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.

Molecular analysis of the immunoglobulin heavy chain gene in the diagnosis of primary cutaneous B cell lymphoma.

The diagnosis of primary cutaneous B cell lymphoma can be difficult on the basis of histologic and immunophenotypic features alone. Previous polymerase chain reaction studies for detection of a clonal population in nodal B cell lymphomas have employed different primer pairs with detection sensitivities varying between 34% and 94% but there have been no comprehensive studies of primary cutaneous B cell lymphoma. We compared the sensitivity of different sets of consensus primers to amplify the CDR3 VDJ region of the immunoglobulin heavy chain gene in combination with an immunoglobulin heavy chain joining region consensus primer to detect a monoclonal population in 39 cases of primary cutaneous B cell lymphoma. Radiolabeled products were analyzed with denaturing 6% polyacrylamide gel electrophoresis. Sequence analysis was used to confirm amplification of clonal immunoglobulin heavy chain gene rearrangements and to establish whether somatic hypermutation can interfere with primer binding. Clonal immunoglobulin heavy chain gene rearrangements were demonstrated in 79% of cases (74% with leader sequences, 64% with FR1, and 45% with FR3 primers). Somatic hypermutation at primer binding sites was confirmed in cases where a false negative result was obtained with the FR3 primer. Although monoplex polymerase chain reaction amplification using the leader sequence primers is the most sensitive method for detecting a clonal population, six primers are required in six different reactions. Our findings suggest initial analysis with the FR3 primer and subsequent analysis using leader sequences in negative cases. Our data indicate that the FR3 consensus primer alone is not sufficient for a comprehensive analysis of primary cutaneous B cell lymphoma.

Allelotyping in mycosis fungoides and Sézary syndrome: common regions of allelic loss identified on 9p, 10q, and 17p.

Allelotyping studies have been extensively used in a wide variety of malignancies to define chromosomal regions of allelic loss and sites of putative tumor suppressor genes; however, until now this technique has not been used in cutaneous lymphoma. We have analyzed 51 samples from patients with mycosis fungoides and 15 with Sézary syndrome using methods to detect loss of heterozygosity. Micro satellite markers were selected on 15 chromosomal arms because of their proximity to either known tumor suppressor genes or chromosomal abnormalities identified in previous cytogenetic studies in cutaneous lymphoma. Allelic loss was present in 45% of patients with mycosis fungoides and 67% with Sézary syndrome. Loss of heterozygosity was found in over 10% of patients with mycosis fungoides on 9p, 10q, 1p, and 17p and was present in 37% with early stage (T1 and T2) and 57% with advanced disease (T3 and T4). Allelic loss on 1p and 9p were found in all stages of mycosis fungoides, whereas losses on 17p and 10q were limited to advanced disease. In Sézary syndrome high rates of loss of heterozygosity were detected on 9p (46%) and 17p (42%) with lower rates on 2p (12%), 6q (7%), and 10q (12%). There was no significant difference in the age at diagnosis or number of treatments received by those with loss of heterozygosity and those without, suggesting that increasing age and multiple treatments do not predispose to allelic loss. These results provide the basis for further studies defining more accurately chromosomal regions of deletions and candidate tumor suppressor genes involved in mycosis fungoides and Sézary syndrome.

Absence of the t(14;18) chromosomal translocation in primary cutaneous B-cell lymphoma.

BACKGROUND: The t(14;18)(q32;q21) chromosomal translocation is found in the majority of nodal follicular lymphomas and in a lower percentage of systemic high-grade diffuse large B-cell lymphomas. The translocation results in the juxtaposition of the bcl-2 gene on chromosome 18 with the immunoglobulin heavy chain joining region on chromosome 14. Bcl-2 protein prevents apoptosis and the translocation leads to overexpression of a functionally normal Bcl-2 protein that prevents apoptosis of neoplastic cells. OBJECTIVES: The purpose of our study was to analyse cases of primary cutaneous B-cell lymphoma (PCBCL) for the presence of the t(14;18) translocation and to correlate the results with Bcl-2 expression and histological subtype. METHODS: Forty-four cutaneous B-cell lymphoid proliferations (36 PCBCL, four follicular B-cell lymphomas with cutaneous presentation and four reactive B-cell infiltrates) were analysed by polymerase chain reaction amplification and polyacrylamide gel electrophoresis using consensus primers for the joining region on the immunoglobulin heavy chain gene in combination with either a primer for the major breakpoint region (MBR) or the minor cluster region (mcr) on chromosome 18. RESULTS: None of 36 PCBCL analysed demonstrated a t(14;18) translocation; however, three of four systemic follicular B-cell lymphomas presenting in the skin were found to have a translocation in the MBR, which was confirmed by sequence analysis. Correlation with Bcl-2 immunostaining showed that of seven patients with high-grade cutaneous diffuse large B-cell lymphoma, four were Bcl-2 positive but had no evidence of a t(14;18) translocation. In the five cases classified as primary cutaneous follicle centre cell lymphoma, the neoplastic cells within the germinal centres failed to express Bcl-2. However, Bcl-2-positive neoplastic cells were present in all four cases of systemic follicular lymphoma, including the case that did not show a t(14;18) translocation. In all cases of marginal zone lymphoma the marginal zone lymphocytes were Bcl-2 positive. CONCLUSIONS: These findings indicate that the t(14;18) translocation does not occur in PCBCL, which suggests the involvement of different pathogenetic mechanisms compared with their nodal counterparts. Furthermore, the detection of a t(14;18) translocation in cutaneous B-cell lymphoma should suggest the presence of systemic disease, which underlies the need for exhaustive staging procedures.

Rituximab in cutaneous B-cell lymphoma: a report of two cases.

We report two patients with primary cutaneous B-cell lymphoma who were treated with rituximab, a new anti-CD20 monoclonal antibody. The first patient, who had a diffuse large B-cell lymphoma of the lower leg, achieved an 85% improvement. The second patient, who had a primary cutaneous B-cell lymphoma, which had undergone high-grade transformation and systemic spread, achieved a minor response of approximately 30%. Both patients subsequently relapsed. The first patient achieved complete clearance with a second course of rituximab given with systemic chemotherapy, but again relapsed. Treatment with rituximab has been reported to produce response rates of 48% in relapsed systemic low-grade or follicular lymphoma, but there are no previous reports of the use of rituximab in primary cutaneous B-cell lymphoma.

Loss of heterozygosity on 10q and microsatellite instability in advanced stages of primary cutaneous T-cell lymphoma and possible association with homozygous deletion of PTEN.

Previous cytogenetic studies of primary cutaneous T-cell lymphoma (CTCL) were based on limited numbers of patients and seldom showed consistent nonrandom chromosomal abnormalities. In this study, 54 tumor DNA samples from patients with CTCL were analyzed for loss of heterozygosity on 10q. Allelic loss was identified in 10 samples, all of which were from the 44 patients with mycosis fungoides (10/44 patients; 23%). Of the patients with allelic loss, 3 were among the 29 patients with early-stage myosis fungoides (T(1) or T(2)) (3/29 patients; 10%), whereas the other 7 were among the 15 patients with advanced cutaneous disease (T(3) or T(4)) (7/15 patients; 47%). The overlapping region of deletion was between 10q23 and 10q24. In addition, microsatellite instability (MSI) was present in 13 of the 54 samples (24%), 12 from patients with mycosis fungoides and 1 from a patient with Sezary syndrome. There was also an association between MSI and disease progression in patients with mycosis fungoides, with 6 of 15 (40%) patients with MSI having advanced cutaneous disease and only 6 of 29 (21%) having early-stage disease. Samples with allelic loss on 10q were analyzed for abnormalities of the tumor suppressor gene PTEN (10q23.3). No tumor-specific mutations were detected, but homozygous deletion was found in 2 patients. Thus, we found loss of heterozygosity on 10q and MSI in advanced cutaneous stages of mycosis fungoides. These findings indicate that a tumor suppressor gene or genes in this region may be associated with disease progression. Furthermore, abnormalities of PTEN may be important in the pathogenesis of mycosis fungoides, but our data imply that this gene is rarely inactivated by small deletions or point mutations. (Blood. 2000;95:2937-2942)

Detection of a peripheral blood T cell clone is an independent prognostic marker in mycosis fungoides.

UNLABELLED: T cell receptor gene analysis is a sensitive method for assessment of peripheral blood involvement in mycosis fungoides. This study uses polymerase chain reaction/single-strand conformational polymorphism (PCR/SSCP) analysis of the T cell receptor gamma gene and relates the results to skin stage and outcome in mycosis fungoides. Seventy-five peripheral blood samples from 66 patients were obtained from 1990 onwards and subjected to PCR/SSCP. Both Southern blot analysis and PCR/SSCP analysis were performed on 63 samples from 56 patients. Fourteen patients had T1 disease (12 IA, two IIA), 20 T2 (14 IB, five IIA, one IVA), 29 T3 (24 IIB, two IVA, three IVB, two patients tested at both T2 and T3), and five T4 (all III). The percentage of positive samples was higher with PCR/SSCP than with Southern blot analysis (29 of 63 vs eight of 63 samples, p < 0.001), and the percentage of positive samples increased with each stage (21% at T1, 35% at T2, 58% at T3, and 71% at T4). Proportional hazards analysis corrected for age, skin, and lymph node stage showed that the presence of a peripheral blood clone is associated with a worse outcome (p = 0.03, CI 1.1-6.03). These results indicate that the presence of a peripheral blood clone is an independent prognostic variable in patients with mycosis fungoides after correcting for age, skin, and lymph node stage, and that peripheral blood involvement is present in a large proportion of patients with early stage mycosis fungoides. KEYWORDS: polymerase chain reaction/single-strand conformational polymorphism/T cell receptor gene rearrangement. J Invest Dermatol 114:117-121, 2000

Regional lymphomatoid papulosis: a report of four cases.

Lymphomatoid papulosis (LyP) is a chronic self-healing cutaneous eruption which is clinically benign but histologically malignant. Lesions occur episodically over the trunk and limbs. We describe four patients with regional LyP. All were male, with a range in age at onset from 12 to 47 years. In all cases, lesions were confined to a segmental unilateral area. Two patients had type A and two type B LyP. We have long-term follow-up on one patient whose lesions were limited to the right buttock for more than 20 years before more widespread lesions developed. Another patient with lesions on the left flank had mycosis fungoides limited to the same region. Only one other case of LyP presenting in a regional distribution has previously been described.

Sequence heterogeneity of an mpb70 gene analogue in Mycobacterium kansasii.

The protein antigen MPB70 is a major component of culture supernatants of Mycobacterium bovis and is an active ingredient of bovine PPD used for skin-testing cattle for tuberculosis. We have shown that Mycobacterium kansasii possesses a similar gene that cross-reacts in a PCR test for M. bovis. Single strand conformational polymorphism analysis, and the DNA sequence of the PCR product, shows differences between M. kansasii strains, supporting the suggestion that M. kansasii is not a homogeneous species.

The RB1 gene mutation in a child with ectopic intracranial retinoblastoma.

The RB1 gene mutation was investigated in a child with ectopic intracranial retinoblastoma using DNA obtained from both the pineal and retinal tumours of the patient. A nonsense mutation in exon 17 (codon 556) of the RB1 gene was found to be present homozygously in both the retinal and the pineal tumours. The same mutation was present heterozygously in the DNA from the constitutional cells of the patient, proving it to be of germline origin. The initial mutation was shown to have occurred in the paternally derived RB1 allele. The mutation is in an area of the gene that encodes the protein-binding region known as the 'pocket' region and has been detected in other cases of retinoblastoma.

Simplified procedures for detection of amplified DNA using fluorescent label incorporation and reverse probing.

Conventional methods of detecting polymerase chain reaction (PCR) products require equipment and expertise which may not be available in diagnostic bacteriology laboratories, especially in developing countries. To this end we have examined other methods of product detection, including fluorescein-12-dUTP incorporation during PCR amplification, and reverse probing, where the PCR product is used as the probe in a scaled down hybridization with a fixed capture probe consisting of a fragment entirely internal to the sequence of the PCR product. These techniques have shown sensitivities of 20 fg of purified mycobacterial DNA, which corresponds to approximately five cells.