Neonatal lupus erythematosus.

Neonatal lupus Erythematosus (NLE) is a disorder characterized by maternal autoantibodies against RNA protein complex, Ro/SSA or SSB/La. These maternal IgG antibodies cross the placenta and potentially lead to fetal tissue damage and the clinical manifestations NLE. NLE is uncommon, affects females more than males, has no race predilection, and involves multiple organs. It has cutaneous manifestations similar to subacute cutaneous lupus erythematosus (SCLE). In addition to skin findings, patients with NLE have a significant risk of congenital heart block (CHB), a potentially fatal complication. Less frequently, hematologic and hepatic abnormalities occur. Approximately half of the reported cases have skin disease and half have CHB. Approximately 10% have both CHB and skin findings. The cutaneous, hematologic, and hepatic abnormalities are transient, clearing by 6 months of age. However, CHB is permanent and requires a pacemaker in many cases. The disorder results from the passive transfer of maternal autoantibodies, anti-RoSSA and anti-La/SSB. Sontheimer and McCauliffe reviewed the pathogenic role of anti-Ro antibody in NLE lesions and summarize evidence supporting its pathogenic role. Additional evidence suggests the possibility that Ro-antigen-specific T-cells may be present in SCLE patients and have the capacity to cause direct injury to the skin. McCuistion and Schoch first suggested this hypothesis in 1954 when they described an infant with LE skin findings born to a mother with systemic lupus erythematosus (SLE). Since this initial observation, a number of researchers have documented the role of maternal autoantibodies in the pathogenesis of this disorder. The true incidence of NLE is not known; however, it is known that NLE accounts for approximately 80% of all cases of CHB, and the incidence of CHB is 1 per 20,000 live births. Therefore, it can be assumed that the incidence of NLE is at least 1 per 12,500 live births.