The relevance of the CD4+ CD26- subset in the identification of circulating Sézary cells

BACKGROUND: The lack of specific markers for the phenotyping of circulating neoplastic T cells in Sézary syndrome (SS) patients makes it difficult both to ascertain the presence of clonal cells and to quantify the tumour burden in the peripheral blood. In previous reports we showed that the lack of CD26 (dipeptidyl-aminopeptidase IV) is a characteristic feature of circulating Sézary cells (SC). OBJECTIVES: The purpose of this study was to ascertain, by means of high-resolution two-, three- or four-parameter flow cytometry, the relationship between CD26 expression on peripheral blood lymphocytes and peripheral blood involvement in cutaneous T-cell lymphoma patients and to assess its significance in SS diagnosis. METHODS: The patient population included 52 SS patients, 151 mycosis fungoides (MF) patients at different clinical stages (including 14 with blood involvement, B1-MF), 88 patients with erythrodermic inflammatory skin diseases (EISD) and 72 healthy donors (HD). CD26+ values were available in all cases, whereas CD4+ CD26- level measurement was performed in 23 SS, 141 MF, 71 EISD and 72 HD. RESULTS: CD4+ CD26- percentage values were higher than 30% in all but one B1-MF and higher than 40% in all SS cases, whereas HD, EISD and B0-MF patient values were always lower than 30%. A statistically significant difference was found in both CD26- and CD4+ CD26- percentage and absolute values between SS and HD, EISD and B0-MF patients. The CD26- and CD4+ CD26- percentage values (but not the absolute values) were significantly higher in B1-MF compared with HD, EISD and B0-MF patients (P < 0.001). Moreover, CD26- absolute values and CD4+ CD26- percentage and absolute values were significantly higher in SS than in B1-MF (P < 0.001). A statistically significant direct relationship was found between CD4+ CD26- percentage values and the percentage of circulating SC within the lymphoid population in SS and B1-MF (r = 0.77; P < 0.001). The lack of CD26 was confirmed on phenotypically clonal cells in patients with an expanded circulating TCRvbeta population or a T-cell antigen loss. Sorted CD4+ CD26- cells from both SS patients and HD showed the characteristic cerebriform nuclei of SC. CONCLUSIONS: We feel that a CD4+ CD26- percentage value higher than 30% of peripheral blood lymphocytes could correctly identify the presence of peripheral blood involvement in SS and MF patients.     

Absence of CD26 expression on skin-homing CLA+ CD4+ T lymphocytes in peripheral blood is a highly sensitive marker for early diagnosis and therapeutic monitoring of patients with Sézary syndrome

Patients with Sézary syndrome (SS) show clonal expansion in the peripheral blood of skin-homing CD4+ T-helper cells expressing cutaneous lymphocyte antigen (CLA). However, an increase of CLA+ CD4+ T cells can also be observed in various inflammatory dermatoses. To facilitate early diagnosis and therapeutic monitoring of SS using flow cytometry, we evaluated the expression of CD7 and CD26 on the CLA+ CD4+ lymphocyte subset. Peripheral lymphocytes from 7 patients with SS, 16 patients with mycosis fungoides (MF) and 11 healthy controls were analysed by flow cytometry for the expression of CD4, CD7, CD26, CLA and CCR4. In addition, a longitudinal study was performed over 16 months in two patients with SS. Absence of CD7 and CD26 on CLA+ CD4+ T cells was highly specific for SS. Importantly, the absence of CD26 on CLA+ CD4+ T cells was very sensitive for SS, at 100% in our patient cohort. The number of CD26- CLA+ CD4+ T cells closely correlated with therapeutic interventions in the longitudinal analysis of two patients over more than 1 year. We conclude that the absence of CD26 expression on skin-homing CLA+ CD4+ T-helper cells is a very sensitive and highly specific parameter for early diagnosis and therapeutic monitoring of patients with SS.     

Secondary malignant neoplasms in 71 patients with Sézary syndrome

BACKGROUND: Sézary syndrome (SS) is characterized by a malignant proliferation of CD4+ve T cells, which may result in a degree of immunoparesis. Immunosuppression is associated with an increased incidence of internal malignant neoplasms and a high rate of nonmelanoma skin cancer, particularly squamous cell carcinoma. Therefore, we reviewed the incidence of secondary malignant neoplasms in patients with SS. OBSERVATIONS: Of 71 patients with SS, 16 (23%) developed 19 secondary and tertiary malignant neoplasms. These malignant neoplasms included 8 cutaneous squamous cell carcinomas, 2 squamous cell carcinomas of the oral mucosa, and 9 other internal malignant neoplasms. The incidence of internal malignant neoplasms was twice that reported in patients of similar age treated for Hodgkin disease (P = .02). Furthermore, the incidence of cutaneous squamous cell carcinoma in the cohort was 42 times that observed in a study conducted in England of an age-matched population (1657 per 1 x 10(5) vs 39 per 1 x 10(5) person-years [95% confidence interval, 626-2856]). CONCLUSIONS: A number of therapeutic modalities for SS are known to be carcinogenic. We compared the different therapeutic modalities received by our patients and found no significant difference between the total cohort of patients with SS and the patients who developed secondary malignant neoplasms. These data indicate that the high incidence of secondary malignant neoplasms in patients with SS is due, at least in part, to the disease itself. The clonal proliferation of CD4+ve T cells and the relative lymphopenia (compared with a healthy population) of nonneoplastic T cells may result in compromised immunosurveillance, so that early neoplasia, whether arising spontaneously or as a result of therapy, are not dealt with appropriately.     

IL-21 enhances antitumor responses without stimulating proliferation of malignant T cells of patients with Sézary syndrome

IL-21, a common gamma-chain cytokine secreted by activated CD4+ T cells, influences both humoral and cell-mediated immune responses through the regulation of T, B, dendritic, and natural killer (NK) cells. Sézary syndrome is an advanced form of cutaneous T-cell lymphoma, a clonally derived malignancy of CD4+ T cells that is characterized by profound defects in host cellular immune function. As a modulator of both innate and adaptive immune responses, IL-21 could play an important role in augmenting cell-mediated immunity in these patients. Normal donor and Sézary syndrome patient peripheral blood mononuclear cells were cultured with IL-21 and tested for CD8+ T- and NK-cell activation, NK-cell cytotoxicity, and tumor cell proliferation and apoptosis. IL-21 resulted in a modest increase in CD8+ T- and NK-cell activation, associated with a marked increase in cytolytic activity against both K562 and malignant CD4+ T-cell targets. Although IL-21 failed to demonstrate pro-apoptotic effects on the malignant CD4+ T cells, it is noteworthy that it had no demonstrable proliferative effects on these cells. Thus, IL-21 may play an important role in enhancing the host immune response of Sézary syndrome patients through the increased cytolytic activity of T and NK cells.     

CD4(+)CD7(-) T cells compose the dominant T-cell clone in the peripheral blood of patients with Sézary syndrome

BACKGROUND: Absence of CD7 antigen expression in T cells defines a subset of normal CD4(+) CD45RO(+) CD45RA(-) memory cells and is furthermore observed in Sézary syndrome (SS). OBJECTIVE: Our purpose was to identify circulating T-cell clones in patients with SS and to elucidate whether the dominant T-cell clones express the CD7 antigen. METHODS: Peripheral blood lymphocytes of patients with SS were analyzed by two-color flow cytometry using antibodies to the V beta region of the T cell receptor (TCR) in combination with an antibody to CD7. In addition, T cells were analyzed for TCR-gamma gene rearrangement by polymerase chain reaction (PCR) techniques. RESULTS: Clonal T-cell expansion was detected in 7 patients with SS by immunostaining of the TCR V beta regions. PCR analysis confirmed the presence of dominant T cell clones. Double-immunostaining revealed that in each case cells of the clonal V beta TCR rearrangement homogeneously express the CD4(+)CD7(-) phenotype. Furthermore, CD4(+)CD7(-) cells express the CD15s antigen but lack expression of CD26 and CD49d. CONCLUSION: Expansion of clonal T cells strongly correlates with the expansion of CD4(+)CD7(-) T cells in 7 tested patients with SS. This supports our model that a subset of late differentiated, normal CD4(+)CD7(-) memory T cells may represent the physiologic counterpart of Sézary cells. Monitoring of circulating T cells with the CD4(+)CD7(-)CD15s(+)CD26(-)CD49d(-) phenotype proved to be useful for the identification of clonal T cells in patients with SS.     

Prognosis of 100 Japanese patients with mycosis fungoides and Sézary syndrome

BackgroundSurvival analysis of a large series of patients with mycosis fungoides (MF) and Sézary syndrome (SS) has not been performed in Japan. Revision to the staging system for MF and SS was recently published.ObjectiveTo determine the long-term prognosis of Japanese patients with MF and SS, to identify factors predictive of survival, and to evaluate the prognostic significance of the revised staging system.MethodsWe performed a retrospective cohort study of 100 Japanese patients with MF and SS managed at the dermatology division of Niigata University Hospital between April 1, 1982 and March 31, 2006. We estimated survival according to the patient's clinical characteristics including the stages, and assessed their prognostic significance.ResultsSurvival rates of Japanese patients with MF and SS were similar to those shown in previous studies conducted in the United States and Europe. Prognosis of patients with skin tumor (stage IIB) and extracutaneous involvement (stage IV) was significantly worse than that of those with early-stage disease (stages IA–IIA), but erythrodermic MF patients without blood involvement (stage IIIA) showed excellent survival. Independent prognostic factors in multivariate analyses were higher age and the presence of skin tumor and extracutaneous disease.ConclusionPatient age and stage are the most important clinical prognostic factors in Japanese patients with MF and SS. The revised staging system is useful for predicting survival of the patients, but at least a subpopulation of stage IIIA patients may have a favorable prognosis.     

Functional and phenotypical alterations of polymorphonuclear cells in Sézary syndrome patients

Sézary syndrome (SS), the leukemic variant of cutaneous T-cell lymphoma (CTCL), has a poor prognosis and infections represent the most frequent cause of death. Polymorphonucleate granulocytes (PMNs) constitute an essential part of the innate immune system: their phagocytic and killing activity against pathogens is mediated by the interactions between Toll-like receptors (TLRs) and the Pathogen-associated molecular patterns (PAMPs). The aim of this study was to investigate PMN functional activity and phenotype in SS patients and their correlation with the onset of infectious complications. This prospective study enrolled 18 consecutive SS patients; PMN functional activity was evaluated by phagocytosis and intracellular killing tests towards Klebsiella pneumoniae. Flow-cytometry was applied to analyze PMN phenotype. PMNs from SS patients displayed a reduced phagocytic activity and intracellular killing against K. pneumoniae at 30 min and 60 min, more pronounced in SS patients with recurrent infections. CD11b and CD66b median fluorescence intensity (MFI) was significantly higher in SS than in healthy subjects, whereas CD62L MFI was decreased. No significant differences in TLR2, 4, 8 and 9 percentage expression or MFI were found. An increased TLR5 percentage expression was documented. The impairment in PMN functional activities in SS could favour the immune-suppression and raise infection risk.     

Variable CD7 expression on T cells in the leukemic phase of cutaneous T cell lymphoma (Sézary syndrome)

CD7, a molecule normally expressed on 90% of normal CD4+ T cells, is often deficient on the malignant T cells of cutaneous T cell lymphoma. To investigate the clinical and biologic implications of CD7 expression, blood lymphocytes from 42 patients with the leukemic phase of cutaneous T cell lymphoma (CD4/CD8 ratio of 10 or more with evidence of a T cell clone in the blood) were analyzed for level of expression of CD7 by flow cytometry. CD7 expression by cells did not clearly segregate into two distinct subgroups that are either CD7 positive or CD7 negative as generally thought; however, nine of 17 patients with a predominantly CD4+CD7+ tumor population on early studies became CD4+CD7- over time whereas the converse situation was not observed. In addition, of three patients with evidence of large tumor cells in the blood coexisting with smaller cells, discordant CD7 expression was observed in one instance. In lymph node specimens, the percentage of cells expressing CD7 and other T cell markers did not correlate with histologic evidence of involvement. CD7 expression on blood lymphocytes also did not correlate with patients' survival nor to serum IgE levels or blood eosinophil counts, a finding suggesting that this marker does not identify functional cell subsets that produce serum interleukin-4 or -5, respectively. We speculate that the level of CD7 expression on malignant T cells may be the effect of sustained antigen stimulation in vivo analogous to what has been proposed to occur with normal T cells during aging.     

Expression pattern of chemokine receptors and chemokine release in inflammatory erythroderma and Sézary syndrome

BACKGROUND: Erythroderma can be caused by inflammatory dermatoses or cutaneous T-cell lymphoma. Even if chemokines and their receptors are involved in the skin-selective lymphocyte recruitment, their role in inflammatory erythroderma is yet unclear. OBJECTIVE: To evaluate the chemokine release (TARC, MDC, IP-10) and to define the expression pattern of Th1- (CCR5, CXCR3) and Th2-related (CCR4) chemokine receptors in inflammatory erythroderma and Sézary syndrome (SS). MATERIALS AND METHODS: Flow cytometry has been carried out on both circulating and skin-infiltrating T lymphocytes; serum chemokine levels have been evaluated using ELISA techniques. RESULTS: CCR4, CCR5 and CXCR3 were expressed on about 40% of peripheral blood lymphocytes and on the majority of skin-infiltrating lymphocytes in the inflammatory erythroderma patients, whereas the leukemic CD4+CD26- subpopulation in SS was characterized by a high CCR4 expression without a concurrent increase in CCR5 or CXCR3. TARC, MDC and IP-10 serum levels were significantly increased in both erythrodermic and SS patients. CONCLUSIONS: Our results confirm that SS is a Th2 disorder with a selective expression of CCR4, whereas inflammatory erythroderma shares an overexpression of both Th1- and Th2-related chemokine receptors, suggesting an activation of different pathways driving reactive lymphocytes to the skin.     

Systemic chemotherapy for the treatment of mycosis fungoides and Sézary syndrome

The treatment of mycosis fungoides and Sézary syndrome is unique. The treatments of choice are highly stage-and practitioner-dependent. For early stage patients, treatment with palliative topical therapies is often adequate to yield excellent, high-quality and durable responses. For the more advanced stages, systemic approaches are more appropriate, either alone or in combination, to palliate patients. There is still little convincing evidence from randomized trials that any single approach is favorable for improving survival. Many practitioners believe the disease can be controlled with the host immune system, but there again is little scientific support for this conclusion. It has been hypothesized that some of our therapies work through this mechanism, such as photopheresis and perhaps even psoralen and ultraviolet A. Unfortunately, even the use of biologic response modifiers, such as interferon and the interleukins, is not absolutely supportive of an active role for immune surveillance since these agents have been shown to have cytotoxic and differentiating effects. Because of the above, many practitioners have actively discouraged the use of chemotherapy because it may impair the host immune system; certainly, the purine analogs would fall into this category. However, there is little evidence supporting significant immune effects for other chemotherapeutics, and clearly, the responses seen would support their use in appropriate patients. As the present authors will detail in this paper, the advances in understanding cancer biology and mechanisms of resistance should, in the future, lead to optimal selection of agents that are predicted to be optimally active, limiting the toxicity and waste associated with ineffective drug usage.     

Mycosis fungoides and Sézary syndrome: focus on the current treatment scenario

Cutaneous T-cell lymphomas are a heterogeneous group of lymphoproliferative disorders, characterized by infiltration of the skin by mature malignant T cells. Mycosis fungoides is the most common form of cutaneous T-cell lymphoma, accounting for more than 60% of cases. Mycosis fungoides in the early-stage is generally an indolent disease, progressing slowly from some patches or plaques to more widespread skin involvement. However, 20% to 25% of patients progress to advanced stages, with the development of skin tumors, extracutaneous spread and poor prognosis. Treatment modalities can be divided into two groups: skin-directed therapies and systemic therapies. Therapies targeting the skin include topical agents, phototherapy and radiotherapy. Systemic therapies include biological response modifiers, immunotherapies and chemotherapeutic agents. For early-stage mycosis fungoides, skin-directed therapies are preferred, to control the disease, improve symptoms and quality of life. When refractory or in advanced-stage disease, systemic treatment is necessary. In this article, the authors present a compilation of current treatment options for mycosis fungoides and Sézary syndrome.     

The man behind the eponym dermatology in historical perspective: Albert Sézary and the Sézary syndrome

In a series of papers from 1938 to 1949, Albert Sézary, a French dermatologist and syphilologist, described erythroderma with cellules monstrueuses (monster cells) in the skin and blood, which is now known as Sézary syndrome or Sézary disease. This historical note reprises the life and work of Sézary. It outlines his original reports and his thoughts about the pathogenesis of the disease as a reticulosis, and lists a composite classification of the reticuloses, which includes that of Sézary. We touch briefly on the articles that first used the terms Sézary reticulosis and Sézary syndrome and the changing concepts of the reticuloses and the reticuloendothelial system. We conclude that Sézary syndrome (Sézary disease, Sézary reticulosis) cannot be separated from mycosis fungoides clinically, histopathologically, hematologically, or viscerally and, therefore, is not a disease sui generis. Despite our conclusions, present day consensus defines Sézary disease clinically as a generalized pruritic erythroderma: histopathologically with an epidermal and dermal infiltrate, lymphadenopathy and visceral involvement all containing monster cells (Lutzner/Sézary cells) in the skin, peripheral blood, lymph nodes, and viscera, a disease different and separate from mycosis fungoides.