Hydroxychloroquine Reduces Low Heartbeat Condition in Newborns
Hydroxychloroquine (HCQ) significantly reduces the incidence of congenital heart block (CHB), a rare and sometimes fatal heart condition in newborns. The condition results in a lower than normal heart rate and affects as many as one in 15,000 live births. CHB is usually detected by the finding of a heart rate under 100 beats per minute and is strongly linked to the presence of immune proteins, or antibodies, in the mother that react with other proteins called SSA/Ro. For mothers with these anti-SSA/Ro antibodies, the risk of this heart problem in their babies is low (2%) but increases nine-fold if a previous pregnancy has resulted in CHB.
In about half the cases of CHB, the mother has an autoimmune condition, such as lupus or Sjogren’s syndrome. This is because in both lupus and Sjogren’s syndrome, patients may have anti-SSA/Ro antibodies. However, many women do not even know they have these antibodies until they given birth to a child with CHB.
Researchers administered HCQ at 400mg by the 10th week of pregnancy til term to women who previously had a child affected by CHB. The therapy reduced the likelihood that the disease recurred in a subsequent pregnancy by 50%, reducing tissue inflammation that is thought to injure the fetal heart.
The findings of this study impact the lupus community. Specifically these results are pertinent to those patients that have anti-SSA/Ro antibodies and are planning pregnancy. These antibodies are present in about 40% of lupus patients. The data suggest that HCQ treatment should be considered for all women who have had a previous child with CHB to reduce the likelihood of a subsequent child having the same condition. It is not yet known whether all women with anti-SSA/Ro should take HCQ since the efficacy of this approach needs further evaluation. This study builds upon research funded by the Lupus Foundation of America’s LIFELINE Grant Program. Learn more about LIFELINE grants.