What percentage of white blood cells do lymphocytes represent at the beginning of life?

At the beginning of life, lymphocytes represent approximately 30% of the total white blood cell count in neonates. This percentage reflects the immune system's developmental state in newborns. Lymphocytes play a crucial role in the immune response, particularly in establishing adaptive immunity, which is essential for protecting newborns against infections as they transition from the intrauterine environment to the external environment. The presence of a significant proportion of lymphocytes is indicative of the developing lymphoid tissue and the importance of cellular immunity in early life. As neonates grow, the composition of white blood cells, including lymphocyte percentages, evolves as their immune system matures and adapts to environmental exposures.