A large international collaboration has reported 46 cases associated with maternal anti-fetal acetylcholine receptor antibodies (fRACh), the largest cohort ever described to date.
- The 30 mothers had anti-fRACh and anti-RACh antibodies, and half of them had not been diagnosed with myasthenia prior to pregnancy.
- There were seven terminations of pregnancy for severe congenital multiple arthrogryposis, and four early deaths from respiratory failure.
- In the 34 children, retractions and early respiratory and bulbar impairment were predominant and improved over time.
- Oral salbutamol improved symptoms in 13 out of 16 patients.
- Maternal immunosuppressive therapy significantly reduced infant mortality compared with no treatment.
The authors propose the term Fetal Acetylcholine Receptor Antibody-related Disorder (FARAD) to describe these pathologies, which range from lethal arthrogryposis to fetal acetylcholine receptor inactivation syndrome (FARIS). Screening is based on systematic measurement of anti-RACh antibodies, including the foetal isoform, before the 16th week of pregnancy. It could be prevented by immunomodulatory treatment during pregnancy, the details of which have yet to be specified.
The Giessen team (Germany) prevented the onset of FARAD in the little sister of a girl suffering from the condition by treating the mother, who was asymptomatic but had high anti-RACh antibodies, with monthly IV immunoglobulins from 12 weeks’ gestation. The initial hypomimia and weakness of the neck muscles in the second baby girl disappeared within two months. She walked at 14 months and spoke her first words at one year.
