The effect of omalizumab treatment on disease severity, hematological parameters and C-reactive protein in chronic spontaneous urticaria patients

Introduction: Chronic spontaneous urticaria (CSU) is a mast cell mediated disease that persists for more than 6 weeks with a known or unknown cause. Omalizumab is a recombinant humanized monoclonal antibody that acts by binding to the high affinity IgE receptor (FcεRI) of immunoglobulin E (IgE). Omalizumab is indicated in the patients older than twelve years with CSU who do not respond to high dose H1 antihistamines. The seven-day urticaria activity score (UAS7) is often used to assess disease severity. However, this scoring system is not an objective tool because it includes the symptoms of the patients. Therefore, different biological indicators are needed to evaluate disease activity. Recently, several studies have been conducted on the use of some markers such as neutrophil-lymphocyte ratio (NLR), thrombocyte-lymphocyte ratio (TLR), mean platelet volume (MPV) and C-reactive protein (CRP) in the evaluation and monitoring of systemic inflammation. In this study, we aimed to investigate the effect of omalizumab treatment on NLR, TLR, MPV, CRP and UAS7 levels in patients with CSU. Materials and Methods: Between January 2016 and December 2018, 57 patients, aged between 18 and 80 years, who were diagnosed as chronic spontaneous urticaria and admitted to the outpatient clinic of the Dermatology Department of Dicle University Hospital, were included in the study. The patients who had omalizumab treatment for the first time, had no disease other than chronic spontaneous urticaria and who had hemogram, CRP and UAS7 values recorded before the treatment and at the third month of the treatment were included in the study. UAS7 was used to evaluate disease severity and treatment responses. Results: 75.4% of the patients were female and 24.6% were male. The mean age was 36.3 years. 87.7% of the patients had angioedema and 12.3% did not. The mean disease duration was 59.4 months (ranged from 3 months to 120 months). In our study, leukocyte (p=0.0021), neutrophil (p=0.00016), thrombocyte (p=0.0349), CRP (p<0.0001) and NLR (p=0.00181) values were significantly decreased at the third month of omalizumab treatment compared to baseline levels in patients with chronic spontaneous urticaria. There was no significant change in lymphocyte values (p= 0.7566). There was a significant increase in MPV after treatment (p=0.00032). There was no significant change in TLR values compared to baseline levels (p=0.3629). Before treatment, 75.4% (n=43) of the patients were evaluated as severe urticaria (UAS7>28) and 24.6% (n=14) of them as moderate severe urticaria (UAS7=16-28). After treatment, 10.5% (n= 6) of the patients had full control (UAS7=0), 43.9% (n=25) had mild severe urticaria (UAS7=7-15), 10.5 (n=6) were considered as severe urticaria and 8.8% (n=5) were considered as moderate urticaria according to UAS7. Treatment responsiveness was observed in 19.3% of the patients. Conclusion: Our findings support the efficacy of omalizumab in moderate and severe CSU patients resistant to high-dose antihistamines. It also shows that omalizumab not only has anti-IgE effect, but may also have inhibitory effects on inflammation and coagulation in CSU patients. However, further prospective studies are needed to evaluate the effects of omalizumab on hematological and inflammatory parameters and to evaluate the correlation between response rate and these parameters. Keywords: Chronic spontaneous urticaria, Omalizumab, NLR, TLR, MPV, CRP, UAS7