Abstract: Objective: To analyze the correlation between neutrophil to lymphocyte ratio (NLR) and PASI in the patients with moderate to severe plaque psoriasis after treated with secukinumab. Methods: The patients with moderate to severe plaque psoriasis were recruited from April 1st, 2017 to July 31, 2017 and were treated with secukinumab, once a week for 4 times, and then, once every 4 weeks for 11 times. Results: Twenty-two patients were treated with secukinumab. After the treatment, the PASI score decreased from 22.28 to 2.31. There was a positive correlation between the decrease level of NLR and the decrease score of PASI (rw12=0.504，rw24=0.604，rw36=0.470，rw48=0.454；Ps<0.05). Conclusion: Secukinumab is effective in the treatment of the patients with moderate to severe plaque psoriasis and there is a positive correlation between the decrease level of NLR and the decrease score of PASI.

Key words: psoriasis, neutrophil to lymphocyte ratio, biologics