Neonatal lupus: Follow-up in infants with anti-SSA/Ro antibodies and review of the literature.

Neonatal Lupus Syndrome (NLS) is a distinct clinical entity caused by transplacental passage of maternal anti-SSA/Ro antibodies (Ab). Mothers may have systemic lupus erythematosus, Sjögren syndrome, or other connective tissue disease, or may be completely healthy at the time of giving birth. NLS includes several clinical manifestations: complete congenital heart block (CCHB) and cutaneous lupus are the most common, while hepatobiliary disease, hematological manifestations and central nervous system involvement may occur. Data from literature on the incidence of the different clinical manifestations of NLS are difficult to compare because they come mostly from retrospective studies or prospective studies, but up to date no systematic follow-up was carried out. We performed a large prospective single-center study with a systematic clinical and instrumental follow-up until 9months of life, in order to evaluate the incidence and the clinical impact of NLS features. From 2004 to 2014 all infants born in our center to mothers with anti-SSA/Ro Ab were enrolled in a specific diagnostic and follow-up (FU) program. At birth, 50 infants born to mothers with anti-SSA/Ro Ab were found positive for anti-SSA/Ro Ab. Infants were tested for anti SSA/Ro Ab at 3months of life, if positive they were re-tested at 6 and 9months. At 9months anti-SSA/Ro Ab were positive in 10% of children. In two cases (4%) a CCHB was identified during pregnancy and required pacemaker implantation at birth. In 10% of cases a transient ECG alterations was found during follow-up. Hematological NLS features (anemia, neutropenia, thrombocytopenia) were found at birth and during FU in several patients, in all cases without clinical manifestations and in most cases with complete normalization at 9months. Mild and transient elevation of aminotransferases between 3 and 6months of life were found in 56% and 40% of patient, respectively; non-specific ultrasound cerebral anomalies in absence of clinical neurological signs were found at birth in 9 patients (18%), subsequently normalized. Prenatal maternal screening is of primary importance in order to early detect CCHB, which requires maternal treatment and pacemaker implantation at birth. Infants born to mothers with anti-SSA/Ro Ab should be monitored for all NLS features at birth. However, during the first months of life, these infants seem to develop only mild, transient and self-limited clinical manifestations, which in most cases are completely solved at 9months of life. This consideration, together with the evidence that only 10% of infants had anti-SSA/Ro Ab persistent in blood at 9months, suggests that follow-up of these children can be performed until 6-9months of life with good clinical safety. Moreover, a clinical and laboratory monitoring at 3months of life, when the highest incidence of hematological features and liver tests alterations are observed, is strongly recommended. In the future, it would be clarified if a follow-up until adulthood would be indicated in cases with persistent anti SSA/Ro or in all infants born to mother with anti SSA/Ro.