Clinical relevance of antibodies to Ro/SS-A and La/SS-B in subacute cutaneous lupus erythematosus and related conditions

Ro/SS-A autoantibodies are frequently associated with subacute cutaneous lupus erythematosus, neonatal lupus erythematosus and Sjögren's syndrome. The Ro/SS-A autoantigen is a ribonucleoprotein complex consisting of at least four protein components and four small cytoplasmic RNA components designated hY RNA 1, 3, 4 and 5. Three of the Ro/SS-A peptides have been isolated and cloned. The function of this ribonucleoprotein complex is as yet unknown.

Route of delivery of infants with congenital anomalies

Obstetric delivery may be accomplished by only two methods, vaginally or abdominally. In the management of the pregnancy complicated by a fetal malformation, the choice of delivery method may be made on obstetrical grounds or in belief that one method offers the fetus benefit over the other. That choice must be based on knowledge of the nature of the individual malformation in question, the presence or absence of associated fetal malformations, the presence or absence of fetal karyotype abnormalities, fetal maturity, and fetal presentation. Clear evidence of benefit from cesarean delivery is not available in the case of many malformations that are often considered for abdominal delivery. The infrequency of many of these anomalies typically precludes the accumulation of sufficient experience in any one center or successful completion of randomized trials to evaluate treatment modalities. Most studies therefore are retrospective or flawed by small numbers of patients. Logic dictates that certain malformations that produce sufficient enlargement of fetal structures are at probable risk for dystocia of labor (e.g., severe hydrops, severe hydrocephalus, large sacrococcygeal teratoma) and may benefit from abdominal delivery. Other malformations may predispose the affected fetus to trauma or decompensation during labor and vaginal delivery. It is these anomalies that have the most controversy surrounding the "best" mode of delivery and of which we have attempted to address. Table 4 includes proposed criteria for choosing abdominal versus vaginal delivery in the gestation complicated by congenital anomaly. The birth method in the context of a fetal malformation is a choice optimally made after careful discussions with the patient, pediatrician, and pediatric surgeons. Such discussion should include a careful review of the nature of the anomaly, the optimal prognosis, and the evidence of benefit for a specific birth method. Once the pregnancy in question has been evaluated, appropriate consultations obtained, and the available data reviewed with the patient, the obstetrician again assumes a role of patient advocate. The obstetrician is the counselor, the educator, and the friend the patient needs during such a difficult time. The discussion of birth method in the case of a fetal malformation creates a conflict of interest for the patient, but typically a paradoxic result of this conflict occurs. The patient's welfare, which is usually best served by vaginal delivery, may be in conflict with the fetal concerns, which might benefit from abdominal delivery. The data might be clear but more often the data are less than convincing.(ABSTRACT TRUNCATED AT 400 WORDS)

[Congenital isolated complete atrioventricular block: long-term experience with 38 patients]

BACKGROUND

The management of patients with isolated congenital complete heart block is controversial, and indications for cardiac pacing are not clearly defined. In the present study we report our long-term experience in the management of patients with this disease.

METHODS

Thirty-eight consecutive patients aged 2 days to 28 years (mean age 10 years) were studied and followed up for 130 +/- 57 months (range 18 to 274). They underwent an extensive evaluation including history, physical examination, electrocardiography and echocardiography; thirty-seven patients had Holter monitoring and exercise test. Electrophysiologic study was performed in 24 patients.

RESULTS

Twenty-two patients were asymptomatic, sixteen had symptoms as syncope or presyncope (7 patients), marked exercise intolerance (1 patient), presyncope and marked exercise intolerance (1 patient), heart failure (1 patient), mild dyspnea on exertion (6 patients). Electrocardiograms showed a narrow QRS in all patients. Holter monitoring showed a marked bradycardia (awake heart rate < or = 55 beats/min in infants, < or = 40 beats/min in children and adults) in 15 patients and junctional pauses of > 3 seconds in 9 of them. The exercise test showed a markedly reduced exercise tolerance in 2 patients and exercise-induced complex ventricular arrhythmias in 3 patients. Echocardiography showed a structurally normal heart and a normal left ventricular function in all patients. The electrophysiologic study always showed a suprahisian site of block. Twenty patients (53%) underwent cardiac pacing at a median age of 14 +/- 10 years and were followed up for 110 +/- 59 months (range 18 to 253) after pacing; prophylactic pacing was performed in 10 patients. Indications for cardiac pacing were: syncope or presyncope (7 patients), presyncope and marked exercise intolerance (1 patient), neonatal heart failure (1 patient), marked exercise intolerance (1 patient), neonatal marked bradycardia (2 patients), marked bradycardia with junctional pauses of > 3 seconds and/or complex ventricular arrhythmias (7 patients), complex ventricular arrhythmias (1 patient). No death occurred during the follow-up. In 9 of 20 patients who had cardiac pacing, indication for this procedure appeared during the follow-up (development of symptoms, marked bradycardia and/or complex ventricular arrhythmias). Complications of pacing were infrequent (9 complications in 7 patients) and mainly occurred in the first years of our experience. At present 12 patients have an atrioventricular sequential pacing and 8 have a rate-responsive ventricular one. All patients who had pacing showed an improvement of exercise tolerance; 11 of them underwent exercise test after pacing which showed a significant increase in exercise duration (from 11.1 +/- 1.9 to 15.3 +/- 1.1 min, p < 0.01). In the 3 patients with complex ventricular arrhythmias we observed their suppression after atrioventricular sequential pacing. At present 35 patients are asymptomatic and 3 have mild dyspnea on exertion.

CONCLUSIONS

Our results confirm that patients with isolated congenital complete heart block often have symptoms and/or signs of electric instability without symptoms. Cardiac pacing relieves symptoms and improves working capacity. Although in this study we are not able to draw conclusions on the therapeutic value of prophylactic pacing, our favourable follow-up results suggest that this therapeutic approach may prevent complications.

Neonatal lupus erythematosus

Neonatal lupus erythematosus (NLE) is an autoimmune disease whose major findings are subacute cutaneous lupus erythematosus (SCLE) skin lesions and congenital heart block. Babies have maternal anti-Ro/SSA, anti-La/SSB, or anti-U1RNP autoantibodies. Anti-Ro/SSA are the predominant autoantibodies, having been found in about 95% of cases. The autoantibodies pass through the placenta from mother to child. Skin disease resolves at about the time that maternal autoantibodies can no longer be detected in the baby. NLE therefore provides the strongest clinical evidence that autoantibodies are involved in at least some manifestations of lupus erythematosus, but there is as yet no definitive evidence implicating autoantibodies in the disease process. Skin disease usually begins after birth, is transient, and does not result in scarring. Cardiac disease begins in utero, and the heart block is almost always permanent. Many babies require pacemakers, and about 10% die from complications related to cardiac disease. In some cases, transient liver disease or thrombocytopenia have been observed. Individuals who had NLE usually have healthy childhoods but may develop autoimmune disease in adulthood. Whether the later development of autoimmune disease is a common or an unusual event is not yet known. Mothers of babies with NLE may be asymptomatic initially, but with time usually develop symptoms of autoimmune disease. The most typical constellation of symptoms in our group of approximately 30 mothers of babies with NLE is that of Sjögren's syndrome. Most babies exposed to anti-Ro/SSA autoantibodies during gestation will not develop NLE. There is no test to determine prospectively which babies will be affected. Treatment during gestation is still controversial and, if attempted, should be reserved for fetuses with potentially life-threatening disease. Treatment after birth consists of topical management for skin disease and pacemaker implantation, if necessary, for heart block. Systemic steroids may be given for serious internal disease.

[Congenital auriculo-ventricular block and anti-Ro (SS-A)/anti-La (SS-B) antibody]

Congenital heart blocks due to immunological causes are rare. A case is reported of a fetus with auriculo-ventricular block diagnosed at 22 weeks of amenorrhoea and intrauterine death at 32 weeks. The authors discussing the case find the most likely link: an anti-RO (SS-A) and anti-LA (SS-B) immunological block and they suggest that there are minor localised lesions in the nodal tissue which gives rise to benign disturbances of cardiac rhythm and they point out ways of preventing intrauterine auriculo-ventricular block.

A case of torsade de pointes occurring in a newborn with persistent 2:1 atrioventricular block

A case of QT interval prolongation with ventricular tachycardia and torsade de pointes is reported. Arrhythmias occurred in a baby with persistent 2:1 atrioventricular block and long QT interval 2 days after birth and were self-limiting. No structural cardiac defect was present. Serum levels of sodium, potassium, magnesium and calcium were in the normal range. Finally, the pathogenetic mechanism of cardiac block is discussed.

Atrioventricular conduction in children of women with systemic lupus erythematosus

The neonatal lupus syndrome consists of transient cutaneous lupus lesions or permanent congenital complete heart block (or hepatic fibrosis), or both, in infants born to mothers with systemic lupus erythematosus (SLE). The frequency of conduction abnormalities was examined in 86 offspring of 53 women affected by SLE. Electrocardiograms from the offspring demonstrated normal sinus rhythm in 84 of 86 offspring. The PR interval was normal for age (< 95th percentile) in 82 offspring and normal for heart rate in 81. Three children had a PR interval > 95th percentile (i.e., first-degree heart block) for both age and heart rate. The PR interval of the other 6 subjects with first-degree heart block for age or heart rate (> or = 95th percentile) was < or = 0.18 second. In contrast, using a rank assignment of PR intervals in relation to heart rate and age derived from published standards, grouped data indicated that heart rate adjusted for age was greater and PR interval adjusted for heart rate longer in offspring of mothers who had the onset of SLE before or during pregnancy than in the normal population; this observation did not hold for offspring whose mothers developed SLE after the pregnancy. These findings indicate that offspring of mothers with SLE, even in the absence of an abnormal electrocardiogram, may have experienced a maternal internal environment that produces subclinical changes in atrioventricular conduction. However, newborns with a normal pulse rate are unlikely to have significant abnormalities in atrioventricular conduction and do not need screening electrocardiograms at birth.

Permanent pacemaker implantation in premature infants less than 2,000 grams of body weight

Pacemaker implantation in premature infants presents technical problems because of the relatively larger size of the pulse generator compared with their bodies. A new technique with which successful generator implantation was performed in 2 premature infants less than 2,000 g of body weight is described. The generator is wrapped in a Gore-Tex surgical membrane. A piece of membrane overlying the electrical contact surface of the generator is removed, and the generator is fixed to the abdominal wall in the peritoneal cavity. The technique is simple to perform and would give relative ease in generator exchange.

Adults with congenital complete heart block: 25-year follow-up

Complete congenital heart block has been recognized since 1846, yet the prognosis of the disease has not been determined by comprehensive long-term studies. We reviewed 14 cases of complete congenital heart block at The Cleveland Clinic Foundation. The patients were followed for a mean of 25 years (range, 20 to 32 years). Ten patients had structurally normal hearts, and 4 had varying degrees of congenital heart disease. The patients were evaluated with regard to symptoms, and indications for permanent pacemaker implantation were studied. Seven patients received permanent pacemakers. Ages at the time of pacemaker implantation ranged from 15 to 38 years (mean, 25 years). Overall, the patients in our study tended to lead normal productive lives. The main indications for pacemaker implantation were symptoms alone. Guidelines for prophylactic pacemaker implantation have yet to be determined, and the development of these guidelines is difficult due to small numbers of patients at isolated centers. A large international study is needed to set these guidelines.

Familial congenital sinus rhythm anomalies: clinical and pathological correlations

We describe pathological abnormalities in a 72-year-old male member of a family with a congenital absence of sinus rhythm and a tendency to develop atrial fibrillation at an early age, and in a 54-year-old female member of a family with cardiomyopathy and progressive conduction system disease manifested by first-degree atrioventricular (AV) block, left bundle branch block, and atrial arrhythmias. Both patients died suddenly. The absence of sinus rhythm in case 1 could be explained by marked atrophy, degeneration, and isolation of the sinoatrial (SA) node. The SA node was also diseased in the member of the other family with atrial arrhythmias. Additional common features in both cases included: fatty metamorphosis and degenerative changes of the approaches to the SA node, the atrial preferential fibers, and the approaches to the AV node, a small AV node, degenerative changes of the bundle branches, and floppy AV valves. These findings show that the pathological substrate of familial supraventricular arrhythmias consists of a diffuse involvement of the entire conduction system, bearing resemblance to pathological findings in elderly subjects with acquired sick sinus syndrome.

Neonatal lupus syndromes

Neonatal lupus is a model of passively acquired autoimmunity in that immune abnormalities in the mother lead to the production of antibodies that cross the placenta and injure the developing fetus. Congenital complete heart block (CCHB), a permanent manifestation of neonatal lupus, is detectable after 18 wk gestation. Transient manifestations include cutaneous, hepatic, and hematologic abnormalities that occur at variable frequency. To date, there is a universal association of CCHB with maternal antibodies to SSA/Ro-SSB/La ribonucleoproteins, detectable by high ratio monomer:crosslinker SDS-immunoblot. Intriguingly, cardiac disease and often other manifestations are not present in the mother, raising the hypothesis that there is differential expression and/or accessibility of SSA/Ro-SSB/La antigens in fetal vs. adult tissues. CCHB may be a final consequence of a more widespread inflammatory response in the heart, including the existence of an associated myocarditis. In contrast to the in utero onset of CCHB, skin lesions generally become apparent after birth. Ultraviolet exposure may be an initiating factor and exacerbate an existing rash. Several studies have documented the predominance of DR3 alleles in mothers of affected offspring, frequently associated with the extended haplotype A1,B8. Available evidence suggests that fetal genetic differences in the major histocompatibility complex (MHC) do not influence susceptibility. The recommended clinical approach includes obstetric and rheumatologic management of both the fetus identified with CCHB and the fetus with a normal heart beat but at high risk of developing CCHB. Fetal echocardiogram is essential in diagnosing and following disease and may suggest the presence of an associated myocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)

Target antigens of the SSA/Ro and SSB/La system

The SSA/Ro and SSB/La antigens are polypeptides which serve as autoantigens in systemic lupus erythematosus and Sjogren's syndrome. The SSA/Ro contains two major isoforms of 60 kD and 52 kD. The former is the main native antigen while the latter is a major autoantigen in its denatured form. The SSB/La is a single phosphorylated protein of 48 kD. Recently a new protein of 46 kD, termed calregulin, was suggested as an additional component of the SSA/Ro antigens. However, extensive investigations failed to confirm its relation to the SSA/Ro system. Based on molecular techniques and cDNA cloning of these antigens, it was demonstrated that the 60 kD protein is capable of binding RNA and DNA molecules, suggesting a regulatory role in transcription for this antigen. The 52 kD polypeptide contains multiple zinc finger motifs and its sequence is homologous to the mouse rptl protein, which is a T-cell regulating peptide. The SSB/La is associated with precursors of 5S RNA and tRNA, implying that it has a role in the synthesis and maturation of RNA polymerase III transcripts. The 60 kD and 52 kD SSA/Ro components may be associated within the cell. The SSA/Ro and SSB/La may also be in complex in some points of the cell cycle.

[Long-term prognosis of congenital atrioventricular block]

The aim of this study was to assess the long term prognosis of congenital atrioventricular block (AVB). From 1965 to 1990, 42 cases of congenital AVB (22 antenatal or natal diagnoses and 20 presumed congenital AVB according to Yater's criteria). The AVB was isolated in 28 cases and associated with cardiac disease in 14 cases (8 of which were corrected transposition of the great arteries). The average age of the patients was 14 years (range 32 years to 18 months) at the time of the study. There was a clear female predominance (64%). Maternal connective tissue disease was present in 18% of cases (in the group of children born after 1977 when maternal connective tissue diseases was systematically looked for). Cardiac failure was present in 10 cases (8 with associated AVB); syncope and sudden death were observed in 11 cases. The indication for pacemaker therapy was the presence of poor prognostic factors: syncope, poorly controlled cardiac failure, low heart rate, increased QRS duration, prolonged QTc, infrahisian AVB, long pauses or arrhythmias on Holter monitoring. The only significant prognostic factors in this series were a previous history of syncope, increased QRS duration and a QTc of over 0.45 seconds. Fourteen patients were paced (endocavitary pacing only from 1981), usually in the DDD mode: 8 for syncope, 2 for cardiac failure, 4 for a poor prognostic factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal echocardiography in the assessment of lupus pregnancies

Fetal echocardiography is the most sensitive tool in detecting the earliest possible changes of the cardiovascular system related to maternal lupus. The institution of aggressive therapy at that time may still be able to reverse the process before permanent fetal cardiac injury occurs. Experience with this technique is described.

Neonatal lupus erythematosus in offspring of mothers with experimental systemic lupus erythematosus

Neonatal lupus erythematosus (NLE) syndrome is a result of the transfer of autoantibodies produced by the mother, across the placenta, to the fetus. NLE is characterized by a transient dermatitis, a variety of systemic and hematological abnormalities, and isolated cases of congenital heart block. The latter has been reported to be due to the presence of autoantibodies specific to La (SS-B) and/or Ro (SS-A). As female mice with experimental SLE, induced by immunization with the monoclonal anti-DNA 16/6 Id, produce a variety of autoantibodies including anti-Ro and anti-La antibodies, we examined the relevance of NLE in the murine system. Offspring of SLE-afflicted BALB/c mothers possessed antibody titers to the 16/6 Id, ssDNA, and nuclear extract, which gradually declined until reduced to normal levels by day 60 after delivery. Antibody titers in the sera of the mothers remained elevated throughout this period. Electrocardiograms were recorded from groups of neonates from mothers with experimental SLE. The results indicated that a high percentage of the offspring had defects in their conduction system including first, second, and third degree heart block; significant bradycardia; and wide QRS complex. Normal patterns were observed in offspring of healthy mothers. Experiments done with mice that were exposed to SLE-related autoantibodies early in their development indicated that offspring to mothers with experimental SLE were neither protected nor more susceptible to disease induction by the 16/6 Id.

Disposition of the atrioventricular conduction tissues in the heart with isomerism of the atrial appendages: its relation to congenital complete heart block

OBJECTIVES

Our goal was to compare histologically the mechanisms producing congenital complete heart block in normally structured hearts and in hearts with isomerism of the atrial appendages.

BACKGROUND

It is known that several different histologic patterns can underscore the existence of congenital complete heart block in the normally structured heart, and that block is particularly frequent in the setting of isomerism of the atrial appendages. The histologic findings in the latter setting were compared and contrasted with those found in the normally structured heart.

METHODS

Serial section techniques were used to study 14 hearts with isomerism of the atrial appendage (12 with left isomerism and 2 with right isomerism) and 7 normally structured hearts.

RESULTS

Discontinuity between the atrioventricular (AV) node and the ventricular conduction tissues was found in 10 of the 12 hearts with left isomerism; the other 2 hearts had a normally formed conduction axis and heart block was not present in these cases. In both hearts with right isomerism, "slings" of ventricular conduction tissue connected dual AV nodes; congenital complete heart block was not present in either case. In six of the seven cases with a normally structured heart, anti-Ro antibodies had been found in the maternal serum. All six of these hearts had discontinuity between the atrial tissues and the ventricular conduction axis. Intraventricular discontinuity was found in the seventh case, in which anti-Ro antibodies were not found in the mother.

CONCLUSIONS

The pattern of congenital complete heart block in cases with left isomerism is discontinuity between the AV node and the conduction axis, in contrast to the pattern of atrial-axis discontinuity produced in the normally structured heart when anti-Ro antibodies are found in the maternal serum.

Congenital complete heart block associated with maternal anti-Ro antibody: a case report

The presence of anti-Ro antibody in maternal serum is a serologic marker for increased risk of the development of congenital complete heart block in the fetus. Current etiology and evaluation of these mothers and their fetuses are examined. A case report is presented.

Cross-reactive maternal autoantibodies and congenital heart block

Epitopes with linear sequences recognized by anti-La autoantibodies from seven mothers of children with congenital heart block were recently defined. Eight of these epitopes share sequence identity with three other proteins in addition to the original autoantigen, La. The three proteins are human cardiac myosin beta heavy chain, laminin B1 chain and the M6 protein of Streptococcus pyogenes. Affinity purified anti-La antibodies from a further three mothers bound to the La antigen and also to human cardiac myosin and mouse laminin. Affinity purified antibodies from three mothers of healthy children bound to the La antigen but showed minimal binding to either human cardiac myosin or mouse laminin. Cardiac myosin inhibited the binding of CHB-related anti-La antibodies to both La and myosin. These data support a role for maternal autoantibodies crossing the placenta and recognizing foetal cardiac antigens accessible at a critical developmental stage during gestation. We suggest that this would lead to complement fixation, inflammation and the subsequent pathology associated with congenital heart block.

Congenital complete heart block associated with QT prolongation

The coexistence of congenital complete heart block and QT prolongation represents a special type of arrhythmia. The electrophysiological and clinical characteristics of this syndrome were studied in eight patients suffering from congenital AV block and QT prolongation. Data from 22 patients suffering from congenital complete heart block only, served as a control. In the study group, the appearance of a torsade de pointes type of ventricular tachycardia could regularly be observed and the tachycardial attack could usually be provoked by ventricular extrastimuli. The corrected QT time was markedly prolonged; on ventricular stimulation, at higher pacing rates the QT interval shortened, but remained significantly higher than in the control group. Syncopal attacks--with the character of polymorphic tachycardia--appeared in each patient of the study group while occurring in only three patients from the control group. Patients were given pacemaker implants (using a higher pacing rate) and long-term administration of beta-receptor blockers. The outcome was favourable; no ventricular tachycardia or syncopal attack was observed in the follow-up period.