One in 50 pregnant women with systemic lupus erythematosus (SLE) are at risk for having a child with neonatal lupus erythematosus (NLE), according to Dr. Jill Buyon, a rheumatologist with New York University School of Medicine.
Although neonatal lupus is rare and is most often benign, when it is not, it can be life-threatening for at-risk newborns. Awareness is important, she said. “Though we think of it as being rare, the recurrence rate is about 18 percent. This is a significant portion of people,” Dr. Buyon said.
The first signs of disease often occur during the first few weeks of birth as nonscarring and non-atrophic skin lesions that resemble subacute cutaneous lupus erythematosus. More serious abnormalities effect the cardiovascular system, but can also effect the hematological, hepatobiliary, central nervous and pulmonary systems (1).
One of the most controversial issues associated with neonatal lupus is whether the use of fluorinated steroids during pregnancy can protect the fetus from worsening heart block, which is associated with NLE. Dr. Buyon’s research shows that it does not.
Neonatal lupus occurs when a mother with active or asymptomatic lupus or other autoimmune disease passes autoantibodies against Ro/SSA, La/SSB and U1-ribonucleoprotein (U1-RNP), through the placenta to the fetus. It is rare and one estimate shows only a 1-2 percent risk of having a child with NLE, regardless of whether the mother is symptomatic (1).
Dexamethasone or fluorinated steroids have been standard treatments to prevent heart block in NLE. “The idea behind this is that maybe heart block is caused by inflammation and maybe we could stop the inflammation in the beginning, during or even after the initial insult. The question is whether this would change the ultimate prognosis for the fetus,” she said.
A 2015 retrospective chart review by Dr. Buyon and colleagues published in the Annals of Rheumatic Diseases addressed whether daily doses of fluorinated steroids effectively treated isolated heart block in utero to prevent the progression of disease beyond the atrioventricular (AV) node. They found that fluorinated steroids did not significantly prevent the development of disease beyond the AV node, reduce mortality or delay or prevent the need for a pacemaker (2).
It is believed inflammation plays a significant role in the development and worsening of heart block, making steroids an attractive treatment option. However, evidence doesn't support the use of these steroids to prevent worsening disease or death from this condition.
The results, she said, should alleviate worries from providers and expectant mothers who have concerns about using steroids, such as dexamethasone, during pregnancy. There has been a concern about the effect of steroids crossing the placenta into the fetal circulation system. Additionally, steroid use can cause complications in the mother, such as increased risk of infection, as well as other problems in the fetus, including low-birth weight and the loss of amniotic fluids.
The 20-year retrospective study analyzed treatment and outcomes for enrollees in the Research Registry for Neonatal Lupus. Only women with diagnosed cases of anti-SSA/Ro-associated cardiac neonatal lupus, meaning their fetus had second- or third-degree heart block, were included. Heart block scars the atrioventricular node, the structure responsible for heart rate. Children born with permanent heart block require pacemaker implantation, and approximately 20 percent die.
Although there is some disagreement with Canadian research that supports the use of fluorinated steroids when second- or third-degree heart block is present, recently published French investigations verify her team's findings, she said.
Previous studies over the last 20 years have shown that the most challenging aspect in heart block is that once it’s reached a third-degree level, it is generally immutable and by then, steroids cannot reverse the course of disease.
“There is a vulnerable period to the development of heart block which is usually about 16 – 26 weeks, with the most heightened time around 19-20 weeks. Once the heart block has happened it’s not common to develop worsening injury because the vulnerable period begins to pass. Admittedly, our colleagues in Canada don’t agree and they almost always subject the mother to steroids for the rest of the pregnancy. And because that carries risk, we felt this study was important,” she said.
Now, with this study, Dr. Buyon hopes that physicians will reconsider steroid therapy in these cases.
“I appreciate that a mother wants to do all she can to save her baby, but there are also health considerations for her part and on part of the fetus. The idea of taking a steroid that will cross into the fetal circulation can be very anxiety provoking both for the patient and physician. This is the study that was needed to help in pregnancy counseling,” she said.
Dr. Buyon discusses the structure, findings and importance of this work with Rheumatology Network in this video.