Role of Estrogen in the Flarring up of Lupus Nepheritis

Systemic lupus erythematosus SLE is an autoimmune disease that affects ∼5.5 per 100,000 individuals worldwide . SLE is characterized by loss of tolerance against nuclear autoantigens, lymphoproliferation, polyclonal autoantibody production, immune complex disease, and multiorgan tissue inflammation. Up to 50% of SLE patients develop some degree of renal involvement, with up to 20% progressing to end-stage renal disease, depending on racial background . Lupus nephritis LN is characterized by anti-nuclear Ab production, immune complex deposition, and immune-mediated kidney damage. Development of LN remains a sign of poor prognosis and is a significant cause of morbidity and mortality . Because 9 of 10 SLE patients are women, the role of the sex hormones estrogens in this disease is of key interest. Estrogens signal through two receptors: estrogen receptor a ERa and estrogen receptor b ERb. In contrast to estrogen receptor b, ERa is found in female reproductive organs, yet is robustly expressed in kidney, liver, heart, and lungs in males and females,as well as on most immune cells however the kidney is considered the most estrogenic nonreproductive organ. The overwhelming female predominance for SLE begins at puberty and extends to menopause , supporting the concept that estrogens or other reproductive factors stimulate lupus development. This concept is further evidenced by reports of menstrual cycle flares of SLE , disease exacerbations by oral contraceptives or estrogen administration , and induction of lupus by ovulation regimens . Ultraviolet rays has arole in the flarring up SLE. There is evidence that fibroblasts and blood lymphocytes from SLE patients are hypersensitive to the cytotoxic effects of UV light radiation

. RNA and protein synthesis is also affected by UV light 18. A study from 1986 found that people were more likely to menstruate during a new moon, which occurs during the opposite half of the lunar cycle than the full moon . There are different evolutionary theories speculating why the human menstrual cycle length evolved to be so close to the lunar cycle in length. Stories and beliefs connecting the two are also found in various cultures and mythologies . The terms menstruation and menses even come from Latin and Greek words meaning month mensis and moon mene