Accordingly, other therapeutic approaches are currently being investigated, including inhibition of transforming growth factor-β to limit fibrosis and prophylaxis with intravenous immune globulin (see box).
Next: IVIG for Heart Block Prevention?
Intravenous immune globulin (IVIG) has a history of safely being used in pregnancy, primarily for autoimmune thrombocytopenia and immune deficiency syndromes. A few cases of successful use in congenital heart block have also been reported.
To determine if this prophylactic approach could reliably decrease the placental transport of anti-Ro/SSA and anti-La/SSB antibodies, the Preventive IVIG Therapy for Congenital Heart Block (PITCH) trial is now enrolling patients. Sponsored by New York University School of Medicine and the Alliance for Lupus Research, the trial aims to enroll 19 women who are antibody positive and have already had a child with congenital heart block or a rash that might have been neonatal lupus. Such mothers are at much higher risk of having another child with congenital heart block than are mothers positive for anti-Ro/La who have not already had an affected child.
Participants will be given 400 mg/kg of IVIG every 3 weeks for a total of five treatments between weeks 12 and 24 of pregnancy. If fewer than three fetuses develop second- or third-degree heart block, another 35 women will be enrolled.
“Then, if there are fewer than six cases of heart block out of 54, we will be on the way to having a prophylactic therapy,” said Dr. Buyon, who is principal investigator for the trial.
Additional information about the PITCH trial is available online at