Analysis of beta, gamma, and delta T-cell receptor genes in mycosis fungoides and Sezary syndrome

Biologic and clinical significance of CD7 expression in acute myeloid leukemia

CD7 antigen, a T-cell lineage associated antigen, is expressed in a minority of patients with acute myeloid leukemia (AML). The biologic and clinical significance of this finding is not clearly established. In this retrospective study of patients with de novo acute myeloid leukemia, we have identified CD7 expression and analyzed its association with markers expressed early in hemopoietic ontogeny and clinical parameters. Among 60 consecutive AML patients, we found six (10%) expressing CD7 on leukemic cells. There were five males and one female and the mean age was 59.6 years (age range: 32-76 years) with no demographic peculiarities. The FAB subtypes were: M0 (2), M1 (1), M2 (1), and M4 (2). CD7 expression was associated with immature antigens CD34, HLA-DR, and terminal deoxynucleotidyl transferase (TdT) and antigen receptor gene rearrangements (rearrangements of T-cell receptor gamma chain in 6/6 and immunoglobulin heavy chain in 2/6). Hepatomegaly was present in three and this was associated with splenomegaly with lymphadenopathy in one patient. Mediastinal or central nervous system involvement was absent. Complete remission was achieved in two patients with standard chemotherapy; one of these is in remission and alive (5 years later), while one died following relapse 9 months later. Three patients had significantly lower response to standard therapeutic regimen (two died during induction and one died 7 months later without ever achieving complete remission). One patient has been excluded in determining the prognostic significance of CD7 due to early death. Our results suggest origin of CD7+ AML from early hemopoietic precursors and indicate biologic aggressiveness in a significant proportion of patients. We suggest evaluation of CD7 in all patients with AML at the time of diagnosis in view of poor clinical outcome.

Value of clonality studies of cutaneous T lymphocytes in the diagnosis and follow-up of patients with mycosis fungoides

Histological features of early mycosis fungoides (MF) can simulate numerous inflammatory lesions and histological confirmation of MF is often delayed, compared with clinical diagnosis. Recently, using molecular techniques, the detection of a dominant T-lymphocyte clone has been reported in cutaneous lesions of MF. The aim of the present study was to determine the diagnostic value of a dominant T-lymphocyte clone as assessed by PCR-DGGE in early MF. Histopathological and molecular analyses were performed on cutaneous lesions from 104 patients clinically suspected as having MF. In this population, the positive predictive value of a PCR gamma(+) was 0.86. In addition, four of six patients whose lesions were PCR gamma(+) (detectable dominant T-cell clone) but not histologically MF progressed to MF within 2-48 months. In order to evaluate the relevance of PCR gamma-DGGE in MF follow-up, serial biopsies were performed in 24 patients. In 89 per cent of cases, the presence or absence of a PCR gamma(+) was constant during the course of the disease. When present, the DGGE imprint of PCR products was case-specific. These data demonstrate the diagnostic value in MF of T-lymphocyte clonality assessed by PCR gamma-DGGE on cutaneous lesions and show that the technique can be used in MF follow-up to evaluate residual disease with high specificity.

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

Clonal T cells have been demonstrated in skin lesions of all stages of cutaneous T-cell lymphomas (CTCLs). However, there are conflicting data regarding the CTCL stage at which dissemination of clonal cells into peripheral blood occurs. Although the multifocal occurrence of cutaneous CTCL lesions and T-cell recirculation suggest an early appearance of neoplastic cells in the blood, circulating clonal T cells have only been detected in advanced stages. We investigated their occurrence by a highly sensitive polymerase chain reaction (PCR) assay amplifying T-cell receptor γ rearrangements and subsequent heteroduplex temperature gradient gel electrophoresis (HD-TGGE) of the amplification products. Circulating clonal T cells were found in 26 of 45 patients with mycosis fungoides (MF ), six of seven with Sezary's syndrome (SS), 10 of 13 pleomorphic CTCLs, and three of four unclassified CTCLs. Corresponding skin specimens carried clonal T cells in 29 of 40 MF, three of four SS, 12 of 12 pleomorphic, and two of two unclassified CTCL patients. Except for the blood specimen of a psoriatic patient, all samples of 60 controls (psoriasis vulgaris, atopic dermatitis, and healthy volunteers) revealed polyclonal amplification products. In 30 of 32 CTCL patients carrying a clonal rearrangement in blood and skin, identity of both clones was indicated by HD-TGGE and confirmed by sequencing six of these cases. We found an unexpected high frequency of identical clonal T cells in peripheral blood and skin of CTCL patients, including early stages of MF. This supports the concept of an early systemic disease in CTCL and raises new questions concerning the pathogenesis.

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

Clonal T cells have been demonstrated in skin lesions of all stages of cutaneous T-cell lymphomas (CTCLs). However, there are conflicting data regarding the CTCL stage at which dissemination of clonal cells into peripheral blood occurs. Although the multifocal occurrence of cutaneous CTCL lesions and T-cell recirculation suggest an early appearance of neoplastic cells in the blood, circulating clonal T cells have only been detected in advanced stages. We investigated their occurrence by a highly sensitive polymerase chain reaction (PCR) assay amplifying T-cell receptor γ rearrangements and subsequent heteroduplex temperature gradient gel electrophoresis (HD-TGGE) of the amplification products. Circulating clonal T cells were found in 26 of 45 patients with mycosis fungoides (MF ), six of seven with Sezary's syndrome (SS), 10 of 13 pleomorphic CTCLs, and three of four unclassified CTCLs. Corresponding skin specimens carried clonal T cells in 29 of 40 MF, three of four SS, 12 of 12 pleomorphic, and two of two unclassified CTCL patients. Except for the blood specimen of a psoriatic patient, all samples of 60 controls (psoriasis vulgaris, atopic dermatitis, and healthy volunteers) revealed polyclonal amplification products. In 30 of 32 CTCL patients carrying a clonal rearrangement in blood and skin, identity of both clones was indicated by HD-TGGE and confirmed by sequencing six of these cases. We found an unexpected high frequency of identical clonal T cells in peripheral blood and skin of CTCL patients, including early stages of MF. This supports the concept of an early systemic disease in CTCL and raises new questions concerning the pathogenesis.

The polymerase chain reaction in the diagnosis of early mycosis fungoides

The earliest or patch stage of mycosis fungoides may present diagnostic difficulty both clinically and pathologically. The present study of the polymerase chain reaction (PCR) as a diagnostic tool in early mycosis fungoides was therefore undertaken, using a rapid PCR method for the detection of gamma- and beta-chain T-cell receptor (TCR) gene rearrangements in routine formalin-fixed, paraffin-embedded histological sections. Forty-two biopsies were studied from 26 patients with mycosis fungoides. Twenty-three skin biopsies with a clinicopathological diagnosis of early, or patch stage, mycosis fungoides were investigated. Of these, 18 (78 per cent) showed TCR-gamma or both beta- and gamma-chain TCR gene rearrangements. TCR gene rearrangements were shown in seven of the 14 plaque stage lesions (50 per cent) and also in the single case of tumour stage disease. Where gene rearrangements were identified, these were identical in all biopsies from an individual patient, irrespective of the site of the lesion, the disease stage, or the time lapse between the biopsies. The PCR is therefore a highly sensitive technique, which can be performed on routine pathological material, in cases where the diagnosis of early mycosis fungoides cannot be made with certainty on conventional histopathological and immunohistochemical grounds.

Cutaneous histopathology of Sézary syndrome: a study of 41 cases with a proven circulating T-cell clone

Sezary syndrome is an uncommon variant of cutaneous T-cell lymphoma (CTCL) characterized by erythroderma, pruritus, adenopathy, and circulating atypical T-lymphocytes with cerebriform nuclei. The definition of Sezary syndrome can be further refined by including only patients with a circulating peripheral blood population of clonal T-cells. We have evaluated 79 skin biopsies from such a group of 41 erythrodermic patients with circulating Sezary cells and a clonal population of T-cells detected by T-cell receptor-beta gene rearrangement on Southern analysis of peripheral blood mononuclear cells. Histopathologic features consistent with chronic dermatitis were observed in 26/79 (33%) skin biopsy specimens, emphasizing that a non-specific histologic appearance is common. Evidence of CTCL was lacking in 11/41 patients on biopsy of their erythrodermic skin. The survival of these patients was not significantly different from 30/41 patients in whom skin biopsies revealed changes diagnostic of CTCL, such as a dermal lymphocytic band with atypical lymphocytes (18/79, 23%) or a mycosis fungoides-like infiltrate (30/79, 38%). This study confirms that non-specific cutaneous histopathologic findings are common in Sezary syndrome, even when a circulating T-cell clone is present. This stresses the need for peripheral blood genetic analysis and for multiple or repeat skin biopsies in erythrodermic patients when there is high clinical suspicion of CTCL.

A rapidly enlarging keratinised 'skull-cap'

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Chromosomal abnormalities in cutaneous T-cell lymphoma and in its premalignant conditions as detected by G-banding and interphase cytogenetic methods

The etiology of cutaneous T-cell lymphomas (CTCL) is unknown. We studied the pattern of chromosomal abnormalities with G-banding and interphase in situ hybridization methods in blood mononuclear cells in 17 patients representing the different phases of CTCL or the premalignant condition, parapsoriasis en plaque, and in 10 control persons. We used biotinylated centromere-specific probes with fluorescent detection (FISH) for chromosomes 1, 11, 8, and 17 and similar, enzymatically detectable, digoxigenin-labeled probes for chromosomes 1, 6, 12, 17, and 18. In G-banding, all patients showed numerical and structural chromosome aberrations. Numerical aberrations of chromosomes 6, 13, 15, and 17, marker chromosomes, and structural aberrations of chromosomes 3, 9, and 13 were increased in mycosis fungoides (MF) compared with healthy controls. In four of five patients the detection of a chromosomal clone preceded relapse or progression of the disease. In FISH of interphase cells, the cells abnormal for chromosomes 8 or 11, and for all four chromosomes collectively, were increased in MF and in Sezary Syndrome (SS). FISH and G-banding methods agreed statistically significantly for the detection of monosomy. Also, digoxigenin-labeled probes hybridized to interphases or mitoses detected aberrations corresponding to those observed with G-banding. Thus, chromosomally abnormal cells can be found in the peripheral blood of both parapsoriasis en plaque and CTCL patients. They can be detected with interphase cytogenetical methods, which obviates the need for dividing cells, often difficult to accomplish in CTCL.

Clinical and pathological heterogeneity in cutaneous gamma-delta T-cell lymphoma: a report of three cases and a review of the literature

Cutaneous gamma-delta (gamma delta) T-cell lymphoma is rare. Eleven cases have been reported to date including four cases of mycosis fungoides (MF), two of pagetoid reticulosis and five of pleomorphic cutaneous T-cell lymphoma (CTCL). We report three further cases of cutaneous gamma delta T-cell lymphoma; one of MF, one of a pleomorphic CTCL and one of a subcutaneous T-cell lymphoma. Combined data suggest that although cutaneous gamma delta T-cell lymphomas do not appear to comprise a single clinicopathological entity, they may be associated with aggressive clinical behaviour and a poor prognosis.

Management of cutaneous lymphoma

The foregoing underlines the advances which have been made in our understanding of cutaneous lymphoma and the areas where further research is needed. With a few noteable exceptions the aim of therapy in CTCL is palliative rather than curative and treatment success is measured in terms of disease-free interval. There is still no evidence that any chemotherapeutic regimen prolongs survival. A possible exception is the effect of photopheresis in Sézary syndrome but our own experience differs from that in the USA and underlines the need to identify patients with clonal disease when defining subjects for study. The combination of genotypic analysis and new treatment methods offers exciting new prospects in the management of patients with cutaneous lymphoma.

Detection of circulating T cells with CD4+CD7- immunophenotype in patients with benign and malignant lymphoproliferative dermatoses

BACKGROUND

Cutaneous T-cell lymphomas (CTCLs) are malignancies of CD4+ T cells that involve the skin. CD4+CD7- cells may represent a malignant population in CTCL.

OBJECTIVE

Our purpose was to compare the percentage of CD4+CD7- cells and the expression of pan-T-cell antigens in blood lymphocytes from 31 patients with benign dermatoses with 35 patients who had CTCL.

METHODS

The patients with CTCL were classified as follows: 10 with mycosis fungoides (MF), seven with pre-Sézary syndrome (pre-SS), and 18 with Sézary syndrome (SS). Flow cytometry was used to determine the percentage of CD4+CD7- cells and the CD4/CD8 ratio and to detect aberrant expression of the pan-T-cell antigens CD2, CD3, and CD5.

RESULTS

We found a mean of 5.8% CD4+CD7- cells for the 16 normal control subjects and 9.3% for the benign cases (p = 0.13). The patients with pre-SS and SS had a higher percentage of CD4+CD7- cells (22.4% and 35.5%, respectively) than patients with benign dermatoses (p < 0.01); no difference was found between patients with benign dermatoses and those with MF (p = 0.80). The mean CD4/CD8 ratio was 3.1 for the normal control subjects compared with 7.4 for the patients with benign dermatoses (p < 0.01). Patients with SS had a ratio of 49, which was higher than the ratio for those with benign dermatoses (p < 0.01); however, the ratio for patients with MF and pre-SS did not differ from that of the group with benign dermatoses (p = 0.71 and 0.55, respectively). Aberrant CD2, CD3, or CD5 expression was observed in 66% of patients with SS, 29% with pre-SS, 30% with MF, but in none of the patients with a benign dermatosis.

CONCLUSION

Small numbers of CD4+CD7- cells can be found by flow cytometry in patients with a benign dermatosis and in normal control subjects. This T-cell subset is expanded in pre-SS and SS but not in MF. Aberrant pan-T-cell antigen expression is commonly observed in patients with SS but not in patients with a benign dermatosis.

Somatostatin receptor scintigraphy in cutaneous malignant lymphomas

BACKGROUND

Lymphoid cells may express somatostatin receptors (SS-Rs) on their cell surface. Therefore radiolabeled somatostatin analogues may be used to visualize SS-R-positive lymphoid neoplasms in vivo. Exact staging is the basis for treatment decisions in cutaneous malignant lymphoma. We considered the possibility that SS-R scintigraphy might offer a clinically useful method of diagnostic imaging in patients with cutaneous malignant lymphoma.

OBJECTIVE

We evaluated SS-R scintigraphy in comparison with conventional staging methods in the staging of cutaneous malignant lymphoma.

METHODS

We conducted a prospective study in 14 consecutive patients with histologically proven cutaneous malignant lymphoma. SS-R scintigraphy was compared with physical, radiologic, and bone marrow examinations. Lymph node excisions were performed in patients with palpable lymph nodes.

RESULTS

SS-R scintigraphy was positive in the lymph nodes in all four patients with malignant lymph node infiltration and negative in the three patients with dermatopathic lymphadenopathy. In two patients, previously unsuspected lymphoma localizations were visualized by SS-R scintigraphy. In only three patients all skin lesions were visualized by SS-R scintigraphy; these three patients had not been treated with topical corticosteroids. SS-R scintigraphy failed to detect an adrenal mass in one patient and bone marrow infiltration in two patients.

CONCLUSION

SS-R scintigraphy may help distinguish dermatopathic lymphadenopathy from malignant lymph node infiltration in patients with cutaneous malignant lymphoma.

Clonal disease in extracutaneous compartments in cutaneous T-cell lymphomas. A comparative study between cutaneous T-cell lymphomas and pseudo lymphomas

Extracutaneous involvement is a sign of poor prognosis in cutaneous T-cell lymphomas (CTCL). Unfortunately it becomes clinically and histologically manifest only late in the course of the disease. It was the purpose of this study to detect clonality in peripheral blood, lymph nodes and bone marrow samples at times when extracutaneous involvement cannot otherwise be demonstrated. In addition to skin biopsies, peripheral blood, lymph node and bone marrow samples from a total of 25 patients were analysed by Southern blotting for clonal gene rearrangement of the T-cell receptor beta-chain. Six of the patients were suffering from mycosis fungoides (MF), four from non-MF CTCL (pleomorphic T-cell lymphomas), seven from Sézary syndrome (SS), eight from pseudolymphoma (insect bites) (PSL), and one from lymphomatoid papulosis (LP). Clonal TcR b gene rearrangements were found in patients with MF in four of five skin probes as well as in two of two lymph node samples and in one of two peripheral blood samples. In SS patients, all skin probes (seven of seven), lymph node samples (six of six), peripheral blood samples (six of six) and one bone marrow specimen had a clonal TcR beta gene rearrangement. In patients with non-MF CTCL, two of four skin, zero of two peripheral blood and one of one bone marrow samples with clonal T cells were detected. All investigated patients showed exactly the same rearrangement pattern at extranodal sites and in the skin, which is proof for the same clone in all compartments. In contrast, no rearrangements were detected in LP and PSL (zero of eight skin probes, zero of two peripheral blood samples). Our results provide strong evidence for an early systemic spread of neoplastic cells in CTCL. However, an initial tumour burden has to be reached in order to lead to a clinically and prognostically relevant manifestation.

The emergence of Sézary cells during the treatment of cutaneous T-cell lymphoma

A 52-year-old man with cutaneous T-cell lymphoma presented with Sézary syndrome-like features including exfoliative erythroderma, lymphadenopathy and leukaemic change without the presence of Sézary cells. Southern blot hybridization analysis revealed T-cell receptor beta-chain gene rearrangements, both in the peripheral blood and in the lymph node. Atypical large cells with convoluted nuclei (Sézary-like cells) first appeared during combined chemotherapy. Although Sézary syndrome is characterized by its particular manifestations and the presence of Sézary cells in the peripheral blood, the clinical significance of Sézary cells has been questioned. It still needs to be decided whether or not the Sézary cell is malignant.

Lymphoma versus pseudolymphoma of the skin: gene rearrangement study of 21 cases with clinicopathologic correlation

BACKGROUND

Diagnosis of cutaneous lymphoma in the absence of systemic lymphoma may be difficult. Reactive lymphoid lesions can mimic lymphoma clinically and histologically and have been designated pseudolymphomas.

OBJECTIVE

Our purpose was to analyze lymphoid gene rearrangements in cutaneous lymphoproliferative lesions and to correlate these findings with the histologic, immunophenotypic, and clinical profile.

METHODS

We examined 21 cases of lymphoproliferative lesions that developed in skin and performed molecular rearrangement analysis of T-cell receptor and immunoglobulin genes. We examined identical tissues by histologic and immunophenotypic criteria and conducted follow-up clinical evaluation of all patients.

RESULTS

Clonal rearrangements of immunoglobulin (seven cases) or T-cell receptor (two cases) gene were detected in 9 of 21 patients. No specific histologic or immunophenotypic feature was consistently associated with a clonal lymphoid gene rearrangement. Systemic lymphoma developed in one patient in whom a clonal rearrangement within the immunoglobulin gene was identified.

CONCLUSION

Gene rearrangement analysis may be helpful in differentiating primary cutaneous lymphoma from pseudolymphoma. The chronic clinical course of patients with clonal lymphoid gene rearrangements supports a lack of correlation between clonality and biologic aggressiveness.

Diagnostic and prognostic significance of clonal T-cell receptor beta gene rearrangements in lymph nodes of patients with mycosis fungoides

In this study, 25 involved and uninvolved lymph nodes from 22 patients with mycosis fungoides (MF) and seven dermatopathic lymph nodes from patients with benign skin disorders were studied for the presence of clonal T-cell receptor beta (TCR beta) gene rearrangements by Southern blot analysis. These results were correlated with the histological classification, follow-up data, and survival. The results of the histological classification and Southern blot analysis were concordant in 26 of 32 cases. Clonal TCR beta gene rearrangements were found in all six MF lymph nodes showing (partial) effacement of the normal lymph node architecture, but in none of the eight uninvolved dermatopathic MF lymph nodes and in none of the seven dermatopathic control lymph nodes. In addition, in 5 of 11 dermatopathic MF lymph nodes that were considered to have early involvement by MF at histological examination, clonal TCR beta gene rearrangements were detected. In the group of MF patients with dermatopathic lymphadenopathy, patients with detectable clonal T-cell populations had a significantly shorter survival than patients without such a population (P < 0.01). The results of this study indicate that within the group of dermatopathic MF lymph nodes, prognostically different groups can be distinguished and that TCR beta gene rearrangement analysis may be an important adjunct in the early diagnosis of lymph node involvement by MF.

T-cell receptor gene rearrangement studies as a diagnostic tool in lymphoproliferative skin diseases

The growth of our knowledge in T-cell biology, in particular the molecular biology of the T-cell receptor (TCR), has provided a means to molecularly characterize lymphoproliferative diseases of the skin based on the presence or absence of a clonal population of T lymphocytes. TCR gene rearrangement studies, by Southern blot analysis, have aided the investigative dermatologist in gaining insights into the pathogenesis and clonal evolution of lymphoproliferative skin diseases. In addition, the application of TCR gene rearrangement studies as a diagnostic aid in the evaluation of lymphoproliferative skin diseases has been introduced into clinical dermatology. Despite its enormous research value, TCR gene rearrangement studies presently have limited applications as an independent diagnostic tool. However, as our knowledge and experience grows and as the application of new techniques provides us with greater detection sensitivity and specificity, the diagnostic utility of TCR gene rearrangement studies will be enhanced.

Combined proliferating cell nuclear antigen and morphometric analysis in the diagnosis of cutaneous lymphoid infiltrates

AIMS

To evaluate the use of morphometry in the diagnosis of benign and malignant cutaneous lymphoid infiltrates; and to determine whether the sensitivity of detection of cutaneous T cell lymphoma (CTCL) could be improved by selectively measuring cells expressing proliferating cell nuclear antigen (PCNA).

METHODS

44 archival biopsy specimens were studied. These included cases of CTCL, non-specific chronic dermatitis, lichen planus and lupus erythematosus. PCNA was identified using a standard immunohistological technique. Reactive cells were identified using automatic colour discrimination, and the size and shape were determined interactively. Similar measurements were made on the total dermal lymphocyte population.

RESULTS

There was no significant difference between the proportions of PCNA reactive cells in any of the diseases studied. The PCNA positive lymphocytes in CTCL were larger than those in lupus erythematosus and lichen planus and were more irregular in shape than those in chronic dermatitis. Differences were also seen in the total lymphocyte population. Plotting cell size and shape(fcircle) for PCNA cells together allowed CTCL to be differentiated from the inflammatory disorders with a sensitivity of 80% and a specificity of 93%. This was better than could be achieved using measurements made on the total cell population.

CONCLUSIONS

This technique can be partly automated and could be useful in the differential diagnosis of cutaneous lymphoid infiltrates. The result are also of some interest in the further understanding of patterns of cell proliferation in skin associated lymphoid tissue.

Coexistent cutaneous T-cell lymphoma and B-cell chronic lymphocytic leukaemia

Three patients with cutaneous T-cell lymphoma (CTCL) are reported who had concurrent B-cell chronic lymphocytic leukaemia (B-CLL). The separate lineage and clonal nature of the individual lymphoid malignancies were confirmed by gene-rearrangement analysis. The chronology of the illnesses did not support the hypothesis that CTCL predisposes to the development of B-cell proliferative disorders. There was no clear association with immunosuppressive therapy, and HTLV-1 studies were negative in all patients. Consequently, we speculate that a lymphoid stem cell defect, which may lead to the development of either aberrant B- or T-cell clones, may be responsible for such cases of dual lymphoid neoplasia.

Phenytoin-induced pseudolymphoma. A report of a case and review of the literature

We report a patient with phenytoin-induced pseudolymphoma mimicking cutaneous T-cell lymphoma (CTCL). Despite withdrawal of phenytoin, there was persistence of the cutaneous eruption and lymphadenopathy. Southern blot analysis of immunoglobulin and T-cell receptor genes was therefore used to assess whether there was a clonal lymphoid expansion. However, no rearrangement of the beta T-cell receptor gene or immunoglobulin heavy-chain gene was detected in tissue DNA from skin and lymph nodes. One year later the patient became asymptomatic, although he is still at risk of developing a true malignant lymphoma in the future, a condition known as pseudo-pseudolymphoma. It is suggested that genotypic studies may help in the initial diagnosis and the subsequent management of such patients.