CHRONIC URTICARIA AND LEAD EXPOSURE: EVALUATION OF IMMUNOLOGICAL MARKERS.

BACKGROUND: Chronic urticaria (CU) is a mast-cell-driven disorder involving inflammatory and autoimmune mechanisms. Lead can affect immune function, but its relationship with CU has been little studied. OBJECTIVE: To examine the association of blood lead levels (BLLs) with CU, active wheals at blood sampling, and selected immunological markers. METHODS: This single-center case-control study included 303 participants from Western Georgia: 211 patients with CU and 92 healthy controls. BLLs were measured by inductively coupled plasma mass spectrometry. Eosinophils, total IgE, histamine, anti-IgE autoantibodies, and FcεRIα autoantibodies were assessed. BLL ≥10 µg/dL was used as the predefined analytical threshold for higher lead exposure. Associations were evaluated using group comparisons, Spearman correlation, and age-adjusted regression analyses. RESULTS: BLLs were higher in patients with CU than in healthy controls. BLL ≥10 µg/dL was present in 66.8% of patients and 33.7% of controls (OR 3.96; 95% CI 2.36-6.66; p<0.001), and the association remained significant after adjustment for age (aOR 4.07; 95% CI 2.38-6.96; p<0.001). Within the CU group, higher BLLs were associated with eosinophilia and higher histamine, anti-IgE, and FcεRIα autoantibody levels, but not with total IgE. BLL ≥10 µg/dL was also associated with active wheals at blood sampling after adjustment for age (aOR 3.36; 95% CI 1.75-6.45; p<0.001). In an exploratory analysis, the dual-positive anti-IgE/FcεRIα group had the highest frequencies of BLL ≥10 µg/dL (83.3%) and active wheals (92.4%). Compared with patients in whom neither autoantibody was elevated, the dual-positive group had the strongest age-adjusted association with BLL ≥10 µg/dL (aOR 5.49; 95% CI 2.38-12.70; p<0.001). CONCLUSIONS: Patients with CU had higher BLLs than healthy controls. Within the CU group, higher BLLs were associated with eosinophilia, histamine, anti-IgE and FcεRIα autoantibodies, and active wheals, but not with total IgE. These associations require confirmation in prospective studies.