Identification of putative noncanonical driver mutations in patients with essential thrombocythemia.

Essential thrombocythemia (ET) cases without canonical JAK2, CALR, or MPL mutations, that is, triple-negative (TN) ET, have been found in 10%-20% of ET cases. Owing to the limited number of TN ET cases, its clinical significance remains unclear. This study evaluated TN ET's clinical characteristics and identified novel driver mutations. Among 119 patients with ET, 20 (16.8%) had no canonical JAK2/CALR/MPL mutations. Patients with TN ET tended to be younger and had lower white blood cell counts and lactate dehydrogenase values. We identified putative driver mutations in 7 (35%): MPL S204P, MPL L265F, JAK2 R683G, and JAK2 T875N were previously reported as candidate driver mutations in ET. Moreover, we identified a THPO splicing site mutation, MPL*636Wext*12, and MPL E237K. Four of the seven identified driver mutations were germline. Functional studies on MPL*636Wext*12 and MPL E237K revealed that they are gain-of-function mutants that increase MPL signaling and confer thrombopoietin hypersensitivity with very low efficiency. Patients with TN ET tended to be younger, although this was thought to be due to the inclusion of germline mutations, hereditary thrombocytosis. Accumulating the genetic and clinical characteristics of noncanonical mutations may help future clinical interventions in TN ET and hereditary thrombocytosis.

Cardiac Involvement of Adult T Cell Leukemia/Lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is a refractory T-cell lymphoma with variable clinical profiles, commonly exhibiting extra-nodal involvement. The myocardial involvement of ATL is often detected at an autopsy; however, the development of a symptomatic cardiac mass due to ATL is extremely rare. We herein report a 65-year-old man with ATL who developed cardiac symptoms due to a rapidly enlarging left ventricular mass soon after the initiation of systemic chemotherapy. We also summarize previously reported cases of symptomatic ATL with cardiac involvement.

Efficacy of palonosetron to prevent delayed nausea and vomiting in non-Hodgkin's lymphoma patients undergoing repeated cycles of the CHOP regimen.

PURPOSE: Few studies have investigated the effect of palonosetron on delayed chemotherapy-induced nausea and vomiting in lymphoma patients receiving the CHOP regimen. We conducted a prospective clinical trial to assess the efficacy of palonosetron in patients receiving the CHOP regimen. METHODS: Complete control (CC: emesis-free and mild nausea) during delayed phase (24-120 h) was the primary endpoint. The secondary endpoint was complete response (CR: emesis-free) during acute (0-24 h), delayed, and overall phases (0-120 h), and CC during acute and overall phases. Palonosetron (0.75 mg) was administered before chemotherapy on day 1 of both the first and second CHOP cycles. RESULTS: The efficacy of palonosetron in preventing emesis was evaluated in 40 patients. Across two cycles, over 85% of patients achieved CR. As the primary endpoint, the proportion of patients achieving CC in the delayed phase increased from 70% (cycle 1) to 85% (cycle 2). CR rate in the delayed phase increased from 85% (cycle 1) to 95% (cycle 2). CONCLUSION: These results suggest that the antiemetic effects during the delayed phase were inferior to those in the acute phase during the first cycle. However, even at the same dose of palonosetron, CR and CC rates increased in the second cycle.

CD20 gene deletion causes a CD20-negative relapse in diffuse large B-cell lymphoma.

In diffuse large B-cell lymphoma (DLBCL), a CD20-negative relapse is clinically significant because it is associated with chemo-refractory phenotypes and loss of a therapeutic target. The alteration of the CD20 gene is reported as infrequent in CD20-negative relapse in B-cell lymphoma. We established a DLBCL cell line with loss of CD20 expression (SD07) from a patient at CD20-negative relapse. She was initially diagnosed with CD20-positive DLBCL and received repeated immuno-chemotherapy that included rituximab. SD07, which has an immunoglobulin κ rearrangement identical to that of lymphoma cells at CD20-negative relapse, showed homozygous deletion of the CD20 gene with loss of the copy number of 11q12. SD07 is the first case in which it is proven that the loss of CD20 expression in relapsed DLBCL is the result of deletion of the CD20 gene. Deletion of the CD20 gene is a molecular mechanism of CD20-negative relapse in a subset of DLBCL.

[Bilateral renal infiltration of acute lymphoblastic leukemia cells at relapse after allogeneic stem cell transplantation].

A 44-year-old male patient was diagnosed with acute lymphoblastic leukemia (CD10+, CD19+, CD20 weak) and underwent unrelated bone marrow transplantation (uBMT) with a conditioning regimen of cyclophosphamide plus total body irradiation during first complete remission (CR). Twenty months post-uBMT, the serum creatinine level (Cre) increased gradually, up to ≥ 1.5 mg/dl at 23 months. Since the increase in Cre was observed continuously, imaging examinations were performed and showed significant bilateral enlargement of the kidneys. Renal biopsy showed diffuse invasion of TdT, CD10 and CD19 positive lymphoid cells in the tubulo-interstitial region. Since leukemia cells were observed in the bone marrow, it was diagnosed as relapse in the bone marrow and kidney. Following reinduction chemotherapy, both kidneys returned to normal size. The patient entered into a second CR, but relapse occurred 6 months thereafter. The patient underwent uBMT again with a reduced-intensity conditioning regimen and CR has been maintained up to 5 months post-second uBMT. Although it is considered rare for relapse to occur with diffuse enlargement of both kidneys, as shown in this case, it is important to confirm the state of the kidney by performing blood tests and image diagnosis during the early phase, when renal dysfunction of an uncertain cause occurs after transplantation.

Primary pulmonary classical hodgkin lymphoma with two recurrences in the mediastinum : a case report.

We report a case of primary pulmonary classical Hodgkin lymphoma (CHL) in a 58-year-old woman. Twelve years ago, the patient complained of slight fever and weight loss. A mass of about 5 cm in diameter was seen in the right lung on radiography and computed tomography (CT). Right total pneumonectomy and resection of mediastinal lymph nodes were performed. A pathological examination led to a strong suspicion of Hodgkin disease (HD) (now referred to as CHL), but a definite diagnosis could not be made at the time. Six years later, a chest CT showed a tumor around the ascending aorta, which was treated successfully by radiation therapy. Six years later, the chest CT revealed a tumor in the anterior mediastinum. CHL was diagnosed based on an immunohistochemical re-examination of lung specimens resected 12 years earlier and CT-guided fine needle tumor biopsy specimens of the second recurrent tumor in the anterior mediastinum were compatible with the recurrence of CHL. Therefore, we diagnosed this case as primary pulmonary CHL that later relapsed in the mediastinum. The tumor size was reduced by radiation therapy and the patient is currently under observation as an outpatient.

[Splenic irradiation as a successful treatment for an elderly patient with B-cell prolymphocytic leukemia].

We report a case of B-cell prolymphocytic leukemia (B-PLL) that was treated successfully with splenic irradiation (SI). An 86-year-old man underwent a medical examination for lumbago and general fatigue at another hospital in June 2007. A compressed lumbar fracture and splenomegaly were found using computed tomography (CT). Thereafter, the patient consulted our hospital because of leukocytosis. Peripheral blood showed hemoglobin level 9.8 g/dl and white blood cell count 38.1x10(9)/l with 91% atypical cells. Surface marker analysis demonstrated that atypical cells were positive for CD20, CD22, FMC7, surface IgM, surface IgD and kappa, but were negative for CD5, TdT and lambda. The morphology of these cells was compatible with prolymphocytes with prominent nucleoli and condensed nuclear chromatin. A diagnosis of B-PLL was made. SI (total dose 20 Gy) was chosen for the treatment and a single course of SI was very effective without causing any significant adverse events. This case demonstrates that SI may remain valuable for the treatment of B-PLL in an elderly patient.

Megakaryopoiesis and platelet function in polycythemia vera and essential thrombocythemia patients with JAK2 V617F mutation.

Patients with Ph chromosome negative myeloproliferative disease (Ph-MPD) have an increased risk of vascular complications. It remains controversial whether patients with the JAK2 V617F mutation (V617F) exhibit increased risk, while recent growing evidence has shown a critical role for V617F in clonal erythropoiesis in Ph-MPD. We studied 53 patients with Ph-MPD especially in relation to megakaryopoiesis, the thrombotic complications and the presence of V617F. Using novel mutation-specific PCR which is a highly sensitive PCR-based assay for detection of JAK2 mutated allele(s), we identified V617F in 38 Ph-MPD, which include 13 polycythemia vera (PV), 23 essential thrombocythemia (ET) and 2 chronic idiopatic myelofibrosis. The numbers of megakaryocytes were significantly increased in PV and ET patients with V617F, but the platelet counts were slightly lower. Although statistically not significant, the incidence of thrombotic events was higher in the group with V617F compared to in those without the mutation. Agonist-induced in vitro platelet aggregation and platelet adhesion were not affected by the presence of this mutation. Nonetheless, we found a hypercoagulable state in Ph-CMPD with V617F by employing whole blood thromboelastography. It suggests pre-thrombotic tendencies in CMPD are complex and JAK2 V617F mutation might have a role in vivo blood coagulation by altering not only the number, but function(s) of all three myeloid cells, including red blood cells, white blood cells and platelets in Ph-CMPD.

Histopathology of bone marrow reconstitution after umbilical cord blood transplantation for hematological diseases.

To study hematopoietic reconstitution in umbilical cord blood transplantation (CBT), bone marrow (BM) histology was investigated in 35 biopsies after bone marrow transplantation (BMT) and in 40 biopsies after CBT. BM biopsies were obtained at different times after transplantation and were evaluated for cellularity, number of megakaryocytes and CD34-positive cells, and fibrosis. In biopsies up to 29 days after BMT, cellularity was increased and megakaryocytes were observed, but at 29 days after CBT, biopsies showed severe cellular depletion and almost no megakaryocytes. In addition, fewer CD34-positive cells were observed after CBT compared to after BMT. After day 30 after CBT, hematopoietic recovery of the BM was gradually observed and after day 100 after transplantation, no essential differences were observed between BMT and CBT. Hematopoietic recovery of the BM after CBT was delayed compared to that after BMT, but engraftment of donor cells after CBT was also observed in histopathologically. To the best of the authors' knowledge this is the first histopathological description of BM reconstitution after CBT.

Histopathological bone marrow changes after reduced-intensity hematopoietic stem cell transplantation for follicular lymphoma involving bone marrow.

Allogeneic stem cell transplantation (allo-SCT) is used as curative therapy for malignant lymphoma, and reduced-intensity hematopoietic stem cell transplantation (RIST) is sometimes performed to avoid the toxicity and mortality associated with myeloablative allo-SCT. RIST is generally preferred for elderly patients with malignant lymphoma. A 62-year-old woman with follicular lymphoma (FL) involving bone marrow (BM) suffered relapse after autologous SCT. RIST was performed; cells were from an unrelated, fully human leukocyte antigen-matched donor. To study the hematopoietic reconstitution, BM biopsy specimens that were obtained at different times after RIST, were evaluated. Engraftment of donor cells was observed on days 19 and 48 after RIST, and residual FL in BM had completely disappeared by day 73 after RIST. This is the first report to document histological BM regeneration after RIST and disappearance of FL involving the BM.

Reversible posterior leukoencephalopathy syndrome after repeat intermediate-dose cytarabine chemotherapy in a patient with acute myeloid leukemia.

A 56-year-old man was admitted to our hospital with leukocytosis, anemia, and thrombocytopenia. Acute monoblastic leukemia was diagnosed. Two subsequent courses of consolidation chemotherapy consisted of conventional doses of cytarabine and intermediate-dose cytarabine. Intermediate-dose cytarabine was infused intravenously every 12 hr for 6 days. On day 15 after the final infusion of cytarabine, the patient suffered headache, and on day 21, he experienced a decrease in sensation on the sole of his left foot. Magnetic resonance imaging (MRI) of the brain revealed widespread areas of white matter edema. Cerebrospinal fluid (CSF) examination revealed an increase in the number of cells to 31 mm(-3); the majority were lymphocytes. No infiltration of leukemia cells was seen. After 2 months, brain MRI findings were normal. The clinicoradiologic features of the case were consistent with reversible posterior leukoencephalopathy syndrome (RPLS). RPLS in the present case was unlikely to have been caused by direct neurotoxicity because (1) the doses of cytarabine (500 mg/m(2); total dose 9.2 g) were much smaller than those in reported cases and were repeatedly infused until RPLS developed; (2) the RPLS developed 21 days after the final infusion of cytarabine, a much longer period than previously reported; (3) the slight leukocytosis in the CSF observed on day 33 might also have been related to the cellular immune responses evoked by the infused cytarabine. These details suggest not only that direct cerebral neurotoxicity of cytarabine but also that some type of allergic response may have been involved in the development of RPLS.

[Successful treatment with prednisolone for autoimmune myelofibrosis accompanied with Sjögren syndrome].

A 66-year-old woman presented with anemia in January 2006. She was admitted to our Department in February, after laboratory data showed pancytopenia and bone marrow biopsy reticulin fibrosis. The results of the diagnostic work-up, which included the anti-SS-A antibody, anti-SS-B antibody positivity and salivary gland scintigraphy, Schirmer test and Rose Bengal test, supported the classification criteria of Sjögren syndrome. Due to secondary myelofibrosis accompanied by Sjögren syndrome, she was started on prednisolone (PSL) and recovered completely from the anemia and thrombocytopenia. After the PSL was tapered, a recent follow-up indicated that the peripheral blood had normalized with the PSL therapy. As a causal disease of autoimmune myelofibrosis in collagen disease, systemic lupus erythematosus occurs frequently. This patient is considered to be a rare case in whom secondary myelofibrosis was accompanied by Sjögren syndrome.

Reproductive swarming of sympatric nereidid polychaetes in an estuary of the Omuta-gawa river in Kyushu, Japan, with special reference to simultaneous swarming of two Hediste species.

Habitat differences and spatial and temporal separation in reproductive swarming among sympatric nereidid polychaetes were examined in an estuary of the Omuta-gawa River, Kyushu, Japan by annual periodical sampling from December 2003 to January 2005. Benthic adults of Tylorrhynchus osawai and Hediste diadroma occupied mainly the upper reaches of the estuary, whereas those of H. japonica usually inhabited the middle reaches, though their distributions overlapped. Reproductive swarming of mature adults occurred in the estuary just after high tide at night during spring tides in four nereidids: H. japonica (in the middle and lower reaches from late December to late February), H. diadroma (throughout the whole estuary from middle December to late April), T. osawai (in the middle reaches and another estuary from late October to late December), and Nectoneanthes oxypoda sensu Imajima, 1972 (in the lower reaches in late April and early May). This result shows that temporal separation of reproductive swarming may act as a reproductive isolation mechanism among these nereidids, except for H. japonica and H. diadroma. Simultaneous swarming and mass-spawning of the two Hediste species were commonly observed in the middle and lower reaches from late December to early February, suggesting the absence of a pre-spawning barrier to reproductive isolation between them. We found no difference in spawning behavior between H. japonica and H. diadroma. Males of both species seemed to participate in swarming earlier than females.