Bleeding complications in bcr-abl-negative myeloproliferative neoplasms (MPN): A retrospective single-center study of 829 MPN patients.

In patients with bcr-abl-negative myeloproliferative neoplasms (MPN), concerns are often raised about the use of anticoagulants because of an increased bleeding risk. However, there are few MPN studies focusing on bleeding. To investigate bleeding complications in MPN, we report our retrospective, single-center study of 829 patients with a median follow-up of 5.5 years (range: 0.1-35.6). A first bleeding event occurred in 143 of 829 patients (17.2%), corresponding to an incidence rate of 2.29% per patient/year. During the follow-up period, one out of 829 patients (0.1%) died due to bleeding. Regarding anticoagulation, most bleeding occurred in patients on antiplatelet therapies (60.1%), followed by patients on anticoagulation therapies (20.3%) and patients not on anticoagulation (19.6%). In multivariate analysis, administration of antiplatelet (HR 2.31 [1.43, 3.71]) and anticoagulation therapies (HR 4.06 [2.32, 7.09]), but not age, gender or mutation status, was associated with an increased bleeding risk. Comparing the "probability of bleeding-free survival" between the MPN subtypes, no significant difference was observed (p = 0.91, log-rank test). Our retrospective study shows that antiplatelet and anticoagulation therapies significantly increase the risk of bleeding in MPN patients without affecting mortality. However, there is no reason to refrain from guideline-conform primary or secondary anticoagulation in MPN patients.

Direct oral anticoagulants (DOAC) for prevention of recurrent arterial or venous thromboembolic events (ATE/VTE) in myeloproliferative neoplasms.

In patients with BCR-ABL-negative myeloproliferative neoplasms (MPN), arterial or venous thromboembolic events (ATE/VTE) are a major burden. In order to control these complications, vitamin K antagonists (VKA) are widely used. There is no robust evidence supporting the use of direct oral anticoagulants (DOAC) in MPN patients. We therefore compared the efficacy and safety of both anticoagulants in 71 cases from a cohort of 782 MPN patients. Seventy-one of 782 MPN patients (9.1%) had ATE/VTE with nine ATE (12.7%) and 62 VTE (87.3%). Forty-five of 71 ATE/VTE (63.4%) were treated with VKA and 26 (36.6%) with DOAC. The duration of anticoagulation therapy (p = 0.984), the number of patients receiving additional aspirin (p = 1.0), and the proportion of patients receiving cytoreductive therapy (p = 0.807) did not differ significantly between the VKA and DOAC groups. During anticoagulation therapy, significantly more relapses occurred under VKA (n = 16) compared to DOAC treatment (n = 0, p = 0.0003). However, during the entire observation period of median 3.2 years (0.1-20.4), ATE/VTE relapse-free survival (p = 0.2) did not differ significantly between the two anticoagulants. For all bleeding events (p = 0.516) or major bleeding (p = 1.0), no significant differences were observed between VKA and DOAC. In our experience, the use of DOAC was as effective and safe as VKA, possibly even potentially beneficial with a lower number of recurrences and no increased risk for bleedings. However, further and larger studies are required before DOAC can be routinely used in MPN patients.

Ruxolitinib-treated polycythemia vera patients and their risk of secondary malignancies.

Recently, there has been increased concern about a risk of secondary malignancies (SM) occurring in myelofibrosis (MF) patients receiving ruxolitinib (RUX). In polycythemia vera (PV), on the other hand, only limited data on the risk of SM under RUX treatment are available. To investigate the association between RUX therapy in PV and SM, we conducted a retrospective, single-center study that included 289 PV patients. RUX was administered to 32.9% (95/289) of patients for a median treatment duration of 48.0 months (range 1.0-101.6). Within a median follow-up of 97 months (1.0-395.0) after PV diagnosis, 24 SM occurred. Comparing the number of PV patients with RUX-associated SM (n = 10, 41.7%) with the 14 (58.3%) patients who developed SM without RUX, no significant difference (p = 0.34, chi square test) was found. No increased incidences of melanoma, lymphoma, or solid "non-skin" malignancies were observed with RUX (p = 0.31, p = 0.60, and p = 0.63, respectively, chi square test). However, significantly more NMSC occurred in association with RUX treatment (p = 0.03, chi-squared test). The "SM-free survival" was not significantly different by log rank test for all 289 patients (p = 0.65), for the patients (n = 208; 72%) receiving cytoreductive therapy (p = 0.48) or for different therapy sequences (p = 0.074). In multivariate analysis, advanced age at PV diagnosis (HR 1.062 [95% CI 1.028, 1.098]) but not administration of RUX (HR 1.068 [95% CI 0.468, 2.463]) was associated with an increased risk for SM (p = 0.005). According to this retrospective analysis, no increased risk of SM due to RUX treatment could be substantiated for PV.

The management, outcome, and postpartum disease course of 41 pregnancies in 20 women with polycythemia vera.

OBJECTIVES: Pregnancies in women with polycythemia vera (PV) are associated with an increased risk of PV-related maternal complications and often result in miscarriage. Recommendations for the management of PV pregnancies are mainly based on studies with a small number of patients. A correlation between pregnancy outcome and postpartum course has been reported for essential thrombocythemia, but corresponding data for PV are lacking so far. METHODS: In 41 PV pregnancies, the pregnancy outcome, the use of PV-specific therapies (ie, acetylsalicylic acid, low-molecular weight heparin and/or interferon-alpha), and the postpartum PV course were investigated. RESULTS: A live birth rate of 51.2% (21/41 pregnancies) was observed. 43.9% of pregnancies ended in spontaneous abortion and 4.9% in stillbirth. A significantly increased live birth rate occurred in pregnancies with PV-specific therapies compared to standard antenatal care (69.0% vs. 8.3%; P < .0019). The use of PV-specific therapy significantly increased the number of maternal hemorrhages (P = .021) without increasing the risk of fetal complications. During the median postpartum follow-up period of 1.2 years (range 0.1-13.7), complicated postpartum PV occurred significantly more often after miscarriages (P = .035). CONCLUSIONS: According to our analysis, PV-specific therapy improved the live birth rate. Significantly more complicated postpartum PV courses were observed after miscarriages.

High risk of recurrent venous thromboembolism in BCR-ABL-negative myeloproliferative neoplasms after termination of anticoagulation.

Venous thromboembolism (VTE) is a major burden in patients with BCR-ABL-negative myeloproliferative neoplasms (MPN). In addition to cytoreductive treatment anticoagulation is mandatory, but optimal duration of anticoagulation is a matter of debate. In our single center study, we retrospectively included 526 MPN patients. In total, 78 of 526 MPN patients (14.8%) had 99 MPN-associated VTE. Median age at first VTE was 52.5 years (range 23-81). During a study period of 3497 years, a VTE event rate of 1.7% per patient/year was detected. 38.4% (38/99) of all VTEs appeared before or at MPN diagnosis and 55.6% (55/99) occurred at "uncommon" sites like splanchnic or cerebral veins. MPN patients with VTEs were significantly more female (p = 0.028), JAK2 positive (p = 0.018), or had a polycythemia vera (p = 0.009). MPN patients without VTEs were more often CALR positive (p = 0.023). Total study period after first VTE was 336 years with 20 VTE recurrences accounting for a recurrence rate of 6% per patient/year. In 36 of 71 MPN patients with anticoagulation therapy after first VTE event (50.7%), prophylactic anticoagulation was terminated after a median time of 6 months (range 1-61); 13 of those 36 patients (36.1%) had a VTE recurrence after a median of 13 months (range 4-168). In contrast, only three of 35 (8.6%) patients with ongoing anticoagulation had a VTE recurrence (p = 0.0127). Thus, termination of prophylactic anticoagulation was associated with a significantly higher risk of VTE recurrence. Our data suggest that in MPN patients with VTE, a prolonged duration of anticoagulation may be beneficial.

Phospholipid transfer protein is expressed in cerebrovascular endothelial cells and involved in high density lipoprotein biogenesis and remodeling at the blood-brain barrier.

Phospholipid transfer protein (PLTP) is a key protein involved in biogenesis and remodeling of plasma HDL. Several neuroprotective properties have been ascribed to HDL. We reported earlier that liver X receptor (LXR) activation promotes cellular cholesterol efflux and formation of HDL-like particles in an established in vitro model of the blood-brain barrier (BBB) consisting of primary porcine brain capillary endothelial cells (pBCEC). Here, we report PLTP synthesis, regulation, and its key role in HDL metabolism at the BBB. We demonstrate that PLTP is highly expressed and secreted by pBCEC. In a polarized in vitro model mimicking the BBB, pBCEC secreted phospholipid-transfer active PLTP preferentially to the basolateral ("brain parenchymal") compartment. PLTP expression levels and phospholipid transfer activity were enhanced (up to 2.5-fold) by LXR activation using 24(S)-hydroxycholesterol (a cerebral cholesterol metabolite) or TO901317 (a synthetic LXR agonist). TO901317 administration elevated PLTP activity in BCEC from C57/BL6 mice. Preincubation of HDL3 with human plasma-derived active PLTP resulted in the formation of smaller and larger HDL particles and enhanced the capacity of the generated HDL particles to remove cholesterol from pBCEC by up to 3-fold. Pre-ß-HDL, detected by two-dimensional crossed immunoelectrophoresis, was generated from HDL3 in pBCEC-derived supernatants, and their generation was markedly enhanced (1.9-fold) upon LXR activation. Furthermore, RNA interference-mediated PLTP silencing (up to 75%) reduced both apoA-I-dependent (67%) and HDL3-dependent (30%) cholesterol efflux from pBCEC. Based on these findings, we propose that PLTP is actively involved in lipid transfer, cholesterol efflux, HDL genesis, and remodeling at the BBB.

Arterial and Venous Thromboembolic Complications in 832 Patients with BCR-ABL-Negative Myeloproliferative Neoplasms.

Arterial (ATE) and venous (VTE) thromboembolic complications are common causes of morbidity and mortality in BCR-ABL-negative myeloproliferative neoplasms (MPNs). However, there are few studies that include all MPN subtypes and focus on both MPN-associated ATE and VTE. In our single-center retrospective study of 832 MPN patients, a total of 180 first thromboembolic events occurred during a median follow-up of 6.6 years (range: 0-37.6 years), of which 105 were VTE and 75 were ATE. The probability of a vascular event at the end of the follow-up period was 36.2%, and the incidence rate for all first ATE/VTE was 2.43% patient/year. The most frequent VTE localizations were deep vein thrombosis with or without pulmonary embolism (incidence rate: 0.59% patient/year), while strokes were the most frequent ATE with an incidence rate of 0.32% patient/year. When comparing the group of patients with ATE/VTE (n = 180) and the group without such an event (n = 652) using multivariate Cox regression analyses, patients with polycythemia vera (hazard ratio [HR]: 1.660; [95% confidence interval [CI] 1.206, 2.286]) had a significantly higher risk of a thromboembolic event than the other MPN subtypes. In contrast, patients with a CALR mutation had a significantly lower risk of thromboembolism compared with JAK2-mutated MPN patients (HR: 0.346; [95% CI: 0.172, 0.699]). In summary, a high incidence of MPN-associated VTE and ATE was observed in our retrospective study. While PV patients or generally JAK2-mutated MPN patients had a significantly increased risk of such vascular events, this risk was reduced in CALR-mutated MPN patients.

Adipose triglyceride lipase affects triacylglycerol metabolism at brain barriers.

Currently, little is known about the role of intracellular triacylglycerol (TAG) lipases in the brain. Adipose triglyceride lipase (ATGL) is encoded by the PNPLA2 gene and catalyzes the rate-limiting step of lipolysis. In this study, we investigated the effects of ATGL deficiency on brain lipid metabolism in vivo using an established knock-out mouse model (ATGL-ko). A moderate decrease in TAG hydrolase activity detected in ATGL-ko versus wild-type brain tissue was accompanied by a 14-fold increase in TAG levels and an altered composition of TAG-associated fatty acids in ATGL-ko brains. Oil Red O staining revealed a severe accumulation of neutral lipids associated to cerebrovascular cells and in distinct brain regions namely the ependymal cell layer and the choroid plexus along the ventricular system. In situ hybridization histochemistry identified ATGL mRNA expression in ependymal cells, the choroid plexus, pyramidal cells of the hippocampus, and the dentate gyrus. Our findings imply that ATGL is involved in brain fatty acid metabolism, particularly in regions mediating transport and exchange processes: the brain-CSF interface, the blood-CSF barrier, and the blood-brain barrier.

Human endothelial cells of the placental barrier efficiently deliver cholesterol to the fetal circulation via ABCA1 and ABCG1.

Although maternal-fetal cholesterol transfer may serve to compensate for insufficient fetal cholesterol biosynthesis under pathological conditions, it may have detrimental consequences under conditions of maternal hypercholesterolemia leading to preatherosclerotic lesion development in fetal aortas. Maternal cholesterol may enter fetal circulation by traversing syncytiotrophoblast and endothelial layers of the placenta. We hypothesized that endothelial cells (ECs) of the fetoplacental vasculature display a high and tightly regulated capacity for cholesterol release. Using ECs isolated from human term placenta (HPECs), we investigated cholesterol release capacity and examined transporters involved in cholesterol efflux pathways controlled by liver-X-receptors (LXRs). HPECs demonstrated 2.5-fold higher cholesterol release to lipid-free apolipoprotein (apo)A-I than human umbilical vein ECs (HUVECs), whereas both cell types showed similar cholesterol efflux to high-density lipoproteins (HDLs). Interestingly, treatment of HPECs with LXR activators increased cholesterol efflux to both types of acceptors, whereas no such response could be observed for HUVECs. In line with enhanced cholesterol efflux, LXR activation in HPECs increased expression of ATP-binding cassette transporters ABCA1 and ABCG1, while not altering expression of ABCG4 and scavenger receptor class B type I (SR-BI). Inhibition of ABCA1 or silencing of ABCG1 decreased cholesterol efflux to apoA-I (-70%) and HDL(3) (-57%), respectively. Immunohistochemistry localized both transporters predominantly to the apical membranes of placental ECs in situ. Thus, ECs of human term placenta exhibit unique, efficient and LXR-regulated cholesterol efflux mechanisms. We propose a sequential pathway mediated by ABCA1 and ABCG1, respectively, by which HPECs participate in forming mature HDL in the fetal blood.

Interferon alpha for essential thrombocythemia during 34 high-risk pregnancies: outcome and safety.

PURPOSE: Pregnancies in women with essential thrombocythemia (ET) are at a higher risk for obstetrical complications. Acetylsalicylic acid (ASA) and low-molecular weight heparin (LMWH) are common options to prevent miscarriages and maternal complications, whereas interferon alpha (IFN) seems to be the cytoreductive therapy of choice. This retrospective study analyzes the largest number of IFN pregnancies to date in terms of outcome and safety. METHODS: Data of 34 high-risk pregnancies in 23 women presenting at the University hospitals of Minden and Jena from 01-Jun-2007 to 01-Jun-2020 were collected. Reasons defining high-risk ET pregnancy in all 23 patients were: Thrombosis (n = 9) or severe hemorrhage (n = 2) in history, platelet count ≥ 1500 × 103/µl (n = 8) or severe microcirculatory disturbances not completely responding to ASA (n = 4). RESULTS: Without the use of IFN, live birth rate was 60% (6/10), however, after the use of IFN live birth rate increased to 73.5% (25/34 pregnancies). Nine pregnancies ended in miscarriages (9/34; 26.5%); all of them spontaneous abortions. Live birth rate significantly improved with ASA (90% versus 50%, p = 0.0168), however, if ASA and LMWH was added (n = 14), live birth rate was 100%. IFN compound (PEGylated versus standard IFN) and JAK2-driver mutation had no impact on pregnancy outcome. One major maternal complication occurred as a major peripartal bleeding after abortion curettage. CONCLUSION: IFN was associated with an encouraging live birth rate of 73.5% with no fatal maternal events and manageable side effects.

Clock gene expression in different synovial cells of patients with rheumatoid arthritis and osteoarthritis.

Patients with rheumatoid arthritis (RA) show modulated circadian rhythms of inflammatory cytokines and cortisol, which may be associated with a modified expression of clock genes. The expression of major clock genes was previously studied in synovial tissues and fibroblasts of patients with RA and osteoarthritis (OA). We therefore especially aimed to examine the localization of clock genes at the cellular level in synovial tissue. Furthermore we were interested in studying the expression of the D site of albumin promoter (albumin D-box) binding protein (DBP) at the immunohistochemical level in human samples. Methods used include the in situ expression of the clock genes Brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (Bmal 1), Circadian Locomotor Output Cycles Kaput (Clock), Period 1 and 2 (Per 1 and Per 2), and DBP was examined by immunohistochemistry in synovial tissues of patients with RA or OA. Additionally, expression profiles of different clock genes were determined over 24h by real time PCR in synovial fibroblasts (SFs) after a 2h serum shock or TNF-α. Results show that all clock genes investigated were found to be expressed both in RA and OA synovial tissues. Double staining against cell specific markers revealed that clock proteins were especially seen in macrophages, SFs and B-lymphocytes. Cell counting showed that clock proteins were found in approximately 5-20% of cells. Additionally, preliminary cell culture experiments showed that TNF-α treatment resulted in differential 24h expression profiles between RA and OA samples and also compared to the results obtained from the serum shock experiments. From our study we conclude that the major clock genes, including DBP, are expressed in samples from RA and OA patients, especially in macrophages and synovial fibroblasts, but also in B-lymphocytes. Preliminary experiments suggest that TNF-α seems to be able to modify clock gene expression in synovial fibroblasts.

Anti-inflammatory and apoptotic effects of the polyphenol curcumin on human fibroblast-like synoviocytes.

BACKGROUND: It has recently been reported that the polyphenol curcumin has pronounced anti-carcinogenic, anti-inflammatory and pro-apoptotic properties. This study investigated possible anti-inflammatory and apoptotic effects of curcumin on the human synovial fibroblast cell line MH7A, and on fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis (RA). METHODS: MH7A cells and RA-FLS were stimulated either with interleukin (IL)-1ß or phorbol 12-myristate 13 acetate (PMA), and treated simultaneously or sequentially with increasing concentrations of curcumin. Release of interleukin (IL)-6 and vascular endothelial growth factor (VEGF)-A was quantified by enzyme-linked immunosorbent assays (ELISAs). In MH7A cells, modulation of the transcription factor nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinases (MAPKs) such as p38 and extracellular-signal regulated kinase (ERK1/2) were analysed by a reporter gene assay and Western blot, respectively. Pro-apoptotic events were monitored by Annexin-V/7-AAD based assay. Cleavage of pro-caspase-3 and -7 was checked with specific antibodies. RESULTS: Curcumin effectively blocked IL-1ß and PMA-induced IL-6 expression both in MH7A cells and RA-FLS. VEGF-A expression could only be detected in RA-FLS and was induced by PMA, but not by IL-1ß. Furthermore, curcumin inhibited activation of NF-κB and induced dephosphorylation of ERK1/2. Treatment of FLS with high concentrations of curcumin was associated with a decrease in cell viability and induction of apoptosis. CONCLUSION: The natural compound curcumin represents strong anti-inflammatory properties and induces apoptosis in FLS. This study provides an insight into possible molecular mechanisms of this substance and suggests it as a natural remedy for the treatment of chronic inflammatory diseases like RA.

Synthetic LXR agonist attenuates plaque formation in apoE-/- mice without inducing liver steatosis and hypertriglyceridemia.

Liver X receptors (LXRs) are important regulators of cholesterol and lipid metabolism. LXR agonists have been shown to limit the cellular cholesterol content by inducing reverse cholesterol transport, increasing bile acid production, and inhibiting intestinal cholesterol absorption. Most of them, however, also increase lipogenesis via sterol regulatory element-binding protein-1c (SREBP1c) and carbohydrate response element-binding protein activation resulting in hypertriglyceridemia and liver steatosis. We report on the antiatherogenic properties of the steroidal liver X receptor agonist N,N-dimethyl-3beta-hydroxy-cholenamide (DMHCA) in apolipoprotein E (apoE)-deficient mice. Long-term administration of DMHCA (11 weeks) significantly reduced lesion formation in male and female apoE-null mice. Notably, DMHCA neither increased hepatic triglyceride (TG) levels in male nor female apoE-deficient mice. ATP binding cassette transporter A1 and G1 and cholesterol 7alpha-hydroxylase mRNA abundances were increased, whereas SREBP1c mRNA expression was unchanged in liver, and even decreased in macrophages and intestine. Short-term treatment revealed even higher changes on mRNA regulation. Our data provide evidence that DMHCA is a strong candidate as therapeutic agent for the treatment or prevention of atherosclerosis, circumventing the negative side effects of other LXR agonists.

LXR-agonists regulate ApoM expression differentially in liver and intestine.

Apolipoprotein M (apoM) has been suggested to play a role in reverse cholesterol transport. Here we studied the influence of liver X-receptor (LXR) agonist on the transcriptional regulation of apoM. Studies were performed in murine liver and intestinal mucosal cells in vivo and in human intestinal Caco-2 cells in vitro. The expression of apoM was analyzed by quantitative real time PCR, and compared to well-established LXR target genes. Mice fed with TO901317 for six days showed a downregulation of apoM and apoAI in the liver to 40 % and 60 % respectively and an upregulation of Cyp7A1 to 280 %. In the small intestine, however, apoM and apoAI were upregulated by 30-60 % and ABCA1 by 250-430 %. In Caco-2 cells TO901317 caused a 60 % upregulation and the natural LXR agonist 22-hydroxycholesterol a 40 % upregulation of apoM. Possible causes for the differential effects in liver and intestine are discussed.