Shinsuke Harada

MUM1/IRF4 expression as a frequent event in mature lymphoid malignancies.

MUM1/IRF4 is a myeloma-associated oncogene transcriptionally activated as a result of t(6;14)(p25,q32) chromosomal translocation and by virtue of its juxtaposition to the immunoglobulin heavy chain gene (IgH) locus. When this oncogene becomes non-functional, no activated B/T lymphocytes and Ig secreting plasma cells are observed, suggesting that MUM1/IRF4 is crucial for lymphoid development. Its expression was analyzed in both reactive lymphoid and lymphoma tissues by means of an immunohistochemical technique using specific goat antiserum against MUM1/IRF4. This analysis detected a 50 kDa MUM1product whose localization was restricted to the nuclei of the lymphocytes. The MUM1+ cells in reactive lymph nodes were found to consist of plasma cells and a small fraction (approximately 7.9%) of B cells harboring CD20+CD38+, which were located in the light zone of the germinal center. MUM1 expression in peripheral blood B/T lymphocytes was upregulated by mitogenic stimuli, suggesting that MUM1 positivity represents the activated state of the B/T cells. In B cell non-Hodgkins lymphoma (NHL), MUM1 expression was observed in 73.2% (30/41) of diffuse large B cell lymphoma (DLBCL), 20% (1/5) of marginal zone lymphoma (MZL) and 43% (3/7) of small lymphocytic lymphoma (SLL) cases, whereas it was not seen in any cases of mantle cell lymphoma (MCL) or follicle center lymphoma (FCL). Also, MUM1 was stained at high intensity in various types of T cell lymphomas including adult T cell leukemia/lymphoma (ATL/L) and anaplastic large cell lymphoma (ALCL) and in the majority of Hodgkins diseases. Our results suggest that a major proportion of lymphomas comprise either physiologically or aberrantly activated neoplastic lymphocytes expressing the MUM1 protein.

Molecular and immunological dissection of diffuse large B cell lymphoma: CD5+, and CD5- with CD10+ groups may constitute clinically relevant subtypes.

Diffuse large B cell lymphoma (DLBL) constitutes the greatest percentage of adult non-Hodgkin’s lymphomas and represents a diverse spectrum of lymphoid neoplasms. Clinicopathologic, phenotypic and genotypic findings were correlated and compared for 63 DLBL cases to investigate whether they represent clinically relevant subtypes. They were all cyclin D1 negative and were phenotypically divided into three groups, ie group I (CD5+ type, n = 11), group II (CD5− CD10+ type, n = 19), and group III (CD5− CD10− type, n = 33). Data were correlated by observing the respective gene rearrangement and expression of BCL2 and BCL6. In clinical aspects, the group I cases demonstrated a significantly inferior survival than those of the other two groups (log-rank test, P = 0.016). Although rearrangement of BCL2 and BCL6 did not show any inclination to a specific subgroup, the immunohistochemical detection of BCL2 was less frequent, at a statistically significant level (P = 0.011), in group II (50%) than in group I (82%) and III (82%) cases. This appears to confirm the unique aspect of the CD5− CD10+ type DLBL, indicating a certain relationship with the normal germinal center cells which usually lack BCL2 expression. The BCL6 protein expression was detected in most of the present DLBL cases (92%) irrespective of this grouping. These data suggest that the phenotypic delineation by the detection of CD5 and CD10 will improve our understanding of DLBL and be helpful in a future subgrouping of DLBL.

Ectopic Expression of MAFB Gene in Human Myeloma Cells Carrying (14;20)(q32;q11) Chromosomal Translocations

Chromosome 14q+, which represents a chromosomal rearrangement involving the immunoglobulin heavy chain gene (IgH) locus, is a genetic hallmark of human multiple myeloma (MM). Here, we report the identification of (14;20)(q32;qll) chromosomal translocations found in MM cells. Double color fluorescence in situ hybridization analyses pinpointed the breakpoints at the 20qll locus in two MM cell lines within a length of at most 680 kb between the KIAA0823 and MAFB gene loci. Among the transcribed sequences in the vicinity of the breakpoints, an ectopic expression of the MAFB gene, which is located at 450‐680 kb telomeric to one of the breakpoints and encodes a member of the MAF family basic region/leucine zipper transcription factor, was demonstrated to be associated with t(14;20). This finding, together with that of a previous study describing its transforming activity, suggests that the MAFB gene may be one of the targets deregulated by regulatory elements of the IgH gene as a result of t(14;20).

MICROSATELLITE INSTABILITY AS A POTENTIAL MARKER FOR POOR PROGNOSIS IN ADULT T CELL LEUKEMIA/LYMPHOMA

Microsatellite instability (MSI) represents a replication error resulting from the dysfunction of mismatch repair gene products. In this study, MSI was analyzed in 18 patients with various subtypes of adult T cell leukemia/lymphoma (ATL/L). Using six different microsatellite loci, we defined MSI as positive when replication errors were observed in at least two loci. The MSI was positive in four cases (22.2%)with acute type ATL, who tended to show more prognostically unfavorable factors and shorter overall survival. These results suggest that genomic instability may be associated with tumor progression rather than the development of ATL/L itself. In addition, the presence of the MSI at initial presentation could appear to warrant consideration as an additional prognostically unfavorable factor.

CC Chemokine Receptor 4-Positive Diffuse Large B-Cell Lymphoma Involving the Skin: A Case Report

Leukocyte trafficking is critically regulated by chemokines and their receptors. The involvement of the skin in certain subsets of T-cell malignancies has been explained by the discovery of an interaction between the thymus and activation-regulated chemokine (TARC), which is abundant in the skin, and its receptor, CC chemokine receptor 4 (CCR4), which is expressed in the tumor cells. We describe a diffuse large B-cell lymphoma (DLBCL) that showed CCR4 expression with involvement of the skin. A 55-year-old man presented with a giant skin ulcer of the right axilla, and his disease was diagnosed as DLBCL. Further clinical examination revealed an ulcerated gastric lymphoma lesion. Immunohistochemical and real-time reverse transcriptase-polymerase chain reaction analyses showed that the tumor cells were positive for CCR4, andTARC was expressed at extremely high levels in the lymphoma-affected skin. These observations suggest that the interaction between CCR4 and TARC played a significant role in the involvement of the skin in this case, similar to what has been observed in certain subsets of T-cell malignancies. To the best of our knowledge, this report is the first of a CCR4-positive B-cell lymphoma. The present case provides new insights into the pathogenesis of skin involvement in B-cell lymphomas.

Successful Treatment of Nasal T-Cell Lymphoma With a Combination of Local Irradiation and High-Dose Chemotherapy

Nasal natural killer (NK)/T-cell lymphoma is characterized by an aggressive clinical course and poor prognosis. The term “NK/T-cell” lymphoma includes both the NK-cell type and the T-cell type, which are classified by immunophenotyping and according to T-cell receptor (TCR) rearrangement. In addition, CD56+ T-cell lymphoma is defined as NK-like T-cell lymphoma. This report concerns a 54-year-old woman with nasal T-cell lymphoma. Its phenotype showed pure T-cell type with CD3+, CD56—, and TCR+ accompanied by Epstein-Barr virus infection. Although the lesions were localized in the nasal mucosa and facial skin (stage IE), local irradiation could not achieve complete remission (CR). We then administered 5 courses of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) regimen followed by high-dose chemotherapy with an autologous peripheral blood stem cell transplantation. This therapy resulted in CR. Our results suggest that this lymphoma subtype may be cured by means of intensive treatment soon after diagnosis.

Microsatellite instability is rare in the clinical course of myelodysplastic syndrome studied with DNA from fresh and paraffin-embedded tissues

Abstract Microsatellite instability (MSI) has been reported to occur in various types of malignant neoplasms. We performed a polymerase-chain-reaction-based assay for MSI between the initial and the most recently available (“latest”) samples from 23 patients with myelodysplastic syndrome (MDS). Of these patients, 15 were informative at more than three microsatellite loci. Seven patients showed an increase in leukemic cells while 8 patients did not during the interval between the two analyses. Only 1 of the patients, who had refractory anemia with excess blasts, which changed to acute myelogenous leukemia, showed microsatellite alteration at the analysis times. Among all 23 patients, two alterations were detected in the 42 informative paired samples that showed an increase in leukemic cells (4.8%), while none was detected in the 59 paired samples without such an increase. In total, therefore only two alterations were detected among 101 informative paired samples (2%). This indicates that MSI is rare in the clinical course of MDS irrespective of disease status, and is consequently not a critical genetic event for disease progression in most MDS patients.

Detection of bcr/abl fusion transcripts by semiquantitative multiplex RT-PCR combined with a colormetric assay in Ph positive leukemia

We studied the feasibility of the clinical application of a new bcr/abl analysis system, C-TRAK t(9;22), consisting of a multiplex RT-PCR and a colormetric assay. With this system, bcr/abl transcripts could be detected in all of 24 cytogenetic Philadelphia chromosome (Ph) positive leukemia patients and in none of eight Ph negative patients. Multiple bcr/abl transcripts could be detected in three of the 24 Ph positive patients, the fusion of bcr exon 1 to abl exon 2 (e1a2 junction) dominated that of bcr exon 13 to abl exon 2 (b2a2 junction) in two cases and that of bcr exon 14 to abl exon 2 (b3a2 junction) and b2a2 dominated e1a2 in one case. This system was sensitive enough to be able to detect even one bcr/abl transcript-producing cell in 50000 bcr/abl negative background cells, thus making it suitable for semiquantitative evaluation. Minimal residual disease (MRD) was monitored in one Ph positive leukemia patient who underwent allogenic bone marrow transplantation (allo-BMT). After allo-BMT, a weak positivity of the bcr/abl transcript continued with no clinical relapse; this result was consistent with that of a conventional nested PCR assay using ethidium bromide staining. Including all the procedures for RNA extraction, it took only about 10 h to detect the bcr/abl transcripts. Our findings indicate that this bcr/abl analysis system provides a quick and sensitive method for screening bcr/abl transcripts and possibly for monitoring MRD in Ph positive leukemia patients.

Effects of olopatadine in limited scleroderma with peripheral eosinophils.

Scleroderma and eosinophilia often occur together, though the pathogenesis is unclear. We investigated the effect of olopatadine hydrochloride in a series of cases of limited scleroderma (LS). Ten patients with LS and positive eosinophil counts (LSE) were enrolled (average age, 85 years; six men and four women). Serum concentrations of the anti‐Scl‐70 antibody were positive. Olopatadine hydrochloride was prescribed at 10 mg/day for 3 weeks. Serum concentrations of the anti‐Scl‐70 antibody significantly decreased, but changes in eosinophil numbers and percentages in peripheral blood were not significant. Factor analysis suggested a correlation between serum concentrations of the anti‐Scl‐70 antibody and complement C4. Olopatadine could be effective in reducing anti‐Scl‐70 antibodies in the elderly with LSE.

Superior Mesenteric Venous Thrombosis Associated With a Familial Missense Mutation (Pro626Leu) in the SHBG-Like Domain of the Protein S Molecule

A 76-year-old Japanese woman was hospitalized for ileus symptoms caused by extensive thrombosis of the superior mesen-teric vein. Because laboratory test results suggested type III protein S (PS) deficiency, molecular changes in PS were investi-gated.A single-base transition, CCG to CTG at codon 626 in exon XV, resulting in the missense mutation Pro626Leu, was identified in an allele of the patient and in her son. Reverse transcriptase polymerase chain reaction analysis indicated the presence of both normal and mutant types of PS messages in platelet-derived messenger RNAs. Our findings thus suggest that Pro626 in SHBG-like domain 7 may be crucial for in vivo antithrombotic activity of the PS molecule.