Albumin‐binding of diclofenac and the effect of a site II inhibitor in the aqueous humor of cataract patients with the instillation of diclofenac

Diclofenac instillation has been used widely in cataract surgery to prevent postoperative inflammation. Since diclofenac binds strongly to albumin in the circulation, it does not have a sufficient effect on patients in whom diclofenac binds strongly to albumin in the aqueous humor. A decrease in diclofenac binding and an increase in free diclofenac levels are necessary in these patients. The binding of diclofenac to albumin was investigated in the aqueous humor. In a diclofenac binding assay with albumin in the aqueous humor of individual patients, diclofenac was extracted from aliquots of the aqueous humor, and its total levels were measured using ultra high performance liquid chromatography (UHPLC). Free diclofenac levels were measured using ultrafiltration and UHPLC. The albumin‐binding fraction of diclofenac was 0.8 or higher in the aqueous humor of some patients. Ibuprofen significantly inhibited diclofenac binding to site II of albumin in mimic aqueous humor, but not in pooled aqueous humor. This difference may have been due to the weak binding of diclofenac to site II in the pooled aqueous humor. Flurbiprofen was used instead of diclofenac. Flurbiprofen has been shown to bind more strongly than diclofenac to the same site of albumin. Thus, the inhibitory effect of ibuprofen on the binding of flurbiprofen to albumin was investigated in pooled aqueous humor. The results indicated that ibuprofen significantly inhibited the flurbiprofen binding. An effective diclofenac administration method may be established for clinical application by the instillation of an appropriate inhibitor of binding to the albumin site II. Copyright © 2014 John Wiley & Sons, Ltd.     

Serum autotaxin measurement in haematological malignancies: a promising marker for follicular lymphoma

Autotaxin (ATX) is a tumour cell motility-stimulating factor originally isolated from melanoma cell supernatants. ATX is identical to lysophospholipase D, which produces a bioactive lipid mediator, lysophosphatidic acid (LPA), from lysophosphatidylcholine. ATX is overexpressed in various malignancies, including Hodgkin lymphoma, and ATX may stimulate tumour progression via LPA production. The present study measured the serum ATX antigen levels in patients with haematological malignancies using a recently developed automated enzyme immunoassay. The serum ATX antigen levels in patients with B-cell neoplasms, especially follicular lymphoma (FL), were higher than those in healthy subjects. Serum ATX antigen levels in FL patients were associated with tumour burden and changed in parallel with the patients' clinical courses. The serum ATX antigen levels were little affected by inflammation, unlike the soluble interleukin-2 receptor and beta2-microglobulin levels. As expected, the plasma LPA levels in FL patients were correlated with the serum ATX antigen levels. Given that leukaemic tumour cells from FL patients expressed ATX, the shedding of ATX from lymphoma cells probably leads to the elevation of serum ATX antigen levels. Our results suggest that the serum ATX antigen level may be a promising and novel marker for FL.     

Favorable outcomes of tacrolimus compared with cyclosporine A for GVHD prophylaxis in HSCT for standard-risk hematological diseases

Although calcineurin inhibitors (CNIs) with short-term methotrexate (stMTX) constitute standard prophylaxis for graft-versus-host diseases (GVHD) in hematopoietic stem cell transplantations (HSCT), comparative efficacy of cyclosporine A (CsA) and tacrolimus (Tac) still remains unclear. We have altered GVHD prophylaxis for standard-risk hematological malignancies from CsA (target trough level, 500 ng/mL) to Tac (15 ng/mL) both with stMTX in May 2008, enabling us to compare the efficacy of CNIs with little selection biases. The cumulative incidence of acute and chronic GVHD was comparable for CsA and Tac. Among the GVHD low-risk patients who received stem cells from matched sibling donors or cord blood, the Tac arm had a trend for favorable control of grade III–IV acute GVHD (6.7 vs. 30.0 %, p?=?0.2), which may contribute to the significantly better overall survival (p?=?0.048) and relapse-free survival (p?=?0.043) in that group. Inadequate concentration of CNIs in early phase of HSCT affected the cumulative incidence of acute GVHD in the CsA but not in the Tac arm. There were no differences in the GVHD incidence and survival outcomes between CsA and Tac in the GVHD high-risk subgroup. This study underlies the significance of maintaining adequate CsA concentration in standard-risk HSCT.     

Genetic variants of ApoE and ApoER2 differentially modulate endothelial function

It is poorly understood why there is greater cardiovascular disease risk associated with the apolipoprotein E4 (apoE) allele vs. apoE3, and also greater risk with the LRP8/apolipoprotein E receptor 2 (ApoER2) variant ApoER2-R952Q. Little is known about the function of the apoE–ApoER2 tandem outside of the central nervous system. We now report that in endothelial cells apoE3 binding to ApoER2 stimulates endothelial NO synthase (eNOS) and endothelial cell migration, and it also attenuates monocyte–endothelial cell adhesion. However, apoE4 does not stimulate eNOS or endothelial cell migration or dampen cell adhesion, and alternatively it selectively antagonizes apoE3/ApoER2 actions. The contrasting endothelial actions of apoE4 vs. apoE3 require the N-terminal to C-terminal interaction in apoE4 that distinguishes it structurally from apoE3. Reconstitution experiments further reveal that ApoER2-R952Q is a loss-of-function variant of the receptor in endothelium. Carotid artery reendothelialization is decreased in ApoER2^−/− mice, and whereas adenoviral-driven apoE3 expression in wild-type mice has no effect, apoE4 impairs reendothelialization. Moreover, in a model of neointima formation invoked by carotid artery endothelial denudation, ApoER2^−/− mice display exaggerated neointima development. Thus, the apoE3/ApoER2 tandem promotes endothelial NO production, endothelial repair, and endothelial anti-inflammatory properties, and it prevents neointima formation. In contrast, apoE4 and ApoER2-R952Q display dominant-negative action and loss of function, respectively. Thus, genetic variants of apoE and ApoER2 impact cardiovascular health by differentially modulating endothelial function.Cardiovascular disease risk is modified by common genetic variants of apolipoprotein E (apoE) and its receptor apolipoprotein E receptor 2 (ApoER2), which is a member of the LDL receptor family. Compared with the most common allele apoE3, individuals with the apoE4 allele have an increased risk of atherosclerosis and coronary heart disease (1, 2). The LRP8 gene, which encodes ApoER2, is a major gene locus for premature atherosclerosis and acute myocardial infarction identified in four independent human populations. In particular, homozygous carriers of the ApoER2-R952Q variant have a twofold increased risk of these conditions (3–5). ApoER2-R952Q also has an additive effect with apoE4, with the combined genotype QQ/E4 showing a 3.9-fold greater susceptibility to cardiovascular disease (5). ApoER2 polymorphism-associated risk is independent of cholesterol levels (3–5), and although apoE4 may impact LDL abundance (2), there is also evidence that apoE4-associated risk goes well beyond changes in lipoprotein status (6–9). Whereas there is considerable understanding of the biology of the apoE–ApoER2 tandem in the central nervous system and in Alzheimer’s disease (10), the basis for the cardiovascular impact of the receptor and apoE variants remains unclear.Our prior work demonstrated that ApoER2 is expressed in endothelial cells, where it plays a critical role in the pathogenesis of the antiphospholipid syndrome (APS) (11). The receptor is enriched in caveolae/lipid rafts in which signaling molecules regulating endothelial NOS (eNOS) are compartmentalized (12, 13). We now know that in APS, antiphospholipid antibody recognition of the cell surface protein β2-GPI on endothelial cells promotes β2-GPI dimerization and interaction with the extracellular domain of ApoER2, causing the activation of PP2A and eNOS antagonism. The resulting decrease in bioavailable NO underlies APS-related thrombosis (11). However, the normal function of the receptor in endothelium, and whether and how it modulates apoE actions on endothelium, are unknown.In addition to regulating thrombogenesis, eNOS-derived NO plays a major role in cardiovascular protection via promotion of the integrity of the endothelial cell monolayer and attenuation of endothelial cell–leukocyte adhesion (13). Recognizing that eNOS enzymatic activity is both positively and negatively modulated by signaling molecules in endothelial caveolae/lipid rafts (14), to better understand the biology of ApoER2 in endothelium we hypothesized that apoE3 binding to the receptor activates eNOS. Experiments were performed in cell culture and in mice to test this hypothesis and to determine whether genetic variants in apoE or ApoER2 disrupt this process and thereby adversely impact endothelial function.     

Outcome of allogeneic hematopoietic stem cell transplantation for mycosis fungoides and Sézary syndrome

Although allogeneic hematopoietic stem cell transplantation (HSCT) has been reported to provide prolonged remission of relapsed/refractory mycosis fungoides (MF) and Sézary syndrome (SS), its role has not been fully evaluated. Here, the outcomes of allogeneic HSCT for patients with MF/SS were retrospectively evaluated by using the registry database of the Japan Society for Hematopoietic Cell Transplantation. Forty-eight patients were evaluable and enrolled in the analysis. Median age was 45.5 years. Eighteen patients (38%) received myeloablative conditioning, and 33 (69%) received HSCT from an alternative donor. Disease status was complete or partial response in 25% of the patients and relapsed or refractory in the others. At the time of analysis, 18 patients were alive, with a median follow-up of 31.0 months (range, 3.8-31.1). Three-year overall survival (OS) and progression-free survival (PFS) were 30% (95%CI, 16-45%) and 19% (95%CI, 9-31%), respectively. Disease progression was not observed later than 17 months after transplantation. Both disease status and performance status at transplant significantly affected OS and PFS. Although our findings suggest that allogeneic HSCT provides long-term PFS in patients with MF/SS, the timing of transplantation should be decided carefully based on the disease status and the patient's condition in order to improve the outcome.     

Nilotinib as frontline therapy for patients with newly diagnosed Ph+ chronic myeloid leukemia in chronic phase: results from the Japanese subgroup of ENESTnd

Recent results from the phase 3 ENESTnd (Evaluating Nilotinib Efficacy and Safety in Clinical Trials-Newly Diagnosed Patients) study have demonstrated superiority of nilotinib over imatinib for the treatment of newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia in the chronic phase (CML-CP). Here, we report results from the Japanese subset of patients in ENESTnd, and assess whether results in this subpopulation are consistent with the overall study population. Seventy-nine Japanese patients with CML-CP were randomized to receive nilotinib 300 mg twice daily (BID) (n = 30), nilotinib 400 mg BID (n = 24) or imatinib 400 mg once daily (QD) (n = 25). Major molecular response rates at 12 months, the primary endpoint, were at least twice as high for nilotinib 300 mg BID (57%) and nilotinib 400 mg BID (50%) compared with imatinib 400 mg QD (24%). No patient on nilotinib progressed, while one patient progressed on imatinib. Both drugs were generally well tolerated and discontinuations due to adverse events were comparable among treatment arms. The results in the subpopulation of Japanese patients from ENESTnd closely mirror the results of the overall population, and support the use of nilotinib at 300 mg BID in Japanese patients with newly diagnosed CML-CP.