Lupus affects women much more often than men (sex ratio: 9 women for each man in adulthood), like most autoimmune diseases. This female predominance can be explained in different ways:

The role of certain female hormones (oestrogens)

The most "classic" explanation is hormonal. Oestrogen generally promote the excess immunity seen in lupus. This explains why the disease can worsen during pregnancy or when taking contraception containing oestrogen.

The role of the female X chromosome

The X chromosome, of which female cells (XX) carry two copies (while male cells (XY) carry only one), is a chromosome on which we find important genes of our immune system. It has recently been shown that a woman with lupus expresses differently the immunity genes carried by the X chromosome compared to other women, which promotes an overactivity of the immune system.

The other reasons?

There are a number of other reasons that we do not know or that are not well known. Recently, it has been suggested that women could produce certain immunity substances in greater quantities.

This hypothesis is very interesting because interferon is a cytokine that can facilitate the emergence of lupus.

While lupus most often affects women, the forms that affect men are usually initially more severe with more frequent kidney involvement.