Use of polymerase chain reaction in the detection of clones in lymphoproliferative diseases of the skin

Clonal T-cell receptor β-chain gene rearrangements in differential diagnosis of lymphomatoid papulosis from skin metastasis of nodal anaplastic large-cell lymphoma

BACKGROUND

In patients with a history of nodal anaplastic large-cell lymphoma (ALCL), differentiation of type C lymphomatoid papulosis from cutaneous involvement of systemic ALCL may be challenging because the 2 entities may exhibit identical histologic features. Although metastatic ALCL generally carries the same clone as the primary lymphoma, expression of a distinct clone likely represents a distinct process.

OBSERVATIONS

A 54-year-old white man had a history of anaplastic lymphoma kinase 1-negative ALCL in the right inguinal lymph node 6 years ago. A complete response was achieved after 6 cycles of CHOP (cyclophosphamide, doxorubicin, vincristine [Oncovin], and prednisone administered in 21-day cycles) and radiation therapy. After 3½ years, the patient observed waxing and waning papules and nodules. Examination of the biopsy specimen revealed a dense CD30(+) lymphocytic infiltrate; no evidence of systemic malignancy was evident on positron emission tomography. Although clinically the presentation was consistent with lymphomatoid papulosis, metastatic ALCL had to be excluded. Polymerase chain reaction analysis with T-cell receptor γ-chain gene rearrangement (TCR-γR) was performed on the original lymph node and new skin lesions. Results of the TCR-γR analysis were positive for clonality in both lesions. However, separate clonal processes were identified. The identification of distinct clones supported the clinical impression of lymphomatoid papulosis.

CONCLUSION

Polymerase chain reaction analysis of TCR-γR is a useful method for distinguishing different clonal processes and is recommended when differentiation of primary and secondary lymphoproliferative disorders is required.

T-cell receptor-gamma gene analysis in evolving to advancing cutaneous T-cell lymphoma

The diagnosis of cutaneous T-cell lymphoma is often a challenge for the dermatopathologist. Early stages can mimic inflammatory dermatoses. Our aim was to explore the applicability of a standard T-cell receptor-gamma polymerase chain reaction in various subtypes of cutaneous T-cell lymphomas. Ninety-six biopsy specimens from 38 patients were selected. These included 72 specimens of mycosis fungoides, 12 specimens of non-mycosis fungoides T-cell lymphomas, and 12 specimens in which histology was non-specific or equivocal in patients who were later diagnosed to have lymphoma. T-cell clones were detected in 53 of 72 specimens of mycosis fungoides and eight of 12 specimens of non-mycosis fungoides lymphomas. Of the 72 specimens of mycosis fungoides, T-cell clones were detected in eight of 10 specimens of mycosis fungoides-associated follicular mucinosis and pigmented purpura-like mycosis fungoides. Four specimens from the 12 prediagnostic for cutaneous T-cell lymphomas showed presence of T-cell clones, identical to subsequent clones detected when lymphoma was fully established. In specimens where histology is not diagnostic and T-cell receptor-gamma gene analysis is positive, patients should be followed up closely. T-cell receptor-gamma gene analysis is a useful adjunct to histological diagnosis of early stage and variant types of mycosis fungoides.

The role of molecular studies in lymphoma diagnosis: a review

Lymphoma classification is based on a multiparametric approach to diagnosis, in which clinical features, morphology, immunophenotype, karyotype and molecular characteristics are important to varying degrees. While in most cases, a diagnosis can be confidently established on the basis of morphology and immunophenotype alone, a small proportion of diagnostically difficult cases will rely on molecular studies to enable a definitive diagnosis. This review discusses the various molecular techniques available including Southern blotting (SB), polymerase chain reaction (PCR), fluorescence in situ hybridisation (FISH)--including multicolour-FISH/spectral karyotyping and comparative genomic hybridisation--and also gene expression profiling using cDNA microarray technology. Emphasis is given to the analysis of antigen receptor gene rearrangements and chromosomal translocations as they relate to lymphoma diagnosis and also in the setting of minimal residual disease (MRD) detection and monitoring. Laboratories performing these tests need to have expertise in these areas of testing, and there is a need for greater standardisation of molecular tests. It is important to know the sensitivity and specificity of each test as well as its limitations and the pitfalls in the interpretation of results. Above all, results of molecular testing should never be considered in isolation, and must always be interpreted in the context of clinical and other laboratory data.

Minimal residual disease in mycosis fungoides follow-up can be assessed by polymerase chain reaction

BACKGROUND

T-cell receptor (TCR) gene rearrangement analysis, i.e. T-cell clonality, using polymerase chain reaction (PCR) is a routine method used to assess the presence of a cutaneous dominant T-cell clone in mycosis fungoides (MF).

OBJECTIVES

To compare the outcome of cutaneous lesions of MF after treatment with the fate of the cutaneous T-cell clonality, and to determine whether minimal residual disease can be detected in patients in clinical complete remission.

METHODS

Fifty-one patients histologically diagnosed as having MF (17 stage IA, 21 stage IB and 13 stage III) were included in this retrospective study. T-cell clonality was analysed by GC-clamp multiplex PCRgamma-denaturing gradient gel electrophoresis. Every patient had two cutaneous biopsies at least 3 months apart. The second biopsy was performed at the site of a treated lesion.

RESULTS

The presence or absence of a dominant T-cell clone in the skin remained identical in 26 of the 31 (84%) patients with persistent disease. Thirteen patients with a detectable dominant T-cell clone at diagnosis went into complete clinical remission. In nine of these 13 (69%) patients, the T-cell clone was no longer detectable after treatment. The remaining four (31%) patients had an unchanged T-cell clonality.

CONCLUSIONS

The TCR gene rearrangement imprint is a stable and reliable tumour marker of MF disease. One-third of patients in complete clinical remission had a cutaneous molecular residual disease, the prognostic value of which will be analysed in an ongoing prospective study.

Clonal T cell receptor gamma-chain gene rearrangement by PCR-based GeneScan analysis in the skin and blood of patients with parapsoriasis and early-stage mycosis fungoides

Cutaneous T cell lymphoma (CTCL) and reactive T cell skin diseases represent opposite ends of a spectrum of diseases ranging from overtly malignant to persistently benign. Within this spectrum, the parapsoriasis group is not clearly defined regarding malignant potential. In contrast to consistent findings in advanced-stage CTCL, clonality analysis of parapsoriasis has produced conflicting results in previous studies. As T cell receptor gamma-chain polymerase chain reaction GeneScan analysis (TCR-gamma-PCR-GSA) stands out by its sensitivity, its accuracy in size determination of PCR products, its capacity to identify false positives by repeated analysis and its easy applicability, this approach was used to analyse the clonality status of 41 patients with borderline T cell lymphoproliferative skin diseases, including parapsoriasis (n=27) and early-stage mycosis fungoides (MF) (n=14). A monoclonal T cell infiltrate was demonstrated by repeated TCR-gamma-PCR-GSA in lesional skin specimens in 19.2% of parapsoriasis patients and in 66.6% of early-stage MF cases (p=0.013). In peripheral blood, a monoclonal T cell population was found in a similar percentage of parapsoriasis and of early-stage MF patients (26.7% versus 12.5%; p=0.611). A detailed analysis of parapsoriasis subentities, namely small and large plaque parapsoriasis, and parapsoriasis lichenoides, revealed monoclonality in 2(6)/2(5), 3(14)/2(8) and 0(6)/0/(3) of the skin and peripheral blood specimens, respectively. The high detection rate of false positive cases by repeated analysis (20-37.5%) provides a corrected perspective for the high rates of dominant T cell clones found by others in the peripheral blood of such patients. From the results obtained, three major conclusions can be drawn: firstly, CTCL is clearly associated with detection of monoclonality, even in its early stages; secondly, monoclonality is not a prerequisite for potential CTCL precursor entities; and thirdly, recirculating malignant T cells identical to the skin clone are not readily detected in parapsoriasis or early-stage MF, but may rather indicate disease progression.

Monoclonal gamma-T-cell receptor rearrangement in vulvar lichen sclerosus and squamous cell carcinomas

Risk factors for vulvar squamous cell carcinoma (SCC) are human papilloma virus (HPV) infections and lichen sclerosus (LS). The significance of monoclonal gamma-T-cell receptor (gamma-TCR) rearrangement in the lymphoid infiltrate of LS and the consequence for vulvar carcinogenesis is unknown. One hundred sixty-one biopsies of vulvar LS and SCC, with and without LS, were examined for monoclonal gamma-TCR rearrangement and HPV16 expression, and for the expression of B- and T-cell markers and fascin. Monoclonal gamma-TCR rearrangement was identified in 8 of 17 patients with LS and 11 of 21 patients with SCC arising in LS with only occasional HPV16 DNA detection. None of the 19 SCC without LS showed monoclonal gamma-TCR rearrangement, but 14 of 19 patients had strong HPV16 detection. The lichenoid infiltrate of LS with germline configuration consisted predominantly of T cells (CD8 > CD4), along with numerous B cells. However, in biopsies with monoclonally rearranged gamma-TCR, CD4-positive T cells dominated along with B cells and fascin-positive cells in the lichenoid infiltrate and in deeply located lymphocyte aggregates (LAs). These LAs additionally contained fascin-positive dendritic cells with only individual CD8, CD57, and granzyme-positive cells. LAs in biopsies with germline configuration demonstrated numerous T cells (CD8 >CD4), but only single peripheral B cells, CD57, and fascin-positive lymphocytes. Our data suggest that monoclonal gamma-TCR rearrangement is characteristic for and limited to LS and SCC arising in LS, raising the question for a LS-associated antigen. We interpret B cells, CD4-positive T cells, and fascin-expressing dendritic cells within LS as a cellular immune response to antigen or proliferating T-cell clones. The resulting local immune dysregulation in LS may provide a permissive environment for the development of a SCC.

The value of clonality in the diagnosis and follow-up of patients with cutaneous T-cell infiltrates

The diagnosis of early stages of cutaneous T-cell lymphoma (CTCL) is often difficult, especially for lesions that are at the borderline between reactive and neoplastic skin T-cell infiltrates. T-cell monoclonality in these lesions is considered by some to be an important prognostic factor of neoplastic evolution, whereas others claim that clonality can also be found in benign skin infiltrates and is therefore of limited diagnostic value. To address this controversy, the authors analyzed retrospectively eight patients with lymphocytic skin lesions who progressed to CTCL, and three patients with recurrent T-cell lymphocytic infiltrates who had not developed CTCL. From a total of 65 biopsies of eight progressing patients, 32 were diagnosed as histologically malignant and 33 were diagnosed as benign or borderline. The authors found clonality by either polymerase chain reaction or Southern blot analysis in 88% of malignant and in 79% of nonmalignant lesions. None of the 37 biopsies of non-progressing patients was clonal. These results indicate strongly that the presence of monoclonality in T-cell skin infiltrates is related closely to the risk of developing CTCL. The value of clonality as a marker of malignancy is supported by the absence of T-cell clonal populations in all infiltrates from patients who had not progressed to lymphoma.

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

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

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

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

PCR-heteroduplex analysis of T-cell receptor gamma gene rearrangement in paraffin-embedded skin biopsies

We developed a rapid, simple, and sensitive method for the detection of T-cell receptor-gamma (TCRgamma) gene rearrangements in paraffin-embedded skin biopsies. Available techniques often require either fresh tissue, several primer pairs, nested amplifications, or specialized electrophoresis steps such as denaturing gradient gel electrophoresis. Our method is based on heteroduplex analysis of polymerase chain reaction (PCR) products of the TCRgamma in a nondenaturing modified polyacrylamide gel using a single pair of primers and is adapted for paraffin-embedded tissue. When tested against Southern blot analysis, the PCR results correlated in 8 of 9 cases. Six mature cutaneous B-cell lymphomas and 29 inflammatory skin disorders all resulted in a polyclonal amplification pattern. When analyzing 3-mm or 4-mm punch biopsies of 51 cases of cutaneous T-cell lymphoma, 37 (72.5%) showed a clonal rearrangement with this technique. For 7 cases of patch stage mycosis fungoides, frozen tissue and formalin-fixed and paraffin-embedded tissue was available, and in 5 of 7 cases (71%), the results in frozen and paraffin-embedded tissue were concordant. One case showed a clonal pattern in frozen tissue but not in paraffin-embedded tissue, and one case was polyclonal in frozen tissue but monoclonal in paraffin-embedded tissue. Using serial dilutions of DNA from a T-cell ALL in a polyclonal background (tonsil), we established a sensitivity of 0.5%. Heteroduplex PCR of the TCRgamma is a rapid, sensitive, and inexpensive screening procedure as well as a useful adjunct to histologic analysis and immunophenotyping of cutaneous T-cell proliferations.

How useful are T-cell receptor gene rearrangement studies as an adjunct to the histopathologic diagnosis of mycosis fungoides?

The diagnosis and differential diagnosis of mycosis fungoides (MF) is often difficult, clinically and histologically. Recent attempts to enhance diagnostic sensitivity have involved T-cell receptor (TCR) gene rearrangement studies, using Southern blot or polymerase chain reaction (PCR) technique. PCR is more widely used because of its increased sensitivity, lower labor- and cost-intensive analytic steps, lack of radioactive substances, and applicability to routinely processed biopsies. Several studies that use this technique detect clonal bands in 50% to 83% of the MF specimens from patch, patch/plaque, and erythrodermic stages, which often pose a diagnostic challenge. This compares with no clonality in the control groups of most of these studies, or with up to 13% in a few studies, although long-term follow-up reveal that some cases of so-called "clonal dermatitis" eventually progress into overt cutaneous T-cell lymphoma. Furthermore, retrospective studies on archival histologic material from patients with MF demonstrate similar rates of clonality in histologically "inconclusive," "borderline," and diagnostic MF biopsies. Therefore, in the proper clinicopathologic setting, and with consideration of the known limitations of this technique, TCR gene rearrangement studies on lesional skin using PCR may be helpful as an adjunct to the histopathologic diagnosis of MF.

Use of the polymerase chain reaction in the evaluation of cutaneous T-cell infiltrates

Histologic evaluation of suspected cutaneous T-cell neoplasia is challenging. There is significant overlap with features of benign condition, and neoplastic cells often occur in a reactive background. Recently, molecular techniques using paraffin-embedded tissue have been applied to the diagnosis of cutaneous T-cell infiltrates. These methods are useful for determining whether a clonal population of T-cells is present. The advantages and limitation of molecular diagnostic methods in the diagnosis of cutaneous T-cell infiltrates are discussed.

Analysis of clonality of atypical cutaneous lymphoid infiltrates associated with drug therapy by PCR/DGGE

Atypical lymphocytic infiltrates that mimic cutaneous lymphoma (ie, pseudolymphoma) are often observed in skin biopsy specimens from patients with altered immune function. The latter may reflect systemic immune dysregulatory states such as collagen vascular disease or human immunodeficiency virus infection. Among the iatrogenic causes are drug therapy with agents that abrogate lymphocyte function. These drugs encompass the anticonvulsants, antidepressants, phenothiazines, calcium channel blockers, and angiotensin-converting enzyme inhibitors. The appellation of lymphomatoid hypersensitivity reaction has been applied to cases of drug-associated pseudolymphoma. Pathologically and clinically, the distinction of such cases from cutaneous lymphoma is difficult. We employed the polymerase chain reaction (PCR) on archival material of proven drug-associated lymphomatoid hypersensitivity reactions both to explore its utility as an adjunct in diagnosis and to investigate the genotypic aberrations induced by drug therapy. Formalin-fixed, paraffin-embedded biopsy specimens from seven cutaneous T-cell lymphomas (CTCL), one nodal T-cell lymphoma, two cutaneous B-cell lymphomas, three typical hypersensitivity reactions, one tonsil, and 14 lymphomatoid hypersensitivity reactions were studied. Control cases for which DNA derived from fresh tissue was used include the Jurkat T-cell tumor line, placenta, one nodal B-cell lymphoma, and one case of reactive lymph node hyperplasia. DNA was obtained and purified by standard methods, then amplified with oligonucleotide primers specific for the T-cell receptor gamma locus and the immunoglobulin heavy chain genes. T-cell amplicons were analyzed by denaturing gradient gel electrophoresis (DGGE) and B-cell amplicons by either nondenaturing polyacrylamide or agarose gel electrophoresis. The nodal and Jurkat T-cell lymphomas, six of seven CTCL, one cutaneous B-cell lymphoma, and 2 of 14 lymphomatoid hypersensitivity reactions showed dominant ("monoclonal") T-cell gene rearrangement patterns, and the remainder of cases were polyclonal. A causal relationship between drug therapy and skin eruption was ascertained in the two patients showing T-cell rearrangements, and both experienced complete and sustained lesional resolution on discontinuation of the implicated drug. The only immunoglobulin heavy chain gene rearrangements detected by PCR were in two of the three B-cell lymphomas. We conclude that PCR/DGGE is a powerful method for assaying T-cell clonality in archival tissue and can aid in the discrimination of reactive from malignant cutaneous infiltrates with appropriate clinicopathologic correlation. Recognition that a monoclonal TCRgamma rearrangement can be observed in cases of drug-associated lymphomatoid hypersensitivity may help in avoiding a misdiagnosis of malignant lymphoma.

Prognostic Significance of a Polymerase Chain Reaction–Detectable Dominant T-Lymphocyte Clone in Cutaneous Lesions of Patients With Mycosis Fungoides

Although mycosis fungoides (MF) is considered to be an indolent lymphoma, survival is highly influenced by TNM stage. At diagnosis, most MF patients present with early stage disease and a high probability of long-term survival. Treatment is generally directed towards skin lesions, and achievement and duration of complete responses are variable. A dominant T-cell clone is detectable in the cutaneous lesions of 60% of patients. The aim of this study was to determine whether the presence of a T-cell clonal population influences the clinical course of the disease after topical therapy. Cutaneous biopsies from 68 patients were histologically diagnosed as MF and T-cell clonality was analyzed by in vitro amplification of TCR-γ chain gene rearrangements (polymerase chain reaction γ [PCRγ]). After a median follow-up of 48 months, response to treatment was clinically assessed. Age, sex, duration of symptoms before diagnosis, type of cutaneous lesions (T stage), TNM stage, and PCRγ were evaluated as predictive factors of response to treatment in univariate and multivariate analyses. Univariate analysis demonstrated that T1 cutaneous lesions (P = .05) and PCRγ negativity (P = .007) were associated with a higher complete remission rate. Using multivariate analysis, T stage (relative risk, 3.13; P = .06) and PCRγ (relative risk, 4.4; P = .01) remained independent significant predictive parameters of response. In conclusion, T stage and cutaneous PCRγ at diagnosis are the two predictive parameters of treatment response for MF. Therefore, the cutaneous PCRγ findings should be considered in the analysis of future therapeutic trials.

© 1998 by The American Society of Hematology.

Prognostic Significance of a Polymerase Chain Reaction–Detectable Dominant T-Lymphocyte Clone in Cutaneous Lesions of Patients With Mycosis Fungoides

Although mycosis fungoides (MF) is considered to be an indolent lymphoma, survival is highly influenced by TNM stage. At diagnosis, most MF patients present with early stage disease and a high probability of long-term survival. Treatment is generally directed towards skin lesions, and achievement and duration of complete responses are variable. A dominant T-cell clone is detectable in the cutaneous lesions of 60% of patients. The aim of this study was to determine whether the presence of a T-cell clonal population influences the clinical course of the disease after topical therapy. Cutaneous biopsies from 68 patients were histologically diagnosed as MF and T-cell clonality was analyzed by in vitro amplification of TCR-γ chain gene rearrangements (polymerase chain reaction γ [PCRγ]). After a median follow-up of 48 months, response to treatment was clinically assessed. Age, sex, duration of symptoms before diagnosis, type of cutaneous lesions (T stage), TNM stage, and PCRγ were evaluated as predictive factors of response to treatment in univariate and multivariate analyses. Univariate analysis demonstrated that T1 cutaneous lesions (P = .05) and PCRγ negativity (P = .007) were associated with a higher complete remission rate. Using multivariate analysis, T stage (relative risk, 3.13; P = .06) and PCRγ (relative risk, 4.4; P = .01) remained independent significant predictive parameters of response. In conclusion, T stage and cutaneous PCRγ at diagnosis are the two predictive parameters of treatment response for MF. Therefore, the cutaneous PCRγ findings should be considered in the analysis of future therapeutic trials.

© 1998 by The American Society of Hematology.