Faculty Bibliography

In previous studies, we detected a frame shift mutation in the gene encoding the autoantigen La of a patient with systemic lupus erythematosus. The mutant La mRNA contains a premature termination codon. mRNAs that prematurely terminate translation should be eliminated by RNA quality control mechanisms. As we find Abs specific for the mutant La form in approximately 30% of sera from anti-La-positive patients, we expected that mutant La mRNAs circumvent RNA control and the expression of mutant La protein could become harmful. Indeed, real-time PCR, immunostaining, and immunoblotting data of mice transgenic for the mutant La form show that mutant La mRNAs are not repressed in these animals and are translated to mutant La protein. In addition to the mutant La protein, we detected a minor portion of native human La in the mutant La-transgenic mice. Therefore, ribosomal frame shifting may allow the mutant La mRNA to escape from RNA control. Interestingly, expression of the mutant La mRNA results in a lupus-like disease in the experimental mice. Consequently, escape of mutant La mRNA from RNA control can have two effects: it 1) results in the expression of an immunogenic (neo)epitope, and 2) predisposes to autoimmunity

OBJECTIVE: The anti-La/SSB response to major B cell epitopes of La/SSB can be blocked by an active idiotypic/antiidiotypic network, which can be identified using synthetic complementary epitopes deduced from the sequence of the major B cell epitopes of the molecule. This study evaluated the role of this network in pregnant women with anti-Ro/SSA and/or anti-La/SSB antibodies in the development of neonatal lupus syndrome (NLS). METHODS. Sixty-three serum samples collected from anti-Ro/anti-La-positive women during pregnancy or within 6 months after delivery were obtained from the Research Registry for Neonatal Lupus and the PR Interval Dexamethasone Evaluation study. These samples, as well as 30 sera from healthy individuals, were tested in a blinded manner by enzyme-linked immunosorbent assay against synthetic peptides corresponding to major B cell epitopes and complementary epitopes of La/SSB. RESULTS. Sera from mothers giving birth to a healthy child and having no history of a child with NLS exhibited higher antiidiotypic antibody activity compared with mothers carrying a child with NLS (P < 0.0001) or mothers giving birth to a healthy child but who previously gave birth to a child with NLS (P = 0.0151). Sera from mothers of healthy children, which exhibited no apparent epitope activity against amino acids 349-364, revealed a significantly greater frequency of hidden anti-349-364aa epitope responses, blocked by antiidiotypic antibodies, as compared with sera from women pregnant with an affected child (P = 0.0094). CONCLUSION: The presence of antiidiotypic antibodies to autoantibodies against La/SSB may protect the fetus by blocking pathogenic maternal autoantibodies. Testing for these antiidiotypic responses may be useful in predicting a decreased risk of NLS

BACKGROUND: Oral contraceptives are rarely prescribed for women with systemic lupus erythematosus, because of concern about potential negative side effects. In this double-blind, randomized, noninferiority trial, we prospectively evaluated the effect of oral contraceptives on lupus activity in premenopausal women with systemic lupus erythematosus. METHODS: A total of 183 women with inactive (76 percent) or stable active (24 percent) systemic lupus erythematosus at 15 U.S. sites were randomly assigned to receive either oral contraceptives (triphasic ethinyl estradiol at a dose of 35 microg plus norethindrone at a dose of 0.5 to 1 mg for 12 cycles of 28 days each; 91 women) or placebo (92 women) and were evaluated at months 1, 2, 3, 6, 9, and 12. Subjects were excluded if they had moderate or high levels of anticardiolipin antibodies, lupus anticoagulant, or a history of thrombosis. RESULTS: The primary end point, a severe lupus flare, occurred in 7 of 91 subjects receiving oral contraceptives (7.7 percent) as compared with 7 of 92 subjects receiving placebo (7.6 percent). The 12-month rates of severe flare were similar: 0.084 for the group receiving oral contraceptives and 0.087 for the placebo group (P=0.95; upper limit of the one-sided 95 percent confidence interval for this difference, 0.069, which is within the prespecified 9 percent margin for noninferiority). Rates of mild or moderate flares were 1.40 flares per person-year for subjects receiving oral contraceptives and 1.44 flares per person-year for subjects receiving placebo (relative risk, 0.98; P=0.86). In the group that was randomized to receive oral contraceptives, there was one deep venous thrombosis and one clotted graft; in the placebo group, there was one deep venous thrombosis, one ocular thrombosis, one superficial thrombophlebitis, and one death (after cessation of the trial). CONCLUSIONS: Our study indicates that oral contraceptives do not increase the risk of flare among women with systemic lupus erythematosus whose disease is stable

OBJECTIVE: Opsonization of apoptotic cells by autoantibodies bound to surface membrane-translocated La/SSB antigens may initiate tissue damage in the setting of congenital heart block. By injecting pregnant mice with human anti-La antibodies, we previously demonstrated the formation of IgG-apoptotic cell complexes in the developing mouse fetus; however, the binding of anti-La antibodies to human-specific epitopes could not be addressed. Accordingly, the objective of the current study was to delineate the epitope specificity of human La antibodies that are exposed on the surface of apoptotic cells. METHODS: We used fluorescence microscopy and flow cytometry to assess the binding of human anti-La antibodies affinity purified against immunodominant epitopes of La to human cells undergoing spontaneous apoptosis, in a murine xenograft model in vivo and in cultured human fetal cardiocytes rendered apoptotic in vitro, respectively. RESULTS: Anti-La antibodies bound to immunodominant epitopes of La within the NH(2)-terminus and the RNA recognition motif (RRM) region of apoptotic human cells, in both xenografts and fetal cardiocytes. In contrast, human antibodies affinity purified against the COOH-terminal La epitope did not bind apoptotic cells in either model. This defines the topology of redistributed La during apoptosis, with surface exposure of the NH(2)-terminus and RRM regions. The potential importance of anti-La NH(2)-terminal and anti-La RRM specificity was confirmed by detection of this reactivity in mothers of children with congenital heart block. CONCLUSION: These findings provide insight into both the molecular modification of the La autoantigen during apoptosis and the specificity of antibodies capable of binding to surface-exposed La. Subsequent formation of surface immune complexes may lead to tissue injury in patients with autoimmune diseases such as congenital heart block

BACKGROUND: Since anecdotal series and small, prospective, controlled trials suggest that mycophenolate mofetil may be effective for treating lupus nephritis, larger trials are desirable. METHODS: We conducted a 24-week randomized, open-label, noninferiority trial comparing oral mycophenolate mofetil (initial dose, 1000 mg per day, increased to 3000 mg per day) with monthly intravenous cyclophosphamide (0.5 g per square meter of body-surface area, increased to 1.0 g per square meter) as induction therapy for active lupus nephritis. A change to the alternative regimen was allowed at 12 weeks in patients who did not have an early response. The study protocol specified adjunctive care and the use and tapering of corticosteroids. The primary end point was complete remission at 24 weeks (normalization of abnormal renal measurements and maintenance of baseline normal measurements). A secondary end point was partial remission at 24 weeks. RESULTS: Of 140 patients recruited, 71 were randomly assigned to receive mycophenolate mofetil and 69 were randomly assigned to receive cyclophosphamide. At 12 weeks, 56 patients receiving mycophenolate mofetil and 42 receiving cyclophosphamide had satisfactory early responses. In the intention-to-treat analysis, 16 of the 71 patients (22.5 percent) receiving mycophenolate mofetil and 4 of the 69 patients receiving cyclophosphamide (5.8 percent) had complete remission, for an absolute difference of 16.7 percentage points (95 percent confidence interval, 5.6 to 27.9 percentage points; P=0.005), meeting the prespecified criteria for noninferiority and demonstrating the superiority of mycophenolate mofetil to cyclophosphamide. Partial remission occurred in 21 of the 71 patients (29.6 percent) and 17 of the 69 patients (24.6 percent), respectively (P=0.51). Three patients assigned to cyclophosphamide died, two during protocol therapy. Fewer severe infections and hospitalizations but more diarrhea occurred among those receiving mycophenolate. CONCLUSIONS: In this 24-week trial, mycophenolate mofetil was more effective than intravenous cyclophosphamide in inducing remission of lupus nephritis and had a more favorable safety profile

OBJECTIVE: To identify a finer level of antibody specificity for risk of congenital heart block (CHB) than reactivity to 52-kd SSA/Ro (Ro 52). METHODS: Serum from mothers enrolled in the Research Registry for Neonatal Lupus and the observational PR Interval and Dexamethasone Evaluation (PRIDE) study was evaluated for reactivity against peptide aa200-239 of Ro 52 (p200), recently reported to be associated with a higher risk of CHB. RESULTS: The majority of 156 Ro 52-positive sera tested were reactive with p200 (>3 SD above control), irrespective of the clinical status of the child. Optical density (OD) values of p200 did not differ significantly among mothers of children with CHB (mean +/- SD 0.187 +/- 0.363), mothers of children with rash (mean +/- SD 0.176 +/- 0.356), and mothers of children without neonatal lupus (mean +/- SD 0.229 +/- 0.315). Reactivity against p200 was found in 80 of 104 mothers of children with CHB (77%), 24 of 30 mothers of children with rash (80%), and 21 of 22 mothers who delivered healthy children and had no children with neonatal lupus (95%) (P not significant for all comparisons). Sera from 4 mothers of children with CHB with varied p200 titers (OD range 0.025-1.818) bound to the surface of non-permeabilized apoptotic, but not proliferating, human fetal cardiocytes. In 32 Ro 52-positive women who completed the PRIDE study (22 with no child with neonatal lupus, 7 with a child with CHB, and 3 with a child with rash) in whom p200 levels were determined during pregnancy, the correlation between level of p200 (OD range 0.000-1.170) and maximal fetal PR interval (range 115-168 msec) was not significant (rho = 0.107, P = 0.58). CONCLUSION: Reactivity to p200 is a dominant but not uniform anti-Ro 52 response in women whose children have CHB. Since exposure to this antibody specificity was observed with a similar frequency in children without CHB born to mothers with anti-Ro 52, additional factors are necessary to convert risk to disease expression