Incompatibilità Rh: dopo l'anti-D, la nuova sfida è fermare gli anticorpi

Haemolytic disease of the foetus and newborn (HDFN), caused by maternal alloimmunization against fetal red blood cell antigens, has been significantly reduced in its RhD-related form by anti-D immunoglobulin prophylaxis in RhD-negative women. However, it remains a serious concern in pregnancies of already alloimmunized women. Non-invasive monitoring of foetal anaemia relies on Doppler ultrasonography to measure the middle cerebral artery peak systolic velocity (MCA-PSV), while intrauter-ine transfusion (IUT) remains the standard treatment for severe fetal anaemia. To prevent the development of anaemia, research is exploring novel therapeutic strate-gies such as nipocalimab, a monoclonal antibody that blocks the neonatal Fc receptor (FcRn), thereby reducing the placental transfer of maternal IgG antibodies. Pre-liminary results from the phase 2 UNITY trial are prom-ising and suggest the potential to reduce the need for in-trauterine transfusions. The ongoing phase 3 AZALEA trial and further safety assessments will help clarify the efficacy and safety of this approach.