Leu-8/CD7 antigen expression by CD3+ T cells: comparative analysis of skin and blood in mycosis fungoides/Sézary syndrome relative to normal blood values

Multidisciplinary Approach to the Diagnosis and Therapy of Mycosis Fungoides

Mycosis fungoides is the most common primary cutaneous T-cell lymphoma, characterized by skin-homing CD4+ T cells derivation, indolent course, and low-grade of malignancy. Mycosis fungoides's classic type typically onsets with cutaneous erythematous patches, plaque, and tumor. In WHO-EORTC classification, folliculotropic mycosis fungoides, pagetoid reticulosis, and granulomatous slack skin are recognized as distinct variants of mycosis fungoides, because of their clinical and histological features, behavior, and /or prognosis. Mycosis fungoides often shows diagnostic difficulties, due to its absence of specific features and lesional polymorphism. A patient's treatment requires staging. In about 10% of cases, mycosis fungoides can progress to lymph nodes and internal organs. Prognosis is poor at advanced stage and management needs a multidisciplinary team approach. Advanced stage disease including tumors, erythroderma, and nodal, visceral, or blood involvement needs skin directed therapy associated with systemic drugs. Skin directed therapy includes steroids, nitrogen mustard, bexarotene gel, phototherapy UVB, and photochemiotherapy, i.e., total skin electron radiotherapy. Systemic therapies include retinoids, bexarotene, interferon, histone deacetylase inhibitors, photopheresis, targeted immunotherapy, and cytotoxic chemotherapy. Complexity of mycosis fungoides associated with long-term chronic evolution and multiple therapy based on disease stage need a multidisciplinary team approach to be treated.

CAR-T cell development for Cutaneous T cell Lymphoma: current limitations and potential treatment strategies

Chimeric antigen receptor (CAR)-T therapy has demonstrated remarkable outcomes for B cell malignancies, however, its application for T cell lymphoma, particularly cutaneous T cell lymphoma (CTCL), has been limited. Barriers to effective CAR-T cell therapy in treating CTCL include T cell aplasia in autologous transplants, CAR-T product contamination with leukemic T cells, CAR-T fratricide (when the target antigen is present on normal T cells), and tumor heterogeneity. To address these critical challenges, innovative CAR engineering by targeting multiple antigens to strike a balance between efficacy and safety of the therapy is necessary. In this review, we discuss the current obstacles to CAR-T cell therapy and highlight potential targets in treating CTCL. Looking forward, we propose strategies to develop more powerful dual CARs that are advancing towards the clinic in CTCL therapy.

Subtlety of Granulomatous Mycosis Fungoides: A Retrospective Case Series Study and Proposal of Helpful Multimodal Diagnostic Approach With Literature Review

ABSTRACT

Granulomatous mycosis fungoides (GMF) harbors a worse prognosis compared with classic MF and remains a significant diagnostic dilemma. We analyzed clinicopathologic, immunophenotypic, and molecular characteristics of GMF to develop a diagnostic algorithm. Our methodology involved a retrospective case series study of patients with GMF from our database between 2014 and 2020. A total of 8 patients with 9 biopsies of GMF were identified. Skin manifestations had variable clinical phenotype. Histologically, all cases demonstrated atypical CD4+ T-cell infiltrate with scant in 50% (n = 4), focal 37.5% (n = 3), and absent 25% (n = 2) epidermotropism. Granuloma formation was seen in 77.8% biopsies (n = 7) with sarcoid-type granulomas in 57.1% (n = 4) and granuloma annulare-like type in 42.9% (n = 3). In 66.7% of biopsies (n = 6), the CD4:CD8 ratio was >4:1 and 66.6% (n = 6) of biopsies showed ≥50% loss of CD7 expression. T-cell receptor gene rearrangement studies performed on biopsy sections were positive in all biopsies (n = 6), whereas peripheral blood T-cell receptor gene rearrangement studies did not identify clonality. In conclusion, GMF has subtle or absent epidermotropism and variable granulomatous reaction; thus, the diagnosis requires a multimodal approach, and our proposed algorithm provides a framework to approach this diagnostic challenge.

Flow cytometry for the assessment of blood tumour burden in cutaneous T-cell lymphoma: towards a standardised approach

Mycosis fungoides (MF) and Sézary syndrome (SS) are the best-studied subtypes of cutaneous T-cell lymphoma, a rare non-Hodgkin lymphoma that primarily presents in the skin but can also involve blood, lymph nodes, and viscera. The role of blood involvement in the assessment and staging of MF and SS has evolved in recent years from being classed as simply 'present' or 'absent', with no impact on staging, to full analysis of abnormal peripheral-blood T cells using flow cytometry (FC) to detect and quantify aberrant T-cell phenotypes and polymerase chain reaction (PCR) to characterise T-cell receptor gene rearrangements. These sensitive peripheral-blood assessments are replacing manual Sézary cell counts and have become an important part of clinical work-up in MF and SS, providing the potential for more accurate prognostication and appropriate management. However, although international recommendations now include guidelines for FC analysis of peripheral-blood markers for staging purposes, many clinics only perform these analyses in advanced-stage patients, if at all, and there is still a need for standardised use of validated markers. Standardisation of a single effective multiparameter FC panel would allow for accurate identification and quantification of blood tumour burden for diagnosis, staging, assessment of therapeutic response, and monitoring of disease progression at all stages of disease. Once defined, validation of an MF/SS biomarker FC panel will enable uptake into clinical settings along with associated standardisation of protocols and reagents. This review discusses the evolution of the role of FC in evaluating blood involvement in MF and SS, considers recently published international guidelines, and identifies evidence gaps for future research that will allow for standardisation of FC in MF and SS.

The Serine Protease CD26/DPP4 in Non-Transformed and Malignant T Cells

Simple Summary

The transmembrane serine protease CD26/Dipeptidylpeptidase 4 modulates T-cell activation, proliferation, and effector function. Due to their remarkable tumoricidal properties CD26-positive T cells are considered promising candidates for T cell-based immunotherapies while in cutaneous T cell lymphoma CD26/DPP4 expression patterns are established markers for diagnosis and possibly prognosis. With a focus on T cells, we review current knowledge on the regulation of CD26/DPP4 expression and release, its implication in T-cell effector function and the suitability CD26/DPP4 as a diagnostic and/or prognostic factor in T-cell malignancies.

Abstract

CD26/Dipeptidylpeptidase 4 is a transmembrane serine protease that cleaves off N-terminal dipeptides. CD26/DPP4 is expressed on several immune cell types including T and NK cells, dendritic cells, and activated B cells. A catalytically active soluble form of CD26/DPP4 can be released from the plasma membrane. Given its wide array of substrates and interaction partners CD26/DPP4 has been implicated in numerous biological processes and effects can be dependent or independent of its enzymatic activity and are exerted by the transmembrane protein and/or the soluble form. CD26/DPP4 has been implicated in the modulation of T-cell activation and proliferation and CD26/DPP4-positive T cells are characterized by remarkable anti-tumor properties rendering them interesting candidates for T cell-based immunotherapies. Moreover, especially in cutaneous T-cell lymphoma CD26/DPP4 expression patterns emerged as an established marker for diagnosis and treatment monitoring. Surprisingly, besides a profound knowledge on substrates, interaction partners, and associated signal transduction pathways, the precise role of CD26/DPP4 for T cell-based immune responses is only partially understood.

Evaluation of the International Society for Cutaneous Lymphoma Algorithm for the Diagnosis of Early Mycosis Fungoides

The International Society for Cutaneous Lymphoma (ISCL) proposes a diagnostic algorithm for early mycosis fungoides (MF) that includes clinical, histological, immunophenotypical, and molecular criteria. Here, we analyzed the immunologic markers and features of T-cell clonality in 38 early MF cases and 22 non-MF cases to validate the ISCL algorithm. We found that CD5 and CD7 expression differed significantly between early MF and non-MF cases, with epidermal discordance of CD7 expression more frequently identified in early MF. Notably, increasing the cut-off value for CD7 expression from 10% to 22.5% improved its sensitivity. Furthermore, TCR-γ and β chain rearrangements were more frequently detected in early MF than in non-MF cases. Based on these findings, we propose CD5 and CD7 deficiency as mandatory immunopathologic criteria and PCR-based testing for TCR-γ and β chains as required molecular/biologic criteria to improve the efficiency of early MF diagnosis using the ISCL algorithm.

Diagnosis of Early Mycosis Fungoides

Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphomas, generally has a favorable clinical course. Early MF typically presents erythematous patches and/or plaques and lasts for many years without affecting the life expectancy. Only limited cases progress to develop skin tumors, with subsequent lymph nodes and rarely visceral organ involvement. One of the clinical problems in early MF is the difficulty in differentiating the disease from benign inflammatory disorders (BIDs), such as atopic dermatitis, chronic eczema, and psoriasis. In some MF cases, clinical and pathological findings are similar to those of BIDs. However, the accurate diagnosis of early MF is quite important, as inappropriate treatment including immunosuppressants can cause unfavorable or even fatal outcomes. This article focuses on general methods and novel tools for diagnosis of early MF.

The immunopathogenesis and immunotherapy of cutaneous T cell lymphoma: Pathways and targets for immune restoration and tumor eradication

Cutaneous T cell lymphomas (CTCLs) are malignancies of skin-trafficking T cells. Patients with advanced CTCL manifest immune dysfunction that predisposes to infection and suppresses the antitumor immune response. Therapies that stimulate immunity have produced superior progression-free survival compared with conventional chemotherapy, reinforcing the importance of addressing the immune deficient state in the care of patients with CTCL. Recent research has better defined the pathogenesis of these immune deficits, explaining the mechanisms of disease progression and revealing potential therapeutic targets. The features of the malignant cell in mycosis fungoides and Sézary syndrome are now significantly better understood, including the T helper 2 cell phenotype, regulatory T cell cytokine production, immune checkpoint molecule expression, chemokine receptors, and interactions with the microenvironment. The updated model of CTCL immunopathogenesis provides understanding into clinical progression and therapeutic response.

Phenotypical Markers, Molecular Mutations, and Immune Microenvironment as Targets for New Treatments in Patients with Mycosis Fungoides and/or Sézary Syndrome

Primary cutaneous lymphomas encompass a wide spectrum of rare lymphoproliferative disorders originating in the skin, among which, mycosis fungoides (MF) is the most common subtype. The treatment of this disease is based on skin-directed therapies eventually in association with biologic response modifiers in the early phases, whereas in patients with the advanced stages, several therapeutic strategies can be used including mono and/or polychemotherapy and bone marrow transplantation. In recent years, the identification of specific markers (phenotypical, immunological, and molecular) has led to the development of several studies (including two randomized phase III trials). The results of these studies are modifying our therapeutic strategy toward a personalized treatment approach in which the clinical characteristics of the patients and tumor-node-metastasis-blood stage are considered together with the expression of specific markers (i.e., a CD30-positive expression for the use of brentuximab vedotin). This review will provide a comprehensive scenario of the main phenotypical, molecular, and immunological markers related to MF pathogenesis and disease evolution, which could represent the target for the development of innovative effective treatments in this disease.

Validation of an algorithm based on clinical, histopathological and immunohistochemical data for the diagnosis of early-stage mycosis fungoides

Background

Diagnosis of mycosis fungoides is challenging due to the non-specificity of clinical and histopathological findings. The literature indicates an average delay of 4–6 years for a conclusive diagnosis. Refinement of the histopathological criteria for the diagnosis of patients in early stages of the disease is considered of interest.

Objectives

To study the histopathological aspects of early-stage mycosis fungoides and the applicability, in a retrospective form, of the diagnostic algorithm proposed by Pimpinelli et al.

Methods

Observational, retrospective, transversal study based on revision of histopathological exams of patients with suspected mycosis fungoides. Medical records were reviewed, and complementary immunohistochemistry performed.

Results

Sixty-seven patients were included. The most frequent histopathological features were superficial perivascular lymphoid infiltrate (71.6%), epidermotropism (68.7%), lymphocytic atypia (63.8%), hyperkeratosis (62.7%) and acanthosis (62.7%). Forty-three patients scored 4 points at the algorithm, by clinical and histological evaluation. Immunohistochemistry was performed on 23 of the 24 patients with less than 4 points. Of those 23, 22 scored 1 point, allowing a total of 61 patients (91%) with the diagnosis of early-stage mycosis fungoides.

Study limitations

Its retrospective character, reduced sample size and incomplete application of the algorithm.

Conclusions

Application of the Pimpinelli et al. algorithm, even in an incomplete form, increased the percentage of cases diagnosed as mycosis fungoides. Routine application of the algorithm may contribute to earlier and specific management and improvement of the patients’ outcome.

Mycosis Fungoides: A Clinicopathological Study of 60 Cases from a Tertiary Care Center

Background:

Mycosis fungoides (MF) is the most common primary cutaneous lymphoma. It affects usually the covered areas of the body in elderly males in 6^th and 7^th decades of life. Atypical dermal lymphoid infiltrate is seen along with epidermotropism. Nuclei of neoplastic cells are convoluted. The neoplastic cells demonstrate positivity for CD3 (Pan T) immunohistochemical stain. Majority show increased CD4 to CD8 ratio. The present study was done to study the clinicopathological features, which might be of help in reaching a correct diagnosis in these cases.

Materials and Methods:

A retrospective descriptive study was conducted on 60 reported cases of MF. The retrieved slides were reviewed for clinical and histopathological features and immunohistochemical profile.

Results:

The ages ranged from 20–84 years, mean age was 47 years. Majority (75%) of patients were male. Trunk and extremities were the sites most commonly affected. There was significant inverse correlation between epidermal thickness and tumor stage (P = 0.02). Thickened epidermis was seen in patch stage and thickness reduced with progressing stage. The intensity of dermal infiltrate and cell size was also statistically significantly linked to stage progression (P < 0.001 each). In addition, proliferation index also correlated significantly with tumor stage (P = 0.002).

Conclusion:

Clinical information and histological features are equally important in the accurate diagnosis of MF. Papillary dermal fibrosis is a useful diagnostic clue. CD4:CD8 ratio is not increased in all cases; it may be decreased or remain unchanged.

Follicular Eruption With Folliculotropic Lymphocytic Infiltrates Associated With Iatrogenic Immunosuppression: Report and Study of 3 Cases, and Review of the Literature

BACKGROUND

Several cases of folliculotropic mycosis fungoides, associated with immunosuppressive therapy, including calcineurin inhibitors, have been reported in solid organ transplant patients. We have encountered 3 patients on immunosuppressive therapy who developed follicular eruptions with folliculocentric infiltrates of nonatypical lymphocytes.

OBJECTIVE

To characterize these follicular eruptions and review the literature.

METHODS

Three patients, aged 7-15 years, who were treated with systemic immunosuppressive therapy developed follicular eruptions characterized histopathologically by folliculocentric lymphocytic infiltrates. These were studied clinically, histopathologically, immunophenotypically, and molecularly for T-cell receptor (TCR) gene rearrangement.

RESULTS

All 3 cases were characterized histopathologically by folliculocentric infiltrates of nonatypical CD3 T lymphocytes with variable follicular exocytosis. Two cases also showed follicular mucinosis. Marked reduction in CD7 staining, and marked predominance of CD4 cells over CD8 cells was observed in all 3 cases. The TCR gene rearrangement studies were monoclonal in 2 cases. Oral calcineurin inhibitors (2 cyclosporine A and 1 tacrolimus) were part of the therapeutic regimen in all 3 patients. Their cessation along with local corticosteroid creams in 2 patients, and phototherapy with oral acitretin in one patient, was associated with complete clinical remission.

CONCLUSIONS

Patients undergoing systemic immunosuppressive therapy that includes calcineurin inhibitors might develop follicular eruption with some immunophenotypical variations and a monoclonal TCR gene rearrangement but lack sufficient cytomorphological features of folliculotropic mycosis fungoides. Altering the immunosuppressive agent including calcineurin inhibitors may result in regression of the eruptions.

Follicular eruption with folliculotropic lymphocytic infiltrates associated with anti-tumor necrosis factor alpha therapy: Report and study of 3 cases

BACKGROUND

We have encountered three cases of follicular eruptions with folliculotropic infiltrates of non-atypical lymphocytes associated with anti-tumor necrosis factor alpha (TNF-α) therapy.

METHODS

Three patients aged 15 to 56 years treated with anti-TNF-α therapy (one with adalimumab, and two with infliximab) developed follicular eruptions characterized histopathologically by folliculotropic lymphocytic infiltrates. These were studied clinically, histopathologically, immunophenotypically, and molecularly.

RESULTS

All three cases were characterized histopathologically by folliculotropic cell infiltrates of non-atypical T (CD3+) lymphocytes with variable follicular exocytosis. Marked reduction in CD7 staining and marked predominance of CD4+ cells over CD8+ cells were observed in 1 and 2 cases, respectively. T-cell receptor (TCR) gene rearrangement studies were monoclonal in 1 case. Discontinuation of anti-TNF-α therapy in all three cases, with corticosteroid creams in 1 case, led to complete resolution. Rechallenge with adalimumab in 1 case resulted in exacerbation. Replacement of therapy with non-anti-TNF-α biologic agents in 2 cases was not associated with recurrence.

CONCLUSION

Follicular eruptions with folliculotropic lymphocytic infiltrates associated with anti-TNF-α therapy may show some immunophenotypical variations and/or monoclonal TCR gene rearrangements but lack sufficient cytomorphological features of folliculotropic MF. They may resolve with discontinuation of anti-TNF-α therapy.

Relationship Between Pityriasis Lichenoides and Mycosis Fungoides: A Clinicopathological, Immunohistochemical, and Molecular Study

BACKGROUND

Several cases of pityriasis lichenoides (PL) have been reported to evolve into mycosis fungoides (MF).

OBJECTIVE

To elucidate clues to this progression.

METHODS

Fifty-eight patients with PL between 2000 and 2013 (follow-up: 3-16 years, average: 8.3).

RESULTS

A total of 3 (5.2%) of the 58 patients with PL developed MF after 3-11 years of prolonged clinical course. Papules and small plaques characterized PLs, and patches and larger plaques subsequent MFs. A total of 35 of 41 (85%) followed up non-MF associated patients with PL reported lasting complete remissions. Histopathologically, apoptotic keratinocytes disappeared mostly or completely in subsequent MFs. The presence of epidermotropism, folliculotropism, and epidermal lymphocytic nuclear atypia in PLs was not predictive of MF. CD8 cells were the dominant intraepidermal lymphocytes in the 3 PLs but remained so in only 1 subsequent MF. CD7 lymphocytes decreased substantially in 2 MFs, and lymphocytic nuclear atypia increased markedly in 1. T-cell receptor gene rearrangement studies demonstrated clonal populations in 1 of 2 studied PLs and in all 3 subsequent MFs.

CONCLUSIONS

A few PLs may evolve into MF. Prolonged clinical course, appearance of patches and larger plaques, markedly increased lymphocytic nuclear atypia, marked diminution of apoptotic keratinocytes and CD7 and CD8 lymphocytes, and clonal T-cell receptor gene rearrangement may serve as clues.

The clinical importance of CD4+ CD7- in human diseases

The CD7 antigen is a member of the immunoglobulin superfamily that expresses on the surface of all thymocytes, a majority of mature T cells, and also natural killer cells. Interestingly, under physiological and different pathological conditions, the loss of CD7 antigen occurred in the subset of CD4⁺ memory T cells. Various functions have been proposed for CD7, including its role in the activation and intercellular adhesiveness of T cells. Several studies indicate that the number of CD4⁺ CD7^- T cells increases in diseases such as chronic inflammation and T-cell malignancies, these being skin inflammatory lesions. Therefore, this can be useful for the diagnosis of cancer cells, especially with reference to blood origin, treatment monitoring, and establishment of new therapies. Therefore, a comprehensive review could be useful to increase our knowledge about the clinical importance of these cells in human disease.

Blood flow cytometry in Sézary syndrome: new insights on prognostic relevance and immunophenotypic changes during follow-up

OBJECTIVES

Sézary syndrome (SS) is characterized by erythroderma, generalized lymphadenopathy, and the presence of circulating atypical lymphocytes, which are difficult to identify by morphologic data.

METHODS

We revised our series of 107 patients in an attempt to better define the phenotypic aberrancies in blood at diagnosis and the immunophenotypic stability over time detected by flow cytometry. Polymerase chain reaction assay was also used to study CD26/dipeptidyl peptidase IV (DPPIV) gene methylation.

RESULTS

The most common aberrancies were represented by the lack of CD26 (96/107) or CD38 (101/107) expression and the presence of a "dim" CD3, CD4, or CD2 population. There was a high variability in CD7 expression. In total, 31% of the patients had phenotypical heterogeneity in CD26 and CD7 expression at diagnosis. The phenotype was stable over time in 73 of 95 patients with available follow-up data, while 22 of 95 patients developed changes in CD26, CD7, or CD2 expression. CD4+CD26- SS showed hypermethylation of the CpG islands for the promoter region of CD26/DPPIV. Multivariate analysis showed that CD26 expression is a favorable prognostic factor (hazard ratio, 2.94; P = .045).

CONCLUSIONS

We confirm the relevance of CD26 negativity in SS diagnosis and monitoring. Nevertheless, the presence of rare CD26+ cases suggests that a multiparameter flow cytometry approach should be used. Changes in methylation profile could account for phenotypical heterogeneity.

Simplified flow cytometric assessment in mycosis fungoides and Sézary syndrome

By using flow cytometry with markers for CD3, CD4, CD26, and CD7, we examined the blood samples of 109 patients for abnormal T cells: 69 patients with mycosis fungoides (MF)/Sézary syndrome (SS), 31 hospitalized control subjects, and 9 patients with inflammatory skin disease. T cells were identified as quantitatively abnormal (>15% CD26- or CD7- T cells) or phenotypically abnormal (CD26- or CD7- T cells with bright or dim CD3 or CD4 or bright CD7). Patients were followed for a median of 82 months, and abnormal T cells were correlated with diagnosis, clinical outcome, and other laboratory parameters. Abnormal T-cell populations were identified in 46% of patients with MF/SS (32/69) and correlated with disease extent. Quantitative abnormalities were more frequent than phenotypic abnormalities, and CD4+/CD26- T cells were more frequent than CD4+/CD7- T cells. CD26- T cells correlated better with disease extent than did CD7 -. Increasing numbers of abnormal T cells were associated with worsening disease. Flow cytometry provides valuable information for diagnosis, prognosis, and therapeutic efficacy in MF/SS.

A practical approach to the flow cytometric detection and diagnosis of T-cell lymphoproliferative disorders

The flow cytometric analysis of T-cell malignancies is difficult due to the heterogeneity of T-cells and the lack of convenient methods to detect T-cell clonality. Neoplastic T-cells are most often detected by their altered level of surface antigen expression, and detection requires an extensive knowledge of the phenotype of normal T-lymphocytes. This review focuses on the methods to distinguish malignant T-cells from their normal counterparts and the phenotypic features of the T-cell lymphoproliferative disorders.

Flow cytometric detection of peripheral blood involvement by mycosis fungoides and Sézary syndrome using T-cell receptor Vbeta chain antibodies and its application in blood staging

Peripheral blood involvement has been recognized as an adverse prognostic factor in patients with mycosis fungoides and Sézary syndrome. However, accurate identification and enumeration of the neoplastic cells in these diseases can be challenging. We assessed the clinical utility of flow cytometric immunophenotypic analysis of T-cell receptor Vbeta expression in 82 mycosis fungoides and 6 Sézary syndrome patients, with an atypical T-cell immunophenotype, or abnormal CD4:CD8 ratio, identified from peripheral blood specimens of 723 patients submitted for routine mycosis fungoides/Sézary syndrome blood staging. To improve detection sensitivity, Vbeta expression was analyzed on gated CD3+CD4+ T cells or T cells with an aberrant immunophenotype, if present. The flow cytometric results were compared with traditional morphologic assessment (n=88) and molecular methods to assess the T-cell receptor gamma or beta genes (n=41 tested in parallel). Flow cytometric immunophenotyping yielded a clonal Vbeta pattern in 60/82 mycosis fungoides and 6/6 Sézary syndrome patients. By contrast, flow cytometric Vbeta was negative in all 10 healthy donors and 18 control patients, showing a specificity of 100% and concordance with molecular testing of 86%. Using flow cytometric Vbeta results instead of morphologic assessment, 12 patients were upstaged from B1 to B2, and 20 patients from B0 to B1 (P<0.0001). The 12 upstaged B2 patients had no morphologic evidence of involvement, but had an aggressive clinical course similar to those staged by traditional morphologic assessment (median survival 27 vs 41 months, log-rank P=0.701). In 30/44 patients with a tumor-associated Vbeta expression, a single Vbeta tube was used to monitor treatment response. In conclusion, flow cytometric Vbeta analysis is rapid and convenient, can assess T-cell clonality and tumor quantity simultaneously, and is useful both in initial blood staging and monitoring tumor burden during therapy in patients with mycosis fungoides or Sézary syndrome.

Prevalence of genetically defined tumor cells in CD7 as well as CD26 positive and negative circulating T-cell subsets in Sézary syndrome

For diagnosis and monitoring of Sézary syndrome flow cytometric quantification of CD7- and CD26- T-cells is widely used. Because antigen loss is a characteristic but not disease-specific finding we investigated the significance of this approach. Therefore we analyzed the prevalence of tumor cells in FACS-sorted CD7+/- as well as CD26+/- circulating T-cells applying a clone-specific qualitative and quantitative T-cell receptor PCR. Tumor cells varied considerably in the CD7+ and CD7- cell subset but were largely confined to the CD26- population. We conclude that quantification of CD26- T-cells reflects the tumor cell amount more accurate and should be preferred in the clinical setting.

Immune function abnormalities in peripheral blood mononuclear cell cytokine expression differentiates stages of cutaneous T-cell lymphoma/mycosis fungoides

PURPOSE

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma (CTCL) characterized by neoplastic skin-homing T cells. To better understand the immunopathogenesis of MF, we analyzed the functional ability of peripheral blood mononuclear cells (PBMC) from early and late MF/CTCL patients to express cytokine genes. In late stage MF/CTCL, patients were separated into those with blood involvement (+B) and without blood involvement (-B).

EXPERIMENTAL DESIGN

We analyzed T(H)1 (interleukin 2 (IL-2), IFN-gamma), T(H)2 (IL-4, IL-5, IL-10, IL-13), and T(H)17 (IL-17) cytokine gene expression from activated PBMCs from normal (n = 12), psoriasis (n = 6), early MF/CTCL (n = 11), and late MF/CTCL+B (n = 4) and MF/CTCL-B (n = 3) by quantitative real-time PCR.

RESULTS

PBMCs from early MF/CTCL and psoriasis showed higher induction of IL-2, IL-4, and IFN-gamma genes than those from normal and late MF/CTCL-B and MF/CTCL+B (P < 0.05) in descending order. PBMCs from late MF/CTCL-B exhibited generally the highest level of IL-5, IL-10, IL-13, and IL-17 expression compared with the other groups. PBMCs from early MF/CTCL and late MF/CTCL-B had similarly elevated IL-13 and IL-17. Of all groups, PBMCs from late MF/CTCL+B had the lowest levels of IL-2 (P < 0.05), IL-4, IFN-gamma, IL-13, and IL-17.

CONCLUSIONS

The different pattern of cytokine gene expression suggests a change in immune function in MF/CTCL from early MF/CTCL to late MF/CTCL-B to late MF/CTCL+B. These stages are consistent with localized disease associated with an anti-tumor immune response and late MF/CTCL associated with a loss of immune function mediated by malignant T cells that share regulatory T cell-like properties.

Usefulness of flow cytometry in the diagnosis of mycosis fungoides

BACKGROUND

The pathologic evaluation of mycosis fungoides (MF) is a challenging area in dermatopathology.

OBJECTIVE

We sought to determine the usefulness of flow cytometry for the diagnosis of MF from skin biopsy specimens.

METHODS

Skin biopsy specimens from 22 patients with a clinical suggestion for MF were evaluated by 4-color flow cytometry. The results were correlated with the International Society for Cutaneous Lymphoma (ISCL) MF diagnostic score and molecular studies for T-cell receptor gene rearrangement.

RESULTS

A T-cell abnormality by flow cytometry was identified in all 11 patients with diagnostic ISCL scores whereas the 7 patients with either subdiagnostic ISCL scores or reactive histology showed no phenotypic abnormality by flow cytometry. In all, 10 of 11 patients with diagnostic skin biopsy specimens for MF had T-cell receptor gene rearrangements by polymerase chain reaction. Gene rearrangements were not detected in the subdiagnostic group.

LIMITATIONS

Small study size was a limitation.

CONCLUSION

Flow cytometry of skin biopsy specimens is a sensitive method for detecting abnormalities in MF and should be considered part of the routine workup of patients with a clinical suggestion of MF.

Pigmented purpuric dermatosis: classification by phenotypic and molecular profiles

The categorization of pigmented purpuric dermatosis (PPD) as a form of cutaneous lymphoid dyscrasia has been suggested. Phenotypic and molecular studies were done on 43 patients with PPD. The molecular studies used a capillary gel electrophoresis T-cell receptor beta multiplex polymerase chain reaction assay. There were 2 principal categories: polyclonal PPD represented by 22 cases and monoclonal variants comprising 21 cases. Monoclonal cases had extensive skin lesions. An identical restricted T-cell repertoire independent of time and location was observed. Approximately 40% of the monoclonal cases had clinical and pathologic features of mycosis fungoides (MF). In the polyclonal variant, disease outside the lower extremities was uncommon; there were no patients with MF. Striking reductions in CD7 and CD62L were seen in both groups. PPD is a form of cutaneous T-cell lymphoid dyscrasia, based on the frequency of monoclonality, the preservation of persistent T-cell clonotypes, and extent of pan-T-cell marker loss. Stratification of lesions of PPD according to the molecular profile may be of significant value prognostically and influence therapeutic intervention.

Pediatric pityriasis lichenoides and cutaneous T-cell lymphoma

PURPOSE OF REVIEW

The purpose of this review is to educate the reader about two cutaneous lymphoproliferative diseases in childhood: pityriasis lichenoides and cutaneous T-cell lymphoma. Pityriasis lichenoides has traditionally been divided into acute and chronic subtypes. The two forms of the disease, however, are best thought of as two ends of a benign lymphoproliferative spectrum. Cutaneous T-cell lymphoma is a rare but underrecognized cutaneous malignancy in children. Early stage disease and hypopigmented presentation are characteristic of pediatric cutaneous T-cell lymphoma. The optimal investigation and treatment plans are still controversial.

RECENT FINDINGS

This article will summarize recent articles on pityriasis lichenoides and pediatric cutaneous T-cell lymphoma, including recent findings from an international registry of pediatric cutaneous T-cell lymphoma.

SUMMARY

After reading this review, the reader should be able to recognize the clinical presentation of pityriasis lichenoides, to understand the overlap between its acute and chronic forms, and to recognize its relationship with cutaneous T-cell lymphoma. In addition, the reader will appreciate the challenges in diagnosing and treating pediatric cutaneous T-cell lymphoma.

Lymphocytic Variant Hypereosinophilic Syndromes

A large body of evidence establishing the existence of an underlying T-cell disorder in a subset of patients fulfilling hypereosinophilic syndrome (HES) diagnostic criteria has accumulated over the past decade, resulting in the definition of a novel HES variant termed "lymphocytic" HES. Although end-organ complications of hypereosinophilia are generally benign, with predominant cutaneous manifestations, long-term prognosis is overshadowed by an increased risk of developing T-cell lymphoma, as a result of malignant transformation of aberrant T cells years after HES diagnosis. Therapeutic strategies should target pathogenic T cells in addition to eosinophils, but the practical implications remain largely unexplored.

Chemokine receptor expression by leukemic T cells of cutaneous T-cell lymphoma: clinical and histopathological correlations

Chemokine receptors expressed by normal and neoplastic lymphocytes provide an important mechanism for cells to traffic into the skin and skin-associated lymph nodes. The goal of this study was to correlate chemokine receptor and CD62L expression by circulating neoplastic T cells with the clinical and pathological findings of the leukemic phase of cutaneous T-cell lymphoma, primarily Sézary syndrome (SS). Chemokine receptor mRNA transcripts were found in the majority of leukemic cells for CCR1, CCR4, CCR7, CCR10, CXCR3, and CD62L and in 20-50% of the samples for CXCR5. In patients with SS, relatively high expression levels of CCR7 and CCR10 by circulating neoplastic T cells correlated with epidermotropism, CXCR5 expression correlated with density of the dermal infiltrate, and CD62L correlated with extent of lymphadenopathy. Of note, CXCR5 expression and a dense dermal infiltrate correlated with a poor prognosis. The chemokine receptor profile supports the concept that neoplastic T cells are central memory T cells, and that CCR10 and CD62L play a fundamental role respectively in epidermotropism and lymphadenopathy that is observed in SS.

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.

Immunohistochemical staining for CD45R isoforms in paraffin sections to diagnose mycosis fungoides-type cutaneous T-cell lymphoma

The definitive diagnosis of mycosis fungoides (MF)-type cutaneous T-cell lymphoma (CTCL) is difficult because a cumulative set of information is typically required: clinical features, histopathology, and special diagnostic tests (typically immunophenotyping and T-cell receptor gamma [TCRgamma] gene rearrangement). Fresh tissue is not always available for the special tests. We report a simple and readily available procedure evaluating the staining pattern on formalin-fixed, paraffin-embedded skin that can help with the diagnosis of patch/plaque stage MF. We reviewed 92 cases of MF or probable MF that had clinical information, immunophenotyping and TCRgamma gene rearrangement studies and that had been evaluated in our multidisciplinary lymphoma conference. We used antibodies to the isoforms of CD45, CD45RO for mature T cells and CD45RB for subsets of T cells. When atypical CD45RB-positive/CD45RO-negative cells were seen in nonspongiotic epidermis, the individuals had a high cumulative clinical and histologic score for MF. In contrast, 15 cases of known contact dermatitis showed a reactive pattern of both CD45RB- and CD45RO-positive cells in spongiotic epidermis. We compared the epidermal CD45RB-positive/CD45RO-negative staining pattern with CD7 deficiency by immunophenotyping and TCRgamma gene rearrangement, two commonly used methods in the diagnosis of MF. The epidermal CD45RB-positive/CD45RO-negative staining pattern is comparable and may be better in equivocal cases of possible MF. Therefore immunostaining for CD45RB and CD45RO on paraffin sections is a simple, reliable, and convenient modality in the diagnosis of MF.

Diagnosis of Mycosis Fungoides

Mycosis fungoides (MF) is the most common form of primary cutaneous T-cell lymphoma. In its early stage it may mimic benign dermatoses both on a clinical and histologic basis. MF usually expresses CD3 and CD4 (T-cell) markers. CD7 is expressed on about 90% of CD4 T cells and is often deficient on malignant T cells. Thus, CD7 may be useful in evaluating the nature of dermal lymphoid infiltrates. The aim of this study was to evaluate the usefulness of immunohistochemical detection of T-cell markers on paraffin-embedded sections, CD3 and CD7 (clone CBC.37), in the differential diagnosis of MF and benign dermatoses. Forty-two patients with diffuse dermal T-lymphocytic infiltrates were selected. Previous clinicopathologic correlation and follow-up had established the diagnosis of MF in 31 patients and benign dermatoses in 11. The mean value of stained cells in MF was 86.45% for CD3 and 53.09% for CD7 (P<0.001); in benign dermatoses it was 79.09% for CD3 and 73.63% for CD7 (P=0.669). CD7 immunolabeling was significantly lower in the MF group (P=0.048). A semiquantitative evaluation revealed a considerable loss of CD7 immunolabeling in comparison with CD3 in patients with MF. The authors conclude that CD7 study may represent a valuable tool in the distinction between inflammation and neoplasia in T-lymphoproliferative skin disorders.

Evidence for an oncogenic role of AHI-1 in Sezary syndrome, a leukemic variant of human cutaneous T-cell lymphomas

Ahi-1 (Abelson helper integration site 1) is a novel gene frequently activated by provirus insertional mutagenesis in murine leukemias and lymphomas. Its involvement in human leukemogenesis is demonstrated by gross perturbations in its expression in human leukemia cells, particularly in cutaneous T-cell lymphoma cell lines where increases in AHI-1 transcripts of 40-fold are seen. To test directly whether deregulated expression of AHI-1 contributes to their transformed properties, knockdown of AHI-1 expression in Hut78 cells, a cell line derived from a patient with Sezary syndrome (SS), was performed using retroviral-mediated RNA interference. Retroviral-mediated suppression specifically inhibited expression of AHI-1 and its isoforms in transduced cells by 80% and also reduced autocrine production of interleukin (IL)-2, IL-4 and tumor necrosis factor-alpha (TNFalpha) by up to 85%. It further significantly reduced their growth factor independence in vitro and the ability to produce tumors in immunodeficient mice. Interestingly, aberrant expression of AHI-1, particularly truncated isoforms, was present in CD4+CD7- Sezary cells from some patients with SS. Elevated expression of IL-2 and TNFalpha was also found in these cells. These findings provide strong evidence of the oncogenic activity of AHI-1 in human leukemogenesis and demonstrate that its deregulation may contribute to the development of SS.

Processos linfoproliferativos da pele: parte 2 - linfomas cutâneos de células T e de células NK

Os linfomas cutâneos de células T/NK constituem um grupo de doenças linfoproliferativas extranodais atualmente classificadas e subdivididas de acordo com o comportamento clínico segundo consenso da Organização Mundial de Saúde e da Organização Européia para Pesquisa e Tratamento do Câncer. Os linfomas cutâneos de células T/NK de comportamento clínico indolente compreendem a micose fungóide clássica, a micose fungóide foliculotrópica, a reticulose pagetóide, a cútis laxa granulomatosa, o linfoma cutâneo primário de grande célula anaplásica, a papulose linfomatóide, o linfoma subcutâneo de célula T paniculite-símile e o linfoma cutâneo primário de pequena e média célula T CD4+ pleomórfica. Os linfomas cutâneos de células T/NK de comportamento agressivo incluem a síndrome de Sézary, o linfoma extranodal de célula T/NK, tipo nasal, o linfoma cutâneo primário agressivo de célula T CD8+ epidermotrópica, o linfoma cutâneo de célula T <FONT FACE=Symbol>gd</FONT> e o linfoma cutâneo primário de célula T periférica, não especificado. O linfoma-leucemia de células T do adulto e a neoplasia hematodémica CD4+CD56+, embora considerados linfomas sistêmicos, são aqui abordados por apresentarem-se inicialmente na pele em significativo número de pacientes. O diagnóstico desses processos é realizado pelo exame histopatológico complementado pela análise do fenótipo das células neoplásicas, imprescindível no processo classificatório. O estadiamento para a avaliação da extensão anatômica da doença considera além do envolvimento cutâneo, o estado clínico e histológico dos linfonodos e das vísceras. Avaliação hematológica é fundamental na caracterização da síndrome de Sézary. Os tratamentos preconizados incluem terapêuticas dirigidas exclusivamente à pele, modificadores da resposta biológica e quimioterapia sistêmica.

On the diagnosis of erythrodermic cutaneous T-cell lymphoma

Erythrodermic cutaneous T-cell lymphoma (E-CTCL) is the cause of less than 5% of all cases of generalized erythroderma. A methodical evaluation of skin, blood, and lymph node samples using standard histology, immunohistochemistry (IHC), flow cytometry (FC), and molecular analysis for evidence of a dominant T-cell clone has been recommended in a recently published diagnostic algorithm. In this commentary, the author discusses available information regarding the role of these diagnostic methods for the diagnosis of E-CTCL with emphasis on personal observations regarding skin IHC and polymerase chain reaction (PCR)-based molecular studies as adjunct diagnostic studies on a series of 55 patients with erythrodermic mycosis fungoides and 50 patients with Sézary syndrome compared to 50 patients with extensive benign inflammatory skin disease. The conclusions are (1) IHC of the skin does not reliably differentiate E-CTCL from benign simulants, (2) presence of phenotypically abnormal T cells in the blood or expanded subsets of CD4+CD7- or CD4+CD26- cells by FC is particularly helpful as a diagnostic study, (3) the presence of an identical T-cell clone in the skin and blood also is a specific diagnostic criterion for E-CTCL, but exceptions may occur, and (4) the PCRgamma-denaturing gradient gel electrophoresis technique appears to be more reliable than PCRgamma-single-stranded conformational polymorphism for diagnostic purposes.

Defining early mycosis fungoides

This editorial review summarizes the results of 5 meetings sponsored by the International Society for Cutaneous Lymphoma at which the clinicopathologic and ancillary features of early mycosis fungoides were critically examined. Based on this analysis, an algorithm was developed for the diagnosis of early mycosis fungoides involving a holistic integration of clinical, histopathologic, immunopathologic, and molecular biological characteristics. A novel aspect of this algorithm is that it relies on multiple types of criteria rather than just one, for example, histopathology. Before its finalization, the proposed diagnostic algorithm will require validation and possibly further refinement at multiple centers during the next several years. It is anticipated that a more standardized approach to the diagnosis of early mycosis fungoides will have a beneficial impact on the epidemiology, prognostication, treatment, and analysis of clinical trials pertaining to this most common type of cutaneous lymphoma.

Skin homing of Sézary cells involves SDF-1-CXCR4 signaling and down-regulation of CD26/dipeptidylpeptidase IV

Sézary syndrome (SS) is a rare form of cutaneous T-cell lymphoma (CTCL) characterized by a distinct metastatic pattern mainly involving blood and skin. Chemokines and their receptors play a critical role in cellular recruitment and homing to tissues and in the metastatic process of several tumors including non-Hodgkin T-cell lymphomas (NHLs). Here we report that SS cells express a functionally active CXCR4 and that its ligand SDF-1 is abundantly produced in the skin, which represents the main destination of SS cell spreading. SDF-1 is normally inactivated by proteolytic cleavage by the CD26/dipeptidylpeptidase IV (DPPIV). The lack of CD26 from the cell surface is a hallmark of circulating SS cells. We also show that the CD26(-) phenotype is maintained also in skin-infiltrating neoplastic T lymphocytes and that SS-affected individuals exhibit a reduced activity of plasma soluble CD26. Finally, we observe that the addition of soluble CD26 reduces the migratory response of SS cells to SDF-1 whereas the inhibition of the CD26 peptidase activity in Hut78, a CD26(+) CTCL cell line, enhances the SDF-1-induced migration of these cells. Our findings suggest that the SDF-1-CXCR4 axis could play an important role in skin homing of SS through the regulatory activity of CD26.

Immunopathogenesis and therapy of cutaneous T cell lymphoma

Cutaneous T cell lymphomas (CTCLs) are a heterogenous group of lymphoproliferative disorders caused by clonally derived, skin-invasive T cells. Mycosis fungoides (MF) and Sezary syndrome (SS) are the most common types of CTCLs and are characterized by malignant CD4(+)/CLA(+)/CCR4(+) T cells that also lack the usual T cell surface markers CD7 and/or CD26. As MF/SS advances, the clonal dominance of the malignant cells results in the expression of predominantly Th2 cytokines, progressive immune dysregulation in patients, and further tumor cell growth. This review summarizes recent insights into the pathogenesis and immunobiology of MF/SS and how these have shaped current therapeutic approaches, in particular the growing emphasis on enhancement of host antitumor immune responses as the key to successful therapy.

Drug-induced reversible lymphoid dyscrasia: a clonal lymphomatoid dermatitis of memory and activated T cells

Certain systemic conditions predispose patients to excessive lymphocyte responses to immune-perturbing drugs, which may progress to malignant lymphoma. Many pathologists and clinicians believe that differentiation of pseudolymphoma from cutaneous T cell lymphoma (CTCL) can be reliably made through phenotypic and molecular analysis. We encountered 15 cases of atypical cutaneous T-cell lymphoid hyperplasia in the setting of drug therapy. We explored phenotypic anomalies using antibodies to CD2, 3, 4, 7, 8, 20, 30 and CD62 K and sought T-cell receptor gene rearrangements by a polymerase chain reaction methodology. The lymphoid infiltrates showed reproducible CD7 and/or CD62 K deletion in concert with T cell clonality and variable CD30 positivity-findings similar to those of CTCL-but the rashes resolved or improved substantially after drug modulation. We hypothesize that the infiltrates represent an unrepressed expansion of CD7- and CD62 K-negative activated memory T lymphocytes in response to antigenic triggers. We propose the term "drug-induced reversible lymphoid dyscrasia" to describe this entity.

Effect of insulin-dependent diabetes mellitus on response to extracorporeal photopheresis in patients with Sézary syndrome

BACKGROUND

Extracorporeal photopheresis (ECP) has become a primary therapy for selected forms of cutaneous T-cell lymphoma, especially Sézary syndrome. Variability in response of patients with Sézary syndrome to ECP has been reported.

OBJECTIVE

Our purpose was to determine whether underlying medical conditions influence the efficacy of ECP in patients with Sézary syndrome.

METHODS

We retrospectively reviewed the medical records of 55 patients with Sézary syndrome who received ECP between 1987 and 2000. Efficacy criteria included decrease in Sézary cell count, erythroderma, lymphadenopathy, organomegaly, and pruritus.

RESULTS

Thirty-four patients responded well and 10 patients responded partially to ECP; 11 patients had no response. Nine patients with no response to ECP had insulin-dependent diabetes mellitus (IDDM). IDDM was documented in only 2 patients with a good response and in no patients with a partial response to ECP.

CONCLUSION

Patients with Sézary syndrome and IDDM typically respond poorly to the standard ECP treatment regimen.

Low CD7 expression in benign and malignant cutaneous lymphocytic infiltrates: experience with an antibody reactive with paraffin-embedded tissue

Loss of CD7 expression by neoplastic lymphocytes is considered a distinguishing characteristic of mycosis fungoides (MF) and cutaneous T-cell lymphoma. Reports to date examining for the CD7 immunophenotype in MF have been performed on fresh-frozen tissue. In this study, we used a paraffin-reactive antibody directed against CD7 to determine its range of expression in MF and to compare these results with those in controls. Examining 22 cases of MF and 61 controls, we found minimal CD7 expression by lymphocytes in MF and in a few cases of benign inflammatory dermatosis (BID). The lowest mean CD7 counts (as a percentage of total lymphocytes) were found in MF (patch stage: 5% +/- 5%, range: 0-10; plaque and tumor stages: 15% +/- 5%, range: 5-25), and these counts were significantly lower than those for BID (35% +/- 20%, range: 5-80; p = 0.001). By logistic regression analysis, low CD7 expression (<10% lymphocytes labeling) had sensitivity and positive predictive values of 80% and 72%, respectively, and specificity and negative predictive values of 93% and 96%, respectively, for the diagnosis of patch stage MF. False-positive results were found for spongiotic dermatitis. Moreover, spongiotic dermatitides exhibited a progressive decrease in mean CD7 counts from acute to subacute to chronic stages (50% versus 35% versus 30%, respectively). In conclusion, minimal CD7 expression is a specific finding for MF. Benign inflammatory infiltrates can also show low CD7 expression, however, which rarely matches that of patch stage MF. Progressive loss of CD7 expression in BID is the likely consequence of expansion of antigen-selected CD3+CD4+CD7- T cells. These inflammatory CD4+CD7- T cells may represent the physiologic counterpart to the neoplastic lymphocyte of MF.

Diagnostic and prognostic importance of T-cell receptor gene analysis in patients with Sézary syndrome

BACKGROUND

Sézary syndrome (SS) is characterized by erythroderma, peripheral lymphadenopathy, and circulating Sézary cells and is clinically heterogeneous.

METHODS

T-cell receptor (TCR) gene analysis was performed using DNA extracted from peripheral blood mononuclear cells from 74 patients, and the results were correlated with a variety of other diagnostic parameters and patient outcomes.

RESULTS

Two groups were identified: 66 patients with clonal TCR gene rearrangement (clonal patients) detected with Southern blot analysis and/or polymerase chain reaction/single-strand conformational polymorphism analysis and 8 patients with no clonal rearrangement detected (nonclonal patients) using either technique. Clonal patients were compared with nonclonal patients. The following median blood parameters were significantly greater in the clonal group: total white cell count (13.7 10(9)/L vs. 9.6 10(9)/L), lymphocyte count (4.9 10(9)/L vs. 2.2 10(9)/L), absolute Sézary count (3.22 10(9)/L vs. 0.99 10(9)/L), CD4 count (3.17 10(9)/L vs. 1.36 10(9)/L), and CD4:CD8 ratio (15.86 vs. 3.21). An expanded population of T-cells of a specific TCR variable beta subset was detected in 7 of 36 clonal patients and in 1 of 4 nonclonal patients. Cytogenetic analysis of peripheral blood from 1 nonclonal patient and 6 clonal patients was normal. The median survival from the time of diagnosis was 45 months in the clonal group, and 40 of 49 deaths were cutaneous T-cell lymphoma (CTCL)-related, whereas 3 deaths in the nonclonal group were unrelated to CTCL (P < 0.01; log-rank test). Multivariate proportional hazards analysis showed that the absolute Sézary count and lymph node status were independent prognostic variables (P = 0.016 and P = 0.036, respectively).

CONCLUSIONS

TCR gene analysis defines a distinct clinicopathologic group of patients with SS. Clonal patients have a poor prognosis and are likely to die from leukemia/lymphoma, whereas nonclonal patients may have a reactive, inflammatory T-cell disorder. The authors suggest that the definitive diagnostic criteria for patients with SS should include the presence of a clonal TCR gene rearrangement.

Evaluation of a new paraffin-reactive CD7 T-cell deletion marker and a polymerase chain reaction-based T-cell receptor gene rearrangement assay: implications for diagnosis of mycosis fungoides in community clinical practice

BACKGROUND

T-cell deletion and T-cell receptor (TCR) gene rearrangement studies are helpful in the early diagnosis and subsequent management of mycosis fungoides (MF). However, this often requires fresh-frozen tissue that can be difficult to obtain and evaluate in community clinical practice. A new CD7 antibody, the most sensitive and specific T-cell deletion marker, and a new TCR-gamma gene rearrangement polymerase chain reaction (PCR) assay (TCR-gamma PCR) are now available on routine paraffin-embedded biopsy specimens.

OBJECTIVE

Our purpose was to assess the utility of CD7 deletion and TCR-gamma PCR in the diagnosis of MF using routine paraffin-embedded biopsy material.

METHODS

Cases of MF (n = 17) with matching frozen tissue immunohistochemistry and benign reactive dermatoses (lichen planus; n = 27) were assessed for CD7 (Clone: CD7-272) deletion and TCR-gamma PCR using paraffin-embedded biopsy specimens.

RESULTS

Excellent concordance comparing frozen and paraffin embedded CD7 immunostaining (88%) was observed. CD7 deletion and TCR-gamma PCR was sensitive (94%) and specific (96%) for a diagnosis of MF using paraffin-embedded biopsy specimens.

CONCLUSION

In the diagnosis of MF, detection of CD7 deletion and monoclonal TCR rearrangements can be successfully performed in a cost-effective, timely fashion using routine formalin-fixed paraffin-embedded biopsy specimens.

Nonerythrodermic, leukemic variant of cutaneous T-cell lymphoma with indolent clinical course: Th2-type tumor cells lacking T-cell receptor/CD3 expression and coinfiltrating tumoricidal CD8 T cells

As typically represented by Sézary syndrome, the leukemic form of cutaneous T-cell lymphoma (CTCL) mostly exhibits erythroderma. A patient with CTCL had slowly developing skin tumors as well as chronic leukemia. The tumor cell was CD4+ CD7- Th2 cells lacking T-cell receptor/CD3 complex and persistently occupied 27% to 48% of peripheral blood lymphocytes. In skin tumors, only 13% of tumor-infiltrating lymphocytes were malignant cells and substantial numbers of nonmalignant CD4+ or CD8+ T cells and B cells coinfiltrated. CD8+-infiltrating T cells had cytotoxic activity against the malignant T cell. Our case demonstrates the existence of the leukemic form of CTCL presenting with skin manifestation other than erythroderma and parapsoriatic patches. The nonerythrodermic feature and indolent course may be associated with the lack of T-cell receptor/CD3 expression and coinfiltration of a high percentage of nontumor lymphocytes, including tumoricidal CD8+ T cells.

Clonal Th2 lymphocytes in patients with the idiopathic hypereosinophilic syndrome

Idiopathic hypereosinophilic syndrome (HES) and Gleich's syndrome are related disorders characterized by persistent or recurrent hypereosinophilia of unknown origin. Elevated IgE levels and polyclonal hypergammaglobulinaemia are considered as markers of benign outcome in this setting as they are generally associated with predominant cutaneous manifestations and favourable response to glucocorticoid therapy. In a previous study, we identified a clonal population of CD3-CD4+ Th2-like lymphocytes secreting interleukin (IL)-5 and IL-4 in peripheral blood of a patient fulfilling the diagnostic criteria of HES with associated serum hyper-IgE. We now extend this observation by describing identical findings in three additional patients, and we compare their clinical and biological parameters with five other patients with HES. Chromosomal abnormalities were detected in purified CD3-CD4+ Th2 cells from three patients, among whom one developed anaplastic null cell lymphoma. We therefore suggest that a careful search for T-lymphocyte clonality and cytogenetic changes should be included in the work-up of HES for adequate management.