Antiribonucleoprotein antibodies in children with human immunodeficiency virus infection: comparative study with childhood-onset systemic lupus erythematosus

A number of clinical and laboratory features of human immunodeficiency virus (HIV) infection are found in systemic lupus erythematosus (SLE).To analyze the presence of circulating antibodies to small nuclear ribonucleoproteins (snRNP) in both diseases.We studied sera from 44 HIV-infected children, from 22 patients with childhood-onset SLE, and from 50 healthy children. Anti-snRNP antibodies were detected by (ELISA) using recombinant and affinity-purified nuclear antigens, by counterimmunoelectrophoresis (CIE), and by immunoblotting using extractable nuclear antigens.Anti-snRNP antibodies were detected by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE patients (86.3%). These antibodies were directed against U1-RNP (61.3% and 77.2%), Sm (29.5% and 54.5%), 60kD-Ro/SS-A (47.7% and 50%), and La/SS-B proteins (18.1% and 9%), respectively. None of the HIV-infected children and 11 SLE patients (50%) showed anti-snRNP antibodies by CIE. None of the HIV-infected patients showed anti-70 kD U1-RNP or anti-D-Sm antibodies by immunoblotting. No differences between the two groups were noted relative to the presence of nonprecipitating anti-snRNP antibodies. No such reactivities were observed among the normal sera tested.Nonprecipitating anti-snRNP antibodies in HIV-infected children are as frequent as in childhood-onset SLE. The significance of these antibodies is not clear at present. Perhaps they are polyreactive and low-affinity antibodies and a mechanism of molecular mimicry may explain these results; however, we cannot exclude a specific stimulation of B-cells by nuclear antigens.