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Cancer patients occasionally have anemia with high mean corpuscular volume in addition to iron deficiency anemia. Secondary autoimmune hemolytic anemia (AIHA) following cancer is also observed with low frequency. To date, no causal mechanisms for these disease states have been reported. Here, we present the case of an 80-year-old woman with AIHA that was resistant to prednisolone. Further examinations revealed primary adenocarcinoma of the sigmoid colon and primary squamous cell carcinoma in the right lung. After resections of these tumors, her anemia partially improved until a colon cancer-derived metastatic tumor was detected in the left lung. Immunoprecipitation of erythrocyte membrane proteins with an autoantibody followed by mass spectrometry/Western blotting identified band 3 as the target of the autoantibody. Immunohistochemical analysis revealed ectopic expression of band 3 in the colon adenocarcinoma. To our knowledge, this is the first report that identifies the cause in a case of anemia without bleeding in a cancer patient and that defines a mechanism underlying secondary AIHA following cancer progression.

Objective Evaluation the activities of the dementia support care team (D-CAST). Method A total of 350 patients received intervention from the D-CAST from January 1, 2017, to December 31, 2017. At the beginning and end of the team intervention, the following items were evaluated: changes in the degree of life independence, period (days) from hospitalization to team intervention, request for team intervention, and duration of hospitalization. Results The average age of the 350 patients in this study was 81±9 years old. The major diseases causing hospitalization were heart failure in 94 patients (27%) and aortic valve disease for transcatheter aortic valve implantation (TAVI) in 45 patients (13%). The main reasons for requesting team intervention were cognitive impairment in 40% and delirium (prevention included) in 36%. Regarding the change in the degree of life independence, 29 people saw improvement (16%), 165 maintained their degree of independence (66%), and 46 experienced a decrease (18%). The team intervention was delayed as criteria for degree of independence of everyday life was lower for mild patients. Conclusion We need to learn how to assess dementia patients with relatively mild life independence (potentially including mild cognitive impairment).

We conducted an open-label, randomized study to evaluate the clinical efficacy of cefozopran, meropenem or imipenem-cilastatin using cefepime as a control in febrile neutropenia (FN) patients. Three hundred and seventy-six patients received cefepime, cefozopran, meropenem or imipenem-cilastatinas initial therapy for FN. The primary endpoint was the non-inferiority of response rates including modification at day 7 in cefozopran, meropenem or imipenem-cilastatin patients compared with cefepime in the per-protocol population (delta = 10%). The response rates for cefozopran, meropenem and imipenem-cilastatin were not significantly different compared with cefepime (cefozopran: 54/90 (60%), meropenem: 60/92 (65%), and IPM/CS: 63/88 (72%) versus cefepime: 56/85 (66%) (p = 0.44, 1.0 and 0.51, respectively)), and the differences in treatment success for cefozopran, meropenem and imipenem-cilastatin compared with cefepime were -5.9% (95% confidence interval (CI): -20.1-8.4), -0.7% (95% CI: -14.6-13.3), and 5.7% (95% CI: -8.1-19.4), respectively. The same tendency was seen in the modified intention-to-treat population. Based on the evaluation of initial drug efficacy performed on days 3-5, there was no significant difference between the four drugs. In the subgroup with an absolute neutrophil count ≤ 100 × 10(6)/L for longer than seven days, there was significantly better efficacy in the carbapenem arm compared to 4th generation beta-lactams (52% versus 27% at days 3-5, p = 0.006, and 76% versus 48% at day 7, p = 0.002). Our results suggest that the effects of these four drugs as empiric therapy were virtually the same for adult FN patients, although non-inferiority was shown only in imipenem-cilastatin compared with cefepime (clinical trial number: UMIN000000462).

We report a patient with non-Hodgkin's lymphoma of small lymphocytic type with IgM-kappa monoclonal gammopathy who developed extranodal involvement with orbital and nasal manifestations, followed by generalized subcutaneous nodules. Immunological study disclosed that the peripheral blood and the subcutaneous nodule were both involved in a common monoclonal proliferation of B cells at various stages of differentiation, including secretory cells which accounted for the serum paraprotein. The secretory capacity was far greater in the peripheral blood than in the subcutaneous tissue. These clinical and immunological manifestations might reflect the physiological behaviour of a particular B cell subset which shows a preference for mucocutaneous sites to secrete IgM in the peripheral blood.

40 patients with idiopathic thrombocytopenic purpura (ITP) were studied for T-cell abnormalities using a panel of monoclonal antibodies (Mc Abs). These patients showed a tendency to have a decreased OKT4+: OKT8+ ratio compared with normal subjects and a significant increase was observed in OKT10-positive cells in ITP patients. Further analyses were made utilizing McAbs of different subclasses in combination (BMA040 mouse IgG1 McAb, helper/inducer T and BMA081 mouse IgG2 McAb, suppressor/cytotoxic T). An increased proportion of cells reactive with both BMA040 and BMA081 McAbs (double-labelled cells) was demonstrated in patients with ITP compared with the normal controls. Furthermore, there was an inverse correlation between the proportion of “double-labelled cells” and the platelet counts. These data suggest that abnormalities of the T-cell subsets in the peripheral blood may play an important role in the pathogenesis of ITP.

We conducted a nation-wide survey of 112 adult Japanese patients who underwent reduced-intensity stem cell transplantation (RIST) from 1999 to 2002. Underlying diseases included indolent (n=45), aggressive (n=58) and highly aggressive lymphomas (n=9). Median age of the patients was 49 years. A total of 40 patients (36%) had relapsed diseases after autologous stem cell transplantation and 36 patients (32%) had received radiotherapy. RIST regimens were fludarabine-based (n=95), low-dose total body irradiation-based (n=6) and others (n=11). Cumulative incidences of grade II-IV acute graft-versus-host disease (GVHD) and chronic GVHD were, respectively, 49 and 59%. Cumulative incidences of progression and progression-free mortality were 18 and 25%, respectively. With a median follow-up of 23.9 months, 3-year overall survival rates were 59%. A multivariate analysis identified three significant factors for progression, which are history of radiation (relative risk (RR) 3.45, confidential interval (CI) 1.12-10.0, P=0.03), central nervous system involvement (RR 6.25, CI 2.08-20.0, P=0.001) and development of GVHD (RR 0.28, CI 0.090-0.86, P=0.026). RIST may have decreased the rate of transplant-related mortality, and GVHD may have induced a graft-versus-lymphoma effect. However, whether or not these potential benefits can be directly translated into improved patient survival should be evaluated in further studies.

A successful case of a hand-assisted laparoscopic splenectomy with low-pressure pneumoperitoneum for autoimmune thrombocytopenic purpura in a patient at 23 weeks' gestation is reported. Preoperative splenic arterial embolization was performed on the same day as the operation using painless contour embolic material and super-absorbent polymer microspheres. The abdominal wall retraction method first was applied to avoid the effects of pneumoperitoneum on systemic hemodynamic alterations. However, a sufficient surgical view could not be obtained, as the intra-abdominal organs were elevated because of the enlarged uterus. A surgical view with 4 to 6-mm Hg pneumoperitoneum was available for the hand-assisted splenectomy. The postoperative course was uneventful, and the patient vaginally delivered a healthy infant. A hand-assisted laparoscopic splenectomy with low-pressure pneumoperitoneum after splenic arterial embolization would be feasible for patients with autoimmune thrombocytopenic purpura during a relatively advanced pregnancy.

Laparoscopically assisted splenectomy with an 8- to 10-cm left upper paramedian laparotomy was performed following preoperative splenic artery embolization using painless contour emboli (super absorbent polymer microsphere) with early successful results in two men (46 and 37 years old) with myelofibrosis accompanied by massive splenomegaly. Dissection around the lower part of the spleen and the hilum initially was performed intracorporeally with the usual laparoscopic view under 12 mm Hg pneumoperitoneum. The alternating changes of viewpoints between the direct view through an 8- to 10-cm incision and the usual laparoscopic view with or without application of a retraction method were effective for safe hilar devascularization. Preoperative splenic artery embolization at the distal site was effective for safe dissection around the enlarged spleen. The patients did not complain of pain before operation. Preoperative painless embolization and laparoscopically assisted splenectomy with small laparotomy promotes the feasibility and safety of minimally invasive splenectomy for myelofibrosis with massive splenomegaly.

当院の院内感染対策委員会では，感染防止研修会(1つのテーマを4回，年間5つのテーマについて実施)と病棟ラウンドによる直接指導を行っている．しかし，感染防止研修会において，勤務時間外の30分間の研修会に参加出来ない・疲労感から集中出来ない・覚えられないなどの問題が生じた．今回，上記の問題点を加味し，新たに「ミニ勉強会」と題し2006年8月より，全職員を対象に，各部署で具体的にポイントを絞りパソコンを使用した1テーマ10分以内での勉強会を実施した．ミニ勉強会と院内研修会の参加率の比較では，一部病棟と医師では若干の減少を認めたが，外来・手術室・コメディカルでは上昇した．ミニ勉強会終了後のアンケートの結果では，院内研修会と比較して，参加しやすい等の概ね良い評価が得られた．ミニ勉強会は，現場の都合に合わせ短時間に集中して行う教育方法としては効果的であったと考える．

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is an uncommon type of peripheral T-cell lymphoma (PTCL) usually presenting with erythematous, subcutaneous nodules and fever [1]. It is consi...

Abnormalities of chromosome 14 involving band q32.33 are among the most commonly observed cytogenetic alterations in B-cell malignancies. To assess the incidence and pathogenetic implications of 14q32.33 translocation in chronic B-cell leukemia/lymphomas, we performed fluorescence in situ hybridization (FISH) analysis with variable region (VH) and gamma constant region (Cγ) gene probes in 37 patients with these disorders. Chromosome 14q32.33 translocation was detected in 2 of 18 patients with chronic lymphocytic leukemia (CLL), 1 of 2 with CLL of mixed cell types (CLL/PL), 1 of 2 with pro-lymphocytic leukemia (PLL), 5 of 6 with leukemic mantle-cell lymphoma (MCL), 2 of 7 with splenic B-cell leukemia/lymphoma of possible marginal zone origin (SBLL) and 2 with leukemic follicular lymphoma (FL). To further characterize 14q32.33 translocations in these patients, we developed a new procedure using double-color FISH with PRAD1, BCL2, VH and Cγ gene probes. Chromosome t(11;14) was detected in 1 patient with CLL/PL, 1 with PLL and 5 with MCL. Chromosome t(14;18) was detected in 2 patients with FL. In a PLL patient with t(11;14), the cosmid CPP29 containing the PRAD1 gene and its 5′-flanking region split and co-localized with both Cγ and VH gene probes, thus spanning the breakpoint. In CLL and SBLL patients, donor chromosomes were other than chromosomes 2, 11, 18 and 19, suggesting the involvement of a novel oncogene(s) in the pathogenesis of these diseases. Interphase FISH rapidly detected 14q32.33 translocation, t(11;14) and t(14;18) in B-cell malignancies with low mitotic activity at the single-cell level, facilitating the correlation of the molecular features of these translocations with clinical characteristics. Int. J. Cancer 72:31–38, 1997. © 1997 Wiley-Liss Inc.

A 60-year-old myelodysplastic syndrome patient underwent tandem cord blood transplantation. The primary cord blood graft was rejected, and human herpesvirus 6 (HHV6) encephalitis developed after engraftment of secondary cord blood. Polyuria and adipsic hypernatremia were observed during treatment of the encephalitis. The patient died of bacteremia caused by methicillin-resistant Streptococcus epidermis. HHV6 infection in the posterior pituitary was confirmed on autopsy, as was infection of the hippocampus, but not of the hypothalamus. This is the first case report of central diabetes insipidus caused by an HHV6 posterior pituitary infection demonstrated on a pathological examination.

To compare the different stem cell sources used in salvage transplantation for graft failure (GF) after cord blood transplantation (CBT), we retrospectively analyzed data of 220 patients who developed GF after undergoing CBT between January 2001 and December 2007 and underwent a second hematopoietic stem cell transplantation (HSCT) within 3 months. The donor sources for salvage HSCT were cord blood (n = 180), peripheral blood stem cells (PBSCs; n = 24), and bone marrow (BM; n = 16). The cumulative incidence of neutrophil engraftment on day 30 after the second HSCT was 39% with CB, 71% with PBSCs, and 75% with BM. Multivariate analysis revealed that PBSC and BM grafts were associated with a significantly higher engraftment rate than CB (hazard ratio [HR], 7.77; P < .001 and HR, 2.81; P = .016, respectively). Although the incidence of grade II-IV acute graft-versus-host disease was significantly higher in the PBSC group than in the CB group (HR, 2.83; P = .011), the incidence of 1-year nonrelapse mortality was lower in the PBSC group than in the CB group (HR, 0.43; P = .019), and 1-year overall survival was superior in the PBSC group compared with the CB group (HR, 0.45; P = .036). Our results suggest that PBSC is the preferable source of stem cells in salvage HSCT for GF after CBT.

We report a 62-year-old male who underwent non-myeloablative allogeneic peripheral blood stem cell transplantation (PBSCT) because of his life-threatening severe pancytopenia due to refractory Waldenström's macroglobulinemia. This therapy was performed safely and he made a marked recovery from his cytopenia that had not been improved with any other therapy. Bone marrow aspirates showed post-transplant mixed chimerism during engraftment, and became completely donor-derived after a series of GVHD symptoms, without subsequent donor lymphocyte infusion. Our results suggest that non-myeloablative allogeneic PBSCT could be a good alternative for patients suffering from multi-drug resistant Waldenström's macroglobulinemia.

We retrospectively analyzed the potential of Wilms' tumor gene 1 (WT1) mRNA levels in peripheral blood for predicting the prognosis of 50 patients with AML. After achieving complete remission (CR), 34 patients (69.4%) were determined to be positive and 15 (30.6%) were negative for WT1. The relapse rate of the positive and negative patients was 73.5% and 40.0% (p#x2009;=#x2009;0.02), respectively. After consolidation therapy, only 15 patients (32.6%) were positive and 31 (67.4%) were negative for WT1. Although the relapse rate of the positive and negative patients was 80.0% and 54.8% (p#x2009;=#x2009;0.10), respectively, the rate of relapse within 1 year was 73.3% in positive patients and only 33.3% in negative patients (p#x2009;=#x2009;0.01), respectively. The disease-free survival (DFS) rate at 3 years was 20.0% for positive patients and 50.0% for negative patients (p#x2009;=#x2009;0.01). The overall survival (OS) rate at 3 years was 42.8% in positive patients and 69.8% in negative patients (p#x2009;=#x2009;0.04), respectively. WT1 mRNA levels in the peripheral blood can predict relapse after CR, and its levels after consolidation therapy are closely correlated with DFS, OS, and early relapse.

High-dose chemotherapy supported by autologous peripheral blood stem cell transplantation (PBSCT) is beneficial for patients with relapsed or refractory but chemosensitive diffuse large B-cell lymphoma (DLBCL). However, most elderly patients are not indicated for that therapy and receive supportive treatment only. We describe here two elderly patients with relapsed or refractory DLBCL who achieved prolonged disease-free survival after undergoing intermediate-dose melphalan therapy supported by PBSCT (MEL100) three times. Case 1 was an early relapse (within one year) after the first remission and case 2 was a second relapse. Both cases are currently alive without relapse and have maintained a good performance status for 41 months and 32 months, respectively, after MEL100. Febrile neutropenia and herpes zoster as non-hematological toxicities (gradeor = 3) occurred only in case 1. Considering the benefits vs. toxic effects, this regimen may improve the prognosis of elderly patients with relapsed or refractory DLBCL by MEL100.

To clarify the components of cellular immunity responsible for defense against the clonal development of myeloma cells, we tested the capacity of human peripheral blood lymphocytes (PBLs) to inhibit the growth of 3 human myeloma cell lines (RPMI 8226, OPM-1, and OPM-2). RPMI 8226 was found to be sensitive to PBLs, showing almost complete growth arrest when cultured with PBLs for 72 h. Inhibition of the growth of RPMI 8226 cells required direct cell-to-cell contact but not presensitization of the PBLs to the target cells, and did not depend on the generation of soluble factors. CD3+, CD4-, CD8- and CD16- cells were found to be the major subset contributing to inhibition of the growth of RPMI 8226 cells, and this growth inhibition was cytostatic rather than cytotoxic. These characteristics distinguished it from growth inhibition mediated by the natural killer system. Impaired PBL-mediated growth inhibition of RPMI 8226 cells was found in patients with various hematologic diseases, including myeloma. It therefore appears that the CD3+, CD4-, CD8- and CD16- cell subset might be involved in tumor immunity in myeloma.

In order to obtain patterns for foundry, liquid photopolymer is cured by the exposure of ultraviolet rays through negative film. Single-and multiayer photopolymer patterns for foundry are investigated. The curing behavior of photopolymer is investigated through the relation between the exposure of UV rays and the curing of photopolymer at various spots. Positive and negative patterns in four layers are manufactured by the exposure of UV rays through four sheets of negative film. Applied examples of this process for civil castings in Kawaguchi are shown. The advantages and disadvantages of the process are discussed. Improvement of the exposure unit of UV rays and new photopolymers which have low viscosity, high sensitivity for UV rays and little shrinhage after curing are expected for further devolopment of the process.

The c-kit proto-oncogene encodes a receptor tyrosine kinase that is thought to play an important role in hematopoiesis. In a series of human acute myeloblastic leukemia (AML), the expression of the c-kit proto-oncogene and its product was studied by means of Northern blot and immunoblot analyses. The c-kit mRNA was expressed in 20 of 25 cases of AML, and in those cases the product of the c-kit proto-oncogene was detected by immunoblotting with anti-c-kit antibody. The expression of c-kit transcripts and protein was barely detectable in normal bone marrow cells as a control. The expression of c-kit transcript did not correlate with the French-American-British classification nor clinical manifestations. In 6 of 11 cases that expressed c-kit product, AML cells were found to proliferate in response to recombinant human stem cell factor (rhSCF), the ligand for c-kit, and the synergistic stimulation of AML cells was observed by rhSCF and granulocyte- macrophage colony-stimulating factor. Immunoblotting with anti- phosphotyrosine antibody showed that the c-kit receptor protein was detectably phosphorylated in 7 of 12 cases tested before the stimulation with rhSCF, while the rhSCF treatment resulted in an increased tyrosine phosphorylation of c-kit in AML cells. These results indicate that c-kit proto-oncogene is expressed in most cases of AML and is functional in terms of supporting proliferation.

Functional and structural characteristics of interleukin 2 (IL-2) receptors on B-cell chronic lymphocytic leukemia (B-CLL) cells were analyzed by a proliferation assay, IL-2 binding assay and cross-linking study. In the 3H-thymidine incorporation assay, purified B-CLL cells from four out of sixteen cases, in which the percentage of Tac antigen (Tac Ag) positive cells in peripheral blood lymphocytes ranged from 0 to 48.8%, responded to IL-2 (100 U/ml) after both 3- and 6-day incubation. No relationship was found between the responsiveness to IL-2 and the percentage of Tac Ag positive cells. In the radiolabeled IL-2 binding assay, however, B-CLL cells from all seven cases examined, including three cases with mitogenic response to IL-2 and four cases without mitogenic response, were shown to have both high- and low-affinity receptors. The number of high- and low-affinity receptors per cell ranged from 29-186 and from 420 to 1,800, respectively. Furthermore, with the affinity cross-linking method p55 (Tac Ag) and p70/75 were found even in cases without mitogenic response in their B-CLL cells. In conclusion, the B-CLL cells so far examined possessed high-affinity IL-2 receptors consisting of p55 and p70/75; nevertheless, this was not sufficient to respond to the mitogenic signal of IL-2.

We evaluated the clinical course of acute myeloid leukemia (AML) and the levels of WT1 mRNA in 191 AML patients. Of 114 previously untreated patients with AML, 107 cases were positive for WT1 mRNA (93.9% : 107/114). WT1 mRNA expression-levels declined to below 50 copies/microg RNA ("negative") after remission was achieved in all 66 patients who achieved remission and 84.8% (47/54) cases were "negative" at the end of the follow-up periods. On the other hand, WT1 mRNA was expressed in 87.0% of non-remission cases (47/54), maintaining 50 copies/microg of RNA or higher ("positive"). In all 29 cases who relapsed during the follow-up observation period after achieving remission, WT1 mRNA levels declined transiently approximately around the time of achieving remission and then rose again when the disease relapsed. Moreover, we determined the time of elevation of WT1 mRNA in 29 relapsed cases. In 79.3% of relapsed cases (23/29), WT1 mRNA levels rose above 200 copies/microg RNA, 43 days (median) before the diagnosis of "relapse". Given the percent of the correct diagnosis, WT1 mRNA at 200 copies/microg RNA appeared to be a reasonable cut-off level for early detection of AML-relapse. The WT1 mRNA level reflected the clinical condition. Taken together, these findings indicate that WT1 mRNA levels allow us to detect the presence of so-called "minimal residual disease" (leukemic cells) that cannot be detected by morphological examination. Besides these promising data, this kit is suitable for routine monitoring of AML because this kit utilizes peripheral blood as a test specimen, reducing the patient's burden at the time of collection of clinical samples as compared with bone marrow aspirate.

Background: Bone marrow necrosis, a rare condition, characterized by necrosis of the medullary stroma and myeloid tissues of the bone marrow. The etiology is diverse, including hematopoietic malignancies. Case report: A 54-year-old male arrived by ambulance with collapse and high fever. On clinical examination, he had numerous petechiae and ecchymoses in the mouth and on the limbs. Laboratory findings revealed anemia and thrombocytopenia (WBC 15,140/μl, Hb 4.7g/dl, Plt 3.8X104/μl). A blood culture was positive for Staphylococcus aureus, diagnosed as septic shock, complicated by disseminated intravascular coagulation (DIC). When his medical condition was improved after treatment, blood examination showed pancytopenia (WBC 2,170/μl, blast 1.5%, Hb 9.2g/dl, Plt 1.1X104/μl). Multiple bone marrow aspiration displayed only small amount of the cells, which were difficult to be classified and were negative for peroxidase. Bone marrow biopsy showed marked bone marrow necrosis. During being treated for DIC, the abnormal cells were appeared in the peripheral blood, which were analyzed by flow cytometry and cytogenetics and eventually he was diagnosed as AML (M0, FAB classification). The sudden appearance of consolidation in the lungs by chest X-ray indicated leukemic cells infiltration into the lungs. His physical status was allowed chemotherapy consisting of cytarabine and aclarubicin only for the first four days of the standard protocol. Laboratory findings were improved, however, he suffered from repeated hemoptysis. Thoracic CT scan demonstrated diffuse alveolar damage and possible pneumonia. Despite of supportive treatment, his condition was complicated with chemotherapy associated-febrile neutropenia and he expired four weeks after admission. Conclusion: Bone marrow necrosis prognosis is related to underlying diseases and is generally poor. Therefore, multiple bone marrow aspirations and biopsies are needed to achieve appropriate diagnosis.

Laparoscopically assisted splenectomy with an 8- to 10-cm left upper paramedian laparotomy was performed following preoperative splenic artery embolization using painless contour emboli (super absorbent polymer microsphere) with early successful results in two men (46 and 37 years old) with myelofibrosis accompanied by massive splenomegaly. Dissection around the lower part of the spleen and the hilum initially was performed intracorporeally with the usual laparoscopic view under 12 mm Hg pneumoperitoneum. The alternating changes of viewpoints between the direct view through an 8- to 10-cm incision and the usual laparoscopic view with or without application of a retraction method were effective for safe hilar devascularization. Preoperative splenic artery embolization at the distal site was effective for safe dissection around the enlarged spleen. The patients did not complain of pain before operation. Preoperative painless embolization and laparoscopically assisted splenectomy with small laparotomy promotes the feasibility and safety of minimally invasive splenectomy for myelofibrosis with massive splenomegaly.

Abstract 1037 Background: In the IDSA guideline published in 2010 on the use of antimicrobial agents in neutropenic cancer patients, monotherapy with an anti-pseudomonal beta-lactam agent, such as cefepime (CFPM), carbapenem [meropenem (MEPM) or imipenem-cilastatin (IPM)], or piperacillin-tazobactam, is recommended as an empiric therapy for high risk febrile neutropenia (FN) patients. There have been few reports on the efficacy of cefozopran (CZOP), one of the 4thgeneration beta-lactams, in the treatment of such patients. We conducted an open-label randomized controlled study to evaluate the clinical efficacy of CZOP, MEPM, or IPM in high-risk FN adult patients with hematologic malignancies and solid tumors, using CFPM as a control. Methods: In this trial, 386 patients registered from 23 centers were randomized to receive either 4thgeneration beta-lactam (CFPM 2g, q12h IV or CZOP 2g, q12h IV) or carbapenem (MEPM 1g, q12h IV or IPM 1g, q12h IV). The primary endpoint was response to treatment defined as complete defervescence by day 7 with improvement in infection-related symptoms and laboratory findings. The clinical data were analyzed both by intention to treat and per protocol. We also evaluated the efficacy of each of the initial four drugs at days 3 to 5as a secondary endpoint. Results: 386 patients received the assigned antibiotic (CFPM: n=95, CZOP: n=98, MEPM: n=96, IPM: n=97) and 377 were evaluated for efficacy (CFPM: n=94, CZOP: n=95, MEPM: n=94, IPM: n=94). The 4 groups were comparable in terms of the baseline characteristics, including as age (median: 59 years (range: 17–87)), sex (male: n=215, female: n=171), body weight (median: 55 kg (range: 32–100)), underlying malignancy (leukemia: n=212 (54.9%), lymphoma: n=122 (31.6%), multiple myeloma: n=37 (9.6%), myelodysplastic syndrome: n=6 (1.6%), and other malignancy: n=9 (2.3%)), duration of initial antibiotic therapy (median: 7 days (range: 1–29)), median duration of severe neutropenia (neutrophil count < 100×106/L) (median: 6 days (range: 0–56)) and MASCC score (median: 21 (range:3–26)). Only neutrophil count at onset of IPM was significantly lower compared to the other treatments (CFPM: 38×106/L, CZOP: 35 x106/L, MEPM: 18×106/L, and IPM: 3×106/L, p=0.003). In intention-to-treat analysis, the response rates at day 7 were not significantly different among the four arms (CFPM: 63%, CZOP: 59%, MEPM: 61%, IPM: 69% (P=0.52)). The three antibiotics investigated in this trial were as effective as the reference agent, CFPM, in both the intention-to-treat and per-protocol populations. In both the intention-to-treat and per protocol analyses, success rates of the initial therapy at days 3 to 5 were not significantly different among four drugs [CFPM: 52 and 54%, CZOP: 46 and 47%, MEPM: 54 and 55%, IPM: 49 and 53% (P=0.70 and 0.68, respectively)]. Conclusions: CZOP, MEPM, and IPM were as effective as CFPM for adult FN patients with hematological malignancies and solid tumors as an empiric therapy. Disclosures: Tamura: Kyowa Hakko Kirin Co., Ltd,: Consultancy.

Abstract 3759 Imatinib treatment dramatically improves survival in chronic myeloid leukemia (CML) patients, but whether its effects of imatinib can be considered a cure remains controversial. This is because primitive, quiescent, Philadelphia-positive stem cells from patients with CML are insensitive to imatinib in vitro. Nonetheless, it was recently recognized that some patients with a complete molecular response (CMR) could sustain that response after discontinuation of imatinib. In a non-randomized prospective study, Mahon et al. reported that among patients with CMR lasting at least 2 years, CMR was sustained in 41% after discontinuation of imatinib. To characterize the clinical outcomes and profiles of chronic phase CML patients who discontinued imatinib, we conducted a nationwide survey in Japan. Among 3,242 imatinib-treated CML patients, 50 (1.5%) were identified who discontinued imatinib therapy for at least 6 months; of those, 43 were analyzed further. Molecular recurrence was detected in 19 patients, and the complete molecular response (CMR) rate was estimated to be 47% following imatinib discontinuation. Notably, the durations of imatinib therapy and CMR before cessation of therapy were significantly longer, and imatinib dose intensity and the frequency of prior IFN-a administration were significantly higher, in patients sustaining CMR for 12 months after cessation than in those with molecular recurrence. No significant correlations were detected between molecular recurrence and age, sex, Sokal risk, imatinib daily dose, combination with IFN-a, or time to achieve CMR. Moreover, we found a significant difference in estimated CMR rate following discontinuation between patients who had sustained CMR for greater than 24 months prior to imatinib discontinuation and those with less than 24 months (78% vs. 15%, p =0.0002 by Log-rank test, Figure). Based on multivariate regression analysis, only imatinib dose intensity and prior IFN-a administration were independently predictive of molecular recurrence within 12 months (p =0.0035, p =0.0060). The identified prediction formula was: Y= −0.0061 x dose intensity of imatinib(g)-3.17171 x prior IFN-a(Yes=1/No=0) +4.0124. If 1/(1+exp(-1 × Y)) > 0.5, molecular recurrence was predicted; the total accuracy rate of the formula was 82.5%. Although the depth of the molecular response should be a factor influencing long-term sustained CMR after discontinuation of imatinib, other factors, for example an immunological mechanism modified by IFN-a, might control quiescent CML stem cells. To increase the “cure” rate among CML patients, it will be necessary to establish a treatment strategy on the basis of large prospective study of imatinib discontinuation. This should entail the use of a highly sensitive and strict method for monitoring minimal residual disease over the course of a long follow-up period. Disclosures: No relevant conflicts of interest to declare.

A case of extramedullary plasmacytoma presenting with biclonal gammopathy is reported. The patient was an 82-year-old man in whom monoclonal-protein (M-protein) was not noted during his first hospitalization. On his second hospitalization generalized lymph node swelling and biclonal gammopathy (IgG-k, IgA-k) were observed. Histological findings were compatible with those of extramedullary plasmacytoma. In the terminal stages, the patient became cachexic. The autopsy disclosed dissemination of the plasmacytoma. Only two other cases have been reported in the literature, and a review of these previous reports is included.(Internal Medicine 32: 412-415, 1993)

A 66-year-old Japanese male with diffuse non-Hodgkin's lymphoma, of the pleomorphic type, complicated with Klinefelter's syndrome is reported. His phisique was characterized by a long arm span, disproportionately longer lower body dimensions and a small sized penis. He had no children. Chromosomal study revealed 47, XXY and hormonal quantification showed hypergonadtropic hypogonadism. Although chemotherapy was administered, his disease took a progressive course and he died. A discussion of chromosomal alteration and oncogenesis and review of the literature are included.(Internal Medicine 31 : 496-499, 1992)

Autologous mixed lymphocyte reaction (AMLR)-induced suppressor function was studied in 12 patients with chronic idiopathic thrombocytopenic purpura (ITP). The function was found to be significantly impaired (20 +/- 55%; p less than 0.005) compared with normal subjects (69 +/- 25%). AMLRs in these patients were significantly decreased (p less than 0.05) compared with normal subjects. There was no significant correlation between AMLR-induced suppressor function and platelet counts. Nine patients were studied for AMLR-induced suppressor function before and after splenectomy. The platelet counts increased significantly as a result of splenectomy, but the AMLR-induced suppressor function showed no significant improvement. The results of this study suggest that suppressor dysfunction in ITP may be an immunologic defect irrespective of disease activity. We consider that this abnormality may reflect in vivo failure of the immunoregulatory (feedback) mechanism in ITP.

A new B-cell line (ONHL-I) was established from non-Hodgkin's lymphoma. ONHL-I was free from Epstein-Barr virus nuclear antigen and expressed CD20, CD24, and slg (μ, δ, γ and κ), thus being equivalent to the mature B-cell stage. Chromosome analysis revealed a markedly abnormal pattern including 14q+ and 6q- In accordance with the positive expression of surface K light chains, one of the K genes was found to be rearranged. However, rearrangement of the A locus was also detected, contrary to the supposed hierarchy for the rearrangement of the light-chain genes. The cell line showed rearrangement of the bcl-2 gene. Further, the rearranged fragments of the JH, CA, and bci-2 genes were of the same size in the EcoRI and HindIII digests on the same filter. This may suggest that the bcl-2 gene is juxtaposed with the JH and CA locus. The proliferation of ONHL-I was inhibited by adding Staphylococcus aureus Cowan I or 12-O-tetradecanoyl-phorbol-13-acetate. During this growth inhibition, the expression of c-myc decreased, while that of bcl-2 mRNA remained steady. This result suggests that not the bcl-2 gene but other oncogenes, such as c-myc, play a key role in the proliferation of ONHL-I. This agrees with the hypothesis that the bcl-2 gene is not concerned with aggressive proliferation but with cell survival. This new cell line will therefore be of value in studying the differentiation and tumorigenesis of B cells.

A 53-year-old Japanese woman with Evans syndrome and colon cancer had two episodes of herpes zoster. The first painful vesicular rashes involved the right lower abdomen and buttock and healed in one month. After one more month, a second attack occurred on the right thigh and leg and developed into generalized hemorrhagic lesions, which became crusted in about 90 days. The patient died 131 days after the second attack, when the lesions had almost subsided. Varicella-zoster virus (VZV) was isolated on the 59th day of the second attack. Her intracutaneous reactions to VZV antigen was negative, but the humoral antibodies were continuously positive.

Media conditioned by an interleukin 3 (IL-3)-producing T-cell line, STIL-3, as well as recombinant mouse IL-3 showed granulocyte/macrophage (GM) colony-stimulating activity in the semi-solid culture medium containing horse serum (HS) or bovine serum, but the activity was not apparent when fetal calf serum (FCS) was used. No such serum-dependency of GM colony formation was observed when abdominal wall conditioned medium or L-cell conditioned medium containing GM colony-stimulating factor was used. Although the levels of albumin and total protein were lower in FCS than HS, increase of FCS concentration did not affect the GM colony-stimulating activity of IL-3. Addition of bovine serum albumin (BSA) preparation to FCS, however, increased the number of GM colonies to the same level as that observed with HS. The levels of bacterial lipopolysaccharide (LPS) in sera and BSA and the effect on the bone marrow cells from LPS-nonresponsive C3H/HeJ mice indicated that the observed effect of BSA was not due to the contaminating LPS. The activity of BSA was not substituted by IL-1, IL-2, IL-4, IFN-gamma, TNF, NGF or erythropoietin. The present study suggests the presence in BSA of co-factor(s) of IL-3 in stimulating GM colony formation.

[Background] We report the results of a prospective multi-institutional clinical trial of BMT from an HLA-matched URD following RIC. [Patients and Methods] The conditioning regimen included cladribine 0.11 mg/kg on day -8 to day -3, busulfan 4 mg/kg po on day -6 and day -5, and 4 Gy TBI on day -1. GVHD prophylaxis included cyclosporine and short-term methotrexate. Patients with hematologic diseases were eligible for this study if they were either older than 50 years or had significant medical contraindications to undergo conventional transplantation. Primary endpoints were neutrophil engraftment and achievement of complete donor-type chimerism (CD3+ cells >90%) on day 90. Regimen-related toxicities (RRT) between day -8 and day 28 were assessed by the NCI-CTC v2.0. A total of 27 patients were registered, but one patient was removed before transplant because of severe fungal infection. [Results] The median follow-up time was 722 days (range, 324–996) among survivors. The median age of patients was 56.5 years (36–64). Nine of the 26 patients (36%) had advanced-stage diseases and 3 (11%) had failed previous high-dose autologous or allogeneic transplantation. The diagnoses included AML (n=9), MDS/MPD (n=7), NHL (n=3), ALL (n=2), CML, ATLL, PCL, biphenotypic acute leukemia, and severe aplastic anemia (n=1). The median number of infused nucleated cells was 2.2 × 108/kg. After transplant, while one patient experienced engraftment failure and subsequent sepsis, and died on day 34, the remaining 25 patients achieved neutrophil engraftment (median, 17th day). Another patient was censored from the study due to grade 4 liver dysfunction, which developed on day 19, which left 24 patients for the chimerism analysis. The percentage of donor chimerism in CD3+ cells on days 28, 56 and 90 was, respectively, 88% (21/24), 100% (24/24) and 100% (24/24). Grade 3 RRT included arrhythmia (n=1), hypoxia (n=3), hyperbilirubinemia or hypertransaminasemia (n=7), stomatitis (n=18) and diarrhea (n=4), and grade 4 RRT included hypoxia (n=1) and hyperbilirubinemia (n=1). Acute GVHD of grade II, III and IV occurred in 27%, 27% and 4%, respectively. Ten of 15 evaluable patients (67%) had extensive chronic GVHD. CMV reactivation occurred in 23 patients (89%); 4 had histologically confirmed CMV colitis, 1 had CMV pneumonitis and 1 had CMV hepatitis, while the remaining patients had asymptomatic viremia. Of the 16 patients with measurable disease at the time of BMT, 15 achieved complete remission. The 100-day and 1-year cumulative incidences of non-relapse mortality (NRM) estimated by the Kaplan-Meier method were 20% and 54%, respectively. The cause of death that contributed to NRM was infection, with grade 0–I acute GVHD in 29% and grade II–IV acute GVHD in 71%. The 100-day and 1-year cumulative incidences of relapse were 8% and 35%, respectively, and the 1-year overall and progression-free survival rates were 42% and 30%, respectively. [Conclusions] The results support the feasibility of this procedure with a high response rate, but there is still a problem with the high NRM due to uncontrollable infections primarily associated with GVHD.

Background: Approximately 70–80% of all newly diagnosed patients with adult AML achieve a complete remission (CR). However, only about one third of those pts remain free of disease for more than 5 years. It is therefore important to predict which pts are most likely to suffer a relapse and thus perform alternative treatments such as stem cell transplantation in order to improve the prognosis of AML. We evaluated the impact of the detection of Wilms’ tumor gene1 (WT1) mRNA in the peripheral blood on the prognosis of AML pts. Patients and Methods: From June 1, 2001 to October 30, 2003 a study was performed on 191 pts with AML which evaluated the clinical usefulness of a WT1 mRNA assay kit for the early detection of relapse in AML pts (submitted in Rinsho Ketsueki). From these 191 pts, we selected the subjects for this study. All selected subjects achieved a complete remission, and also had their WT1 expression analyzed after consolidation therapy. The pts were excluded if they had received a stem cell transplantation before relapse. The WT1 mRNA levels were determined using the WT1 mRNA assay kit (Otsuka Pharmaceutical Co. Ltd) in accordance with the standard operating procedures using peripheral blood. The lower limit of detection was 50 copy/μgRNA. Therefore, less than 50 copy/μgRNA was judged as negative. All induction, consolidation and maintenance therapies were performed according to institutional standards. Results: Of 118 pts who achieved a complete remission, 50 pts (median age: 56 yrs 22–86) were evaluable. Their median WT1 mRNA levels before induction therapy was 48327 copy/μgRNA (137–329185). The WT1 mRNA levels at diagnosis did not correlate with either the relapse rate, DFS or OS, respectively. After CR, the WT1 mRNA level ranged from Conclusion: This study shows that the detection of the WT1 mRNA in the peripheral blood after treatment closely correlated with the prognosis in AML.

Using our electron microscopic method for polysome analysis and an immunofluorescent technique we studied Ig production and secretion by tumor cells in seven BJP myeloma patients and seven "nonsecretory" myeloma patients. In BJP myeloma Ig production and secretion is of three types: Type 1, only L-chains are synthesized and secreted; Type 2, the myeloma cells show fluorescence for H-chains, but upon polysome analysis there is no peak at polysomes corresponding H-chain production; Type 3, the myeloma cells show fluorescence for H-chains, and polysome analysis shows two peaks corresponding to L- and H-chain production. Polysome analysis of "nonsecretory myelomas show the presence of only very few membrane-bound polysomes and their distribution curves are entirely different from those of "ordinary" myeloma. Furthermore, the distribution patterns vary among seven cases. Results obtained by polysome analysis and immunofluorescent technique suggest that the "nonsecretory" myeloma could be divided into several subtypes.

Neoplastic cells of 18 patients with multiple myeloma were studied using a panel of 6 monoclonal antibodies to B cells and monospecific antisera against the light chain types of immunoglobulin. OKT10 bound to the myeloma cells of all the patients, although only a small percentage of the cells reacted in 3 instances. Monoclonal sIg was present in 5 patients. HLA-DR antigen detected with OKIa-1 was found in 5 patients. B1 bound to a small percentage of the myeloma cells only in 2 patients who had received treatment. The B1+ cells were always sIg+. In 3 patients, BA-2 reacted with the myeloma cells. BA-1 and BA-3 invariably did not react with the cells. Myeloma cells with B cell markers were found more frequently in treated patients than in untreated patients. The RPMI8226 line was also studied and found to react with OKT10 and BA-2. The results of this study show the presence of phenotypic variety in myeloma cells.

A case of chronic leukemia is reported. Malignant cells had the morphology of lymphocytes and an affinity for skin. Cytochemically, they were peroxidase negative, and NaF-resistant alpha-naphthyl esterase positive. The peripheral mononuclear cells formed E-rosettes and reacted with Leu 1 and OKM1. They were unreactive with OKT3, OKT4, OKT6, OKT8, and OKIa1. The cells did not possess surface IG, C3b receptors, or IgG Fc receptors (EAIgG). They responded weakly to phytohemagglutinin, and did not respond to concanavalin A. The cells did not adhere to Petri dishes or phagocytose latex beads. It is concluded that it was a case of OKT3-, OKM1+, EAIgG- T-cell chronic lymphocytic leukemia. This suggests that OKT3 does not recognize all peripheral T-cells, and that OKM1 is not specific for the monocyte-myeloid lineage. These cells may be useful in the characterization of E+, OKM1+ subset of peripheral mononuclear cells.

After a 3-month leukopenic phase, a patient developed hematologic pictures of acute promyelocytic leukemia (APL). Treatment with chemotherapy and radiotherapy had been given 10 months previously for a non-Hodgkin's lymphoma (NHL) of diffuse large cell type arising in the Waldeyer's ring. A computed tomographic scan demonstrated a high density mass in the left frontal cerebrum, which was enhanced uniformly by the contrast material. Cytocentrifuge examination of cerebrospinal fluid also showed an excess of promyelocytes. From these observations, the mass was considered to be an infiltration of leukemic cells. The intracerebral mass and meningeal involvement were resolved concomitantly with a hematologic remission of APL after intrathecal injection of cytosine arabinoside and systemic combination chemotherapy. This is a particular case of APL previously undescribed, representing an unusual presentation with intracerebral APL mass as well as a rare posttherapeutic APL following NHL. Cancer 59:94–98, 1987.

Tubuloreticular inclusions (TRI) and paired cisternae (PC) were induced in lymphocytes of normal individuals after incubation with Staphylococcus aureus Cowan 1. TRI were initially detected in lymphoid cells on day 2 (48-h culture). The frequency of TRI-positive cell sections on day 5 increased about twofold over those on days 2-4. On day 7, TRI were predominantly seen in lymphoplasmacytoid cells or plasmacytoid cells, with an incidence of up to 18% of sections. The regions in these cells were most extensive and anastomosed with the cisternae of adjacent well-developed rough endoplasmic reticulum (RER). TRI formation appears not to be essential for mitogen-induced B-cell differentiation to plasmacytoid cells, because pokeweed mitogen (PWM) failed to induce TRI. The diverse expressions of TRI induction between these two mitogens may be due to a difference in B-cell activation mechanisms. Paired cisternae were observed in a great majority of mitotic cells at various stages. These were encountered most frequently on day 4. PC were also seen in the PWM-stimulated culture. Our observations suggest that PC formation may be related to new formation of RER as well as to reconstruction of the nuclear envelope.

Tubuloreticular inclusions (TRI) were induced in normal blood lymphocytes after incubation with Staphylococcus aureus Cowan 1 (STA), but they were not induced by pokeweed mitogen (PWM), as we reported previously. TRI were also induced in Raji cells when grown in the medium of STA culture. Alpha-interferon (alpha IFN) was detected only in the medium of STA culture and not in PWM culture. The cells of PWM cultures formed TRI when exposed to various concentrations of human leukocyte alpha IFN. The incidences of TRI-positive cells in the presence of 50-500 IU/ml of alpha IFN were 3-5% on day 2 and increased to 10% on day 7. On days 5-7 of the PWM cultures, plasmacytoid cells containing TRI were seen not infrequently. In the presence of a high concentration of alpha IFN (10,000 IU/ml), which was sufficient to inhibit cell growth and differentiation, the growth of the TRI region was not altered and the incidence of TRI-positive cells was 9% on day 2 and increased to 15% on day 7. Our observations suggest that the TRI formation in STA culture is attributable to the alpha IFN produced endogenously by STA-stimulated cells and that some relationship might exist between the incidences of TRI-positive cells in these mitogen-stimulated cultures and the biologic functions of IFN.

The morphologic features, phenotype, and functions of OKM1+ leukemic T-cells were studied. The leukemic T-cells in two patients with chronic lymphocytic leukemia (CLL) had specific features of large granular lymphocytes (LGL), and those in two patients with acute lymphocytic leukemia (ALL) had L2 morphologic characteristics. The phenotype of the leukemic cells from one patient with CLL was OKM1+, ER+, OKT3+, OKT4+, OKT8-, OKIa1-, IgGFc receptor (EA gamma)+, Leu-7+, Leu-11b+, and anti-Tac-. The cells had antibody-dependent cell-mediated cytotoxicity (ADCC), but no natural killer (NK) activity. They had a definitive helper effect on pokeweed mitogen-induced normal B-cell differentiation. The leukemic cells from the other patient with CLL were Leu-7-, and Leu-11b-, and lacked both ADCC and NK activity. The leukemic cells in the two patients with ALL were ER+, OKM1+, Leu-7-, and Leu-11-, and did not have any cytotoxicity. One was EA gamma +, and the other was EA gamma -. These findings suggest that OKM1+ leukemic T-cells consist of at least two subgroups: (1) T-cells with the morphologic features of LGL; and (2) those with a lymphoblastic morphologic type. In either case, the phenotype is novel and suggests the emergence of a small, distinct lymphocyte subset.

Ultrastructures of normal T-cell subpopulations, Tγ and Tμ cells, were studied. Tγ cells were isolated and identified by repeating the rosetting method; firstly, by E rosette formation with neuraminidase-treated sheep red blood cells (SRBC), and next by EAy-rosette formation with ox red blood cells coated with IgG antibody (EAox). Before EAox rosetting, SRBC on isolated T cells were lysed by autologous plasma instead of ammonium chloride solution. Normal Tγ cells were heterogeneous with regard to their granules; the majority of Tγ cells had parallel tubular arrays (PTA) and a few had electron-dense granules. When ammonium chloride solution was employed to lyse SRBC, PTA were never observed; PTA in normal Tγ cells and in chronic lympho-cytic leukemia cells with Tγ character both seemed to change into electron-dense granules after ammonium chloride treatment. In contrast to Tγ cells, Tμ cells were characterized by clustered dense bodies, i.e. focal aggregates of electron-dense granules.

A case of "nonsecretory" myeloma is described. The patient had typical osteolytic lesions and marked infiltration of myeloma cells in the bone marrow, and plasma cell leukemia. A good partial remission was obtained with Melphalan, but the patient relapsed and died one year later. Immunofluorescent and immunoelectroscopic studies on the myeloma cells demonstrated the presence of cytoplasmic gamma-and kappa-chains at the initial stage and of only kappa-chains at a relapse. The electron microscopic method for polysome analysis indicated that both L-and H-chains were synthesized on membrane-bound polysomes initially, but the ability to produce H-chain was missing at the relapse.

Summary Human myeloma cells are malignant counterparts of plasma cells which represent the most differentiated B cells. Myeloma cells are, however, heterogeneous in their surface antigen expression (Katagiri et al, 1984, 1985), which may reflect that normal plasma cells have a spectrum of differentiation. To test this hypothesis, immunoglobulinsecreting cells (ISC) of non-neoplastic nature were studied with regard to their surface antigen expression by using a combination of reverse haemolytic plaque assay and complement-dependent cytolysis. Non-neoplastic ISC were found to have a broad spectrum of differentiation stages from the immature type of CD20+, HLA-DR+, CD38+ in the peripheral blood to the mature type of CD20–, HLA-DR–, CD38+ in the bone marrow. In patients with polyclonal B cell activation (PBA), ISC showed a more immature antigen expression in comparison with ISC in normal controls or patients without PBA. The surface antigen development of ISC was clearly demonstrated throughout the stages in the analysis of mitogen-induced ISC in vitro. No significant difference in the surface phenotype of ISC was found among heavy chain classes. Thus, non-neoplastic ISC show a spectrum of differentiation similar to that of myeloma cells, depending on the site where ISC are located, and on the degree of PBA in vivo.

Two distinct cell lines (OPM-1 and OPM-2) were established from the peripheral blood of a 56-year-old female myeloma patient at the stage of terminal leukemic evolution associated with loss of cytoplasmic immunoglobulin heavy chain (G lambda----lambda). The lines grew in suspension with a doubling time of 36-42 hr and 30-36 hr, respectively. EBNA was absent from both lines. The lines synthesized cytoplasmic lambda-chain, but had no detectable surface immunoglobulins. Fc receptors and complement receptors could not be detected in either line. The lines had very complex chromosomal abnormalities, but the patterns of chromosomes differed greatly between the two lines. The two lines, together with the RPMI 8226 line established by Matsuoka et al. (1967), were analyzed for phenotypic expression as defined by a panel of monoclonal antibodies to B cells (B1, BA-1, BA-2, BA-3, OKIa-1 and OKT10/BMA0100). Neither OPM-1 nor OPM-2 reacted with any of the antibodies tested except OKT10. OPM-1 cells reacted weakly (less than 30%) with OKT10/BMA0100, while OPM-2 cells showed a fluctuating reactivity, ranging from 40 to 80%, with OKT10/BMA0100. In contrast, RPMI 8226 reacted strongly with OKT10 and BA-2. These results demonstrate the presence of phenotypic heterogeneity in all 3 myeloma cell lines, suggesting that the lines might represent different stages of terminal B-cell development.