Prophylaxis of occupational allergic sensitization in individuals exposed to laboratory animals

• Grant number: 24/18827-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2024
• End date: November 30, 2025
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Elcio dos Santos Oliveira Vianna
• Grantee: Líris Marini Dias Coelho
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 17/21035-8 - Work-related allergic sensitization and asthma: longitudinal studies for characterization and prevention, AP.TEM

Abstract

People exposed to laboratory animal allergens, sensitization may occur in 10 to 40% of cases. In a previous study, we detected 16% of sensitization in laboratory animals. Probiotics have an effect on preventing atopic dermatitis in high-risk newborns. There is a lack of data on its effects in adults in preventing allergic sensitization. The objective would be to understand the effect of probiotics on the development of allergic sensitization. It will be a controlled and randomized study that will involve workers and students who will begin exposure to laboratory animals: rats, mice, hamsters, guinea pigs or rabbits. The recruitment and study will take place with individuals from the university who do not present a positive allergic skin test to any of these animals. These volunteers will be divided into 2 groups, treatment group (n = 100) and placebo group (n = 100), both groups will be followed for 2 years. The treatment group will receive a capsule daily containing 3 strains of probiotics, 109 colony forming units (CFU) of Lactobacillus rhamnosus, Lactobacillus paracasei and Bifidobacterium animalis ssp lactis. The control group will receive a capsule containing placebo. Procedures: blood collection with cell count, measurement of total and specific IgE to these animals, fecal parasitology and PCR (feces) to identify colonization by these strains of probiotics, immediate hypersensitivity skin test for common allergens and animal allergens of interest, spirometry and bronchoprovocation, and these last two tests will be carried out when symptoms compatible with asthma appear. Data analysis: At the end of the two years, differences in the prevalence of sensitization or symptoms will be considered an effect of the treatment. Prevalences will be compared using the chi-square test for categorical variables, for example, prevalence of positive skin tests. Continuous variables will be compared using the unpaired Student's t test, for example, IgE measurement. These same comparisons will be carried out at the beginning of the study to assess homogeneity between the groups. An intention-to-treat analysis will be carried out. Statistical evaluation will be carried out at the end of the first and second year.