JAK2V617F-positive essential thrombocythemia and multiple myeloma with IGH/CCND1 gene translocation coexist, but originate from separate clones

Overlapping of essential thrombocythemia (ET) and multiple myeloma (MM) has been extremely rare. Our report concerns a case with concomitant ET and MM, where JAK2V617F was present in non-myeloma peripheral blood leukocytes and bone marrow (BM) hematopoietic cells, but not in BM-derived CD138-positive myeloma cells. In contrast, double-color fluorescence in situ hybridization analysis showed that BM-derived CD138-positive myeloma cells possessed the gene translocation between the immunoglobulin heavy chain gene and the cyclin D1 gene, which was not involved in non-myeloma hematopoietic cells. This is the first case with concomitant ET and MM in which the 2 hematologic neoplasms were shown to have originated from separate malignant clones at hierarchically different differentiation levels resulting from independent acquisition of different molecular aberrations. Among the 10 reported cases, including ours, ET preceded MM in 8 cases, but MM never preceded ET. We suggest that MM clones may have greater proliferative potency compared with ET clones, and that the treatment modification from ET to MM did not seem to exacerbate ET in most reported cases, perhaps because of the suppression of the ET clone by both the cytotoxic effect of anti-myeloma therapy and the clonal repression by MM progression.

Immunoglobulin light chain gene translocations in non-Hodgkin's lymphoma as assessed by fluorescence in situ hybridisation

In non-Hodgkin's lymphoma (NHL), the majority of translocations involve the immunoglobulin heavy chain gene (IGH) locus, while a few involve the immunoglobulin light chain gene (IGL) locus, consisting of the kappa light chain gene (IGkappa) and the lambda light chain gene (IGlambda). Although many reports have dealt with the translocation and/or amplification of IGH in NHL, only a few have identified IGL translocations. To identify cytogenetic abnormalities and the partner chromosomes of IGL translocations in NHL, we performed dual-colour fluorescence in situ hybridisation (DC-FISH) and spectral karyotyping (SKY) in seven NHL cell lines and 40 patients with NHL. We detected IGL translocations in two cell lines and nine patients: four patients with diffuse large B-cell lymphoma, three with follicular lymphoma, one with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue and one with mantle cell lymphoma. Five distinct partners of IGlambda translocation were identified by SKY analysis: 3q27 in three patients, and 1p13, 6p25, 17p11.2 and 17q21 in one patient each. Three cases featured double translocations of IGH and IGL. These findings warrant the identification of novel genes 1p13, 6p25, 17p11.2 and 17q21.

Protein-losing enteropathy in a case of nodal follicular lymphoma without a gastrointestinal mucosal lesion

Protein-losing enteropathy (PLE) is characterized by gastrointestinal loss of serum protein. It is usually caused by hypersecretion from a tumor, ulcer, or long standing lymphangiectasia. However, we report a 47-year-old man of peritoneal nodal follicular lymphoma who developed PLE with none of them. Oozing of whitish fluid from duodenal bulbar mucosa was endoscopically seen, resulting in continuous loss of protein. Chemotherapy was effective and PLE was rapidly diminished. Nodal lymphoma lesion was considered to disturb lymphatic flow and to regurgitate it to duodenal mucosa. To our knowledge, this is the second report of a lymphoma patient presenting PLE without a gastrointestinal mucosal lesion.

Population pharmacokinetics of levofloxacin as prophylaxis for febrile neutropenia

BACKGROUND

Levofloxacin (LVFX) is widely used against a broad spectrum of bacteria. To prevent the emerging of resistance resulting from its abuse, an optimal method and dosage are needed. In the field of hematological malignancies, LVFX is one of the choices for prophylaxis for febrile neutropenia (FN). There is no consensus about the optimal dosage and method among hematologists. Aims To determine the population pharmacological parameters based on the population pharmacokinetics of LVFX. We considered the optimal dosage and method of LVFX based on various simulations depicted by personal computer.

METHODS

We performed population pharmacokinetic analysis for seven patients receiving LVFX as prophylaxis (200 mg, b.i.d.) for FN with blood sampling. One patient received 100 mg t.i.d. All patients were treated at Kyoto Prefectural University of Medicine.

RESULTS

Clearance (CL) is 5.8 L/hr, distribution volume (Vd) is 58.5 L, area under the blood concentration-time curve (AUC(0-24)) is 69.0 microg x hr/mL, t1/2 is 6.9 hr, Cmax is 3.4 microg/mL at administration of 200 mg b.i.d. Cmax (peak) of 500 mg, and q.d. is simulated as 8.54 microg/mL.

CONCLUSION

For LVFX 500 mg q.d. is predicted to be the most effective dosage and method. Because the predicted Cmax value is similar to that of western countries, the frequency of adverse effects is thought to be same as in western countries. 500 mg, q.d., may also be an optimal dosage and method for Japanese.

Real-time therapeutic drug monitoring of cefozopran in plasma using high-performance liquid chromatography with ultraviolet detection

A simple, rapid, and precise HPLC method using ultrafiltration to remove plasma protein was developed to determine cefozopran concentrations in human plasma for real-time therapeutic drug monitoring. Plasma was separated by centrifugation at 4 degrees C from blood collected in heparinized vacuum tubes. Cefozopran and an internal standard were detected by ultraviolet absorbances at 235 nm with no interfering plasma peak. The calibration curve of cefozopran in human plasma was linear from 0.2 to 200 microg/ml. The limit of detection was 0.05 microg/ml. The assay was applied to febrile neutropenia patients in a clinical setting.

[Cytogenetic and molecular basis of multiple myeloma]

Multiple myeloma(MM) originating from plasma cells is characterized by complex chromosomal aberrations. The most prominent chromosomal abnormalities of MM are aneuploidy and translocations affecting the immunoglobulin heavy chain locus on chromosome 14q32. Additionally, a variety of genetic aberrations such as ras mutations have been found in MM. Because these chromosomal and genetic abnormalities are closely associated with clinical behavior including prognosis, cytogenetic findings have a great impact on planning treatment strategy. Furthermore, studies of signal transductions and mechanisms of oncogenesis in association with these abnormalities will provide targets to develop novel therapeutic agents. Here we summarize the chromosomal and genetic abnormalities of MM and their clinical implications.

ABT-737 is a useful component of combinatory chemotherapies for chronic myeloid leukaemias with diverse drug-resistance mechanisms

The effect of ABT-737, a BH3-mimicking inhibitor for anti-apoptotic Bcl-2 and Bcl-X(L), but not Mcl-1, against Bcr-Abl-positive (Bcr-Abl(+)) leukaemic cells was examined. ABT-737 potently induced apoptosis in Bcr-Abl(+) chronic myeloid leukaemia (CML) cell lines and primary CML samples in vitro and prolonged the survival of mice xenografted with BV173 cells, a CML cell line. Higher expression of anti-apoptotic Bcl-2 proteins reduced cell killing by ABT-737 in each cell line, but there was no correlation between the sensitivities to ABT-737 and the specific expression patterns of Bcl-2 family proteins among cell lines. Thus, the cell killing effect of ABT-737 must be determined not only by the expression patterns of Bcl-2 family proteins but also by other mechanisms, such as high expression of Bcr-Abl, or a drug-efflux pump, in CML cells. ABT-737 augmented the cell killing effect of imatinib in Bcr-Abl(+) cells with diverse drug-resistance mechanisms unless leukaemic cells harboured imatinib-insensitive Abl kinase domain mutations, such as T315I. The combination of homoharringtonine that reduces Mcl-1 enhanced the killing by ABT-737 strongly in Bcr-Abl(+) cells even with T315I mutation. These results suggest that ABT-737 is a useful component of chemotherapies for CML with diverse drug-resistance mechanisms.

[Combination therapy with rituximab and cladribine for patients with follicular lymphoma]

Treatment strategies for follicular lymphoma have not been established. We report the outcome after combination therapy with rituximab and cladribine (RC) for 8 patients with follicular lymphoma treated between January 2005 and December 2006 in our hospitals. Median patient age was 57 (range 42 approximately 73) years. There were 4 males and 4 females. Only 1 patient had refractory disease, while the others had untreated disease. On the follicular lymphoma international prognostic index, 4 patients were in the low-risk group, 3 in the intermediate-risk group and 1 in the high-risk group. The median follow-up period was 36 (range 22 approximately 90) weeks. The RC protocol consisted of intravenous rituximab at a dose of 375 mg/m (2) on day 1 and cladribine at a dose of 0.1 mg /kg per day for 2-hours on day 1 through 5. The median number of RC courses was 5 (range 3 approximately 8). The median interval between the 2 courses was 7 (range 3 approximately 26) weeks. The overall response rate was 87.5%. Grade 3 neutropenia was observed in 50% patients, although G-CSF was not needed. There was no apparent thrombocytopenia or anemia. Herpes zoster was observed after treatment in 1 patient. RC is considered highly effective and well tolerated.

Clinicopathological analysis of a case with mesenteric solitary Castleman's disease: diagnostic value of radiological findings

We report a case with rare solitary mesenteric Castleman's disease (CD). A 45-year-old woman complaining of nausea was presented. A round-shaped, smooth margin, and hypoechoic mass was seen on screening abdominal ultrasonography. Computed tomography showed a markedly enhanced tumor anterior to the left iliopsoas muscle. Selective jejunal arteriography revealed an extreme hypervascularity without vascular invasion. These results retrospectively seem to differ from those of malignant lymphoma or sarcoma. The tumor was surgically resected, and hyaline-vascular type CD was pathologically diagnosed. We postulate that these radiological findings might suggest hyaline-vascular type CD as one of the differential diagnoses in similar cases, although more clinical data should be evaluated.

[Prophylactic effect of tropisetron hydrochloride against nausea and vomiting in patients receiving chemotherapy for hematological malignancies]

To establish the effectiveness of oral 5-HT(3) antagonist, oral 5 mg tropisetron was introduced in the 21 cases with hematological malignancies for the prevention of chemotherapy-induced nausea and vomiting. Nausea and vomiting did not develop in 81% of patients receiving the tropisetron in this study. The results suggested that oral tropisetron is effective for the control of acute, and to a lesser extent, delayed, nausea and vomiting. The drug enhanced patients' quality of life and reduced the clinical cost. In conclusion, tropisetron is effective for the prevention of chemotherapy-induced nausea and vomiting in treatment for hematological malignancies. It is suitable as first-line therapy for outpatients.

Effectiveness and limitation of gamma knife radiosurgery for relapsed central nervous system lymphoma: a retrospective analysis in one institution

We describe 6 patients with relapsed central nervous system lymphoma (CNSL) treated with Gamma Knife radiosurgery (GKR). The histologic diagnosis in all 6 patients was diffuse large B-cell lymphoma without human immunodeficiency virus infection. Two patients had intracranial relapse of primary CNSL, and the remaining 4 had CNS relapse of systemic lymphoma. All patients were treated with GKR without severe adverse effects, and all but 1 patient received subsequent chemotherapy shortly after GKR. Four patients showed a complete response, and the remaining 2 patients had a partial response or stable disease. Although the neurologic symptoms disappeared or improved markedly in all patients, all of the diseases recurred or progressed 3 to 13 months after the first GKR. A second GKR was eventually performed in 4 patients. The median overall survival and progression-free survival times after the first GKR were 17 and 11 months, respectively. In our experience, GKR seems to be a useful procedure for the treatment of relapsed CNSL, because it facilitates excellent local control in a short-term treatment period without severe complications, although the efficacy period is not long enough.

Detection of NOTCH1 mutations in adult T-cell leukemia/lymphoma and peripheral T-cell lymphoma

We analyzed NOTCH1 gene mutation in 53 adults with mature T-cell leukemia/lymphoma: 21 patients with adult T-cell leukemia (ATL), 25 with T-cell non-Hodgkin's lymphoma (T-NHL), and 7 with T-cell prolymphocytic leukemia. We detected a nonsense mutation, C7249T (resulting in Q2417X, where X is a termination codon) in the PEST domain of NOTCH1 in an ATL patient and detected a 3-bp deletion (positions 7234-7236) that resulted in deletion of a proline codon at codon 2412 in the PEST domain of NOTCH1 in a patient with a T-NHL, peripheral T-cell lymphoma-unspecified (PTCL-u). We also analyzed the expression of NOTCH1 target genes (HES1, CCND1, and MYC), all of which were expressed in the sample of the PTCL-u patient with the NOTCH1 mutation, but found only MYC to be expressed in the sample from the ATL patient. These findings suggest that nonsense mutation in the PEST domain in the ATL case was associated with NOTCH1 signaling through a pathway different from that for T-cell acute lymphoblastic leukemia (T-ALL). Although NOTCH1 mutation occurs infrequently in mature T-cell leukemia/lymphoma, NOTCH1 may be involved in leukemogenesis associated with various forms of T-cell leukemia/lymphoma rather than only with T-ALL.

Dasatinib phase I/II study of patients with chronic myeloid leukemia (CML) resistant or intolerant to imatinib: Results of the CA180031 study in Japan

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Background: Dasatinib is a potent, orally active, multi-targeted kinase inhibitor of BCR-ABL and SRC family kinases. Studies outside Japan have shown dasatinib to be highly effective in overcoming resistance and intolerance to imatinib, inducing durable cytogenetic (CyR) and hematologic responses (HR) in this population. The maximum tolerated dose was not reached in the Phase-I trial outside Japan and a 70-mg BID dose was determined to provide the optimal benefit-risk profile. Methods: This Phase-I/-II study was designed to assess the safety and efficacy of dasatinib in Japanese patients with imatinib-resistant or -intolerant CML or Ph+ALL. In the 4-week Phase-I portion in patients with chronic-phase (CP) CML, three dose levels were evaluated: 50 mg, 70 mg, and 90 mg BID. The Phase-II portion is currently evaluating the CyR of dasatinib in patients with CP-CML at 24 weeks, and the HR rate in accelerated- (AP) or blast-phase (BP) CML and Ph+ ALL at 12 weeks. Results: As of December 2006, 17 eligible patients have been treated in Phase I. Six patients (4F, 2M; median age 43 y [range 27–56]) were treated with 50 mg BID and 1 dose-limiting toxicity (DLT) was observed (Grade 4 thrombocytopenia). Two patients experienced transient Grade 3 ALT elevations but as treatment was uninterrupted, these were not considered DLTs. Six patients (6M; median age 42 y [range 27–55]) were treated with 70 mg BID and again 1 DLT was observed (Grade 4 thrombocytopenia). No DLT has been observed among 4 patients (3M, 1F; median age 41 y [range 27–64]) at the 90-mg BID dose. Major CyRs have been achieved in all three cohorts in the Phase-I segment of the trial. Thirty six patients were enrolled and treated in the Phase-II part of the trial (12 CP-CML, 7 AP- CML, 4 BP-CML, and 13 Ph+ALL). Efficacy and safety data as well as the baseline BCR-ABL mutation data are currently being assessed and will be presented. Conclusions: Dasatinib can be safely administered at doses of up to 90 mg BID to Japanese patients with imatinib-resistant or -intolerant CP-CML.

No significant financial relationships to disclose.

Apoptosis-based dual molecular targeting by INNO-406, a second-generation Bcr-Abl inhibitor, and ABT-737, an inhibitor of antiapoptotic Bcl-2 proteins, against Bcr-Abl-positive leukemia

Bcr-Abl is the cause of Philadelphia-positive (Ph(+)) leukemias and also constitutes their principal therapeutic target, as exemplified by dramatic effects of imatinib mesylate. However, mono-targeting of Bcr-Abl does not always achieve complete leukemia eradication, and additional strategies those enable complete elimination of leukemic cells are desired to develop. Here we demonstrate that INNO-406, a much more active Bcr-Abl tyrosine kinase inhibitor than imatinib, augments the activities of several proapoptotic Bcl-2 homology (BH)3-only proteins (Bim, Bad, Bmf and Bik) and induces apoptosis in Ph(+) leukemia cells via Bcl-2 family-regulated intrinsic apoptosis pathway. ABT-737, an inhibitor of antiapoptotic Bcl-2 and Bcl-X(L), greatly enhanced the apoptosis by INNO-406, even in INNO-406-less sensitive cells with Bcr-Abl point mutations except T315I mutation. In contrast, co-treatment with INNO-406 and other pharmacologic inducers of those BH3-only proteins, such as 17-allylaminogeldanamycin, an heat shock protein-90 inhibitor, or PS-341, a proteasome inhibitor, did not further increase the BH3-only protein levels or sensitize leukemic cells to INNO-406-induced apoptosis, suggesting a limit to how much expression levels of BH3-only proteins can be increased by anticancer agents. Thus, double-barrelled molecular targeting for Bcr-Abl-driven oncogenic signaling and the cell protection by antiapoptotic Bcl-2 family proteins may be the rational therapeutic approach for eradicating Ph(+) leukemic cells.

Establishment and characterization of the new splenic marginal zone lymphoma-derived cell line UCH1 carrying a complex rearrangement involving t(8;14) and chromosome 3

A new cell line, designated UCH1, was established from a patient with splenic marginal zone lymphoma (SMZL). UCH1 cells feature a mature B-cell phenotype, characterized by surface IgM +, kappa+, CD5-, CD10-, CD19+ and CD20+. The BCL2 and BCL6 genes retained their germ-line configurations and overexpression of cyclin D1 was not detected. UCH1 cells carry numerical and structural aberrations in chromosome 3, but these were too complex to be analyzed with the conventional G-banding method. Spectral karyotyping (SKY) and fluorescence in situ hybridization analysis clearly demonstrated the presence of a balanced translocation between chromosomes 8 and 14 [t(8;14)(q24;q32)] in the complex aberrations involving chromosome 3. The results of Southern blot analysis supported this finding by showing rearrangement of the c-myc gene in UCH1 cells. SKY analysis also identified a translocation involving chromosome band 18q21, to which BCL2 and MALT1 genes were assigned, suggesting their implication in the development or progression of SMZL.

γδT cells kill myeloma cells by sensing mevalonate metabolites and ICAM-1 molecules on cell surface

We evaluated the mechanism of recognition of myeloma cells by gammadeltaT cells. The expanded gammadeltaT cells killed RPMI8226 and U266 myeloma cells in a gammadeltaT-cell dose-dependent manner. Pretreatment of myeloma cells with zoledronic acid or mevastatin showed that gammadeltaT cells kill myeloma cells by recognizing the mevalonate metabolites. The expression level of intercellular cell adhesion molecule-1 (ICAM-1) on myeloma cells correlates with the cytotoxicity by gammadeltaT cells. Pretreatment of RPMI8226 and U266 with an anti-ICAM-1 monoclonal antibody inhibited their cytolysis. Moreover, AMO-1 myeloma cells transfected with of human ICAM-1 cDNA were susceptible to gammadeltaT cells compared to parental AMO-1 cells. In conclusion, gammadeltaT cells recognize the mevalonate metabolites and ICAM-1 on myeloma cells.

Successful induction of clinically competent dendritic cells from granulocyte colony-stimulating factor-mobilized monocytes for cancer vaccine therapy

Recent studies have suggested that dendritic cell (DC)-based immunotherapy is one promising approach for the treatment of cancer. We previously studied the clinical toxicity, feasibility, and efficacy of cancer vaccine therapy with peptide-pulsed DCs. In that study, we used granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood monocytes as a cell source of DCs. However, previous investigations have suggested that G-CSF-mobilized peripheral blood monocytes produce reduced levels of proinflammatory cytokines such as interleukin (IL)-12 and tumor necrosis factor (TNF)-alpha. These T helper (Th)-1-type cytokines are thought to promote antitumor immune response. In this study, we assessed the functional abilities of DCs generated from G-CSF-mobilized monocytes obtained from 13 patients with CEA-positive advanced solid cancers. Peripheral blood mononuclear cells were obtained from leukapheresis products collected before and after systemic administration of G-CSF (subcutaneous administration of high-dose [5-10 microg/kg] human recombinant G-CSF for five consecutive days). In vitro cytokine production profiles after stimulation with lipopolysaccharide (LPS) were compared between monocytes with and without G-CSF mobilization. DCs generated from monocytes were also examined with respect to cytokine production and the capacity to induce peptide-specific T cell responses. Administration of G-CSF was found to efficiently mobilize peripheral blood monocytes. Although G-CSF-mobilized monocytes (G/Mo) less effectively produced Th-1-type cytokines than control monocytes (C/Mo), DCs generated from G/Mo restored the same level of IL-12 production as that seen in DCs generated from C/Mo. T cell induction assay using recall antigen peptide and phenotypic analyses also demonstrated that DCs generated from G/Mo retained characteristics identical to those generated from C/Mo. Our results suggest that G-CSF mobilization can be used to collect monocytes as a cell source for the generation of DCs for cancer immunotherapy. DCs generated in this fashion were pulsed with HLA-A24-restricted CEA epitope peptide and administered to patients safely; immunological responses were induced in some patients.

Hyperbaric oxygen in addition to antibiotic therapy is effective for bisphosphonate-induced osteonecrosis of the jaw in a patient with multiple myeloma

A 60-year-old man with multiple myeloma (MM) (IgG-kappa, stage IIIA) had been treated with minodronate at 6 mg orally as a phase 1 clinical trial for myeloma bone disease for 13 months (total dose, 4032 mg). Then he received incadronate at 10mg intravenously every 1 to 4 weeks (total dose, 350 mg). In July 2005, he complained of mild right mandibular pain, and bone scintigram showed a hot spot at the right side of the mandible. Panoramic radiograph showed osteonecrosis of the jaw (ONJ) and axial and 3-dimensional computed tomography confirmed ONJ. Oral examination showed massive gingival swelling of the right side of the mandible without exposed necrotic bone. He was given clarithromycin in addition to levofloxacin, followed by hyperbaric oxygen (HBO) therapy, which resulted in the complete disappearance of the pain. This is a first reported case of ONJ induced by incadronate. The present case suggests that early detection of ONJ by regular dental check-ups is important in the management of patients with MM who have received bisphosphonate therapy, and HBO in combination with antibiotic therapy is effective in the early stage of ONJ.

Expression and role of MHC class I-related chain in myeloma cells

BACKGROUND

The molecular mechanism of natural killer (NK) cell cytotoxicity to myeloma cells remains unclear. We investigated whether MHC class I-related chain (MIC), a ligand of NKG2D that is an activating NK cell receptor, is involved in the cytotoxicity of NK cells toward myeloma cells, and examined the effects of various drugs on the cytotoxicity.

METHODS

Two human myeloma cell lines and fresh myeloma cells from 10 patients were used. MIC expression was examined by flow cytometry and reverse transcription (RT)-PCR. NK cell cytotoxicity was examined using a 51Cr-release assay. The effects of various drugs, including thalidomide, all-trans retinoic acid, dexamethasone, IFN-alpha and incadronate, on the MIC expression and NK cell cytotoxicity were examined.

RESULTS

MIC was highly expressed on the human myeloma cell lines U266 and RPMI-8226 and in myeloma cells of one of 10 patients examined. MIC expression on these cells was not changed by various drugs except IFN-alpha, by which MIC expression was down-regulated. Although MIC and HLA class I molecules were similarly expressed at high levels on both cell lines, U266 was sensitive to NK cells whereas RPMI-8226 was not. Furthermore, cytolysis by NK cells was not inhibited by the addition of anti-MIC Ab or decreased expression of MIC caused by IFN-alpha.

DISCUSSION

MIC plays a role in the cytolysis by NK cells in multiple myeloma.

Simultaneous complication of multiple myeloma with Sjögren syndrome

We report a 72-year-old female case of IgG-kappa type multiple myeloma (MM) simultaneously complicated with Sjögren syndrome (SS). She also presented marked hyperamylasemia of salivary-type isozyme. Although she had received sequential chemotherapy completed with high-dose therapy with autologous hematopoietic stem cell transplantation, she died of relapse fifteen months after the initial diagnosis. Various autoantibodies indicated that her sicca symptoms were due to true SS and not caused by MM cell infiltration to exocrine glands. MM cells appeared to produce amylase that fluctuated correspondingly to the disease status of MM. To our knowledge, this is the first English report of simultaneous complication of SS and MM referring to hyperamylasemia. Accumulation of this rare clinical manifestation is important to elucidate the pathogenesis of MM under condition of immunological disorder caused by SS.

Comparison of human herpes virus 8 related primary effusion lymphoma with human herpes virus 8 unrelated primary effusion lymphoma-like lymphoma on the basis of HIV: report of 2 cases and review of 212 cases in the literature

BACKGROUND

Primary lymphomatous effusion is a rare lymphoma that arises in the body cavity and has a peculiar proliferative form, lacking a tumor. This primary lymphomatous effusion includes human herpes virus 8 (HHV8)-related primary effusion lymphoma (PEL) and HHV8-unrelated PEL-like lymphoma. We attempted to clarify the nature of the primary lymphomatous effusion.

METHODS

Using 'PEL' and 'body cavity-based lymphoma' (BCBL) as key words, reports written in English were collected from PubMed. Primary lymphomatous effusion was defined as BCBL with primary effusion and without tumor at onset. Adding our 2 PEL-like lymphoma cases, each case was studied as to the patients' and lymphomas' characteristics, therapy and survival time. Moreover, each item was compared among four groups according to the presence of HHV8 and HIV.

RESULTS

In 214 cases investigated, there was no difference in proliferation, but an apparent difference in age, gender, phenotype, effectiveness and prognosis among the four groups.

CONCLUSIONS

Both PEL and PEL-like lymphoma are thought to be characterized by a peculiar proliferation, regardless of the presence of HHV8. Dividing PEL or PEL-like lymphoma into two subgroups on the basis of HIV presentation might also be appropriate.

Role of SPA-1 in Phenotypes of Chronic Myelogenous Leukemia Induced by BCR-ABL–Expressing Hematopoietic Progenitors in a Mouse Model

SPA-1 is a negative regulator of Rap1 signal in hematopoietic cells, and SPA-1-deficient mice develop myeloproliferative disorders (MPD) of long latency. In the present study, we showed that the MPDs in SPA-1(-/-) mice were associated with the increased hematopoietic stem cells expressing LFA-1 in bone marrow and their premature mobilization to spleen with extensive extramedullary hematopoiesis, resembling human chronic myelogenous leukemia (CML). We further showed that human BCR-ABL oncogene caused a partial down-regulation of endogenous SPA-1 gene expression in mouse hematopoietic progenitor cells (HPC) and immature hematopoietic cell lines. Although both BCR-ABL-transduced wild-type (wt) and SPA-1(-/-) HPC rapidly developed CML-like MPD when transferred to severe combined immunodeficient mice, the latter recipients showed significantly increased proportions of BCR-ABL(+) Lin(-) c-Kit(+) cells compared with the former ones. Serial transfer experiments revealed that spleen cells of secondary recipients of BCR-ABL(+) wt HPC failed to transfer MPD to tertiary recipients due to a progressive reduction of BCR-ABL(+) Lin(-) c-Kit(+) cells. In contrast, SPA-1(-/-) BCR-ABL(+) Lin(-) c-Kit(+) cells were sustained at high level in secondary recipients, and their spleen cells could transfer MPD to tertiary recipients, a part of which rapidly developed blast crisis. Present results suggest that endogenous SPA-1 plays a significant role in regulating expansion and/or survival of BCR-ABL(+) leukemic progenitors albeit partial repression by BCR-ABL and that Rap1 signal may represent a new molecular target for controlling leukemic progenitors in CML.