RESUMO
Objective To measure serum levels of 25-hydroxyvitamin D (25HVD) in patients with chronic urticaria (CU),and to explore its role in the occurrence of CU.Methods Peripheral blood samples were obtained from 50 patients with CU and 40 healthy controls.The urticaria activity score (UAS) was used to assess the severity of CU and to group the patients with CU.Enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum levels of 25HVD,interferon-γ (IFN-γ),interleukin-4 (IL-4) and immunoglobulin E (IgE).Statistical analysis was carried out by t test,rank sum test and linear correlation analysis.Results The serum level of 25HVD was significantly lower in the patients with CU than in the healthy controls (15.20 ± 7.72 vs.21.54 ± 8.31 μg/L,t =3.75,P ＜ 0.05).Moreover,there was a significant difference in the distribution of serum 25HVD levels between the patients and healthy controls (H =17.9,P ＜ 0.05).However,no significant difference was observed in the serum level of 25HVD between severe and mild CU groups (15.57 ± 7.38 vs.14.86 ± 6.28 μg/L,t =0.37,P ＞ 0.05).Compared with the control group,the patient group showed significantly decreased serum levels of IFN-γ (t =15.34,P ＜ 0.05),but increased serum levels of IL-4 and IgE (t =6.54,4.88,respectively,both P ＜ 0.05).Among the patients with CU,the serum level of 25HVD was positively correlated with that of IFN-γ(r =0.738,P ＜ 0.05),but negatively correlated with that of IL-4 (r =-0.689,P ＜ 0.05),and uncorrelated with that of IgE (r =-0.271,P ＞ 0.05).Conclusion The serum level of 25HVD evidently decreased in patients with CU,and it may participate in the occurrence of CU by mediating the Th 1/Th2 imbalance.