Tohru Inaba

An Asian variant of intravascular large B-cell lymphoma: clinical, pathological and cytogenetic approaches to diffuse large B-cell lymphoma associated with haemophagocytic syndrome

Diffuse large B‐cell lymphoma with haemophagocytic syndrome (BCL‐HS) has been reported mainly in Asia and is regarded as a distinct variant of intravascular lymphoma (IVL). However, it is unclear whether all cases of BCL‐HS fall within the framework of IVL and available clinical information is limited. We analysed 25 cases with BCL‐HS, including 11 autopsied cases (median, 66 years; male–female ratio, 1·1:1). The patients presented with fever, anaemia, thrombocytopenia, hepatosplenomegaly, haemophagocytosis, bone marrow invasion, respiratory disturbance and disseminated intravascular coagulopathy, but usually lacked lymphadenopathy, mass formation, neurological abnormalities and skin lesions. The clinical course was aggressive with a median survival of 7 months. The morphological findings were uniform: large lymphoid cells infiltrated vessels and/or sinusoids of the liver, marrow, lung, kidney and other organs. They were positive for CD19, CD20, CD79a and HLA‐DR, but negative for CD10, CD23 and CD30. CD5 was positive in five out of 17 cases. Our critical review indicates that BCL‐HS is the equivalent of the Asian variant of IVL.

Characteristic perforin gene mutations of haemophagocytic lymphohistiocytosis patients in Japan

Summary. Perforin gene (PRF1) mutations appear to occur in about 30% of patients with haemophagocytic lymphohistiocytosis (HLH). We tested perforin expression and gene mutations in 14 HLH patients and six patients with Epstein–Barr virus‐associated HLH (EBV‐HLH) in Japan. Five of the 14 HLH patients had perforin abnormalities. The presence of PRF1 genetic abnormality correlated well with the lack of perforin expression as determined by flow cytometry. Sequencing showed that four patients had a compound heterozygous mutation while the fifth patient had a homozygous mutation. Three of the mutations we detected were novel. In contrast, none of the six EBV‐HLH patients showed perforin abnormalities. Our data, combined with the PRF1 mutations in three previously reported Japanese patients, suggest that the 1090–1091delCT and 207delC mutations of the perforin gene are frequently present in Japanese HLH patients (62·5% and 37·5% respectively). Examination of the geographical origins of the ancestors in the perforin‐mutant HLH patients revealed that they mostly came from the Western part of Japan, suggesting that the present‐day cases may largely derive from a common ancestor.

Rituximab is effective for steroid-refractory sclerodermatous chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) is the most common late complication following allogeneic stem cell transplantation, occurring in 25–80% of transplant recipients.1 It is becoming a more frequent problem due to the increasing recipient age at transplantation as well as the increasing use of alternative donors, peripheral blood stem cells, and donor lymphocyte infusions. The most widely employed first line therapy for chronic GVHD is a combination of cyclosporine (CSA) and prednisolone, but patients who failed to respond to the initial steroid-based therapy have a poor outcome.1 Therefore, various agents have been investigated as salvage therapy for chronic GVHD, but there is no standard approach that is uniformly accepted.

B‐cell lymphoma associated with haemophagocytic syndrome: a clinical, immunological and cytogenetic study

B‐cell lymphoma associated with haemophagocytic syndrome (HPS) is extremely rare in Western countries but has recently been increasingly reported in Asian countries. We describe seven patients with B‐cell lymphoma associated with HPS, six males and one female, age range 41–82 years (median 63 years). All patients had fever and splenomegaly, and six of the seven patients had hepatomegaly with no associated lymphadenopathy. The bone marrow showed haemophagocytosis and an infiltration of lymphoma cells. All patients showed increased levels of lactate dehydrogenase, C‐reactive protein, ferritin and soluble interleukin‐2 receptor. Lymphoma cells were positive for CD19, CD20 and surface immunoglobulin in all patients examined, and positive for CD5 in four of seven patients. Cytogenetic analyses of bone marrow cells showed a complex structural abnormality including chromosome 14q32 in two patients, 19q13 in three patients and deletion of the terminal part of 8p21 in six patients. The prognosis was poor; only two of the seven patients have survived in complete remission with a median survival of 11 months. These data suggested that B‐cell lymphoma associated with HPS might constitute a distinct biological and clinical disease entity. Abnormality of chromosome 19q13 and loss of 8p21 might be involved in the pathogenesis of this disease.

B-Cell Lymphoma-Associated Hemophagocytic Syndrome

B-cell lymphoma-associated hemophagocytic syndrome (B-LAHS) is extremely rare in Western countries but has recently been increasingly reported in Asian countries, especially Japan. Here, we reviewed 25 previously reported Japanese cases of B-LAHS and summarized its clinicopathologic features and therapeutic outcome. The median age of onset was 63 years old with initial presentation of fever, hepatomegaly, and splenomegaly without associated lymphadenopathy. Laboratory findings showed increased levels of lactate dehydrogenase, C-reactive protein, ferritin and soluble interleukin-2 receptor. Histopathologically, hemo-phagocytosis was often seen in the bone marrow and spleen. Various percentages of lym-phoma cells were seen in the bone marrow, positive for CD19, CD20 and surface immunoglobulin, and some were also positive for CD5. Cytogenetic analysis showed a complex structural abnormality including chromosome 14q32, 19q13 and deletion of the terminal part of 8~21. Some patients had histological features of intravascular lymphomatosis (IVL). The prognosis was poor with a median survival period of 9 months. We treated five patients using autologous peripheral blood stem cell transplantation (PBSCT), and four are still in complete remission nine to 24 months after PBSCT, suggesting that high-dose chemotherapy followed by PBSCT might improve the survival rate.

Mobilization of hematopoietic primitive and committed progenitor cells into blood in mice by anti-vascular adhesion molecule-1 antibody alone or in combination with granulocyte colony-stimulating factor

OBJECTIVE One of the mechanisms for mobilization of hematopoietic stem cells and progenitor cells is alternation of adhesion molecules. We investigated the mobilization of hematopoietic progenitor cells in blood by administration of anti-vascular cell adhesion molecule (VCAM)-1 antibody (Ab) in mice. MATERIALS AND METHODS Twelve- to 14-week old C57BL/6J mice were injected intravenously with anti-VCAM-1 Ab and anti-very late antigen (VLA)-4 Ab at a dose of 5 mg/kg for 2 days. RESULTS The number of colony-forming cells (CFCs) in blood was increased 11.4-fold after anti-VCAM-1 Ab treatment, but the number of CFCs was not increased after treatment with anti-VLA-4 Ab. The number of colony-forming unit spleen (CFU-S) also was increased 21.6-fold in the peripheral blood by administration of anti-VCAM-1 Ab. The number of CFCs and CFU-S in the bone marrow of mice treated with anti-VCAM-1 Ab was decreased and that in the spleen also was decreased. On administration of recombinant human granulocyte colony-stimulating factor (125 microg/kg twice daily) with anti-VCAM-1 Ab, the numbers of CFCs and CFU-S were increased 141.8-fold and 439-fold, respectively. CONCLUSIONS These observations demonstrated that administration of anti-VCAM-1 Ab induced mobilization of hematopoietic progenitor cells into blood from bone marrow and spleen and that granulocyte colony-stimulating factor has synergistic effects on anti-VCAM-1 Ab-induced mobilization.

High serum bone-specific alkaline phosphatase level after bortezomib-combined therapy in refractory multiple myeloma: possible role of bortezomib on osteoblast differentiation

High serum bone-specific alkaline phosphatase level after bortezomib-combined therapy in refractory multiple myeloma: possible role of bortezomib on osteoblast differentiation

A newly developed bisphosphonate, YM529, is a potent apoptosis inducer of human myeloma cells.

We examined the effect of YM529, a newly developed third-generation bisphosphonate (BP), on the growth of human myeloma cell lines using the trypan blue dye exclusion test and Alamar blue assay. BPs induced inhibition of proliferation in all cell lines dose-dependently, and YM529 had a most potent growth inhibitory effect, followed by incadronate and pamidronate. Flow cytometric analysis using annexinV and 7AAD showed that YM529 most significantly induced apoptosis of all myeloma cell lines. These observations suggested that YM529 is a potent apoptosis inducer of myeloma cells, and might have some benefit not only on the improvement of bone lesions but also on survival in some myeloma patients.

β-Catenin Small Interfering RNA Successfully Suppressed Progression of Multiple Myeloma in a Mouse Model

Purpose: β-catenin is the downstream effector of the Wnt signaling pathway, and it regulates cell proliferation. β-catenin overexpression correlates positively with prognosis in several types of malignancies. We herein assessed its effects on growth of multiple myeloma cells using a xenograft model. Experimental Design: We first investigated the expression of β-catenin in multiple myeloma cell lines and multiple myeloma cells obtained from patients. Next, we investigated the growth inhibitory effects of β-catenin small interfering RNA on the growth of multiple myeloma cells in vivo. Six-week-old male BALB/c nu/nu mice were inoculated s.c. in the right flank with 5 × 106 RPMI8226 cells, followed by s.c. injections of β-catenin small interfering RNA, scramble small interfering RNA, or PBS/atelocollagen complex twice a week for a total of eight injections. Results: Significantly higher levels of β-catenin expression were observed in multiple myeloma cell lines and in samples from patients with multiple myeloma than those found in mononuclear cells obtained from healthy volunteers. In in vivo experiments, no inhibitory effects were observed following treatment with scramble small interfering RNA or PBS/atelocollagen complexes, whereas treatment with β-catenin small interfering RNA/atelocollagen complex significantly inhibited growth of multiple myeloma tumors (P < 0.05). Conclusions: β-catenin small interfering RNA treatment inhibited the growth of multiple myeloma tumors in a xenograft model. To our knowledge, this is the first report showing that the treatment with β-catenin small interfering RNA produces an inhibitory effects on growth of hematologic malignancies in vivo. Because treatment with β-catenin small interfering RNA inhibited growth of multiple myeloma cells, β-catenin is the attractive novel target for treating multiple myeloma.

CD34 + /CD41a + cells best predict platelet recovery after autologous peripheral blood stem cell transplantation

Reliable markers for megakaryocytic reconstitution after peripheral blood stem cell transplantation (PBSCT) have not been established. To determine a convenient and reliable predictor, we measured the number of megakaryocyte progenitor cells in PBSC grafts by clonogenic and flow cytometric assays. Seventeen patients with hematological and solid malignancies were included in this study. For the clonogenic assay, we used thrombopoietin (TPO) as a growth factor to evaluate the maximum number of megakaryocyte progenitor cells. Using a flow cytometric assay, we examined the expression of platelet glycoproteins on CD34+ cells to count the number of megakaryocyte progenitor cells. We used buffer containing EDTA to prevent platelet adhesion to CD34+ cells and selected CD34+ cells by immunomagnetic beads. The best correlation was observed between the number of CD34+/CD41a+ cells and the time to platelet recovery (P = 0.0205), rather than the total number of CD34+ cells. In addition, a close correlation was observed between the number of CD34+/CD41a+ cells and colony-forming unit megakaryocyte (CFU-MK) (P = 0.0018). These observations suggest that the number of CD34+/CD41a+ cells is the best predictor for platelet reconstitution after PBSCT.