« Lupus is the ultimate autoimmune disease, » nephrologist Dr. Naveed N. Masani says. « 60-90% of patients with the disease have kidney involvement. »
As Selena Gomez has documented over the last two years, lupus can affect multiple facets of life, sapping energy, inducing arthritis, cardiovascular problems and kidney failure.
On Thursday, the actress/singer/producer, 25, went public with the news that she received a kidney transplant from friend Francia Raisa .
So what is lupus and how cause her to require a kidney transplant?
It’s an autoimmune disease, meaning the body cannot differentiate between its own healthy tissue and foreign invaders. The antibodies or blood-borne proteins responsible for deciding biological friend from foe cause inflammation in various parts of the body. These problems tend to flare up and then abate over time.
It’s especially common with women, who comprise nine out of 10 lupus patients, according to the National Institutes of Health . (But men don’t get off so easy — the ones who do get lupus tend to have more severe cases.)
« It’s a very rough disease, » says Naveed N. Masani, a nephrologist and the medical director of the outpatient dialysis unit of New York University’s Winthrop Hospital. « You feel for these patients and what they go through. It’s not just the kidneys, but joint pain, rashes, fatigue. They feel lousy. »
Lupus can also affect a patient’s bone density, heart, liver, pancreas, and brain.
« Lupus is the ultimate autoimmune disease, » Masani says, adding that « 60-90% of patients with the disease have kidney involvement. »
The kidneys, Masani explains, « are kind of prime real estate, if you will, for the combination of your body attacking itself and the products they make. The kidneys are your filters. Every minute of the day, 100 drops of your blood pass through your kidneys to get cleaned. »
In the case of lupus nephritis patients, he says, granola-shaped clumps of waste get stuck in the kidneys and accumulate, progressively damaging the kidneys.
Masani says it’s not unusual for kidney function to decline to the point of needing dialysis or a transplant within a couple of years, as Gomez did.
« Depending on when patients get diagnosed and how bad things are, (kidneys) can deteriorate rapidly. » But not always, he notes, adding that new medications have helped slow the decay and topple kidney failure as the leading cause of death for lupus patients . (Now it’s premature cardiac disease, he says.)
But they have to be able to tolerate those meds, Masani cautions. « They have a lot of side effects. »
According to the National Institutes of Health, symptoms of lupus nephritis include swelling in the legs, feet, ankles and face; muscle pain and fever.
Doctors measure kidney function by testing blood and urine for creatine, a waste product generated by normal muscle breakdown. Failing kidneys aren’t able to remove it efficiently, causing rising creatine levels.
From there, a kidney biopsy is performed in order to examine the filtration cells to detect damage and gauge its severity.
Once diagnosed, the lupus patient’s overactive immune system is then knocked out with a combination of drugs with the goal of either slowing down the rate of kidney damage or putting the nephritis into remission.
But doing so leaves them at high risk of infection, Masani notes.
The base medication is the steroid prednisone, which he calls a « horrible drug. Any patient that has taken it will tell you that… It gives young women the heart and bones of a 60-year-old. »
Over the last 20 years, he says, doctors have had increasing success with a new anti-rejection drug called Mycophenolate Mofetil.
« It’s made a huge difference for transplant patients and for lupus patients, » he says, noting it has come to usurp chemotherapy (which Gomez says she received) as a first-line treatment.
The newer regimen is still rough on patients, he cautions. « All of these drugs have side effects. You get nothing for free. These young women with lupus go through hell on this stuff. »
The bottom line: Doctors can’t cure lupus nephritis, Masani emphasizes, but « we can treat it and hopefully slow it down so that not everyone ends up needing a transplant or dialysis. »
« In 2017, the best treatment for kidney failure is a kidney transplant, » Masani says, crediting revolutionary anti-rejection meds like ciclosporin and mycophenilate, which have been in use since the 1990s.
But transplant is not a cure for kidney failure, he specifies. « Dialysis keeps your head above water; transplant restores organ function. »
Lupus patients tend not to fare as well with long-term dialysis compared to other diseases because of the relationship between the heart and kidneys, he adds.
Transplant patients will need anti-rejection medications for the rest of their lives, but Masani says there is an upside: « One ‘advantage’ is that once they get the transplant is that the same drugs that keep the body from rejecting the new kidney also quiet down the lupus. »
Improvements are evident within the first few months following the transplant: « Ideally, they should go hand in hand, » Masani explains. « The immune system is kept at bay. The kidney does good, their lupus does good. »
However, transnplated kidneys don’t last forever: « The average life of a good kidney is 15-20 years, » he estimates. « There’s a decent chance (Gomez) may need another one, but some people last five years and others last 30. »
« If (Gomez) takes her medicine and follows up with her doctors (including monthly blood tests) , she should do really well, » Masani predicts.
Lupus and the medications used to keep it in check can hamper a woman’s ability to have children, notes Emily Somers, an associate professor of medicine at the University of Michigan who studies the disease’s impact on the reproductive system.
« The disease often strikes during the reproductive years, » she explains. « In fact, the risk of lupus among minority women peaks during their twenties. »
As a result, she says, « Pregnancy among women with lupus can carry risks to both the mother and fetus, so pre-conception planning is incredibly important.
