Anti-BB'-Sm antibodies, anticardiolipin antibodies, and thrombosis in systemic lupus erythematosus

OBJECTIVE

Anticardiolipin antibodies (aCL) are associated with thrombosis in patients with systemic lupus erythematosus (SLE). Our aim was to determine whether there is an association between aCL, anti-Sm antibodies, and thrombosis in patients with SLE.

METHODS

Sera from 153 patients with SLE were studied by ELISA, immunoblotting, and counter-immunoelectrophoresis (CIE) for anti-Sm antibodies, aCL and anti-dsDNA antibodies were detected by ELISA and radioimmunoassay, respectively.

RESULTS

Anti-Sm antibodies were detected in 62 patients (40.5%) by ELISA and in 16 (10.4%) by CIE; IgG-anti-BB'-Sm in 44 (28.7%) by immunoblotting; IgG-aCL in 82 (53.5%), IgM-aCL in 44 (28.7%), and anti-dsDNA antibodies in 128 (83.6%). Anti-Sm and anti-dsDNA antibodies were significantly more frequent in patients with than in patients without aCL. Of the 89 patients with aCL, 36 (40.4%) showed IgG-anti-BB'-Sm antibodies (OR: 4.7; 95% CI: 2-10.5). Thrombosis was present in 20 (22.4%) SLE patients with aCL and in two (3.1 %) SLE patients without aCL (OR: 8.9; 95% CI: 2.4-31.8). Of the 22 patients with thrombosis, five (22.7%) had precipitating anti-Sm antibodies (OR: 3.2; 95% CI: 1.04-9.8) and 14 (63.6%) showed IgG-anti-BB'-Sm antibodies (OR: 5.8; 95% CI: 2.3-14). Anti-BB'-Sm and aCL were significantly more frequent in patients with anti-dsDNA antibodies (32 and 62%) than in patients without these antibodies (12 and 36%) (OR: 3.4 and 2.9; 95% CI: 1.03-11.1 and 1.2-6.7, respectively).

CONCLUSION

IgG-anti-BB'-Sm antibodies are associated with aCL, anti-dsDNA, and thrombosis in patients with SLE. Our findings suggest a possible association between anti-Sm, anti-dsDNA, and aCL responses in these patients.

[Clinical expression of systemic lupus erythematosus with anti-U1-RNP and anti-Sm antibodies]

The frequency of anti-U1-RNP and anti-Sm antibodies in systemic lupus erythematosus (SLE) varies according to the technique used for their detection.

OBJECTIVE

To study the clinical manifestations associated with anti-U1-RNP and anti-Sm antibodies identified by different techniques.

METHODS

112 patients diagnosed with SLE were studied. Anti-U1-RNP and anti-Sm antibodies were detected by ELISA with a mixture of recombinant antigens, antigens obtained by immunoaffinity and by immunoblotting and counterimmunoelectrophoresis (CIE) with a saline extract of rabbit thymus.

RESULTS

Anti-U1-RNP antibodies were detected in 70 (62.5%), 37 (33%) and 16 (14.2%) patients, and anti-Sm antibodies in 43 (38.3%), 36 (32.1%) and 10 (8.9%) patients by ELISA, immunoblotting, and CIE, respectively. Anti-U1-RNP antibodies are associated with edema in the dorsal hand region, sclerodactylia, Raynaud phenomenon and pericarditis (CIE); arthritis, hand edema, Raynaud phenomenon and sclerodactylia (anti-70 KD-U1-RNP and anti-A-U1-RNP by immunoblotting); and a lower incidence of discoid lupus and chronic renal insufficiency by lupus renal disease (ELISA). Anti-Sm antibodies are associated with Raynaud phenomenon and renal disease (CIE); cutaneous vasculitis, Raynaud phenomenon and thrombosis (anti-BB'-Sm immunoblotting); and arthritis and lower incidence of chronic renal insufficiency (ELISA).

CONCLUSIONS

Anti-U1-RNP and anti-Sm antibodies detected by ELISA do not have the same clinical significance than those detected by immunoblotting or CIE. The clinical manifestations associated with such antibodies in the same SLE population vary according to the detection technique used.

Anticardiolipin antibodies in pediatric patients with human immunodeficiency virus

OBJECTIVE

To study the presence of IgG and IgM anticardiolipin antibodies (aCL) in children with human immunodeficiency virus (HIV) infection and to determine their prevalence and clinical significance.

METHODS

We studied 34 children with HIV infection: 26 patients were classified P-2, and 8 were P-1 according to the Centers for Disease Control classification. HIV transmission was from mother to child in 33 cases. aCL were measured by ELISA:

RESULTS

IgG aCL were found in 28 (82%) and IgM aCL in 7 (20%). No difference in frequency and levels was found between class P-2 (85%, mean 54.5 PL units) and class P-1 (75%, mean 50.3 PL units). aCL were not related to the duration of the infection, clinical stage of disease, or with events like opportunistic infections. Children from sexually infected or intravenous drug user mothers showed no differences.

CONCLUSION

As in adults, aCL are commonly found in children with HIV infection. The significance of this finding is still unclear.