ANTIRIBONUCLEOPROTEIN ANTIBODIES IN CHILDREN WITH HIV-INFECTION - A COMPARATIVE-STUDY WITH CHILDHOOD-ONSET SYSTEMIC LUPUS-ERYTHEMATOSUS

A number of clinical and laboratory features of HIV infection are foun d in systemic lupus erythematosus (SLE). The objective of this study w as to analyze the presence of circulating antibodies to small nuclear ribonucleoproteins (snRNP) in both diseases. Sera from 44 HIV-infected children, from 22 patients with childhood-onset SLE, and from 50 heal thy children were studied. Anti-snRNP antibodies were detected by ELIS A using recombinant and affinity-purified nuclear antigens, by counter immunoelectrophoresis (CIE), and by immunoblotting using extractable n uclear antigens. Results included the detection of anti-snRNP antibodi es by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE patients (8 6.3%). These antibodies were directed against U1-RNP (61.3% and 77.2%, respectively), Sm (29.5% and 54.5%, respectively), 60 kDa Ro/SS-A (47 .7% and 50%, respectively), and La/SS-B proteins (18.1% and 9%, respec tively). None of the HIV-infected children and 11 SLE patients (50%) s howed anti-snRNP antibodies by CIE. None of the HIV-infected patients showed anti-70 kDa U1-RNP or anti-D-Sm antibodies by immunoblotting. N o differences between the two groups were noted on the presence of non precipitating anti-snRNP antibodies. No such reactivities were observe d among the normal sera tested. The authors concluded that nonprecipit ating anti-snRNP antibodies in HIV-infected children are as frequent a s in childhood-onset SLE. The significance of these antibodies is not clear at present. Although polyreactive and low-affinity antibodies an d a mechanism of molecular mimicry may explain these results, a specif ic stimulation of B cells by nuclear antigens could not be excluded.