Development of Immune System Depends on Month of Birth

Though a newborn is not as strong as older infants, it is said that its immune system is remarkably competent. Focusing on the development of the immune system, a recent study states that the levels of vitamin D and immune system development in newborn babies differ according to their month of birth.

The study, conducted by scientists at Queen Mary, University of London and the University of Oxford, explains why an infant's risk of developing multiple sclerosis (MS) is influenced by the month he/she is born in.

These findings demand the need for further investigation to analyze the benefits of consuming vitamin D supplements during pregnancy.

MS is a neurological condition that damages the central nervous system. It restricts the passage of information from the brain to other parts of the body, causing problems to vision, poor memory, muscle control, hearing, and also lowers cognitive skills. It is said that MS occurs due to the complex relations between genes and the environment.

Prior to this, a number of studies have highlighted that the month a person is born in greatly influences the risk of developing MS. Known as 'month of birth' effect, it is very prominent in England. MS chances are high for those born in May and the risk lowers for those born in November. The 'month of birth' effect is taken as an evidence of a prenatal role for vitamin D in MS risk.

In order to measure levels of vitamin D and levels of autoreactive T-cells, the study focused on blood samples taken from the umbilical cord of kids born between 2009 and 2010 in London. They took blood samples from 50 kids born in November and 50 kids born in May.

T-cells are known to play an important role in the body's immune response by damaging foreign agents in the body. However, some T-cells are known to be 'autoreactive', attacking the body's own cells, triggering autoimmune disease. The thymus, a specialized organ in the immune system, processes T-cells.

Researchers noticed that babies born in May had low levels of vitamin D, nearly 20 percent lower when compared to those kids born in November. But they had high levels of autoreactive T-cells when compared to kids born in November.

"By showing that month of birth has a measurable impact on in utero immune system development, this 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," co-author Dr. Sreeram Ramagopalan, a lecturer in neuroscience at Barts and The London School of Medicine and Dentistry, part of Queen Mary, said in a press statement.

The study was published in the journal JAMA Neurology.