Why Lupus More Common in Females?
Each year, more cases of lupus are reported in the United States. Nine out of ten are female.
Scientists have long believed that gender differences help to explain women's predisposition to autoimmune diseases. But researchers say they may now have an explanation for why the presence of two X chromosomes increases a person's chance of developing lupus.
Dozens of genes have been associated with lupus. The researchers focused on the overexpression of the Tlr7 gene, which is on the X chromosome. In female cells, the gene on one of the X chromosomes becomes inactivated, as a way to control the expression of the Tlr7 gene that can avoid attempts to limit its expression.
Meaning for Lupus
Lupus is a chronic autoimmune disease which affects more women than men. If you have lupus, you are at a higher risk of developing other health problems common in women, such as osteoporosis and heart disease.
Lupus is a chronic autoimmune disease which can harm any part of the body. With autoimmune diseases, the body's immune system cannot distinguish viruses, bacteria, and other germs from healthy cells, tissues, or organs. Hence, the immune system attacks and destroys healthy cells, tissues, or organs.
Who Can Get Lupus?
Anyone can develop lupus. It's hard to know how many people in the United States have lupus, because the symptoms are different for everyone. It is estimated that 1.5 million Americans have lupus.
Other estimates have ranged from 161,000 to 322,000 Americans with systemic lupus erythematosus (SLE).
Approximately 9 in 10 lupus diagnoses occur in women ages 15 to 44.3 years.
Does Lupus Only Affect Females?
Lupus develops because of the interaction between genetic susceptibility and environmental triggers. A number of genes are referred to as lupus susceptibility genes, whose presence is thought to increase the likelihood of developing lupus.
Lupus is thought to be 9 times more common in women than men. This increased susceptibility is possible, at least in part due to hormonal and sex chromosome differences. However, how much sex this contribution to the development of lupus is not known.
Some of the most common symptoms of women with lupus are tiredness, joint pain, fever and some are nonspecific. It's only after people get really sick, with symptoms such as kidney disease, debilitating arthritis, or serious skin conditions, that most doctors start thinking about lupus.
Usually the person has been sick for months, or years before that.
Genetic risk factors
When asked why a person has lupus, the answer is complex. To some extent, it is a congenital disease; 70% of your lupus risk is in your genes. But that doesn't mean that your parents or grandparents had to have lupus in order for you to get it. In fact, that rarely happens.
Sometimes, a parent or sibling will have another autoimmune condition that shares the same genetic risk factors as lupus.
In other cases, family members will have a positive ANA test, but they won't be sick at all. And sometimes, there are no traces of lupus in family members.
Genetics is a big component, but it's not all. People inherit the susceptibility, but other factors are needed to bring the disease out until it is expressed.
Genetic samples were processed according to strict quality guidelines, to determine the frequency of small but important changes in eighteen lupus susceptibility genes, which are known to be found on non-sex chromosomes in women and men with and without lupus.
Based on the differences from these analyses, including the subset of genetic samples, genetic risk was calculated for lupus patients in a sex-specific manner.
Changes in 10 of 18 susceptibility genes in men and 15 of 18 in women were found to be significantly different between lupus patients and healthy individuals. (goodrx.com) Three of the 18 genes did not meet these criteria, were not associated with lupus in the current study, and were thus excluded from further analysis.
A comparison of the frequency of changes in 18 lupus susceptibility genes between women and men with lupus showed that 4 of them differed significantly by gender. Two of these genes were found in the human leukocyte antigen (HLA) region (hereinafter referred to as the "HLA gene") and two were found outside the HLA region (hereinafter referred to as the "non-HLA gene").
The HLA gene encodes a protein that is important for the proper functioning of the immune system and helps elicit a strong, specific immune response.
The frequency of 2 HLA genes (plus one non-HLA gene, IRF5, a gene involved in the interferon pathway important in the pathogenesis of lupus) was significantly greater in men than women with lupus. Only 1 of the 4 genes, of interest here, one of the non-HLA genes (KIAA1542, a gene whose function is unknown), is significantly greater in frequency in women than men. The frequencies of these three genes were not different between women and men without lupus.
No significant sex-related differences were found in the levels of anti-dsDNA between women and men with lupus. Further statistical comparisons showed that the frequency of alterations in the four lupus susceptibility genes mentioned above was not associated with differences in disease severity in women or men with lupus.
Comparison of sex differences in genetic risk shows that men with lupus require a greater cumulative genetic burden of the lupus susceptibility gene on average than women to develop lupus.
How Does A Woman Get Lupus?
There are many theories about why women have more autoimmune diseases, but there is no definitive answer. Hormones play a role, and inflammation leads to a role.
Men have hormones too, but women are affected more. Estrogens make women vulnerable to autoimmune diseases. Some women with autoimmune diseases experience remission during pregnancy.
During pregnancy, your body is protecting you and your baby. However, diseases such as rheumatoid arthritis can develop quite severe after she has delivered her baby. Women had a lower incidence of pre-menopausal gout than they did after menopause. DHEA, a mild androgenizing hormone can help those who suffer from Lupus.
Lupus most commonly affects women between the ages of 15 and 44. Lupus can cause these problems to occur earlier in life, compared to women who don't have lupus. These health issues include:
Kidney disease
More than half of people with lupus have a kidney problem, which is known as lupus nephritis. Kidney problems often start within the first five years after lupus symptoms begin to appear.
This is one of the more serious lupus complications. Also, inflammation of the kidneys is usually painless, so you don't know when it occurs.
That is why it is important for people with lupus to have regular blood and urine tests for kidney disease. Treatment for lupus nephritis works best if it is caught early.
Heart disease
Lupus raises your risk for the most common type of heart disease, called coronary artery disease (CAD) This is because people with lupus have many more risk factors for CAD, which include high blood pressure, high cholesterol, and type 2 diabetes.
Lupus causes inflammation (swelling), which also increases your risk for CAD. Women with lupus may be less active due to fatigue, joint problems, and muscle aches, and this also puts them at risk for heart disease.
In one study, women with lupus were 50 times more likely to experience chest pain or heart attack than other women of the same age.
Osteoporosis.
Medications that treat lupus can cause bone loss. Bone loss can lead to osteoporosis, a condition that causes weak and fractured bones. In addition, pain and fatigue can prevent women with lupus from engaging in physical activity. Keeping active can help prevent bone loss.
Why’s Lupus More Common in Woman?
While the exact answer is unknown, it's thought that sex hormones play a big role in why lupus is more common in women. Estrogen, which is commonly associated with women, and androgens, which are generally associated with men, are produced in both sexes. Estrogen is believed to promote the development of autoimmune disorders and its higher levels in women may be one reason why lupus is more common in women.
