To the Editor,I am grateful to have read with great interest the article entitled “The association between platelet-lymphocyte ratio and coronary artery disease severity” by Yüksel et al. (1), published in Anatol J Cardiol 2015; 15: 640-7. In this well-presented study, the authors aimed that the platelet-lymphocyte ratio (PLR) was associated with the severity of coronary artery disease, assessed by the Gensini score, because a high PLR was shown to be closely related with inflammation and atherosclerosis. They found that a high PLR was significantly and independently related with the severity of coronary artery disease.Prior studies investigated that PLR, a combination of both platelet and lymphocyte counts, is a novel inflammatory marker and predictor of adverse cardiovascular outcomes (2–6). Yüksel et al. (1) showed that PLR was significantly higher in the group of severe atherosclerosis than in the other control and mild atherosclerosis groups. As known, the mild atherosclerosis group has a more severe inflammation than the control group; however, there was no difference between the mild atherosclerosis and control groups (p=0.729).In conclusion, according to these results, it was not clear to highlight the pathogenesis role of PLR in the severity of coronary artery disease. According to me, further larger studies are needed to show and clarify this situation.