Midkine (MK) is a multifunctional molecule functioning in the developmental period of the fetus. It was first discovered in embryonic carcinoma cells with increased expression in early stages of differentiation. 1 In adults, MK is expressed in limited sites such as epidermis, kidney, lymphocytes and gut. 2 MK has critical function in development and repair mech-anisms in normal cells as well as tumor growth, invasion and angiogenesis in cancer cells. 3,4 Various studies have shown that tumor prognosis is worse in the patients with higher MK levels. 5-7 Moreover, higher serum MK levels were detected in various inflammatory diseases such as rheumatoid arthritis, inflammatory bowel diseases, atherosclerosis and Turkiye Klinikleri J Dermatol. 2020;30(1):1-5 ABS TRACT Objectives: Midkine is a heparin-binding growth factor which functions in development and repair mechanisms. It also has roles in tumor growth, invasion and angiogenesis in cancer cells. Recently, higher serum midkine levels were detected in inflammatory diseases such as rheumatoid arthritis, inflammatory bowel diseases, atherosclerosis and obesity. In the present study, we aimed to investigate serum midkine levels in patients with psoriasis. We also tried to reveal if there is a relationship between serum midkine levels and psoriasis disease activity. Material and Methods: Forty-five patients with psoriasis and age, sex-matched healthy controls were enrolled in the study. Serum midkine level, complete blood count, fasting serum glucose level, lipid profile (HDL, LDL, triglyceride, cholesterol), CRP (C-reactive protein), serum liver function tests (ALT; AST) and kidney function tests (urea and creatinine) were studied. Psoriasis area severity index (PASI) scores and body mass indexes were calculated for each patient. Results: We found significantly higher serum midkine levels in patients with psoriasis compared to control group. There was no correlation between serum midkine levels and PASI scores. Serum midkine levels were correlated with serum triglyceride levels in patients with psoriasis. Conclusion: This study showed that serum midkine levels were significantly higher in psoriatic patients than controls. As midkine is only correlated with serum triglyceride level and not correlated with PASI, we think serum midkine is not an ideal serum marker for the evaluation of psoriasis activity.ÖZET Amaç: Midkin, büyüme, gelişme ve tamir mekanizmalarında görevli bir büyüme faktörüdür. Ayrıca, kanser hücrelerinde tümör büyümesi, invazyon ve anjiyogenezden sorumludur. Son zamanlarda, romatoid artrit, inflamatuar bağırsak hastalıkları, ateroskleroz ve obezite gibi bircok inflamatuvar hastalıkta yüksek serum midkin seviyeleri tespit edilmiştir. Çalışmamızda, psöriyazisli hastalarda serum midkin seviyesini ve bu seviyelerin hastalık aktivitesi ile ilişkisini belirlemeyi hedefledik. Gereç ve Yöntemler: Psöriyazis tanısı almış 45 hasta ile yaş ve cinsiyet açısından eşleşmiş kontroller çalışmaya dahil edildi. Tüm hasta ve kontrollerde, serum midkin seviyeleri, tam kan...