Faculty Bibliography

Oral contraceptives containing oestrogens and hormone replacement therapy are generally not prescribed for women with systemic lupus erythematosus (SLE). The concern regarding oestrogens is based on the greater incidence of SLE in women, abnormalities of oestrogen metabolism, murine models of lupus, several anecdotes of patients having disease flares while receiving hormones, and one retrospective study in patients with pre-existing renal disease. For healthy women and those with SLE, there are clinical settings in which exogenous oestrogens provide benefit. For pre-menopausal women, these include provision of safe and effective birth control, protection against bone loss, and the consideration of oral contraceptives to preserve fertility in patients taking cyclophosphamide. For post-menopausal women, these include treatment of hot flushes and vaginal dryness, prevention of osteoporosis and, more controversial, prevention of atherosclerosis. Other exogenous hormones (clomiphene citrate, gonadotropins, gonadotropin-releasing hormones) may be used to elevate levels of endogenous oestrogen and stimulate ovulation in patients with diminished fertility.This chapter focuses on three broad categories: birth control, assisted reproduction and hormone replacement

OBJECTIVE: In isolated congenital heart block, the mechanism by which maternal autoantibodies target the intracellular components of the Ro/La RNP complex is unclear. Previous studies have demonstrated that cultured fetal cardiac myocytes rendered apoptotic bind antibodies to 48-kd La/SSB. This study further investigated the subcellular distribution of the La antigen during apoptosis in the fetal mouse heart and conduction system. METHODS: The atrioventricular (AV) node, AV bundle, and sinoatrial (SA) node were identified in serial sections prepared from paraffin blocks of normal mouse fetuses on days 15, 17, and 19 of gestation. Apoptosis was detected by TUNEL assay. Under confocal microscopy, fluorescent labeling of fragmented DNA in apoptotic cells was assessed by TUNEL, and La protein localization was visualized simultaneously using a murine monoclonal antibody or affinity-purified human polyclonal anti-La antibodies. RESULTS: Apoptotic cells were detected in and at the periphery of the AV and SA nodes as well as in the fetal heart valve insertions and working myocardium. In contrast, no apoptosis was detected in the adult heart AV node or surrounding myocardium. As expected, the La antigen was predominantly immunolocalized to the nucleus in nonapoptotic cells. However, apoptotic cells showed a marked reduction of nuclear La and redistribution of La to the cytoplasm. High-resolution confocal microscopy revealed that in cells that had undergone apoptosis, La antigen asymmetrically clustered near the surface of TUNEL-positive nuclei and apoptotic bodies. CONCLUSION: These data provide the first in vivo demonstration of the subcellular translocation of La autoantigen during apoptosis in the fetal heart and the conduction system under physiologic conditions. This observation supports the hypothesis that subcellular redistribution of La in the normally developing heart facilitates the binding of cognate maternal antibodies and subsequent tissue damage

OBJECTIVE: To extend the information base on the hepatobiliary manifestations of neonatal lupus erythematosus (NLE) with regard to frequency of occurrence, clinical characteristics, and outcome. METHODS: Review of records from the Research Registry for Neonatal Lupus. RESULTS: Nineteen (9%) of 219 patients who had NLE and were enrolled in a national registry had probable or possible NLE hepatobiliary disease. In 16 cases, hepatobiliary disease occurred in addition to cardiac or cutaneous NLE. In 3 cases, hepatobiliary disease occurred as the sole clinical manifestation of NLE. Three clinical variants of hepatobiliary disease were observed: 1) severe liver failure present during gestation or in the neonatal period, often with the phenotype of neonatal iron storage disease; 2) conjugated hyperbilirubinemia with mild or no elevations of aminotransferases, occurring in the first few weeks of life; and 3) mild elevations of aminotransferases occurring at approximately 2 to 3 months of life. The prognosis for the children in the last 2 categories is excellent. CONCLUSIONS: Hepatobiliary disease is a relatively common finding in NLE and can be the sole clinical manifestation of NLE. Clinicians should be aware of the broad range of hepatobiliary disease that may occur in children with NLE

The classic cardiac manifestation of neonatal lupus is congenital heart block, attributed to antibody-mediated inflammation and subsequent fibrosis of the atrioventricular (AV) node. In considering the pathologic process of injury it may be that tissue damage results in a range of conduction abnormalities. Identification of less-advanced degrees of block or of fibrosis around the AV node without any conduction abnormality on EKG would support this pathologic model, and serve as a potential marker for treatment if the conduction defect could be shown to progress. To ascertain the spectrum of arrhythmias associated with maternal anti-SSA/Ro-SSB/La antibodies, records of all children enrolled in the Research Registry for Neonatal Lupus were reviewed. Of 187 children with congenital heart block whose mothers have anti-SSA/Ro-SSB/La antibodies, nine had a prolonged PR interval on EKG at birth, four of whom progressed to more advanced AV block. A child whose younger sibling had third degree block was diagnosed with first degree block at age 10 years at the time of surgery for a broken wrist. Two children diagnosed in utero with second degree block were treated with dexamethasone and reverted to normal sinus rhythm by birth, but ultimately progressed to third degree block. Four children had second degree block at birth: of these, two progressed to third degree block. Sinus bradycardia (< 100 bpm) was present in three (3.8%) of 78 fetuses for whom atrial rates were recorded by echocardiogram. Of 40 neonates for whom EKGs were available, the mean atrial rate was 137+/-20 bpm (range 75-200). These data have important research and clinical implications. In contrast to the AV node, permanent sinoatrial nodal involvement is not clinically apparent. Perhaps many fetuses sustain mild inflammation, but resolution is variable, as suggested by the presence of incomplete AV block. Since subsequent progression of less-advanced degrees of block can occur, an EKG should be performed on all infants born to mothers with anti-SSA/Ro-SSB/La antibodies

Two forms of the human 52 kDa SS-A/Ro protein autoantigen, 52alpha and 52beta, are products of alternative mRNA splicing. The 52alpha form is ubiquitously expressed whereas 52beta, lacking the central leucine zipper domain, has been detected at higher levels than 52alpha during certain stages of fetal development. Because 52alpha has sequence similarity with macromolecules associated with transcriptional regulation and the two forms differ only in that 52beta does not contain the leucine zipper, their roles in protein dimer formation and in transcriptional activity were examined. Employing the yeast two-hybrid system, 52alpha was shown to interact with itself but not 52beta. The homodimerization of 52alpha was independently confirmed in gel filtration chromatography using in vitro cDNA template derived translation products and in HL-60 cell extracts; two peaks were observed corresponding to dimer and monomer of 52alpha, while in vitro the translation product of 52beta exhibited only a single monomer peak. In addition, dimer formation was also demonstrated in a chemical cross-linking experiment using HeLa cells transfected with 52alpha. To evaluate effects on transcription, eukaryotic expression plasmids encoding 52alpha or 52beta fused with the GAL4 DNA binding (DB) domain were co-transfected into 293 cells together with a luciferase reporter vector. A 6-fold increase in transcription activity of the reporter was detected with the GAL4-DB-52beta fusion constructs compared to GAL4-DB-52alpha or the empty vector control. We speculate that the ratio of cellular 52alpha and 52beta may play an important role in regulating gene expression as potential repressor and activator respectively

The detection of isolated heart block in utero strongly predicts the presence of maternal autoantibodies reactive with 52 kDa SSA/Ro. The mechanisms that underlie this observation may be elucidated by defining the function of the target antigen. The initial approach was to identify proteins interactive with 52Ro using transcriptional activity in the yeast 2-hybrid system. A cDNA library was constructed using RNA isolated from human fetal hearts (12-23 weeks) and cloned into the HybriZAP vector encoding the activation domain of GAL4(AD) as target. Approximately 7x10(6) cDNAs were cotransformed with the bait into YRG-2. Plasmids from five interactive colonies were sequenced and three identified as the specific human deubiquitinating enzyme, UnpEL. UnpEL did not interact with bait plasmid encoding 52beta, an alternative leucine zipper-minus form of 52 kDa SSA/Ro which is maximally expressed in fetal life. The mammalian 2-hybrid assay confirmed the interaction between full-length 52Ro and UnpEL. Further support for a biologic interaction was the marked redistribution in cellular localization of UnpEL following cotransfection of the two proteins into cultured human cardiocytes, human renal carcinoma cells (293 cells), and monkey kidney fibroblasts (COS-1). In conclusion, the interaction of full-length 52Ro and UnpEL implies that the former may also be involved in the ubiquitin pathway, an observation of particular interest since 52Ro contains a RING finger domain, a motif common to several recently reported proteins involved in modulating ubiquitination. The absence of an interaction with 52beta raises the consideration that regulation of protein ubiquitination might differ in fetal life