What Impact for Sex Difference on Immune Thrombocytopenic Purpura?

Emmanuel Andrès*

What Impact for Sex Difference on Immune Thrombocytopenic Purpura?

Despite the progress in medicine the impact of gender on many diseases remains unknown or unstudied. In this context, it seemed appropriate to us, with a bit of provocation, to study the impact of gender on Immune Thrombocytopenic Purpura (ITP).

ITP, currently also known as primary immune thrombocytopenia, is an autoimmune disorder that results in acute or chronic thrombocytopenia and that may potentially lead to a life-threatening hemorrhagic event. While ITP in childhood is usually an acute, self-limiting condition (the thrombocytopenia is transient and recovers spontaneously despite an initially severe presentation), ITP is more often a chronic disease in adults (at least 30% of cases) with an insidious onset requiring multiple therapeutic approache.

ITP mainly occurs in young adults, particularly women in their third or fourth decade, with an overall female to male ratio of 3-4 to 1. These figures suggest that sex hormones, as in other immune disorders (systemic lupus, multiple sclerosis, etc.) may play a role in the susceptibility to ITP. In addition to having an impact on the immune system, sex hormones may also alter the clinical picture and response to therapy.

In recent years, it has become clear that women and men may differ for drug response. There is an increasing recognition on the role of sex hormones on pharmacokinetics and pharmacodynamics as mechanism accounting for sex differences in drug effects. The available evidence suggests that sex hormones influence drug absorption, distribution, metabolism, pharmacodynamics, and adverse effects. For instance, many cardiovascular drugs are metabolized by enzymes of the cytochrome system, which is more expressed in females than in males, showing sex differences in drug response. 

Women Health Open J. 2016; 2(1): e1-e3. doi: 10.17140/WHOJ-2-e004