Chronic Spontaneous Urticaria in Belgium: Deciphering the Clinical Profile and Treatment of Patients Visiting an Urban City Immunology Department.

BACKGROUND: Chronic urticaria (CSU) is a chronic inflammatory mast cell-driven disorder of which reliable clinical data in Belgium are lacking. This study focusses on clinical characteristics of CSU patients presenting at an urban Immunology-Allergology department. METHODS: Outpatients with CSU were included from 2018 to 2021. Clinical characteristics, Dermatology Life Quality Index (DLQI) and Urticaria activity score (UAS7) were collected by thorough anamnesis and questionnaires. Furthermore, patients underwent provocational testing, an autologous serum skin test (ASST) and a blood analysis. RESULTS: The study included 49 CSU patients and 20 non-CSU subjects. CSU was distributed differently with age and sex, showing higher numbers in female patients below the age of 46 years. 67% of CSU patients had accompanying angioedema of which 9% were reported genital. CSU patients scored a mean 8/30 on their DLQI questionnaire. There was no significant difference in immunoglobulin E (IgE), C-reactive protein, and tryptase levels between CSU patients and controls. Oral glucocorticosteroids were prescribed in 23% of CSU patients during their disease course though only half of these patients had a severity grade 4 CSU. In 82% of the included CSU patients, Urticaria Control Test (UCT) scores were below 12. When we hypothetically considered low IgE levels and high IgG anti-thyroid peroxidase levels as differentiation marker for autoimmune (ai)CSU and non-aiCSU, we found that 4% of all included CSU patients could be considered aiCSU. CONCLUSION: Generally, the inner-city population displayed the same clinical characteristics, as previous cohorts from Northern Europe. The relatively high rate of CSU patients receiving oral glucocorticosteroid treatment for their disease though not always classified as severe, underlines the need to train doctors of various specialties in the treatment algorithms of CSU. Furthermore, by looking at potential autoimmune characteristics, our findings open perspectives on the identification of new routinely used clinical parameters for the detection of aiCSU, a relatively small immunological subtype of CSU.

Durability of tetanus seroprotection in people living with HIV.

OBJECTIVES: The aim of this study was to estimate the durability of tetanus toxoid specific seroprotection in a cohort of people with HIV (PWH). DESIGN: A cross-sectional study. METHODS: PWH with a last date of tetanus toxoid booster available were identified. Tetanus toxoid specific IgG were detected using commercial ELISA kit. Durability of seroprotection was estimated using a linear regression model and analyzed according to the country of birth. The impact of baseline parameters at the time of vaccination (CD4 + T cell count, viral load, and antiretroviral therapy) was also assessed. RESULTS: One hundred three individuals were included. The median duration between last tetanus toxoid booster and sampling was 5.6years (IQR 2.6-8.9). Using a linear regression model, half-life of tetanus toxoid specific antibody was estimated at 9.9 years [95% confidence interval (95% CI: 5.5-50)] in the whole cohort. Half-life was reduced in individuals born outside Europe: 4.4 years (95% CI: 2.9-8.5). PWH born outside Europe had lower CD4 + T cell count at the time of immunization and more frequently a CD4 + T cell count nadir less than 200 cells/µl before vaccination. CONCLUSION: PWH born outside Europe have lower half-life of tetanus toxoid specific antibody as compared to previous study performed in the general population. Possible causes include lower nadir or current CD4 + T cell count or under-immunization status in country of origin before migration. Longer interval of booster vaccination, as recommended in the general population, might not be appropriate in this subgroup of PWH. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.

Tetanus seroprotection in people living with HIV: Risk factors for seronegativity, evaluation of medical history and a rapid dipstick test.

OBJECTIVES: Tetanus is a vaccine-preventable disease. Booster immunization is required in order to induce long-lived tetanus-toxoid (TT) specific antibody response. We investigated the prevalence and risk factors of TT seronegativity in a cohort of people living with HIV (PWH) in Belgium along with the respective performance of vaccine history and a rapid dipstick test (Tetanus Quick Stick ® or TQS) compared to ELISA testing. METHODS: PWH were prospectively enrolled and answered a questionnaire. ELISA was performed on serum or plasma using a commercial kit. A TT antibody level ≥ 0.15 IU / mL was considered protective. The TQS test was performed on a limited number of subjects. RESULTS: Three-hundred forty-four subjects were included. The prevalence of tetanus seroprotection was 84,9%. Median age was 46.7 and 68% were born outside Belgium. Antiretroviral therapy coverage was almost universal (98.5%). After multivariable analysis, two risk factors were independently associated with TT seronegativity: an education level equivalent or below than secondary school and being born outside Europe. Vaccine history was shown to be unreliable (sensitivity: 43.8%; specificity: 76.5%; positive predictive value: 91.4% and negative predictive value :19.3%). The correlation between vaccine history and tetanus seroprotection was low (kappa coefficient = 0.09). The TQS performances were good (sensitivity 86.4%, specificity 96.0%, positive predictive value 99.3%, negative predictive value 52.17%). The correlation between TQS and tetanus seroprotection was substantial (kappa coefficient = 0.61). CONCLUSIONS: In this cohort of PWH with a high proportion of migrants, socio-demographic and educational factors were associated with TT seronegativity while HIV-related factors were not, indicating that vaccine information should be tailored to cultural and educational background. As vaccine history is not reliable, TQS could represent an efficient tool for screening of TT-seronegativity.