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) . Objective. To analyze the presence of circulating antibodies to smal l nuclear ribonucleoproteins (snRNP) in both diseases. Methods. We stu died sera from 44 HIV-infected children, from 22 patients with childho od-onset SLE, and from 50 healthy children. Anti-snRNP antibodies were detected by (ELISA) using recombinant and affinity-purified nuclear a ntigens, by counterimmunoelectrophoresis (CIE), and by immunoblotting using extractable nuclear antigens. Results. Anti-snRNP antibodies wer e detected by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE pat ients (86.3%). These antibodies were directed against U1-RNP (61.3% an d 77.2%), Sm (29.5% and 54.5%), 60kD-Ro/SS-A (47.7% and 50%), and La/S S-B proteins (18.1% and 9%), respectively. None of the HIV-infected ch ildren 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-S m antibodies by immunoblotting. No differences between the two groups were noted relative to the presence of nonprecipitating anti-snRNP ant ibodies. No such reactivities were observed among the normal sera test ed. Conclusions. Nonprecipitating anti-snRNP antibodies in HIV-infecte d children are as frequent as in childhood-onset SLE. The significance of these antibodies is not clear at present. Perhaps they are polyrea ctive and low-affinity antibodies and a mechanism of molecular mimicry may explain these results; however, we cannot exclude a specific stim ulation of B-cells by nuclear antigens.