Month of birth impacts baby’s immune system development
Newborn babies’ immune system development and levels of vitamin D have been found to vary according to the month in which they were born, according to a new research co-authored by an Indian-origin researcher.
The new research, from scientists at Queen Mary, University of London and the University of Oxford, provides a potential biological basis as to why a person’s risk of developing the neurological condition multiple sclerosis (MS) is influenced by their month of birth.
In the study, samples of cord blood were taken from 50 babies born in November and 50 born in May between 2009 and 2010 in London.
The blood was analysed to measure levels of vitamin D and levels of autoreactive T-cells. T-cells are white blood cells which play a crucial role in the body’s immune response by identifying and destroying infectious agents, such as viruses.
However, some T-cells are “autoreactive” and capable of attacking the body’s own cells, triggering autoimmune diseases, and should be eliminated by the immune system during its development. This job of processing T-cells is carried out by the thymus, a specialised organ in the immune system located in the upper chest cavity.
The results showed that the May babies had around 20 percent lower vitamin D than those born in November and approximately double of these potentially harmful autoreactive T-cells, compared to the sample of November babies.
Co-author Dr Sreeram Ramagopalan, a lecturer in neuroscience at Barts and The London School of Medicine and Dentistry, part of Queen Mary, said that by showing that month of birth has a measurable impact on in utero immune system development, the study provides a potential biological explanation for the widely observed “month of birth” effect in MS. Higher levels of autoreactive T-cells, which have the ability to turn on the body, could explain why babies born in May are at a higher risk of developing MS.