Lupus is a non-infectious autoimmune disease and cannot be transmitted between people. You cannot contract lupus through physical contact or any form of intimacy with a person who has it. The condition arises from a complex interaction of internal and external factors, not an external pathogen. An autoimmune disease occurs when the body’s immune system mistakenly attacks its own healthy tissues, causing the inflammation and wide-ranging symptoms associated with lupus.
The Role of Genetics in Lupus
Lupus has a recognized genetic component, though it is not contagious. The disease is not inherited directly, but through a genetic predisposition. This means individuals can inherit genes from their parents that make them more susceptible to developing lupus, but these genes do not guarantee the disease will manifest. The presence of these genes only increases the statistical risk.
Most people who have a relative with lupus will never develop the condition. For instance, studies show that only about 5% of children whose mothers have lupus will go on to develop it. This highlights that genetics are just one piece of the puzzle, as many people carry the associated genes and remain healthy.
Scientists have identified several genes linked to the immune system that contribute to this predisposition. These genes are involved in processes like identifying foreign invaders and clearing damaged cells from the body. Specific variations in these genes can disrupt normal immune function, setting the stage for an autoimmune reaction if other factors come into play.
Environmental and Hormonal Triggers
For an individual with a genetic predisposition to lupus, an environmental or internal trigger often initiates the disease’s activity. These triggers vary between people and act as the catalyst for the underlying genetic susceptibility. Without exposure to such a trigger, a genetically predisposed person may never show signs of the illness.
Common environmental factors include exposure to ultraviolet (UV) light from the sun, which can provoke an immune response. Certain viral infections, like Epstein-Barr, have also been implicated as potential triggers in susceptible individuals. Other environmental exposures, such as to silica dust or cigarette smoke, have been linked to an increased risk.
Hormones also play a significant part in lupus. The female hormone estrogen is believed to enhance the immune response, which may explain why lupus is about nine times more common in women than in men. Onset frequently occurs during childbearing years when estrogen levels are highest. Major hormonal shifts during events like puberty, childbirth, and menopause can also act as triggers.
Lupus and Pregnancy Considerations
Expectant mothers with lupus often worry about passing the disease to their child. A mother does not transmit lupus to her baby during pregnancy, so the infant will not be born with the chronic disease. However, a specific and rare condition known as neonatal lupus can occur.
Neonatal lupus is not the same as the systemic lupus erythematosus (SLE) affecting the mother. This temporary condition is caused when the mother’s Ro/SSA and La/SSB autoantibodies cross the placenta. These antibodies can cause temporary symptoms in the newborn, most commonly a skin rash and low blood cell counts.
The symptoms of neonatal lupus are transient because the mother’s antibodies are gradually cleared from the baby’s system. The rash and blood count issues typically resolve completely within about six months and do not result in long-term lupus for the child.
In rare instances, these maternal antibodies can affect the fetus’s developing heart, leading to a permanent condition called congenital heart block. Because of this risk, mothers with these specific antibodies are monitored closely throughout pregnancy with specialized heart scans to track the baby’s development.