Neonatal lupus syndrome associated with ribonucleoprotein antibodies.

Neonatal lupus erythematosus (NLE) is a rare acquired autoimmune disease caused by transplacental transfer of maternal immunoglobulin G antibodies to the fetus. NLE has well-recognized cutaneous features and may also manifest in other organs. The majority of cases are associated with Ro/SSA and La/SSB antibodies. Neonatal lupus due to antiribonucleoprotein (RNP) antibodies has rarely been reported. On rare occasions RNP has been found in association with other antibodies. We report a case of NLE occurring solely due to RNP antibodies presenting as varicelliform lesions at birth. We recorded the features in our case and 14 additional cases identified in the literature. It is important to recognize that maternal transfer of RNP antibodies may produce the classic cutaneous features of neonatal lupus. The limited case reports of this condition suggest that manifestations are limited to the skin; specifically, there are no reports of cardiac involvement. The long-term outcome remains unknown. RNP-positive, Ro/La-negative NLE seems to represent a different clinical subset of NLE. The recognition of RNP antibody NLE as a benign condition limited to the skin is helpful in planning antenatal care for subsequent pregnancies.