Research Article Plasma Protein Biomarker Candidates for Myelodysplastic Syndrome Subgroups Pavel Majek, 1 Klara Pecankova, 1 Jaroslav Cermak, 2 and Jan E. Dyr 1 1 Department of Biochemistry, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20 Prague 2, Czech Republic 2 Clinical Department, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20 Prague 2, Czech Republic Correspondence should be addressed to Pavel Majek; pavel.majek@uhkt.cz Received 31 August 2014; Revised 19 December 2014; Accepted 13 January 2015 Academic Editor: Konstantinos Arnaoutakis Copyright © 2015 Pavel Majek et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In recent years the plasma proteomes of several diferent myelodysplastic syndrome (MDS) subgroups have been investigated and compared with those of healthy donors. However, the resulting data do not facilitate a direct and statistical comparison of the changes among the diferent MDS subgroups that would be useful for the selection and proposal of diagnostic biomarker candidates. he aim of this work was to identify plasma protein biomarker candidates for diferent MDS subgroups by reanalyzing the proteomic data of four MDS subgroups: refractory cytopenia with multilineage dysplasia (RCMD), refractory anemia or refractory anemia with ringed sideroblasts (RA-RARS), refractory anemia with excess blasts subtype 1 (RAEB-1), and refractory anemia with excess blasts subtype 2 (RAEB-2). Reanalysis of a total of 47 MDS patients revealed biomarker candidates, with alpha-2-HS-glycoprotein and leucine-rich alpha-2-glycoprotein as the most promising candidates. 1. Introduction Myelodysplastic syndrome (MDS) is a group of heteroge- neous oncohematological bone marrow disorders character- ized by peripheral blood cytopenias, inefective hemato- poiesis, bone marrow hypercellularity, and so forth [1]. MDS classiication covers a range from low-risk subgroups with good patient outlook and survival, to high-risk subgroups characterized by a progression of the disease toward acute myeloid leukemia and a poor outcome [2, 3]. he molecular mechanisms that lead to the genesis of MDS and its develop- ment are not yet fully understood. Moreover, our knowledge of the changes occurring in MDS remains limited. Some indings at the DNA (chromosomal aberrations [4], up- or downregulation of genes [5], DNA methylation changes [6], single nucleotide polymorphisms [7], etc.) and RNA levels (altered expression of microRNAs in CD34+ cells [8, 9]) have been observed; however, there is a lack of detailed characterization of the changes at the protein level. Protein changes, whether in protein levels or posttranslational mod- iications, are expected to play a crucial role in the modern diagnostic toolkit. Considerable efort has been expended in the preparation of such tools in recent years (from the studies of plasma protein interactions with antifouling sur- faces [10] to the preparation of low- or even nonfouling surfaces suitable for biochip construction [11, 12]); the topic of clinical applications in oncohematology has been reviewed by Fracchiolla et al. [13]; however, the irst step has to be the identiication of protein biomarker candidates. In our previous studies, we used a proteomic approach to investigate plasma proteome changes in the diferent MDS subgroups, covering the range from low- to high-risk sub- groups: refractory cytopenia with multilineage dysplasia [14], refractory anemia with excess blasts subtype 1 [15], refractory anemia and refractory anemia with ringed sideroblasts [16], and refractory anemia with excess blasts subtype 2 [17]. Several proteins were proposed as potential biomarkers of diferent MDS subgroups in comparison with control groups of healthy donors. Although the control group study designs were kept similar to maintain consistency in the interpreta- tion of the results and to facilitate comparison of the changes among the diferent MDS subgroups, only rough estimation may be obtained on this basis. Moreover, some criteria (statistical signiicance) cannot be estimated by this method Hindawi Publishing Corporation BioMed Research International Volume 2015, Article ID 209745, 9 pages http://dx.doi.org/10.1155/2015/209745