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Amsterdam-Zuidoost, Netherlands

Zeerleder S.,Sanquin Research at CLB | Zeerleder S.,University of Amsterdam
Netherlands Journal of Medicine | Year: 2011

Autoimmune haemolytic anaemia (AIHA) is a rare disease. in clinical practice, diagnosis and treatment of ai Ha turns out to be troublesome. Correct diagnosis is dependent on proper comprehension of the pathophysiology and the laboratory tests performed by the transfusion laboratory. the present review provides a short overview on the pathogenesis of autoimmune haemolytic anaemia. the diagnostic pitfalls will be discussed and a diagnostic algorithm for proper diagnosis of AIHA will be given. Moreover, a brief overview on the treatment of different forms of AIHA is given. © Van Zuiden Communications B.V. All rights reserved. Source


Krijnen P.A.J.,Medical Center | Sipkens J.A.,Medical Center | Molling J.W.,Medical Center | Rauwerda J.A.,Medical Center | And 8 more authors.
Journal of Molecular and Cellular Cardiology | Year: 2010

Subsequent to myocardial infarction, cardiomyocytes within the infarcted areas and border zones expose phosphatidylserine (PS) in the outer plasma membrane leaflet (flip-flop). We showed earlier that in addition to apoptosis, this flip-flop can be reversible in cardiomyocytes. We now investigated a possible role for Rho and downstream effector Rho-associated kinase (ROCK) in the process of (reversible) PS exposure and apoptosis in cardiomyocytes. In rat cardiomyoblasts (H9c2 cells) and isolated adult ventricular rat cardiomyocytes Clostridium difficile Toxin B (TcdB), a Rho GTPase family inhibitor, C3 transferase (C3), a Rho(A,B,C) inhibitor and the ROCK inhibitors Y27632 and H1152 were used to inhibit Rho-ROCK signaling. PS exposure was assessed via flow cytometry and fluorescent digital imaging microscopy using annexin V. Akt expression and phosphorylation were analyzed via Western blot, and Akt activity was inhibited by wortmannin. The cellular concentration activated caspase 3 was determined as a measure of apoptosis, and flippase activity was assessed via flow cytometry using NBD-labeled PS. TcdB, C3, Y27632 and H1152 all significantly increased PS exposure. TcdB, Y27632 and H1152 all significantly inhibited phosphorylation of the anti-apoptotic protein Akt and Akt inhibition by wortmannin lead to increased PS exposure. However, only TcdB and C3, but not ROCK- or Akt inhibition led to caspase 3 activation and thus apoptosis. Notably, pancaspase inhibitor zVAD only partially inhibited TcdB-induced PS exposure indicating the existence of apoptotic and non-apoptotic PS exposure. The induced PS exposure coincided with decreased flippase activity as measured with NBD-labeled PS flip-flop. In this study, we show a regulatory role for a novel signaling route, Rho-ROCK-flippase signaling, in maintaining asymmetrical membrane phospholipid distribution in cardiomyocytes. © 2010 Elsevier Ltd. Source


Daniels G.,Bristol Institute for Transfusion science | van der Schoot C.E.,Sanquin Research at CLB | Olsson M.L.,Lund University
Vox Sanguinis | Year: 2011

The fourth International Society of Blood Transfusion (ISBT) workshop on molecular blood group genotyping was held in 2010, with a feedback meeting at the ISBT Congress in Berlin, Germany. Fifty laboratories participated, 17 more than in 2008. Six samples were distributed. Samples 1-3 were DNA samples for all red cell blood group tests available to the participants. Of the 46 laboratories that tested these samples, 37 obtained completely correct results, although the extent of testing varied considerably. Sample 4, also a DNA sample, was an Rh problem in which RHDΨ and RHCE*ceCF were present, but the participants were only informed that the donor's red cells typed as positive with some monoclonal anti-D. Of the 42 laboratories that participated in this exercise, seven performed the sequencing necessary to obtain the correct result. Samples 5 and 6 were plasma samples from RhD-negative pregnant women, for foetal RhD testing. These were sent to 25 laboratories, and two incorrect results were reported. Overall, the level of accuracy was about equal to that of the previous workshop. The main conclusion for the last two workshops can be reiterated: with greater care and attention to detail, very high standards could be set for molecular blood group genotyping. © 2011 The Author(s). Vox Sanguinis © 2011 International Society of Blood Transfusion. Source


Collette S.,EORTC Headquarters | Suciu S.,EORTC Headquarters | De Groot E.R.,Sanquin Research at CLB | Kruit W.H.,Erasmus Medical Center | And 3 more authors.
Melanoma Research | Year: 2011

Adjuvant therapy with interferon-α (IFN) only benefits a small subgroup of melanoma patients and a predictive marker selecting responders does not exist. IFN induces increased ferritin and decreased C-reactive protein (CRP) levels; however, an association with treatment effect was not studied. Serum was collected from patients participating in the European Organization for Research and Treatment of Cancer 18 952 trial comparing adjuvant treatment with IFN to observation. Serial ferritin and CRP levels were determined using enzyme-linked immusorbent assays, before treatment and up to 24 months. Ferritin levels are influenced by sex and age; therefore ratios of serial ferritin and CRP values with corresponding pretreatment values were calculated. Cox regression model and landmark method at end of induction and 6 months were used to evaluate the association between ferritin, CRP and distant metastasis-free survival (DMFS). Baseline ferritin levels were comparable in the two treatment groups (P=0.92). However, ferritin ratios were significantly higher in IFN-treated patients (N=96) compared with untreated patients (N=21) at end of induction (mean: 2.88 vs. 0.75; P=0.0003) and at 6 months (mean: 3.18 vs. 1.02; P=0.009). In the IFN arm, higher ferritin ratios at end of induction and at 6 months were not associated with improved outcome (respectively, P=0.66 and 0.86). Concerning CRP ratios, no differences between the treatment groups, neither an association with DMFS, were observed. Administration of IFN in melanoma patients induced increase in ferritin levels but not in CRP levels. Ferritin and CRP ratios have no prognostic value regarding DMFS. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins. Source


Ter Weeme M.,OLVG | Vonk A.B.A.,Medical Center | Kupreishvili K.,Medical Center | Kupreishvili K.,Institute for Cardiovascular Research ICaR VU | And 13 more authors.
European Journal of Clinical Investigation | Year: 2010

Background Recent studies indicate a role for complement in the pathogenesis of aortic valve disease. However, the role of naturally occurring anti-complement mediators in this context is unknown. In this study, we have analysed this in three different pathological conditions of the aortic valve: degeneration, atherosclerosis and bacterial endocarditis. Materials and methods Human aortic valves were obtained at autopsy (n = 30): 5 control valves, 10 aortic valves with atherosclerotic changes, 10 aortic valves with degenerative changes and 5 degenerative changed aortic valves with bacterial infection. These valves were analysed immunohistochemically for the presence of activated complement (C3d and C5b9) and the complement inhibitors C1-inh and clusterin. Areas of positivity were then quantified. Results C3d, C5b9 and the complement inhibitors C1-inh and clusterin depositions were mainly found in the endothelium and extracellular matrix in aortic valves. All these mediators were already present in control valves, but the area of positivity increased significantly in response to the different diseases, with the highest increase in response to bacterial endocarditis. Interestingly, in all three aortic diseases, the depositions of complement were significantly more widespread than that of their inhibitors. Conclusions Our study indicates that anti-complement mediators (C1-inh and clusterin) are deposited in diseased aortic valves together with activated complement, indicating an existing counter response against complement locally in the valve. However, deposition of activated complement is significantly more widespread than that of its inhibitors, which could explain ongoing inflammation in those diseased aortic valves. © 2009 Stichting European Society for Clinical Investigation Journal Foundation. Source

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