and PCR-FCE in 19 of the 22 cases, giving a concordance rate of 86.4%. PCR-FCE had a higher sensitivity of 77.3%, compared to 63.6% for PCR-PAGE, allowing the detection of 3 additional cases of clonal T-cell rearrangements, which had equivocal or polyclonal bands on PAGE. Two of these 3 cases were in erythrodermic MF patients. PCR-FCE also allowed the detection of matching clones in serial specimens taken from different sites and at different time intervals in patients with MF. However, matching clones from different specimens can be achieved qualitatively in PCR-PAGE by running and comparing these on the same polyacrylamide gel block. Conclusions: Both PCR-PAGE and PCR-FCE are useful in detecting T-cell clones in CTCL, with both methods being comparable in sensitivity and showing a high concordance rate of 86.4%. PCR-FCE has the added advantage of exhibiting semiquantitative properties, which may be important in early or erythrodermic MF cases, but the requirement for sophisticated and costly machinery limits its availability to high-capacity laboratories. The well-established PCR-PAGE method is a suitable alternative in routine clinical applications. Key words: Cutaneous T-cell lymphoma, Mycosis fungoides

Revisions to the staging and classification of mycosis fungoides and Sezary syndrome: a proposal of the International Society for Cutaneous Lymphomas (ISCL) and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (EORTC)

The ISCL/EORTC recommends revisions to the Mycosis Fungoides Cooperative Group classification and staging system for cutaneous T-cell lymphoma (CTCL). These revisions are made to incorporate advances related to tumor cell biology and diagnostic techniques as pertains to mycosis fungoides (MF) and Sézary syndrome (SS) since the 1979 publication of the original guidelines, to clarify certain variables that currently impede effective interinstitution and interinvestigator communication and/or the development of standardized clinical trials in MF and SS, and to provide a platform for tracking other variables of potential prognostic significance. Moreover, given the difference in prognosis and clinical characteristics of the non-MF/non-SS subtypes of cutaneous lymphoma, this revision pertains specifically to MF and SS. The evidence supporting the revisions is discussed as well as recommendations for evaluation and staging procedures based on these revisions.

Presence of circulating CCR10+ T cells and elevated serum CTACK/CCL27 in the early stage of mycosis fungoides

PURPOSE

Mycosis fungoides (MF), a common type of cutaneous T cell lymphoma with an indolent clinical course, has the characteristic that malignant T cell clones are recruited into the skin from the early disease stages. The mechanisms of recruitment have been suggested from our knowledge of various chemokine-chemokine receptor interactions. Recently, CCR10 and CTACK/CCL27 were proposed to play a role in the recruitment of other types of cutaneous T cell lymphoma. We examined the expression of CCR10 in peripheral blood and serum CTACK/CCL27 levels in patients with MF.

EXPERIMENTAL DESIGN

Eighteen patients with MF, six patients with atopic dermatitis, and nine healthy volunteers were enrolled in our investigation. We investigated the differences in CCR10+ CD4+ expression in peripheral blood mononuclear cells by flow cytometry. Serum CTACK/CCL27 levels were determined using a CTACK/CCL27 ELISA assay kit.

RESULTS

The number of circulating CCR10+ CD4+ cells was significantly higher in MF peripheral blood than in controls, even during the early stages. In lesional MF skin, infiltrating tumor cells also showed extensive expression of CCR10. The serum level of CTACK/CCL27 was higher in patients with MF than normal controls, but no statistical difference was found compared with atopic dermatitis patients.

CONCLUSIONS

CCR10-CTACK/CCL27 interactions between circulating T cells and keratinocytes would seem to play an important role in the pathophysiology of MF from the early disease stages.

Decreased T-Cell Receptor Excision Circles in Cutaneous T-Cell Lymphoma

PURPOSE

The T cell repertoire in patients with advanced cutaneous T cell lymphoma (CTCL) is significantly contracted despite the presence of relatively normal absolute numbers of T cells. We propose that many normal T cells were being lost in patients with CTCL, with the remaining normal T cells expanding clonally to fill the T cell compartment. T-cell receptor excision circles (TREC) form as a result of the initial gene rearrangement in naïve T cells. Although they are stable, they do not replicate and are subsequently diluted with the expansion of a population of T cells. Their concentration is therefore a measure of unexpanded naïve T cells relative to T cells that have undergone expansion.

EXPERIMENTAL DESIGN

We analyzed TRECs from unfractionated peripheral blood T cells from 108 CTCL patients by quantitative PCR. In patients with obvious peripheral blood involvement, we also analyzed TRECs from clonal and nonclonal T cells.

RESULTS

We found a decrease in the number of TRECs in peripheral blood of patients with CTCL at all stages of disease, and this decrease was proportional to the loss of complexity of the T cell repertoire as measured by complementarity-determining region 3 spectratyping. In patients with leukemic CTCL and a numerically expanded clone, we also found a significantly lower-than-expected number of TRECs in the nonclonal normal T cells.

CONCLUSIONS

We hypothesize that the nonmalignant T cells have proliferated to fill the empty T cell repertoire space left by the loss of other T cells, leading to diminished TRECs and loss of T-cell receptor diversity.

Clonal heterogeneity in mycosis fungoides and its relationship to clinical course

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma characterized by multifocal disease and protracted clinical course. The few studies that have assessed T-cell receptor (TCR) gene rearrangements (GRs) present at different anatomic sites in MF have generally reported a common clone. We used a previously validated 4-color polymerase chain reaction (PCR) assay to assess the size and V-family usage of TCR-gamma GRs in 102 concurrent and/or sequential morphologically involved biopsy specimens (91 skin and 11 lymph nodes) from 39 MF patients. This assay detected TCR-gamma clonal GRs in 89 samples (87%) from 36 patients (92%). In 24 patients (77%), an identical clonal GR was present in at least 2 skin samples. However, in one third of these patients, additional different clonal GRs were also noted. Four patients (13%) had clonal GRs that were distinct in different skin samples. In 3 patients (10%), no GR was detected in any sample. In a comparison of lymph node and skin samples, 8 patients had the identical clonal GRs at both sites, 2 patients had different clonal GRs, and 1 patient had no GR identified at either site. Independent of clinical stage, patients who had the same GR detected in multiple concurrent biopsy specimens at the time of diagnosis were more likely to have progressive disease than those who had different GRs (P =.04). Four-color TCR-gamma PCR analysis can uncover multiple distinct clonal GRs in different samples consistent with multiclonal or oligoclonal disease in a significant proportion of MF patients. Demonstration of identical clonal GRs in multiple biopsy specimens at the time of diagnosis may provide prognostic information related to disease progression.

Bexarotene is effective and safe for treatment of refractory advanced-stage cutaneous T-cell lymphoma: multinational phase II-III trial results

PURPOSE

Cutaneous T-cell lymphomas (CTCL) are malignancies of T cells appearing as skin lesions and are responsive to retinoid therapy. Safety and efficacy of a novel RXR-selective retinoid (rexinoid) bexarotene (Targretin, LGD1069; Ligand Pharmaceuticals Inc, San Diego, CA) was evaluated as a single-agent oral therapy administered once daily in an open-label study in patients with refractory advanced-stage CTCL.

PATIENTS AND METHODS

Ninety-four patients with biopsy-confirmed CTCL in advanced stages (IIB-IVB) were enrolled at 26 centers. Fifty-six patients received an initial dose of 300 mg/m2/d oral bexarotene and 38 started at more than 300 mg/m2/d.

RESULTS

Clinical complete and partial responses were reported by Primary End point Classification for the study in 45% (25 of 56) of patients enrolled at 300 mg/m2/d dosing. At more than 300 mg/m2/d, 55% (21 of 38) of patients responded, including 13% (five of 38) clinical complete. For the 300 mg/m2/d initial dose group, the rate of relapse after response was 36% and the projected median duration of response was 299 days. Improvements were also seen in overall body-surface area involvement, median index lesion surface area, adenopathy, cutaneous tumors, pruritus, and CTCL-specific quality of life. The most frequent drug-related adverse events included hypertriglyceridemia (associated rarely with pancreatitis), hypercholesterolemia, hypothyroidism, and headache.

CONCLUSION

Bexarotene is the first in a novel class of pharmacologic agents, the RXR-selective retinoids, or rexinoids. Bexarotene is orally administered, safe, and generally well tolerated with reversible side effects, and is effective for the treatment of advanced, refractory CTCL.

Decreased expression of Fas (APO-1/CD95) on peripheral blood CD4+ T lymphocytes in cutaneous T-cell lymphomas

BACKGROUND

The usually protracted and indolent course of cutaneous T-cell lymphoma (CTCL) is consistent with an accumulation of lymphocytes rather than being a true proliferative disorder, perhaps as the result of defective lymphocyte apoptosis. Fas (CD95) is the main signalling membrane molecule involved in postactivation T-lymphocyte apoptosis.

OBJECTIVES

To evaluate expression of Fas on circulating CD4+ lymphocytes in patients with CTCL.

METHODS

Fas expression on peripheral blood CD4+ T cells in 16 patients with mycosis fungoides (patch and infiltrated plaque stages) and in four patients with Sézary syndrome was compared with that in 25 matched patients with lymphocyte-mediated cutaneous benign inflammatory disorders and in 15 subjects without inflammatory cutaneous diseases.

RESULTS

Fas expression on peripheral CD4+ lymphocytes was significantly lower in patients with CTCL compared with subjects with benign inflammatory cutaneous disorders and with healthy donors.

CONCLUSIONS

This pattern supports the hypothesis that a defect in T-cell apoptosis may play a part in the pathophysiology of CTCL, perhaps through abnormalities of the Fas/Fas ligand system. Alternatively, this decrease could be the result of the presence of the soluble Fas ligand molecule in the sera of patients with CTCL.

Diagnostic value of dominant T-cell clones in peripheral blood in 363 patients presenting consecutively with a clinical suspicion of cutaneous lymphoma

It is now widely accepted that polymerase chain reaction (PCR) analysis of cutaneous T-cell clonality is of diagnostic value in cutaneous T-cell lymphomas (CTCLs) and most helpful in the diagnosis of mycosis fungoides (MF). However, the diagnostic and prognostic value of circulating clonal T cells remains unclear. We studied T-cell clonality in the peripheral blood (PB) and the cutaneous lesion, sampled at the same time, in 363 consecutively seen patients with a clinical suspicion of cutaneous lymphoma. Using a PCR technique providing a specific imprint of T-cell clones (PCRγ–denaturing gradient gel electrophoresis), we found that detection of identical circulating and cutaneous T-cell clones was associated with the diagnosis of CTCL (P < .001). Detection of circulating tumor cells in patients with MF was infrequent (12.5%), except in those with erythrodermic MF (42%; P = .003). Moreover, among the 46 patients who had identical circulating and cutaneous T-cell clones, 25 (56%) had erythroderma. The finding of a dominant clone in the PB but not in the skin was frequent, regardless of the clinicohistologic classification; it occurred in 30% of patients with CTCL, 41% with non-CTCL malignant infiltrates, and 34% with benign infiltrates. This pattern was significantly more frequent in patients over 60 years of age (P < .002), even in the CTCL group (P < .01). In conclusion, dominant T-cell clones detected in the PB of patients with MF by using a routine PCR technique are rarely tumoral and are more often related to age. A multicenter prospective study is under way to establish the prognostic value of circulating tumor cells.

Primary cutaneous T-cell lymphoma: review and current concepts

PURPOSE

Primary cutaneous T-cell lymphomas (CTCLs) encompass a wide variety of lymphomas that are characterized by the localization of the malignant lymphocytes to the skin at presentation. Advances in molecular biologic techniques, including immunophenotyping and gene rearrangement studies to determine clonality, have led to more frequent diagnosis of CTCL as well as more consistent subclassification of these entities. However, there continues to be confusion in the classification, prognosis, and management of patients with CTCL. The purpose of this review is to present a summary of the diagnosis, prognosis, and treatment of CTCL, with specific emphasis on mycosis fungoides (MF) and Sézary syndrome (SS). We also present a detailed discussion of the entities that make up the differential diagnosis of CTCL.

DESIGN

We reviewed the medical literature on CTCL and other diseases that make up the differential diagnosis of CTCL.

RESULTS AND CONCLUSION

MF and SS are the most common forms of CTCL. The etiology of this disease is still unknown. Patients may go for months to years with skin abnormalities before being diagnosed. MF/SS is an indolent disease and patients with T1 disease have a normal life expectancy. Patients who undergo transformation to large-cell lymphoma (8% to 23% of patients) have a poor prognosis, with mean survival ranging from 2 to 19 months. Treatment for MF/SS continues to be palliative. There are many new therapies that are currently being investigated in clinical trials, and the DAB(389)IL-2 fusion protein was recently approved for the treatment of refractory MF/SS.

Demonstration of Frequent Occurrence of Clonal T Cells in the Peripheral Blood But Not in the Skin of Patients With Small Plaque Parapsoriasis

Clinical, immunohistological, and molecular biological data suggest the chronic dermatosis small plaque parapsoriasis (SPP) to be a precursor of mycosis fungoides (MF). However, most data are contradictory and confusing due to inexact definition of SPP. Recently, clonal T cells were detected in skin and blood samples of early MF. Because demonstration of identical T-cell clones in skin and blood of SPP patients would indicate a close relationship of SPP to MF, we investigated the clonality of skin and blood specimens from 14 well-defined SPP patients. By a polymerase chain reaction (PCR) amplifying T-cell receptor γ rearrangements and subsequent high-resolution electrophoresis, clonal T cells were detected in 9 of 14 initial and 32 of 49 follow-up blood samples, but in 0 of 14 initial skin specimens. Even a clone-specific PCR showing the persistence of the initial blood T-cell clone in 20 of 20 follow-up samples, failed to detect the T-cell clone in the skin. In 2 patients, the clonal T cells were shown to be CD4+. For the first time, the majority of SPP patients was shown to carry a T-cell clone in the peripheral blood. Although a relation between circulating clonal T cells and SPP cannot directly be proven by the applied techniques, our results indicate blood T-cell clonality to be a characteristic feature of SPP and CTCL because analysis of multiple controls and clinical workup of our SPP patients excluded other factors simulating or causing a clonal T-cell proliferation. A sufficient cutaneous antitumor response but also an extracutaneous origin of the T-cell clones might explain the failure to detect skin infiltrating clonal T cells.

Treatment of multifocal primary cutaneous B-cell lymphoma: a clinical follow-up study of 29 patients

PURPOSE

Although patients with primary cutaneous B-cell lymphoma (CBCL) and localized skin lesions are generally treated with radiotherapy and have an excellent prognosis, the clinical behavior and optimal treatment of CBCL presenting with multifocal skin lesions are less well defined. In this study, we evaluated the clinical behavior of and results of treatment for multifocal CBCL in 29 patients, and we formulated therapeutic guidelines.

PATIENTS AND METHODS

The study group included 16 patients with primary cutaneous follicular center-cell lymphoma (PCFCCL), eight with primary cutaneous immunocytoma (PCI), and five with primary cutaneous large B-cell lymphoma presenting on the legs (PCLBCL of the leg).

RESULTS

Only one of the 24 patients with multifocal PCFCCL or PCI developed extracutaneous disease, and no patient died from lymphoma (median follow-up, 54 months). In patients with PCFCCL, treatment with either multiagent chemotherapy (nine patients) or radiotherapy directed toward all skin lesions (five patients) proved equally effective in terms of complete remission, relapse, and survival. In contrast, all five patients with PCLBCL of the leg developed extracutaneous disease, and four of the five died from systemic lymphoma, 8 to 36 months (median, 21 months) after diagnosis.

CONCLUSION

The results of these preliminary studies suggest that patients with PCFCCL or PCI presenting with multifocal skin lesions have the same excellent prognosis that patients with localized PCFCCL or PCI have and that radiotherapy directed toward all skin lesions is as effective as multiagent chemotherapy. Patients with PCLBCL of the leg have a more unfavorable prognosis, particularly patients presenting with multifocal skin lesions. This last group should always be treated with multiagent chemotherapy.