Hormone replacement therapy and autoimmune diseases

Autoimmune diseases affect more frequently women. Hormonal variations in menopause modify the incidence and trend of autoimmune diseases. The dramatic decrease in estrogen levels due to ovarian exhaustion and the constant DHEA production are regarded as protective hormonal factors even though menopause has multifactorial traits: age, age at menopause onset, duration and gravity of the disease, estrogen receptor alteration, genetic alteration, interaction between estrogen and androgen receptors, progesterone and prolactin. Hormone replacement therapy (HRT) does not seem to be linked to relapses nor to a new disease in patients with rheumatoid arthritis. It is quite controversial though the use of estrogens in the presence of systemic lupus erythematosus. In this case, the risk of low to medium disease relapse in women undergoing HRT is quite significant. The use of NOR progesterone derivates and of transdermal estrogen can be more effective than E.E.C.-M.A.P. system. SERMs have proven to be an effective option for the treatment of osteoporosis which is often linked to autoimmune diseases. Tibolone appears to show tissue specific androgen activity with no added mammary risk. HRT needs to be administered in low dosage to patients with autoimmune diseases and for no longer than 2 years (WHI). An alternative to HRT are: microdose TTS estrogen therapy for osteoprotection, topical estrogen for genital dystrophy, progestins for vasomotor syndrome.