In a groundbreaking study conducted by the University of Cape Town’s (UCT) Division of Paediatric Dermatology and Paediatric Allergy, researchers have discovered that a rural upbringing positively influences immune development in South African children, whether they suffer from allergic conditions or not.
Published in the January issue of the prestigious journal Allergy – the European Journal of Allergy and Clinical Immunology, the study focuses on the molecular profiles of children with atopic dermatitis (AD), a debilitating skin disorder prevalent among children globally, particularly in South Africa.
Lead author Dr Nonhlanhla Lunjani highlights the significance of early childhood as a crucial window for shaping immune development. The research suggests the existence of an “immunological window of opportunity” during this period, where the immune system is particularly responsive to environmental exposures. These exposures play a pivotal role in establishing immune functional trajectories, with potential long-term consequences on the risk of immune-mediated diseases such as allergies.
Epidemiological studies have indicated a rapid increase in allergic diseases in South Africa, contrasting with lower disease prevalence in rural communities. Dr Lunjani emphasizes the impact of living environments on immune profiles, citing previous work by the research group that demonstrated allergic immune profiles in both urban and rural children with atopic dermatitis.
The study utilized RNA sequencing of peripheral blood mononuclear cells (PBMCs) from children with AD and healthy controls within the same ethnolinguistic population in Cape Town and Mthatha. Bioinformatic analysis revealed differentially expressed genes in AD cases, with IgE, a key antibody isotype in allergic disease, being one of them.
Notably, the living environment strongly influenced PBMC gene expression clustering. Rural children showed higher expression of multiple gene expression pathways known to regulate or suppress aberrant inflammatory immune responses. Factors such as exposure to pets, maternal antenatal and childhood farm animal exposure, vaginal delivery, and sunlight exposure were associated with the rural cluster.
Conversely, urban living exposures were associated with peanut and Amasi consumption, higher household income, and increased paracetamol use. These findings highlight the critical role of environmental interactions and molecular switches in developing a healthy immune system.
Dr Lunjani concluded that understanding these environmental interactions can pave the way for public health interventions and provide guidance to mothers of young children. The research signifies a step forward in unravelling the complexities of immune development, offering hope for tailored interventions that promote lifelong health among South African children.
Tags: Study University of Cape Town