Development of Philadelphia chromosome-negative acute myeloid leukemia with IDH2 and NPM1 mutations in a patient with chronic myeloid leukemia who showed a major molecular response to tyrosine kinase inhibitor therapy

Tyrosine kinase inhibitors (TKIs) are standard therapies for chronic myeloid leukemia (CML) that can eradicate Ph-positive leukemic cells. However, disease control is not achievable in a minority of cases, most commonly due to evolution of TKI-resistant clones. There have also been rare cases of emergence of Ph-negative clones with other cytogenetic abnormalities, and, less commonly, development of Ph-negative acute myeloid leukemia (AML), whose molecular pathogenesis is largely unknown. Here we report molecular features of a patient with Ph + CML who developed Ph-negative AML after showing a major molecular response to dasatinib. A 55-year-old man was diagnosed with CML. He achieved a complete cytogenetic response three months after dasatinib therapy but developed AML with normal karyotype 1 year later. After receiving induction and consolidation chemotherapy for AML, the patient achieved complete remission with no evidence of CML under maintenance with bosutinib. Targeted sequencing of serial bone marrow samples identified mutations in IDH2 and NPM1 in the Ph-negative AML cells, which had not been detected in CML cells. These results suggest that Ph-negative AML in this patient originated from a preleukemic population, which might have expanded during or after the successful elimination of CML clones with TKI therapy.

[Acquired hemophilia A requiring plasma exchange and mechanical ventilation]

A 56-year-old man who sustained a right waist injury 1 month ago, reported to our department complaining of pain in the right waist and femur for 1 day. In a computed tomography examination, hematoma of the right iliopsoas muscle was revealed, and arterial embolization was immediately performed but was not effective. Laboratory findings showed hemoglobin levels as 5.4 g/dl, platelet of 20.2×10⁴/µl, prothrombine time of 13.1 s, partial thromboplastin time (APTT) of 81.1 s, and a convex upward curve of the APTT cross-mixing test. The activity of the coagulation factor VIII was <1.0%, but its amount was 120%, and the level of factor VIII inhibitor was 130 Bethesda Unit/ml. Disseminated intravascular coagulation was not noted. Under the diagnosis of acquired hemophilia A, treatment with prednisolone and recombinant activated factor VII was initiated. However, APTT remained prolonged, and intubation and mechanical ventilation were required because of right hemothorax. After steroid pulse therapy and plasma exchange, APTT returned to its normal range, and the inhibitor disappeared. Thus, we finally succeeded in extubation. This case indicated that intensive care may be necessary in the early phase treatment for acquired hemophilia A.

[Detection of BCR-ABL1 chimeric gene-positive neutrophils in a patient with mixed phenotype acute leukemia]

We experienced two patients with mixed phenotype acute leukemia with t(9;22)(q34;q11.2); BCR-ABL1 according to the WHO classification 2008. The type of BCR/ABL1 was major in both patients, and the chimeric gene was also detected in neutrophils from peripheral blood by the fluorescence in situ hybridization technique. Patient 1 was a 59-year-old Japanese woman, and patient 2 a 45-year-old Japanese man. They had both developed leukemia suddenly. Their leukemic blasts expressed B cell and myeloid cell antigens, but concomitantly in patient 1 (biphenotypic) and separately in patient 2 (biclonal). Percentages of BCR-ABL1-positive neutrophils were 98% and 89%, respectively. Both patients received an imatinib (600 mg/day)-combined Hyper-CVAD regimen as induction therapy, followed by treatment with dasatinib (140 mg/day). MEC therapy was also applied between these two treatments in patient 2. At present, patient 1 has obtained complete molecular remission quantitatively and qualitatively, and patient 2 only quantitatively. Considering their acute onsets with no prior history of chronic myelocytic leukemia (CML), they were both diagnosed as having acute leukemia with Ph1, but not blastic crisis of CML. In this tyrosine kinase inhibitor era, it has become more difficult to differentiate these two types of Ph1-positive leukemia development.

Predictability of the progress of secondary osteoarthritis after developmental dislocation of the hip, utilizing inferior edge (of the teardrop)--center (of the femoral head) distance

We followed-up a group of patients in their youth and then in middle age after they had been treated for developmental dislocation of the hip, and studied whether we could predict the progress of osteoarthritis of the hip when the patients were in the "youth" stage. We studied 21 hips of 21 patients with unilateral dislocation that could be examined twice, in 1975 and 1995, in patients who were treated at our hospital between 1953 and 1963. We measured the acetabular-head index (AHI), center-edge angle (CE angle), and the Sharp angle, and our created index (inferior edge of the teardrop - center of the femoral head distance), and we divided this index by the distance of the inferior edges of the teardrops on both sides. Using these measured values, we studied whether we could predict changes in clinical and radiographic evaluation after a follow-up of 20 years. There was no significant correlation of clinical and radiographic results and AHI, CE angle, and the Sharp angle; however, there was a significant correlation with our created index. The index we created is relatively easily measured and enables us to make a more precise prognosis, in comparison with previously developed indices.

Odor discrimination of 'cAMP-' and 'IP3-increasing' odorants at high temperature and at high NaCl concentration in turtle olfactory system

The ability of the turtle olfactory system to discriminate between various cAMP- and IP3-increasing odorants at high temperature and at high NaCl concentration in the olfactory bulb was examined by the cross-adaptation technique. The degrees of discrimination in high [Na+] solution were similar to those in normal Ringer's solution, suggesting that selectivities of receptors coupled with cAMP- and IP3-dependent pathways are similar to those coupled with both cAMP- and IP3-independent pathways. The mean values of the degree of discrimination among the IP3-increasing odorants were higher than those among the cAMP-increasing odorants at high temperature and at high [Na+] concentration. The degrees of discrimination among the IP3-increasing odorants at 40 degrees C were greater than those at 25 degrees C, while those among the cAMP-increasing odorants at 40 degrees C were similar to those at 25 degrees C, suggesting that the features of the receptors of cAMP-increasing odorants are different from those which respond to IP3-increasing odorants.

Ca2+ and Cl(-)-dependence of the turtle olfactory response to odorants and forskolin

In the turtle olfactory system, large responses to odorants appeared after application of cAMP of forskolin at high concentrations to the isolated olfactory receptor neurons or the olfactory epithelium, suggesting that a cAMP-independent pathway greatly contributes to the generation of odor responses. We measured the effects of the mucosal Ca2+ and Cl- concentrations and a Ca(2+)-activated Cl(-)-channel blocker, 4-acetamide-4'-(isothiocyano) stilbene-2,2'-disulphonic acid (SITS), upon olfactory bulbar responses to explore the contribution of the Ca(2+)-activated Cl(-)-channels to cAMP-dependent and independent pathways. Elimination of mucosal Ca2+ by addition of 2 mM EGTA to the stimulating solution partially inhibited the cAMP-independent responses to 0.1 mM citralva but did not affect those to 0.1 mM lilial or 0.1 mM l-carvone. Substitution of mucosal Cl- with gluconate slightly enhanced the total response to 0.1 mM citralva but practically did not affect the responses to other odorants tested. SITS (2 mM) partially inhibited the responses to 50 microM forskolin and 0.1 mM citralva but did not affect the cAMP-independent response to 0.1 mM citralva in Ca(2+)-free Ringer's solution. These results suggested that the Ca(2+)-activated Cl- channels do not contribute to the generation of the cAMP-independent responses, but that they partially contribute to the generation of the cAMP-dependent responses in the turtle.

Odor discrimination of "IP3-" and "cAMP-increasing" odorants in the turtle olfactory bulb

The ability of the turtle olfactory system to discriminate between various odorants that increase levels of adenosine 3',5'-cyclic monophosphate (cAMP) and inositol trisphosphate (IP3) in the olfactory bulb was examined by the cross-adaptation technique and analyzed by multidimensional scaling. The mean values of the degree of discrimination among the IP3-increasing odorants were higher than those among the cAMP-increasing odorants, and were similar to those between cAMP- and IP3-increasing odorants, suggesting that the features of the receptors of cAMP-increasing odorants are different from those which respond to IP3-increasing odorants. Analysis by multidimensional scaling suggested that differences in second messenger pathways are not related to detecting odor quality in the turtle olfactory system.

Analysis of odor discrimination by multidimensional scaling at different temperatures

Discrimination of odorants by the turtle olfactory bulb at 25 degrees and 37 degrees C was examined by the cross-adaptation technique and analysed by multidimensional scaling. Analysis by multidimensional scaling suggests that at 25 degrees C odorants are grouped according to their odor qualities in the turtle olfactory system. At 37 degrees C, the cluster formation of odorants, which have a similar odor quality,such as minty and floral alcohol odorants and molecular structure, in the plot of multidimensional scaling was poor, indicating that the ability of odor grouping according to their odor qualities was low at 37 degrees C.

Reconfirmation of indirect induction of radiogenic lymphomas using thymectomized, irradiated B10 mice grafted with neonatal thymuses from Thy 1 congenic donors

An experiment was conducted to reexamine earlier observations that lymphomas could develop from lymphocytes present in nonirradiated thymuses grafted into thymectomized, fractionally (170 R, 4 doses) irradiated mice by using B10. Thy 1 congenic donor-host combinations. The results indicated that: (a) 37 of 91 thymectomized, fractionally irradiated B10. Thy 1.2 mice which were grafted s.c. with 7-day-old thymuses from B10. Thy 1.1 donor mice had developed frank lymphomas between 90 and 270 days after thymus grafting; (b) 28 of 37 lymphomas developed in this group were typed individually with respect to Thy 1 alloantigens by the cytotoxicity assay using monoclonal anti-Thy 1.1 (T-11-D7) and anti-Thy 1.2 (F7D5) antibodies plus complement. It was shown that 21 thymic lymphomas (75%) had originated from lymphocytes of the nonirradiated thymus grafts and 5 tumors (17.9%) from cells of the irradiated hosts; 2 thymic lymphomas (7.1%) manifested no Thy 1 antigens; (c) lymphoma cells originated from both nonirradiated thymus grafts and irradiated hosts possessed chromosome abnormalities, which were mainly numerical changes of some chromosomes or polyploidizations.