Development of a Sensitive and High-Throughput Assay for Simultaneous Quantification of 5 Tyrosine Kinase Inhibitors and 2 Active Metabolites in Human Plasma Using Ultra-high Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry.

BACKGROUND: Breakpoint cluster region-Abelson (BCR-ABL) tyrosine kinase inhibitors (TKIs) demonstrate improved therapeutic efficacy in chronic myeloid leukemia (CML). However, drug-drug interactions, nonadherence, and host-related factors may influence plasma concentrations. Therefore, therapeutic drug monitoring may be necessary for patients presenting inadequate treatment responses or adverse events. Herein, the authors aimed to develop a more sensitive and high-throughput method than those previously reported to simultaneously quantify 5 TKIs (imatinib, nilotinib, dasatinib, bosutinib, and ponatinib) and 2 active metabolites (N-desmethyl imatinib and N-desmethyl ponatinib) using ultra-performance liquid chromatography coupled with tandem mass spectrometry. METHODS: Plasma samples were prepared according to a solid-phase extraction protocol using an Oasis MCX µElution plate. The assay fulfilled the requirements of the US Food and Drug Administration for assay validation, with a lower limit of quantification of 0.2 ng/mL for dasatinib, 0.3 ng/mL for N-desmethyl ponatinib, 0.5 ng/mL for N-desmethyl imatinib, bosutinib, and ponatinib, and 2.5 ng/mL for imatinib and nilotinib. RESULTS: Within-batch and batch-to-batch precision at the lower limit of quantification and quality control levels were within 14.3% and 10.9%, respectively. Within-batch and batch-to-batch accuracies ranged from 15.5% to 13.0% and 5.70% to 7.03%, respectively. A positive electrospray ionization mode was used with a run time of 6.0 minutes. The assay applicability was verified by the successful measurement of 78 clinical samples from patients undergoing CML therapy. CONCLUSIONS: The method allows assessment of trough concentrations of TKIs and active metabolites in patients with CML, and hence can be used to assess blood samples in routine clinical settings.

High-throughput simultaneousquantification offive azole anti-fungal agents and one active metabolite in human plasma using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry.

OBJECTIVES: For patients with hematological malignancy, triazole antifungal agents such as fluconazole (FLCZ), itraconazole (ITCZ), voriconazole (VRCZ), posaconazole (PSCZ) and isavuconazole (ISCZ) are often used for prophylaxis of deep mycosis. Since these azoles exhibit large pharmacokinetic variability, dose adjustment by therapeutic drug monitoring is recommended for some azoles. This study aimed to develop and validate a novel method for simultaneous determination of plasma concentrations of FLCZ, ITCZ, VRCZ, PSCZ, ISCZ and ITCZ-OH, an active metabolite of ITCZ, using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). DESIGN & METHODS: A high-throughput solid-phase extraction method using 96-well MCX µElution Plate was selected as the pretreatment procedure. RESULTS: The calibration curves for FLCZ, ITCZ, ITCZ-OH, VRCZ, PSCZ and ISCZ showed good linearity (back-calculation of calibrators: relative error ≤ 15% [LLOQ: ≤ 20%]) over wide ranges of 100-100000, 20-20000, 40-40000, 20-20000, 5-5000 and 50-50000 ng/mL, respectively. The validation results of all six drugs fulfilled the criteria of the guidance for bioanalytical method validation of the US Food and Drug Administration for within-batch and batch-to-batch precision and accuracy. The extraction recovery rates were good at ≥ 74.9%, and almost no matrix effects were found for all the drugs. The trough (10 h post-dose in 1 patient on PSCZ) drug concentrations in patients with hematologic malignancy who received oral FLCZ, ITCZ, VRCZ or PSCZ were quantified using the method developed. The measurements for all samples were within the ranges of the calibration curves, demonstrating the feasibility of clinical application of the novel method. CONCLUSIONS: We have succeeded in developing a novel high-throughput method using UHPLC-MS/MS for simultaneous quantification of plasma concentrations of FLCZ, ITCZ, ITCZ-OH, VRCZ, PSCZ and ISCZ.

[Successful treatment with cidofovir for disseminated adenovirus infection accompanied by hemophagocytic syndrome and meningitis in an allogeneic hematopoietic stem cell transplantation recipient].

A 65-year-old woman received bone marrow transplantation from an HLA-DRB1 one locus mismatched donor for high-risk myelodysplastic syndrome. On day 237 after transplantation, she developed recurrent acute gastrointestinal graft-versus-host disease and adenoviral hemorrhagic cystitis. Hence, the methylprednisolone (mPSL) dose was increased to 2 mg/kg, and mesenchymal stem cells were administered. After the dose was tapered, she developed high fever, gross hematuria, and progressive pancytopenia. Then, the serum LDH, ferritin, and hepatobiliary enzyme levels of the patient increased, and hemophagocytosis was observed based on bone marrow examination. The adenovirus DNA level in the plasma was 6.3×106 copies/ml on day 278, and the volume of cerebrospinal fluid increased. Hence, the patient was diagnosed with meningitis and disseminated adenovirus infection. On day 288, cidofovir was administered at a dose of 1 mg/kg three times a week for 8 doses. The mPSL dose was again increased to 2 mg/kg for the treatment of hemophagocytic syndrome. Then, the patient's symptoms gradually improved, and the adenovirus viral load became negative on day 369. Based on the clinical course of our patient, cidofovir is useful for severe adenovirus infection.

Relationships between dissolved black carbon and dissolved organic matter in streams.

Black carbon (BC) is a pyrolyzed product derived from incomplete combustion. A major fraction of BC produced by landscape fires is initially deposited onto onsite soils. Atmospheric deposition of soot is known to be an important source of soil BC, especially in watersheds that are not affected by landscape fires. The transport of the dissolved fraction of oxidized BC in soil, defined as dissolved black carbon (DBC), to streams is considered one of the important loss pathways of BC in soil, but the mechanism is not well documented. We measured the quantity and quality of DBC, determined by a benzenepolycarboxylic acid method, and the quantitative and qualitative parameters of bulk dissolved organic matter (DOM) in streams in Hokkaido, northern Japan, whose catchments were not affected by landscape fire for at least 110 years. DBC with relatively low polycondensed signatures occurred in the streams, irrespective of differences in watershed characteristics and seasons, suggesting that atmospheric deposition of soot into the catchment is probably a major source of stream DBC. The DBC concentration was linearly related to the dissolved organic carbon (DOC) concentration, irrespective of the differences in watershed characteristics and seasons. Furthermore, the polycondensation degree of DBC was observed to correlate with the qualitative parameters of bulk DOM. Such quantitative and qualitative relationships between DBC and bulk DOM imply that the transfer mechanism from soils to streams of soot-derived polycondensed DBC is linked with that of higher plant-derived, high-molecular-weight aromatic DOM.

Kinetics and clinical significance of human herpesvirus 6 DNA shedding in saliva after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Little is known about the kinetics and clinical significance of saliva human herpesvirus-6 (HHV-6) DNA after hematopoietic stem cell transplantation (HSCT). METHODS: In this observational study, we quantified HHV-6 DNA in serially collected plasma and saliva from allogeneic HSCT recipients. Associations between the status of salivary HHV-6 DNA and the development of HHV-6 encephalitis, depression, and oral mucosal graft-versus-host disease (GVHD) were retrospectively analyzed. RESULTS: A total of 787 plasma and 434 saliva samples were collected from 56 patients. The cumulative incidence of HHV-6 DNA in plasma and saliva at 60 days after transplantation was 51.8% and 83.9%, respectively. The peak level of salivary HHV-6 DNA was significantly higher in patients who displayed plasma HHV-6 DNA than in those who did not (median, 51,584 copies/mL vs 587 copies/mL; P < .0001). Salivary HHV-6 DNA levels increased after positive plasma HHV-6 DNA was detected and remained high during observation period. Despite the frequent occurrence of positive salivary HHV-6 DNA, no patient developed depression. Positivity of salivary HHV-6 DNA was not significantly associated with the development of HHV-6 encephalitis (P = 1.00, Fisher's exact test) or oral mucosal GVHD (P = .71, Grey's test). No significant relationship between salivary HHV-6 DNA and these diseases was found even when comparing higher HHV-6 DNA loads in saliva. CONCLUSION: Salivary HHV-6 DNA levels increased after HHV-6 DNA was detected in the blood. However, no epidemiological evidence was shown to support a role of salivary HHV-6 in the development of HHV-6 encephalitis, depression, and oral mucosal GVHD.

[Successful delivery after chemotherapy for acute myeloid leukemia diagnosed in the second trimester].

Development of acute myeloid leukemia (AML) during pregnancy is rare, and the available data are limited to small retrospective reports. Currently, no guidelines exist for the management of AML during pregnancy in Japan. A 26-year-old female was diagnosed with AML at 19 weeks of gestation, received chemotherapy with daunorubicin and cytarabine, and achieved complete remission. Following the first consolidation therapy, she gave birth to a 1964-g female infant by cesarean section at 33 weeks of gestation. One week later, she was initiated on the second consolidation therapy; however, she developed a pelvic abscess during neutropenia. She underwent urgent surgery for open drainage and recovered soon after surgery. She has been in complete remission for eight months, and the daughter is healthy. Chemotherapy delivered after the second trimester rarely causes congenital malformations and may not require the termination of pregnancy. The clinical course of the present case suggests that chemotherapy can be performed safely and effectively in pregnant patients with AML after the trimester and babies.

[Philadelphia chromosome-positive acute lymphoblastic leukemia relapsing with an anterior chamber lesion of the eye].

A 48-year-old Filipino woman underwent umbilical cord blood stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia under non-remission status. Left aqueous humor puncture was performed owing to the development of left eye pain and exacerbation of anterior eye chamber inflammation 72 days after the transplantation; this revealed the relapse of leukemia in the anterior chamber. Subsequently, the patient tested positive for peripheral blood minimal residual disease. Therefore, doctors should take note that anterior chamber disease may appear as a non-typical relapse of leukemia.

[Successful treatment of secondary graft failure in a mixed-phenotype acute leukemia patient with haploidentical hematopoietic stem cell transplantation and post-transplant cyclophosphamide administration].

A 38-year-old woman in the first remission of mixed-phenotype acute leukemia underwent unrelated bone marrow transplantation from an HLA-DR-mismatched donor in the host-versus-graft (HVG) direction with myeloablative conditioning. Neutrophil engraftment was achieved and complete donor chimera was obtained on days 21 and 29 after transplantation, respectively. Subsequently, with delayed blood cell recovery, continuous transfusion was needed to replace platelets. In the CD3 peripheral blood chimerism test, the percentage of recipient cells on days 50, 63, and 80 was 27.3%, 90%, and 95% or higher, respectively. With no relapse of leukemia observed on bone marrow examination, secondary graft failure associated with autologous hematopoietic recovery was diagnosed. Bone marrow transplantation from the patient's HLA-haploidentical sister was performed because of graft failure on day 111 after the initial transplant using post-transplant cyclophosphamide (PTCy). Neutrophil engraftment was achieved and complete donor chimera was obtained on days 14 and 21 after the second transplantation, respectively. With no serious complications or acute graft versus host disease, the patient was discharged with symptomatic improvement. According to our results, retransplant using PTCy obtained from an HLA-haploidentical sibling donor is a potential treatment for graft failure.

Other Iatrogenic Immunodeficiency-associated Lymphoproliferative Disorder, Hodgkin Type, following Epstein-Barr Viral Hepatitis in a Patient with Rheumatoid Arthritis.

A 59-year-old man with an 18-year history of rheumatoid arthritis who had been treated with steroids, methotrexate, and infliximab presented with a high-grade fever, cervical lymphadenopathy, and hepatosplenomegaly. Epstein-Barr virus (EBV) hepatitis was diagnosed based on the liver histology and EBV antibody titer. The symptoms improved temporarily, but five months later, the fever, skin rash, jaundice, and thrombocytopenia relapsed. Bone marrow and liver biopsies demonstrated infiltration with Reed-Sternberg cells. Based on these findings, the patient was diagnosed with other iatrogenic immunodeficiency-associated lymphoproliferative disorder (OIIA-LPD), Hodgkin lymphoma type. This case followed a rare clinical course, in that acute hepatitis preceded the diagnosis of OIIA-LPD.

Successful Cord Blood Stem Cell Transplantation for an Adult Case of Chronic Active Epstein-Barr Virus Infection.

A 41-year-old man was referred to our hospital for treatment of anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma. Chronic active Epstein-Barr virus (CAEBV) was diagnosed based on the findings of elevated EBV antibody titers and positive EBV-DNA in the peripheral blood, and cord blood stem cell transplantation (CBT) was performed. The EBV-DNA levels in the blood fell below the limit of detection. His lymphoma relapsed on Day 165 with the appearance of eruptions, which disappeared after the withdrawal of tacrolimus. One year after transplantation, there were no signs of recurrence. This encouraging result suggests that CBT should be considered for adult cases of CAEBV with aggressive clinical manifestations.

Identification and characterization of natural microbial products that alter the free d-aspartate content of mammalian cells.

Mammalian cells possess the molecular apparatus necessary to take up, degrade, synthesize, and release free d-aspartate, which plays an important role in physiological functions within the body. Here, biologically active microbial compounds and pre-existing drugs were screened for their ability to alter the intracellular d-aspartate level in mammalian cells, and several candidate compounds were identified. Detailed analytical studies suggested that two of these compounds, mithramycin A and geldanamycin, suppress the biosynthesis of d-aspartate in cells. Further studies suggested that these compounds act at distinct sites within the cell. These compounds may advance our current understanding of biosynthesis of d-aspartate in mammals, a whole picture of which remains to be disclosed.

Splicing of human chloride channel 1.

Expression of chloride channel 1 (CLCN1/ClC-1) in skeletal muscle is driven by alternative splicing, a process regulated in part by RNA-binding protein families MBNL and CELF. Aberrant splicing of CLCN1 produces many mRNAs, which were translated into inactive proteins, resulting in myotonia in myotonic dystrophy (DM), a genetic disorder caused by the expansion of a CTG or CCTG repeat. This increase in abnormal splicing variants containing exons 6B, 7A or the insertion of a TAG stop codon just before exon 7 leads to a decrease in expression of the normal splice pattern. The majority of studies examining splicing in CLCN1 have been performed using mouse Clcn1, as have investigations into the activation and suppression of normal splicing variant expression by MBNL1-3 and CELF3-6, respectively. In contrast, examinations of human CLCN1 have been less common due to the greater complexity of splicing patterns. Here, we constructed a minigene containing CLCN1 exons 5-7 and established a novel assay system to quantify the expression of the normal splicing variant of CLCN1 using real-time RT-PCR. Antisense oligonucleotides could promote normal CLCN1 alternative splicing but the effective sequence was different from that of Clcn1. This result differs from previous reports using Clcn1, highlighting the effect of differences in splicing patterns between mice and humans.

[Hypofibrinogenemia associated with steroid therapy for the patients who developed GVHD after allogeneic stem cell transplantation].

Hypofibrinogenemia (plasma fibrinogen level <150 mg/dl) is occasionally observed after allogeneic hematopoietic stem cell transplantation, and its etiology is often difficult to determine. We herein report that steroids administered for the treatment of graft-versus-host disease (GVHD) are associated with the development of hypofibrinogenemia. We retrospectively analyzed the plasma fibrinogen (Fg) levels in 15 consecutive patients who had been administered 1 mg/kg/day (1 mg/kg group) or 2 mg/kg/day (2 mg/kg group) methylprednisolone for the treatment of Grade II to IV acute GVHD. Hypofibrinogenemia had developed in 8 of the 15 patients (53%) by day 50 after the start of steroid treatment, and was observed in 2 of 6 patients in the 1 mg/kg group and 6 of 9 in the 2 mg/kg group. A significant decrease in the Fg level was observed in the 2 mg/kg group (the median value before starting steroid treatment and that on the 20th day after starting steroid treatment were 506 mg/dl and 180 mg/dl, respectively, P=0.0013). Other possible causes of hypofibrinogenemia, including liver dysfunction or disseminated intravascular coagulation, were confirmed in only 3 patients during the observation period. In conclusion, hypofibrinogenemia commonly occurs in patients treated with steroids, especially those administered 2 mg/kg/day methylprednisolone for the treatment of GVHD.

Decreased elimination clearance of midazolam by doxorubicin through reductions in the metabolic activity of hepatic CYP3A in rats.

1. We examined the effects of doxorubicin (DOX) on the expression level and metabolic activity of CYP3A in the liver as well as on the pharmacokinetics of midazolam (MDZ), a probe for CYP3A, in rats. Changes in the hepatic status of DOX-treated rats were confirmed. 2. Serum levels of the biomarkers of hepatic impairment were elevated by the DOX treatment, which was consistent with the results obtained from a histopathological evaluation of the liver. 3. No significant difference was observed in the expression of proteins for hepatic CYP3A1 and CYP3A2 between the DOX and control groups. The metabolic production of 1'-hydroxylated and 4'-hydroxylated MDZ by hepatic microsomes was significantly lower in DOX-treated rats than in control rats. 4. The area under the curve (AUC) and the half-life (t1/2) of intravenously administered MDZ were significantly increased, and the total clearance (CLtot) and the elimination rate constant at the terminal phase (ke) were significantly decreased without significant changes in the volume of distribution at a steady state (Vdss). 5. These results indicated that a DOX-induced depression in the metabolic activity, but not expression level of CYP3A contributed to a decrease in the elimination clearance of MDZ, and also that reduced CYP3A function may be associated with the hepatotoxicity of DOX.