Evaluation of platelet parameters and neutrophil/lymphocyte ratio during omalizumab treatment in patients with severe chronic spontaneous urticaria

Background/aim: Spontaneous wheals and/or angioedema lasting longer than six weeks are described as chronic spontaneous urticaria (CSU). Omalizumab is used for the treatment of antihistamine-resistant CSU. The neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), mean platelet volume (MPV), and platelet distribution width (PDW) are considered important indicators of inflammation and platelet activation in chronic diseases. We aimed to determine the NLR, PLR, MPV, and PDW levels in patients with CSU compared with healthy controls. We also aimed to investigate the effects of omalizumab therapy on these parameters in CSU patients. Materials and methods: This hospital-based, retrospective study included 143 patients with CSU and 132 healthy controls with a mean age of 40.0 +/- 13.17 and 42.0 +/- 16.34, respectively. Patients with equal or higher-than-baseline UAS scores at week 12 of omalizumab treatment were considered nonresponders, others were considered responders. We analyzed the neutrophils, lymphocytes, platelet counts, NLR, PLR, MPV, and PDW before, during, and after omalizumab treatment and compared the results with those of healthy controls. Results: CSU patients presented higher baseline MPV (P = 0.035) and lower baseline PDW values (P < 0.001) than healthy controls. There were statistically significant increases in the MPV (P < 0.001), MPV/platelet count (P = 0.005), and PDW (P = 0.003) and there was a statistically significant decrease in the NLR (P = 0.018) during omalizumab treatment. The percent increase of MPV was low in nonresponders (P = 0.009). Nonresponders had lower PDW values than responders (P = 0.040). Conclusion: The increase in the MPV and PDW may be due to platelet activation during omalizumab treatment. The decrease in the NLR may be regarded as an antiinflammatory effect of omalizumab. The effect of omalizumab on platelet and inflammatory markers may be used to discriminate the responders from nonresponders.