Faculty Bibliography

Despite the near universal association of congenital heart block and maternal Abs to SSA/Ro and SSB/La, the intracellular location of these Ags has made it difficult to substantiate their involvement in pathogenicity. To define whether components of the SSA/Ro-SSB/La complex, which translocate during apoptosis, are indeed accessible to extracellular Abs, two approaches were taken: immunoprecipitation of surface biotinylated proteins and scanning electron microscopy. Human fetal cardiocytes from 16-24-wk abortuses were cultured and incubated with staurosporine to induce apoptosis. Surface biotinylated 48-kDa SSB/La was reproducibly immunoprecipitated from apoptotic, but not nonapoptotic cardiocytes. Surface expression of SSA/Ro and SSB/La was further substantiated by scanning electron microscopy. Gold particles (following incubation with gold-labeled sera containing various specificities of anti-SSA/Ro-SSB/La Abs and murine mAb to SSB/La and 60-kDa SSA/Ro) were consistently observed on early and late apoptotic cardiocytes. No particles were seen after incubation with control antisera. To evaluate whether opsonized apoptotic cardiocytes promote inflammation, cells were cocultured with macrophages. Compared with nonapoptotic cardiocytes or apoptotic cardiocytes incubated with normal sera, apoptotic cardiocytes preincubated with affinity-purified Abs to SSB/La, 52-kDa SSA/Ro, or 60-kDa SSA/Ro increased the secretion of TNF-alpha from cocultured macrophages. In summary, apoptosis results in surface accessibility of all SSA/Ro-SSB/La Ags for recognition by circulating maternal Abs. It is speculated that in vivo such opsonized apoptotic cardiocytes promote an inflammatory response by resident macrophages with damage to surrounding conducting tissue

OBJECTIVE: To extend the information base on cutaneous manifestations of neonatal lupus erythematosus (NLE) with regard to maternal disease, sex of child, onset, localization, influence of UV light, prognosis, and recurrence rates in subsequent pregnancies. METHODS: Review of records from the Research Registry for Neonatal Lupus. RESULTS: The cohort includes 47 mothers (83% white) whose sera contain anti-SSA/Ro, anti-SSB/La, and/or anti-U1-ribonucleoprotein antibodies and their 57 infants (20 boys and 37 girls) diagnosed with cutaneous NLE (absent heart disease) between 1981 and 1997. At detection of the child's rash, 13 mothers were asymptomatic, 11 had an undifferentiated autoimmune syndrome (UAS), 9 had systemic lupus erythematosus (SLE), 7 Sjogren's syndrome (SS), 6 SLE/SS, and 1 rheumatoid arthritis/SS; 20 reported photosensitivity. Within 5 years, 7 asymptomatic mothers experienced disease progression: 1 developed photosensitivity, 2 SLE, 3 SS, 1 SLE/SS; in 2 mothers UAS progressed to SLE; and 2 mothers with SS developed SLE. The infant's rash often followed UV light exposure; mean age at detection was 6 weeks, and mean duration was 17 weeks. All had facial involvement (periorbital region most common) followed by the scalp, trunk, extremities, neck, and intertriginous areas. In 37, the rash resolved without sequelae, 43% of which were untreated. A quarter had residual sequelae that included telangiectasia and dyspigmentation. One child developed Hashimoto's thyroiditis, and 2 developed systemic-onset juvenile rheumatoid arthritis. Of 20 subsequent births, 7 children were healthy, 2 had congenital heart block (CHB) only, 4 CHB and skin rash, and 7 skin rash only. CONCLUSIONS: Future pregnancies should be monitored by serial echocardiograms, given the substantial risk for heart block. Affected children should be observed for later development of a rheumatic disease

CONTEXT: The reason that only some patients with lupus erythematosus (LE) develop autoantibodies to SS-A/Ro and SS-B/La antigens and photosensitivity is unknown. One hypothesis is that both events are related to the level of expression of these antigens in the skin. OBJECTIVE AND DESIGN: To test this hypothesis, we measured the expression of the 52-kd SS-A/Ro, 60-kd SS-A/Ro, and 48-kd SS-B/La antigens in normal sun-protected and sun-exposed skin in 14 patients with LE with photosensitivity, 12 patients with LE without photosensitivity, and 4 normal individuals. The presence of circulating antibodies to these antigens was measured in all patients. SETTING: Outpatient clinic in an academic medical center. RESULTS: We found that the expression of the 52-kd SS-A/Ro, 60-kd SS-A/Ro, and 48-kd SS-B/La antigens in skin biopsy specimens obtained from the same site was 4- to 10-fold higher in patients with LE with photosensitivity than in those patients with LE without photosensitivity (P<.001). Antigen expression was highly correlated with the presence and titer of circulating anti-SS-A/Ro and anti-SS-B/La antibodies (P<.001). CONCLUSIONS: These findings indicate that photosensitivity and the presence and titer of circulating anti-SS-A/Ro and anti-SS-B/La antibodies are both directly correlated with the expression of accessible and immunoreactive SS-A/Ro and SS-B/La antigens in the skin specimens of patients with LE. Thus, the expression of these antigens in keratinocytes may be an important determinant of the development of both SS-A/Ro and SS-B/La autoantibodies and of photosensitive forms of LE

OBJECTIVE: During ovulation induction (OI), ovarian stimulation is accomplished by hormonal manipulation, which includes administration of gonadotropins, gonadotropin-releasing hormone agonists, follicle-stimulating hormone, and luteinizing hormone. In in vitro fertilization (IVF), progesterone is often added. Because of the possibility of hormone-associated flare or thrombosis, patients with systemic lupus erythematosus (SLE) and primary antiphospholipid syndrome (primary APS) undergoing OI/IVF are potentially at increased risk. The present study was conducted in order to assess this risk. METHODS: Nineteen women who underwent 68 cycles of OI/IVF were studied by interview and retrospective chart review. RESULTS: Four OI/IVF cycles (25%) in SLE patients resulted in increased lupus activity and 2 (13%) in ovarian hyperstimulation syndrome. One patient with primary APS who was given heparin during multiple cycles developed osteopenia. No thrombosis occurred. Pregnancy complications included toxemia, lupus flare, gastrointestinal hemorrhage due to Mallory-Weiss tear, polygestation, and diabetes. Postpartum complications included nephritis flare, costochondritis, and suicidal depression. Lupus flares occurred at expected rates. Five of 16 cycles (31%) in 7 SLE patients, 5 of 48 cycles (10%) in 10 primary APS patients, and 0 of 5 cycles in 2 women with antiphospholipid antibody (without SLE or primary APS) resulted in liveborn children, including multiple gestations (3 twin sets with 4 surviving infants and 2 triplet sets with 3 surviving infants). Seven of 14 living children (50%) were premature, 3 had neonatal lupus, and 1 had pulmonic stenosis. Five surviving infants (38%) had complications unrelated to prematurity. CONCLUSION: Although OI/IVF can be successful in SLE and primary APS patients, rates of fetal and maternal complications are high.

OBJECTIVE: To compare intervention with fluorinated glucocorticoids to the natural history of untreated congenital heart block (CHB) with respect to conduction abnormalities, associated effusions, ascites, and hydrops fetalis, and the requirement for a pacemaker. METHODS: Records of all mothers enrolled in the Research Registry for Neonatal Lupus were reviewed. The cohort includes 47 mothers whose sera contain anti-SSA/Ro or anti-SSB/La antibodies, and their 50 offspring with CHB, in whom at least 4 echocardiograms were performed after in utero diagnosis. In 28 pregnancies, mothers received dexamethasone 4-9 mg/day for 3-19 weeks or betamethasone 12-24 mg/week for >6 weeks (group A). In 22 pregnancies, fluorinated steroids were not used (group B). RESULTS: Third-degree block was present in 21 fetuses in group A and 18 fetuses in group B; none were reversible despite steroid treatment. Three fetuses in group A and 2 in group B progressed from second-degree block, alternating with third-degree block, to permanent third-degree block at birth and postnatally. Of 4 fetuses in group A with second-degree block at presentation, all reverted to first-degree block by birth; 2 remain so at age 4 years, 1 alternates between first-degree and second-degree block at 2 years, and the fourth is in second-degree block at age 4 years. Of 2 fetuses in group B with second-degree block at presentation, both progressed to permanent third-degree block postnatally. Initial echocardiographic evaluation revealed pericardial effusions in 13 group A versus 4 group B fetuses, pleural effusions in 2 group A versus 0 group B, ascites in 8 group A versus 0 group B (P < 0.007), hydrops fetalis in 8 group A versus 0 group B (P < 0.007), and intrauterine growth restriction in 1 group A versus 1 group B. Pericardial effusions resolved and reappeared in both groups. Steroid therapy was most effective in the resolution of pleural effusions (2 of 2), ascites (6 of 8), and hydrops fetalis (5 of 8). Oligohydramnios ensued in 9 group A and 2 group B fetuses. Although fetuses in group A had more complications at presentation than those in group B, there were no significant differences in the duration of pregnancy (35.7 weeks versus 37.0 weeks), the number of deaths (4 versus 1), final degree of heart block, or requirement for a pacemaker (14 versus 11). CONCLUSION: While prospective trials are needed, these data suggest that fluorinated steroids should be considered for fetuses with incomplete block or hydropic changes. Serial echocardiograms are recommended to monitor fetal progress. It remains to be determined whether third-degree block is reversible if therapy is initiated immediately upon detection

Mothers of children with neonatal lupus erythematosus (NLE) and heart block, as well as patients with Sjogren's syndrome (SS) and systemic lupus erythematosus, have serum autoantibodies that recognize SS-A/Ro autoantigens including the 60-kDa ribonucleoprotein. By yeast 2-hybrid screening, we identified a novel 75-kDa protein (pp75) that interacts with the carboxyl 70% of 60-kDa SS-A/Ro. The specificity of interaction was confirmed using mammalian 2-hybrid and chemical crosslinking studies. Immunoprecipitation with radiolabeled HeLa cell extracts showed that pp75 was phosphorylated and associated with 2 other phosphoproteins of 64 kDa. In Northern blot analysis, pp75 was expressed in all tissues analyzed; the highest expression was in the human heart. Based on immunofluorescence of transfected HeLa cells, pp75 is localized predominantly in the cytoplasm, an observation confirmed by immunohistochemistry in untransfected cells. Based on Western blot and ELISA assays, sera from 14 of 84 mothers of children with NLE recognized pp75, including 1 mother in whom anti-SS-A/Ro antibodies were not detected. In addition, sera from 5 of 80 patients with SS were positive for anti-pp75 antibody. Identification of molecular partners is a first step toward elucidating the functions and possible involvement in pathogenesis of long-recognized autoantigens such as 60-kDa SS-A/Ro, which are at present poorly understood

The association of congenital heart block with maternal autoantibodies to SSA/Ro and/or SSB/La ribonucleoproteins suggests a direct role for the autoantibodies in tissue injury. Here, Jill P. Buyon discusses possible pathological mechanisms, including the nature of the target antigen,the role of autoantibodies in altering L-type calcium channel function within the heart, and the potential role of apoptosis in making target antigens available to autoantibodies