Hormonal Effects on Immune System

The immune system is a complex network, regulated by specific cells that are influenced by hormone and cytokine effects. The endogenous steroid hormone synthesis, mainly of glucocorticoids governed by the HPA axis, represents the physiologic response to a variety of external stimuli or pathogen agents. Several other steroid hormones, mainly sex steroids and vitamin D, play important roles in the maintenance of immune system homeostasis. The pregnancy status constitutes an ‘immunologic paradox,’ but is a physiologic event that allows the investigation of sophisticated hormones-immune cell interactions in health and rheumatic diseases. Therefore, the immune system is tightly modulated by the endocrine and neuronal products (hormones and neuro-transmitters): the introduction of a comprehensive physiological human immune-neuro-endocrine model (pregnancy) permits therefore to understand better these highly refined mechanisms.