Hideki Asaoku

Systemic IgG4-related lymphadenopathy: a clinical and pathologic comparison to multicentric Castleman's disease

IgG4-related disease sometimes involves regional and/or systemic lymph nodes, and often clinically and/or histologically mimics multicentric Castlemans disease or malignant lymphoma. In this study, we examined clinical and pathologic findings of nine patients with systemic IgG4-related lymphadenopathy. None of these cases were associated with human herpes virus-8 or human immunodeficiency virus infection, and there was no T-cell receptor or immunoglobulin gene rearrangement. Histologically, systemic IgG4-related lymphadenopathy was classified into two types by the infiltration pattern of IgG4-positive cells: interfollicular plasmacytosis type and intra-germinal center plasmacytosis type. The interfollicular plasmacytosis type showed either Castlemans disease-like features or atypical lymphoplasmacytic and immunoblastic proliferation-like features. By contrast, the intra-germinal center plasmacytosis type showed marked follicular hyperplasia, and infiltration of IgG4-positive cells mainly into the germinal centers, and some cases exhibited features of progressively transformed germinal centers. Interestingly, eight of our nine (89%) cases showed eosinophil infiltration in the affected lymph nodes, and examined patients showed high elevation of serum IgE. Laboratory examinations revealed elevation of serum IgG4 and soluble interleukin-2 receptors. However, the levels of interleukin-6, C-reactive protein, and lactate dehydrogenase were within normal limits or only slightly elevated in almost all patients. One patient showed a high interleukin-6 level whereas C-reactive protein was within the normal limit. Autoantibodies were examined in five patients and detected in four. Compared with the previously reported cases of multicentric Castlemans disease, our patients with systemic IgG4-related lymphadenopathy were significantly older and had significantly lower C-reactive protein and interleukin-6 levels. In conclusion, in our systemic IgG4-related lymphadenopathy showed pathologic features only partially overlapping those of multicentric Castlemans disease, and serum data (especially C-reactive protein and interleukin-6) are useful for differentiating the two. Our findings of eosinophil infiltration in the affected tissue and elevation of serum IgE may suggest an allergic mechanism in the pathogenesis of systemic IgG4-related lymphadenopathy.

Retrospective Analysis of Intravascular Large B-Cell Lymphoma Treated With Rituximab-Containing Chemotherapy As Reported by the IVL Study Group in Japan

PURPOSE To evaluate the safety and efficacy of rituximab-containing chemotherapies for intravascular large B-cell lymphoma (IVLBCL). PATIENTS AND METHODS We retrospectively analyzed 106 patients (59 men, 47 women) with IVLBCL who received chemotherapy either with rituximab (R-chemotherapy, n = 49) or without rituximab (chemotherapy, n = 57) between 1994 and 2007 in Japan. The median patient age was 67 years (range, 34 to 84 years). The International Prognostic Index was high-intermediate/high in 97% of patients. RESULTS The complete response rate was higher for patients in the R-chemotherapy group (82%) than for those in the chemotherapy group (51%; P = .001). The median duration of follow-up for surviving patients was 18 months (range, 1 to 95 months). Progression-free survival (PFS) and overall survival (OS) rates at 2 years after diagnosis were significantly higher for patients in the R-chemotherapy group (PFS, 56%; OS, 66%) than for patients in the chemotherapy group (PFS, 27% with P = .001; OS, 46% with P = 0.01). Multivariate analysis revealed that the use of rituximab was favorably associated with PFS (hazard ratio [HR], 0.45; 95% CI, 0.25 to 0.80; P = .006) and OS (HR, 0.42; 95% CI, 0.21 to 0.85; P = .016). Treatment-related death was observed in three patients (6%) who received R-chemotherapy and in five patients (9%) who received chemotherapy. CONCLUSION Our data suggest improved clinical outcomes for patients with IVLBCL in the rituximab era. Future prospective studies of rituximab-containing chemotherapies are warranted.

Enhanced production of osteopontin in multiple myeloma: clinical and pathogenic implications

Summary. In this study, we examined osteopontin (OPN) production in myeloma cells and plasma OPN levels in multiple myeloma (MM) patients. We assessed OPN production in bone marrow cells (BMCs) by immunocytochemistry and enzyme‐linked immunosorbent assay (ELISA). We also assessed OPN production in various B‐cell malignant cell lines, including three myeloma cell lines by reverse transcription polymerase chain reaction (RT‐PCR) and Western blotting. In addition, we measured plasma OPN concentrations by ELISA in 30 MM patients, 21 monoclonal gammopathy of undetermined significance (MGUS) patients and 30 healthy volunteers. As a result, in an immunocytochemical study, abundant OPN was detected in BMCs from overt MM patients, whereas no OPN was detected in BMCs from patients with other haematological diseases, including MGUS. Cultured BMCs from overt MM patients produced more OPN than those from patients with either smouldering MM or MGUS. Myeloma cell lines spontaneously produced OPN. Plasma OPN levels of MM patients were significantly higher than those of MGUS patients and healthy volunteers (P < 0·05). Moreover, they correlated with both progression and bone destruction of the disease (P < 0·05). These suggest that myeloma cells actively produce OPN, which possibly contributes to osteoclastic bone resorption in MM. Plasma OPN levels may be a useful biomarker for assessing bone destruction in MM and distinguishing MM from MGUS or smouldering MM.

MPC-1^-CD49e^- immature myeloma cells include CD45^+ subpopulations that can proliferate in response to IL-6 in human myelomas

Using three‐colour phenotypic analysis, we detected five subpopulations of myeloma cells (CD38++) in the bone marrow mononuclear cells of human myeloma patients: MPC‐1−CD45−CD49e−, MPC‐1−CD45+CD49e−, MPC‐1+CD45−CD49e−, MPC‐1+CD45+CD49e− and MPC‐1+CD45+CD49e+. Most of the myeloma cells did not express CD45 but a few MPC‐1− immature myeloma cells and some MPC‐1+ myeloma cells expressed CD45 and CD45RO but not CD45RA, whereas all of normal early plasma cells in the peripheral blood, lymph node plasma cells and bone marrow plasma cells expressed CD45 and CD45RA, CD45RB but not CD45RO. In order to clarify the biological character of these myeloma subpopulations, we examined the expression of Ki‐67 antigen. Proliferating myeloma cells (Ki‐67+) were found in the MPC‐1− fractions and the MPC‐1−CD45+ fractions rather than MPC‐1−CD45− fractions. Next, in order to further clarify the biological difference of two immature subpopulations (MPC‐1−CD45−CD49e− and MPC‐1− CD45+CD49e−), determined cell viability and phenotypic change after culturing with interleukin 6 (IL‐6) in vitro. In the presence of IL‐6, MPC‐1−CD45+ cells kept their viability more than MPC‐1−CD45− cells and some MPC‐1−CD45− cells could be converted to MPC‐1−CD45+ cells. In conclusion, these data suggest that human myeloma cells are phenotypically subdivided into five subpopulations, and among these subpopulations MPC‐1−CD45+CD49e− but not MPC‐1−CD45−CD49e− immature cells contain proliferating cells in response to IL‐6, and IL‐6 can also induce expression of CD45 on MPC‐1−CD45− subpopulation of immature myeloma cells.

Genomic Screening for Genes Silenced by DNA Methylation Revealed an Association between RASD1 Inactivation and Dexamethasone Resistance in Multiple Myeloma

Purpose: Epigenetic changes such as DNA methylation play a key role in the development and progression of multiple myeloma. Our aim in the present study was to use genomic screening to identify genes targeted for epigenetic inactivation in multiple myeloma and assess their role in the development of resistance to dexamethasone. Experimental Design: Gene expression was examined using microarray screening, reverse transcription-PCR, and real-time quantitative PCR. DNA methylation was examined using bisulfite PCR, bisulfite sequencing, and bisulfite pyrosequencing in 14 multiple myeloma cell lines, 87 multiple myeloma specimens, and 12 control bone marrow samples. WST-8 assays were used to assess cell viability after treatment with 5-aza-2′-deoxycytidine and/or dexamethasone. Results: Microarray analysis was done to screen for genes up-regulated by 5-aza-2′-deoxycytidine. In RPMI8226 cells, 128 genes were up-regulated, whereas 83 genes were up-regulated in KMS12PE cells. Methylation of 22 genes with CpG islands in their 5′ regions, including RASD1, was confirmed. Methylation of RASD1 was associated with its inactivation, which correlated with resistance to dexamethasone. Treating multiple myeloma cells with 5-aza-2′-deoxycytidine restored sensitivity to dexamethasone. Methylation of RASD1 was also detected in a subset of primary multiple myeloma specimens, and the levels of methylation were increased after repeated antitumor treatments. Gene signature analysis revealed various genes to be synergistically induced by treatment with a combination of 5-aza-2′-deoxycytidine plus dexamethasone. Conclusion: Our findings indicate that epigenetic inactivation of genes, including RASD1, plays a key role in the development of dexamethasone resistance in multiple myeloma. Moreover, they show the utility of demethylation therapy in cases of advanced multiple myeloma.

Central nervous system involvement in intravascular large B-cell lymphoma : A retrospective analysis of 109 patients

Intravascular large B‐cell lymphoma (IVLBCL) is a rare disease entity with a high incidence of central nervous system (CNS) involvement at diagnosis. To evaluate CNS involvement, particularly recurrence including progression on therapy and relapse of IVLBCL, we retrospectively analyzed 109 patients with IVLBCL receiving chemotherapies with or without rituximab. In 82 patients (75%) without CNS involvement at initial diagnosis, risk of CNS recurrence at 3 years was 25% with a median follow‐up in survivors of 39 months (range, 2–158 months). In 27 patients (25%) with CNS involvement at initial diagnosis, risk of CNS recurrence at 1 year was 25% with a median follow‐up in survivors of 18 months (range, 10–77 months). Duration from diagnosis to CNS recurrence tended to be short in patients with CNS involvement at diagnosis. No significant difference in risk of CNS recurrence was found between patients receiving chemotherapies with or without rituximab. On multivariate analysis skin involvement at initial diagnosis was identified as a predictive factor for CNS recurrence in patients without CNS involvement at diagnosis (hazard ratio, 5.27; 95% confidence interval, 1.59–17.4; P = 0.007). Survival rate after CNS recurrence at 2 years was 12% in patients without CNS involvement at diagnosis. Central nervous system recurrence is a serious complication in IVLBCL patients and optimal strategies for CNS involvement should be established to obtain further improvements to clinical outcomes in the rituximab era. (Cancer Sci 2010)

T-cell immunotherapy with a chimeric receptor against CD38 is effective in eliminating myeloma cells.

T-cell immunotherapy with a chimeric receptor against CD38 is effective in eliminating myeloma cells

Association between IgG4-related disease and progressively transformed germinal centers of lymph nodes

Progressively transformed germinal centers is a benign condition of unknown pathogenesis characterized by a distinctive variant form of reactive follicular hyperplasia in lymph nodes. We recently reported Ig G4-related disease in progressively transformed germinal centers. However, no large case series has been reported and clinicopathologic findings remain unclear. Here, we report 40 Japanese patients (28 men, 12 women; median age, 56 years) with progressively transformed germinal centers of the lymph nodes who fulfilled the histological diagnostic criteria for IgG4-related disease (IgG4+ progressively transformed germinal centers), with asymptomatic localized lymphadenopathy involving the submandibular nodes in 24, submandibular and cervical nodes in 14, cervical nodes only in 1, and cervical and supraclavicular nodes in 1. In all, 16 (52%) of 31 examined patients had allergic disease. Histologically, the lymph nodes demonstrated uniform histological findings, namely marked follicular hyperplasia with progressively transformed germinal centers, and localization of the majority of IgG4+ plasma cells in the germinal centers. Serum IgG4, serum IgE and peripheral blood eosinophils were elevated in 87%, 92% and 53% of examined patients, respectively. Eighteen patients subsequently developed extranodal lesions (including five who developed systemic disease), which on histological examination were consistent with IgG4-related disease. IgG4+ progressively transformed germinal centers presents with uniform clinicopathological features of asymptomatic localized submandibular lymphadenopathy, which persists and/or relapses, and sometimes progresses to extranodal lesions or systemic disease. Nine patients were administered steroid therapy when the lesions progressed, to which all responded well. We suggest that IgG4+ progressively transformed germinal centers should be included in the IgG4-related disease spectrum.

Increased expression of the c-myc gene may be related to the aggressive transformation of human myeloma cells

Summary. Alteration and abnormal expression of the c‐myc oncogene were investigated in human multiple myeloma. Human myeloma cells were highly purified (more than 95%) from bone marrow aspirates in 14 cases of advanced multiple myelomas and one case of plasma cell leukaemia. Southern blotting revealed that a rearranged configuration of c‐myc gene was found in only one case of them, but this was a novel truncation of the gene in its coding exon II: a rearranged 3·4 kb band was detected by digestion with Xba I using c‐myc exon II probe, but no rearranged band was found using exon III probe. In this case, the truncated c‐myc allele was not transcribed: normal sized (2·4 kb) c‐myc mRNA was markedly expressed, but no aberrant mRNA was detected. On the other hand, by Northern blotting, the nine cases, including the case with the rearranged c‐myc gene, showed increased expression of normal sized (2·4 kb) c‐myc mRNA. Elevated c‐myc mRNA expressions were well related to the in vitro proliferation (3H‐TdR uptake), but not to IL‐6 response. Interestingly, extremely high expressions of c‐myc mRNA were detected in two cases of aggressive myelomas, including the case with the rearranged c‐myc gene, and in one of plasma cell leukaemia. These two cases of aggressive myelomas were the ones who showed the markedly high 3H‐TdR uptakes, and had the common clinical features with the formation of an extramedullary mass and very short survival. These results suggest that the activation of c‐myc gene could induce high proliferative activities and the subsequent aggressive transformation of myeloma cells.

High expression of MCL1 gene related to vascular endothelial growth factor is associated with poor outcome in non-Hodgkin's lymphoma

Summary. We evaluated the level of MCL1 gene expression using quantitative reverse transcription polymerase chain reaction in lymph nodes of patients with non‐Hodgkin lymphoma (NHL). MCL1 expression in patients in complete remission (CR) was significantly lower than in patients with progressive disease (PD, P = 0·0043). The disease–free survival rate was significantly higher in patients with MCL1 levels below the median level (P = 0·007). We also found that the level of expression of MCL1 mRNA was related to that of vascular endothelial growth factor mRNA in NHL lymph nodes. Our data suggest that the MCL1 expression level could be considered a prognostic factor in NHL.