CONCISE COMMUNICATION A novel approach in psoriasis: first usage of known protein oxidation markers to prove oxidative stress Cevat Yazici 1 • Kader Ko ¨se 1 • Serap Utas ¸ 2 • Esen Tanrikulu 1 • Nazan Tas ¸lidere 2 Received: 19 November 2014 / Revised: 19 November 2015 / Accepted: 12 January 2016 Ó Springer-Verlag Berlin Heidelberg 2016 Abstract Oxidative stress may play a pivotal role in the pathogenesis of psoriasis, an inflammatory/hyperprolifera- tive skin disease characterized by the cutaneous accumu- lation of neutrophils releasing reactive oxygen species, as revealed in a number of studies. This study was performed to demonstrate the presence of oxidative stress in psoriasis, as measured by protein oxidation markers. Twenty-nine psoriasis patients were selected based on disease severity assessment using body surface area as well as the psoriasis area severity index (PASI), and were grouped as mild (PASI B 10) and moderate-to-severe (PASI [ 10). The measured parameters in psoriatic patients and fourteen healthy volunteers were as follows: erythrocyte sedimen- tation rate (ESR), high sensitive C-reactive protein (CRP), myeloperoxidase (MPO) activity, neopterin, total lipid hydroperoxides (LHP), pyrrolized protein (PP), protein carbonyl compounds (PCC), advanced oxidation protein products (AOPP), thiol levels, along with complete blood count. Except lower thiols, all parameters were found to be higher in total patients as well as in subgroups, compared to controls. There was no significant difference among the subgroups. In conclusion, protein oxidation in psoriatics, not only in moderate-to-severe, but also in mild patients, may be explained by the findings of inflammation, phagocytic cell oxidation, and MPO-hypochlorous acid- oxidation reactions; as reflected by increased total/differ- ential leucocytes counts, CRP, ESR as well as MPO, neopterin, AOPP, PCC, PP, LHP, and decreased thiol levels. Demonstrating the AOPP and PP formation for the first time, oxidants from active neutrophils/monocytes may play an important role in the pathogenesis of psoriasis, leading to oxidative stress, especially by protein oxidation. Keywords Psoriasis Á Neutrophils/monocyte activation Á Myeloperoxidase Á Advanced oxidation protein products Á Pyrrolized protein Á Protein carbonyl compounds Introduction Psoriasis is a chronic, inflammatory skin disease charac- terized by pathological skin lesions [35]. Increased pro- duction of reactive oxygen species (ROS) leading to oxidative stress is believed to be a key factor in psoriasis pathogenesis [5]. Oxidative stress in psoriasis patients has long relied solely on lipid peroxidation products such as lipid hydroperoxides (LHP), malondialdehyde (MDA), and hydroxynonenal (HNE), or on enzymatic/nonenzymatic antioxidants [33]. However, the data from these parameters are discordant; found to be increased, decreased or unchanged [5, 33]. Otherwise, the nature of ROS will play a significant role in determining whether to use lipids, DNA, or proteins as markers of oxidative stress [8]. For instance, hypochlorous acid (HOCl) induces the oxidation of proteins, however, causes little modification in DNA/lipids. Hence, when HOCl, the only in vivo source of which is myeloperoxidase (MPO) from activated neutrophils and monocytes [10], is the predominant ROS, specific protein oxidation products of HOCl should be used as the marker [8]. Furthermore, the usage of protein oxidation products as oxidative stress markers, such as pyrrolized protein (PP) [23], protein & Cevat Yazici yazici@erciyes.edu.tr 1 Department of Biochemistry, Faculty of Medicine, Erciyes University, 38039 Kayseri, Turkey 2 Department of Dermatology, Faculty of Medicine, Erciyes University, 38039 Kayseri, Turkey 123 Arch Dermatol Res DOI 10.1007/s00403-016-1624-0