[Neonatal lupus and maternofetal transmission of anti-SSA/Ro and anti-SSB/La antibodies]

Abstract

Neonatal lupus (NL) is a rare syndrome caused by placental transfer of maternal anti-SSA/Ro (60 and 52kDa) or anti-SSB/La antibodies. The aim of this study was to evaluate the clinical and biological profile of NL at the neonatal unit of Sfax, Tunisia, over a 10-year period. Six mother-NB pairs (two sets of twins and two sisters) had positive ANA by transplacental transmission during the study period. The ANA pattern was speckled and the NBs' sera titer was half that of their mothers'. Anti-SSA, anti-Ro52, and anti-SSB were found in 100%, 33%, and 50% of the mothers' sera, respectively. The transmission of anti-SSA was observed in four pregnancies out of six, anti-Ro52 in two pregnancies out of two, and anti-SSB in one pregnancy out of three. The patients' clinical records showed that two NBs had a congenital heart block: one with anti-SSA, whose mother had Sjögren syndrome, and another with anti-SSA, anti-SSB, anti-Ro52, and anti-mitochondrial antibodies (M2 type), whose mother had no diagnosis at the child's birth (cutaneous erythema and positive ANA with the same profile). Cutaneous signs (erythema, petechia) were described in three NBs out of six. The two sets of fraternal twins had cutaneous signs with the same ANA titer and profile (no anti-SSA transmission from their mother with lupus and anti-phospholipid syndrome). The two sisters' (two pregnancies 3 years apart) mother had Sjögren syndrome, one of them had heart block with positive anti-SSA, and the other was asymptomatic with anti-SSA and anti-Ro52. The same mother had a history of three pregnancies with two NBs who died of heart block.