Neonatal lupus erythematosus in association with anti-RNP antibody: a case report.

Neonatal lupus erythematosus (NLE) is a syndrome with the manifestation of dermatological, cardiac, hepatic, or hematological abnormalities. Thrombocytopenia has been documented infrequently in association with congenital heart block or lupus dermatitis in NLE. However, isolated neonatal thrombocytopenia may be the only manifestation of NLE. The strong association with maternal anti-SSA/Ro antibodies suggests a role for these antibodies in the pathogenesis of NLE. There are some data to suggest that anti-SSB/La and, rarely, anti-RNP antibodies play an important pathological role in some cases of NLE. The manifestation of anti-RNP-positive NLE was somewhat atypical. We report a case of anti-RNP-positive NLE with the manifestation of thrombocytopenia. Anti-SSA/Ro antibodies, which were negative based on the use of immunodiffusion, did exhibit low titer when later tested by enzyme-linked immunoadsorbent assay (ELISA).