Comparison of treatment with fluorinated glucocorticoids to the natural history of autoantibody-associated congenital heart block: retrospective review of the research registry for neonatal lupus

Controversies in the therapy of isolated congenital complete heart block

Controversies in the therapy of congenital complete heart block are reviewed in terms of the timing of pacemaker implantation, the type and complications of pacing and its role in the presence of myocardial dysfunction. Drug treatment may be useful in selected cases in the presence of pleural effusions, ascites and hydrops of the fetus, but have no effect on complete heart block. Administration of fluorinated steroids in anti-Ro antibody-positive mothers with the aim of preventing complete heart block has given controversial results. Because of the variety of the clinical presentations, especially in regard to pacing therapy, it is mandatory to refer patients with congenital complete heart block to specialized centers with adequate resources and experienced personnel.

Prevention of complete heart block in children of mothers with anti-SSA/Ro and anti-SSB/La autoantibodies: detection and treatment of first-degree atrioventricular block

PURPOSE OF REVIEW

To describe the results of two recent prospective studies that may indicate how to monitor, diagnose, and treat fetuses with neonatal lupus manifesting with heart involvement and to summarize additional research reports regarding the pathophysiology and outcomes of this rare condition.

RECENT FINDINGS

The PR Interval and Dexamethasone Evaluation study found 10 cases of neonatal lupus (10%) with three first-degree atrioventricular blocks (AVBs) and three complete heart blocks. The study included 98 pregnancies in 95 women with anti-SSA/Ro antibodies who completed weekly fetal Doppler echocardiogram-based evaluation. The authors concluded that they were unable to detect first-degree AVB before progression to complete heart block. A similar observational prospective study was performed in 70 fetuses of 56 mothers using tissue velocity fetal kinetocardiogram for measurement of PR prolongation. In this study, six fetuses (8.5%) showed first-degree AVB, and fast normalization of heart function was achieved through maternal treatment with fluorinated steroids. The authors concluded that fetal kinetocardiogram can detect first-degree AVB in the fetus exposed to maternal anti-SSA/Ro or anti-SSB/La antibodies or both and that fluorinated steroids given on detection were associated with normalized atrioventricular conduction in fetuses with first-degree AVB.

SUMMARY

Echo Doppler seems a less reliable method for early detection of fetus first-degree AVB, and it is suggested that fetal kinetocardiogram or fetal electrocardiography are preferred. Although atrioventricular block reverses spontaneously in some fetuses, parents and treating physicians should consider immediate treatment with fluorinated steroids once a first-degree AVB is detected due to the high risk of rapid progression to complete blockage.

Fetal Doppler mechanical PR interval: correlation with fetal heart rate, gestational age and fetal sex

OBJECTIVES

To establish normal fetal values for the mechanical PR interval by pulsed-wave Doppler at 16-36 weeks of gestation, and to evaluate the influence of fetal heart rate (FHR), gestational age (GA) and fetal sex.

METHODS

Fetal mechanical PR intervals were evaluated prospectively by obstetric ultrasound examination. Healthy mothers with sonographically normal fetuses from singleton pregnancies were included. Mechanical PR intervals were measured from simultaneous mitral and aortic Doppler waveforms, from the onset of left atrial contraction (mitral A-wave) to the onset of left ventricular ejection (aortic pulse wave). Simple and multiple linear regression analyses were performed to examine the correlation between PR interval and GA, FHR and fetal sex.

RESULTS

We evaluated 336 fetuses at 16-36 weeks. The mean +/- SD FHR was 143.4 +/- 8.3 beats per min (bpm). The PR intervals had a typical Gaussian distribution with a mean +/- SD of 122.4 +/- 10.3 ms. Robust linear regression showed that the PR increased by about 0.40 ms (95% CI, 0.22-0.58) per gestational week (P < 0.001), and this relationship remained after adjustment for FHR and fetal sex. PR intervals diminished by 1.4 (95% CI, 0.75 to 2.0) ms for each 5 bpm increase in FHR (P < 0.001), independently of GA and fetal sex. No fetal sex differences were observed.

CONCLUSIONS

We provide normal fetal values for the mechanical PR interval at 16-36 weeks of gestation. Mechanical PR intervals in normal fetuses are influenced by GA and FHR independently, and both variables should be taken into account when evaluating fetuses at risk for congenital heart block.

Congenital heart block associated with Sjögren syndrome: case report

BACKGROUND

Congenital heart block is a rare complication of pregnancy associated with Sjögren Syndrome that may result in the death of the foetus or infant, or the need for pacing in the newborn or at a later stage.

CASE REPORT

The case is presented of a 64-year-old patient with primary Sjögren Syndrome and a history of having given birth to two sons with congenital heart block, both of whom required pacing several years later.

CONCLUSION

The literature relating to this association is discussed including the suggested mechanism, long-term outcome of mothers of children with congenital heart block and preventive treatment strategies.

[Fetal ultrasonography and Doppler in isolated congenital heart block]

Isolated congenital heart block is linked to transplacental passage of maternal anti-SSA/Ro and/or anti-SSB/La antibodies that may be related to a connective tissue disease. Ultrasonography and Doppler are essential to screen fetus at risk. They allow the diagnosis of first- and second-degree blocks which are probably preliminary stages in conducting tissue's injury. In these situations, a maternal treatment by fluorinated steroids can be proposed because of its possible effect on partial blocks. However, these early signs of nodal injury can be lacking: some fetus present a complete heart block without previously detected less advanced block. Moreover, the significance of first-degree block is unclear since it could reverse spontaneously. Other markers of nodal injury would be valuable. In case of complete congenital heart block, ultrasonography is useful to detect congestive heart failure and help the obstetrical management when unfavorable prognostic signs occur.

Cardiac manifestations of neonatal lupus erythematosus: guidelines to management, integrating clues from the bench and bedside

One of the strongest clinical associations with autoantibodies against components of the SSA/Ro-SSB/La ribonucleoprotein complex is the development of congenital heart block in an offspring, an alarming prospect facing 2% of primigravid mothers with these reactivities. This risk is increased tenfold in women who have had a previous child with congenital heart block. Accumulated evidence suggests that anti-SSA/Ro and anti-SSB/La antibodies are necessary but insufficient for fetal disease. Basic and clinical research is heavily focused on identifying fetal and environmental factors that convert disease susceptibility to disease development. A disturbing observation that has emerged from current research efforts is the rapidity of disease progression, with advanced heart block and life-threatening cardiomyopathy being observed less than 2 weeks after detection of a normal sinus rhythm. Once third-degree block is unequivocally identified, reversal has never been achieved, despite dexamethasone treatment. Accordingly, strategies aimed at preventing disease before irrevocable scarring ensues assume a high priority. One approach has been the implementation of serial echocardiography to monitor for a prolonged PR interval. Intravenous immunoglobulin is being evaluated as a potential prophylactic approach in mothers who have previously had an affected child.

Autoimmune associated congenital heart block: integration of clinical and research clues in the management of the maternal / foetal dyad at risk

One of the strongest associations with autoantibodies directed to components of the SSA/Ro-SSB/La ribonucleoprotein complex is the development of congenital heart block (CHB) in an offspring, an alarming prospect facing 2% of primigravid mothers with these reactivities. This risk is 10-fold higher in women who have had a previously affected child with CHB. Anti-Ro/La antibodies are necessary but insufficient to cause disease. In vitro and in vivo experiments suggest that the pathogenesis involves exaggerated apoptosis, macrophage/myfibroblast crosstalk, TGFbeta expression and extensive fibrosis in the conducting system and in some cases surrounding myocardium. A disturbing observation is the rapidity of disease progression, with advanced heart block and life-threatening cardiomyopathy observed <2 weeks from normal sinus rhythm. Once 3rd degree (complete) block is identified, reversal has never been achieved, despite dexamethasone. Current strategies include the evaluation of an early echocardiographic marker of injury, such as a prolonged PR interval and the use of IVIG as a preventative measure for pregnancies of mothers with previously affected children.

Prospective evaluation of fetuses with autoimmune-associated congenital heart block followed in the PR Interval and Dexamethasone Evaluation (PRIDE) Study

We evaluated the efficacy of dexamethasone (DEX) in anti-SSA/Ro-exposed fetuses newly diagnosed with congenital heart block. Previous use of DEX has been anecdotal with varying reports of therapeutic benefit. This was a multicenter, open-label, nonrandomized study involving 30 pregnancies treated with DEX (22 with third-degree block, 6 with second-degree block, 2 with first-degree block) and 10 untreated (9 with third-degree block, 1 with first-degree block). Initial median ventricular rates, age at diagnosis, and degree of cardiac dysfunction were similar between groups. Six deaths occurred in the DEX group. There was no reversal of third-degree block with therapy or spontaneously. In fetuses treated with DEX, 1/6 with second-degree block progressed to third-degree block and 3 remained in second-degree block (postnatally 1 paced, 2 progressed to third degree); 2 reverted to normal sinus rhythm (NSR; postnatally 1 progressed to second degree). DEX reversed the 2 fetuses with first-degree block to NSR by 7 days with no regression at discontinuation. Absent DEX, the 1 with first-degree block detected at 38 weeks had NSR at birth (overall stability or improvement in 4 of 8 in the DEX group vs 1 of 1 in the non-DEX group). Median gestational birth age was 37 weeks in the DEX group versus 38 weeks in the non-DEX group (p = 0.019). Prematurity and small size for gestational age were restricted to the DEX group. Pacemaker use and growth parameters at birth and 1 year were similar between groups. In conclusion, these data confirm the irreversibility of third-degree block and progression of second- to third-degree block despite DEX. A potential benefit of DEX in reversing first- or second-degree block was supported in rare cases but should be weighed against potential steroid side effects such as growth restriction.

Early Diagnosis and Treatment of Atrioventricular Block in the Fetus Exposed to Maternal Anti-SSA/Ro-SSB/La Antibodies

Background— A fetus exposed to maternal anti-SSA/Ro or anti-SSB/La antibodies (or both) may develop complete atrioventricular block (AVB), which results in high prenatal and postnatal morbidity and mortality. Until recently, only high-grade AVB could be diagnosed in utero. The tissue velocity–based fetal kinetocardiogram (FKCG) enables accurate measurement of AV conduction time and diagnosis of low-grade AVB. In the present multicenter observational study, we used FKCG to detect first-degree AVB in fetuses at risk.

Methods and Results— FKCG was performed in 70 fetuses of 56 mothers who were positive for anti-SSA/Ro and/or anti-SSB/La. Fetuses were monitored with weekly FKCG from 13 to 24 weeks’ gestation, followed by monthly assessments until delivery in unaffected fetuses and weekly assessments in affected fetuses. AV conduction in 70 at-risk and 109 normal fetuses was compared. FKCG was obtained readily in all fetuses; 6 showed first-degree AVB (AV conduction time >2 z scores above normal mean) at 21 to 34 gestational weeks. Immediate maternal treatment with dexamethasone resulted in normalization of AV conduction in all affected fetuses within 3 to 14 days. AV conduction time in the remaining 64 untreated fetuses remained normal throughout gestation. The ECG PR interval immediately after birth was normal in all affected newborns. No child developed AVB or cardiomyopathy in the subsequent 1- to 6-year (median 4-year) follow-up.

Conclusions— The present findings suggest that an FKCG can detect first-degree AVB in the fetus exposed to maternal anti-SSA/Ro or anti-SSB/La antibodies (or both). Dexamethasone given on detection was associated with normalized AV conduction in fetuses with first-degree AVB. No fetus in the present study developed complete prenatal or postnatal AVB.

Outcome of prenatally diagnosed isolated congenital complete atrioventricular block treated with transplacental betamethasone or ritodrine therapy

The effectiveness of transplacental drug therapy for prenatally diagnosed isolated congenital complete atrioventricular block (CCAVB) is controversial. Nine cases of prenatal isolated CCAVB were treated from 2002 to 2007. Ritodrine was administered transplacentally to all fetuses and betamethasone to those whose mothers tested positive for maternal anti-SSA/Ro antibodies. Six of the nine patients had an anti-SSA/Ro-positive mother and received transplacental betamethasone 4 mg/day at a median gestational age of 28 weeks (range, 24-31 weeks). No patients exhibited an improvement in the degrees of complete heart block, and one patient died in utero. No serious adverse events occurred. After the mean follow-up period of 1.7 +/- 1.3 years, all five patients treated with transplacental betamethasone experienced a good cardiac function, whereas one of the three patients not treated with transplacental betamethasone experienced cardiomyopathy and died at the age of 4 months. Pacemaker implantation was required for seven of the eight live-born infants. Transplacental betamethasone therapy for the patients with isolated CCAVB neither improved the degree of atrioventricular block nor decreased the rate of patients requiring pacemaker implantation, but it probably reduced the risk for the development of myocardial disease.

Isolated congenital atrioventricular block diagnosed in utero: natural history and outcome

BACKGROUND

Isolated congenital atrioventricular block (CAVB) diagnosed in utero is associated with a high morbidity and mortality. Prognosis is especially poor when heart rate drops below 55 beats per minute (bpm) and when fetal hydrops develops. We describe the natural history and outcome of 24 infants with isolated CAVB diagnosed in utero, review the literature, and assess the risk factors that could predict outcome.

METHODS

This was a retrospective multicenter study of 24 patients with isolated CAVB diagnosed in utero.

RESULTS

CAVB was detected at a mean gestational age (GA) of 24.7 +/- 5.1 weeks. Ten fetuses initially presented with complete heart block. Low heart rate or incomplete heart block was the first documentation of bradyarrhythmia in the other 14 fetuses. In 11 of them, CAVB developed during pregnancy after a median time of 3 (range 1-16) weeks. Fetal hydrops developed in 10 of 24 (42%) fetuses at a mean GA of 27.6 +/- 5.1 weeks. Hydropic fetuses showed lower heart rates during pregnancy (47 +/- 10 bpm) than non-hydropic fetuses (57 +/- 10 bpm). There were three intrauterine deaths; all were hydropic and female. Nine viable females and 12 males were born at a mean GA of 37.1 +/- 6.1 weeks with an average birth weight of 3097 +/- 852 g. Fifteen CAVB patients required pacemaker (PM) intervention, 10 of them immediately after birth. Dilated cardiomyopathy (DCM) developed in three infants of whom two died of congestive heart failure, shortly after the diagnosis was made; one is still alive. Mortality before or after birth was 21%, and was associated with heart rates below 50 bpm and development of fetal hydrops. Poor outcome, defined as death, PM implantation, or development of DCM, occurred in 83% of cases and was associated with heart rates below 60 bpm during pregnancy.

CONCLUSIONS

Isolated CAVB diagnosed in utero is associated with high morbidity and mortality. Patients who develop fetal hydrops show lower heart rates during pregnancy than patients who do not. A fetal heart rate below 50 bpm and development of fetal hydrops is associated with increased mortality. Rates below 60 bpm are associated with PM requirement and/or DCM.

Perinatal Outcome of Fetal Atrioventricular Block

Background— Fetal atrioventricular (AV) block is an uncommon lesion with significant mortality. Because of the rarity of this disorder, the natural course, extensive evaluation of untreated fetuses, and late follow-up remain unclear.

Methods and Results— Of the 116 consecutive cases of fetal AV block studied from 1988 to 2006, only 1 was terminated, and 75% were live births. Fifty-nine cases of AV block were associated with major structural heart disease, mainly left atrial isomerism (n=40), with only 26% of neonatal survivors. Of the 57 fetuses with normal cardiac anatomy, 41 (72%) were positive for maternal antinuclear antibodies, and 32 of these seropositive mothers did not receive any treatment. This untreated group had live-birth and 1-year infant survival rates of 93% and 90%, respectively. Five fetuses from seronegative mothers showed regression to sinus rhythm during pregnancy. The presence of major structural heart disease, hydrops, an atrial rate ≤120 bpm, and a ventricular rate ≤55 bpm were identified as risk factors for mortality. Logistic regression analysis of the whole group showed that the presence of structural heart disease was the only independent predictor of death ( P <0.001).

Conclusions— This long-term study confirms that fetal AV block has a poor outcome when associated with structural heart disease and that spontaneous regression of AV block is possible in seronegative forms. The survival rate of >90% of our untreated patients with isolated forms of AV block raises concerns about any decision to intervene with immunosuppressive agents.

Antibodies to amino acid 200-239 (p200) of Ro52 as serological markers for the risk of developing congenital heart block

Maternal autoantibodies to the p200-epitope of Ro52 have been suggested to correlate with development of congenital heart block. The aim of the present study was to evaluate the clinical relevance and predictive value of p200-antibodies in high-risk pregnancies. Sera from 515 Finnish, Swedish and American women were included in the study. Sera originated from 202 mothers with an infant affected by second- or third-degree atrioventricular block (AVB), 177 mothers with rheumatic disease having infants with normal heart rate and female blood donors (n = 136). A novel serological assay for Ro52 p200-antibodies with intra- and inter-assay variability of 3% and 3.8% respectively was developed. Mothers of children affected by AVB II-III had significantly higher p200-antibody levels than mothers with rheumatic disease having children with normal heart rate (P < 0.001). In the Swedish cohort, a distinction between foetuses with normal conduction, AVB I, AVB II and III was possible. A significant difference in anti-p200 levels between AVB I and AVB II-III groups compared with foetuses with normal conduction (P < 0.05 and P < 0.01) was observed. Using p200-antibodies as a second step analysis in Ro52-positive pregnancies increased the positive predictive value for foetal cardiac involvement (AVB I, II or III) from 0.39 (0.27-0.51) to 0.53 (0.37-0.68). In conclusion, Ro52 p200-antibodies may occur in women with unaffected children, but levels are significantly higher in mothers of children with congenital heart block and are suggested as a relevant marker in evaluating the risk for foetal AV block.

Diagnosis and management of fetal bradyarrhythmias

Complete atrioventricular block (CAVB) is the most common cause of persistent fetal bradycardia. In the presence of a structurally normal heart, it develops primarily in anti-Ro and anti-La positive antibody pregnancies after 20 weeks of gestation. There is a significant risk of perinatal demise, particularly in association with fetal hydrops, poor ventricular function, and heart rates < 55 beats/min. Transplacental treatment strategies are aimed at preventing or modulating these risk factors. Maternal administration of dexamethasone to mitigate or prevent concomitant myocardial inflammation, in combination with beta-stimulation for persistent fetal bradycardia < 55 beats/min to increase fetal cardiac output, has resulted in significantly improved fetal and neonatal outcomes without reversing CAVB.

The challenge of fetal dysrhythmias: echocardiographic diagnosis and clinical management

OBJECTIVE

The present study aimed to evaluate the management of fetal cardiac dysrhythmias based on prior identification of the underlying electrophysiological mechanism.

METHODS

We studied 36 consecutive fetuses with cardiac dysrhythmia. Rhythm diagnosis was based on M-mode, pulsed wave Doppler and tissue Doppler imaging (TDI). Only fetuses with: (i) incessant tachycardia (> 12 h) and mean ventricular rate > 200 beats/min, (ii) signs of left ventricular dysfunction, or (iii) hydrops, were treated using oral maternal drug therapy.

RESULTS

The mean gestational age at diagnosis was 24.3 +/- 4.5 weeks. Twenty-one fetuses had tachycardia with a 1: 1 atrial-ventricular (AV) conduction. Based on ventricular-atrial interval, prenatal diagnosis was: permanent junctional reciprocating (n = 6), atrial ectopic (n = 6) or atrial-ventricular re-entry tachycardia (n = 9). One had atrial flutter, one ventricular tachycardia and four congenital AV block. Nine showed premature atrial or ventricular beats. Fifteen fetuses with incessant tachycardia, left ventricular dysfunction or hydrops were prenatally treated with maternal administration of digoxin, sotalol or flecainide. The total success rate (sinus rhythm or rate control) was 14/15 (93%). Seven fetuses were hydropics. Three of these died (one at 28 weeks of gestation, two in the first week of life). The prenatal diagnosis of dysrhythmia was confirmed at the birth in 31 of 35 live-born. No misdiagnosis was made using TDI. At 3 +/- 1.1-year follow-up, 33/35 children were alive and well.

CONCLUSIONS

Fetal echocardiography could clarify the electrophysiological mechanism of fetal cardiac dysrhythmias and guide the therapy.

Congenital heart block: clinical features and therapeutic approaches

Isolated congenital heart block is strongly associated with anti-Ro antibodies. It occurs in 2% of anti-Ro antibody positive pregnancies with a recurrence rate of 17-19%. Mortality is high in the first year of life (12-41%) and is predominantly due to dilated cardiomyopathy. A prolonged QTc occurs in 15-22% of cases and minor structural defects such as atrial septal defects and patent arterial ducts are well recognized. The 'mechanical' PR interval can now be measured in utero allowing for the detection of first-degree heart block. Both first and second-degree heart block detected in utero respond to therapy with fluorinated steroids. Complete congenital heart block is not reversible. Progression from a normal PR interval to complete heart block can occur within a week. IVIG is under investigation for the prevention of recurrence of congenital heart block, while dexamethasone should not be used for this purpose due to unacceptable toxicity. Data on the use of fluorinated steroids for established complete heart block is conflicting, although their use in cases where there is evidence of hydrops, poor ventricular function or both is not controversial.

Utility of cardiac monitoring in fetuses at risk for congenital heart block: the PR Interval and Dexamethasone Evaluation (PRIDE) prospective study

BACKGROUND

Anti-SSA/Ro-associated third-degree congenital heart block is irreversible, prompting a search for early markers and effective therapy.

METHODS AND RESULTS

One hundred twenty-seven pregnant women with anti-SSA/Ro antibodies were enrolled; 95 completed an evaluable course in 98 pregnancies. The protocol included fetal echocardiograms performed weekly from 16 to 26 weeks' gestation and biweekly from 26 to 34 weeks. PR intervals >150 ms were considered prolonged, consistent with first-degree block. Ninety-two fetuses had normal PR intervals. Neonatal lupus developed in 10 cases; 4 were neonatal lupus rash only. Three fetuses had third-degree block; none had a preceding abnormal PR interval, although in 2 fetuses >1 week elapsed between echocardiographic evaluations. Tricuspid regurgitation preceded third-degree block in 1 fetus, and an atrial echodensity preceded block in a second. Two fetuses had PR intervals >150 ms. Both were detected at or before 22 weeks, and each reversed within 1 week with 4 mg dexamethasone. The ECG of 1 additional newborn revealed a prolonged PR interval persistent at 3 years despite normal intervals throughout gestation. No first-degree block developed after a normal ECG at birth. Heart block occurred in 3 of 16 pregnancies (19%) in mothers with a previous child with congenital heart block and in 3 of 74 pregnancies (4%) in mothers without a previous child with congenital heart block or rash (P=0.067).

CONCLUSIONS

Prolongation of the PR interval was uncommon and did not precede more advanced block. There was a trend toward more congenital heart block in fetuses of women with previously affected offspring than those without previously affected offspring. Advanced block and cardiomyopathy can occur within 1 week of a normal echocardiogram without initial first-degree block. Echodensities and moderate/severe tricuspid regurgitation merit attention as early signs of injury.

Neonatal lupus erythematosus: case report and review of the literature

A neonatalis lupus erythematosus (NLE) az újszülöttek első néhány hónapjának megbetegedése, melyet az édesanya autoimmun betegségének (SLE, Sjögren, rheumatoid arthritis stb.) kapcsán termelődő, placentán átjutó anti-SSA- és anti-SSB-ellenanyagok okoznak. Ritka megbetegedés. Tünetei érinthetik a bőrt (jellegzetes annuláris, erythemás plakkok), a szívet, a májat és a vérképzést. Legsúlyosabb következménye a 20–30%-os mortalitásért elsősorban felelős III. fokú AV-blokk, mely maradandó károsodás, s pacemaker beültetését teszi szükségessé. A tünetek általában kezelés nélkül megszűnnek az anyai ellenanyagok kiürülésével párhuzamosan a csecsemő 6–9 hónapos korára. Esetünkben a tipikus bőrtünetek az egész testet érintették, már születéskor fennálltak, de szívblokk nem alakult ki. A diagnózist jelentősen nehezítette, hogy az édesanya betegsége nem volt ismert a szülés idején. A jelentős thrombocytopenia, progrediáló bőrtünetek és emelkedett májfunkciós értékek miatt szisztémás szteroid adására kényszerültünk.

FETAL BRADYCARDIA. A PRACTICAL APPROACH

Fetal bradycardia may herald fetal demise. This article highlights arrhythmic fetal bradycardia rather than bradycardia caused by perinatal distress. We briefly examine the embryonic conduction system's development and physiology and we review the classification, aetiology, evaluation, and approach to fetal bradycardia. Our aim is to provide the clinician with practical information about fetal bradycardia that enlightens causative conditions and aids management.

Epidemiology, etiology, detection, and treatment of autoantibody-associated congenital heart block in neonatal lupus

Neonatal lupus syndrome is a model of passively acquired autoimmunity in which the pregnant woman's serum contains specific antibodies to 52 or 60 kd SSA/Ro and/or 48 kd SSB/La, which cross the placenta and are associated with the development of congenital heart block in the fetus and/or a transient rash or various liver and blood cell abnormalities in the newborn. To date, congenital heart block is a permanent condition that entails significant morbidity and mortality, with nearly all affected infants requiring pacemakers and with an 80% cumulative probability of survival at 3 years of age. An intensive search is on for the specific etiopathophysiology and for new clinical tools to approach and treat this disease.

Neonatal lupus syndromes

Neonatal lupus has become an important model of passively acquired autoimmunity since the seminal observation in the late 1970s that sera from nearly all mothers of children with isolated congenital heart block (CHB) contain specific autoantibodies.

Drug exposure, pregnancy outcome and fetal and childhood development occurring in the offspring of mothers with systemic lupus erythematosus and other chronic autoimmune diseases

Most autoimmune diseases occur more commonly in females and many of these young women wish to become mothers. For pregnancy to proceed successfully immunomodulation and physiological changes preparing the reproductive system need to occur. Pregnancy occurring in a chronically ill mother who requires medications in order to maintain her own health and who may have already incurred significant organ pathology gives rise to several problems and so four questions arise: 1) What will be the effect of the pregnancy on the underlying disease? 2) What will be the effect of the disease on the outcome of pregnancy? 3) How to manage the disease, just prior to, throughout and immediately after the pregnancy? 4) The long term fetal and childhood effects of maternal disease and its management. This paper reviews the current literature pertaining to these questions in patients with systemic lupus erythematosus (SLE) and other chronic rheumatic and autoimmune diseases.

Characterization of T-cell population in children with prolonged fetal exposure to dexamethasone for anti-Ro/SS-A antibodies associated congenital heart block

The objectives of the study were to characterize the production, function and survival of T lymphocytes of children with prolonged fetal exposure to dexamethasone for anti-Ro/SS-A antibodies associated congenital complete heart block. The analysis of thymic function, studied by measuring the level of T-cell receptor excision circles, was performed by real time PCR, the composition of T-cell subpopulation was evaluated by flow cytometry and the T-cell diversity was assayed by heteroduplex analysis. T-cell competence was gauged at two functional levels by determining the proliferation and the number of T-cell divisions and by measuring gamma-interferon production after mitogenic stimulation. We observed that the thymic output, distribution of T-cell subsets, thymidine incorporation, number of T-cell divisions, and y-interferon production were comparable to those of age-matched control. On the contrary, heteroduplex analysis demonstrated the presence of both polyclonal and oligoclonal peripheral T-cell repertoires. In conclusion, the analysis of the T-cell compartment in children with prolonged intrauterine exposure to high dose dexamethasone did not disclose any relevant abnormality, except a restriction of T-cell receptor diversity in some patients.

Specificity and effector mechanisms of autoantibodies in congenital heart block

Complete congenital atrio-ventricular (AV) heart block develops in 2-5% of fetuses of Ro/SSA and La/SSB autoantibody-positive pregnant women. During pregnancy, the Ro/SSA and La/SSB antibodies are transported across the placenta and affect the fetus. Emerging data suggest that this happens by a two-stage process. In the first step, maternal autoantibodies bind fetal cardiomyocytes, dysregulate calcium homestasis and induce apoptosis in affected cells. This step might clinically correspond to a first-degree heart block, and be reversible. La/SSB antibodies can bind apoptotic cardiomyocytes and thus increase Ig deposition in the heart. The tissue damage could, as a second step, lead to spread of inflammation in genetically pre-disposed fetuses, progressing to fibrosis and calcification of the AV-node and subsequent complete congenital heart block. Early intrauterine treatment of an incomplete AV-block with fluorinated steroids has been shown to prevent progression of the heart block, making it clinically important to find specific markers to identify the high-risk pregnancies.

Outcome of fetal cardiac defects

PURPOSE OF REVIEW

The present review summarizes the prenatal and postnatal outcome of cardiac anomalies and sustained arrhythmias diagnosed during fetal life.

RECENT FINDINGS

The outcome of sustained fetal arrhythmias has improved with greater experience using Sotalol for atrial flutter, and digoxin and amiodarone for 1: 1 reciprocating tachycardia. The outcome of fetal conduction system disease secondary to maternal Sjögren's antibodies has noticeably improved with transplacental dexamethasone. The postnatal prognosis for atrioventricular block associated with left atrial isomerism, however, remains very bleak. Assessing the effect of prenatal diagnosis on the outcome of structural defects remains difficult because of the high number of extracardiac anomalies and chromosome defects in this group. Preoperative survival is improved, but postoperative mortality has not improved. One clear advantage of prenatal diagnosis is the selection of fetuses that may benefit from in-utero intervention to limit the progression of their disease or lessen its severity at birth.

SUMMARY

For the most part, postoperative mortality of structural cardiac defects is not significantly improved by prenatal diagnosis. In-utero management of tachyarrhythmias and conduction system disease has improved postnatal outcome, except for the fetus with atrioventricular block and left atrial isomerism.

Heart involvement in systemic lupus erythematosus, anti-phospholipid syndrome and neonatal lupus

Cardiac involvement is one of the main complications substantially contributing to the morbidity and mortality of patients suffering from systemic autoimmune diseases. All the anatomical heart structures can be affected, and multiple pathogenic mechanisms have been reported. Non-organ-specific autoantibodies have been implicated in immune complex formation and deposition as the initial triggers for inflammatory processes responsible for Libman-Sacks verrucous endocarditis, myocarditis and pericarditis. Anti-phospholipid antibodies have been associated with thrombotic events in coronary arteries, heart valve involvement and intra-myocardial vasculopathy in the context of primary and secondary anti-phospholipid syndrome. Antibodies-SSA/Ro and anti-SSB/La antigens play a major pathogenic role in affecting the heart conduction tissue leading to the electrocardiographic abnormalities of the neonatal lupus syndrome and have been closely associated with endocardial fibroelastosis.

Autoimmunity and pregnancy: autoantibodies and pregnancy in rheumatic diseases

In women who suffer from rheumatic diseases (RDs) the risk of repeated fetal loss, intrauterine growth restriction, and preterm birth remains higher than in the general population. Antiphospholipid antibodies are frequently observed in patients with systemic lupus erythematosus (SLE). They are associated with recurrent pregnancy losses that may occur at any age of gestation. The cause of fetal death is believed to be intraplacental thrombosis, although other pathologic mechanisms have been described. A recent study has described the increased frequency of learning disabilities in the offspring of SLE patients; case reports of neonatal thrombosis are very rare. Transplacental passage of IgG anti-Ro/SS-A antibodies is linked to neonatal lupus (2%). The main manifestation is congenital heart block (CHB) due to the binding of anti-Ro/SS-A antibodies to cardiac conduction tissue and to the consequent inflammatory/fibroid reaction. Neonatal lupus also includes cutaneous, hematologic, and hepatobiliary manifestations, which are typically transient. Incomplete CHB can be treated with fluorinated corticosteroids to prevent the progression and decrease inflammation. Intravenous immunoglobulin, decreasing the tranplacental passage of anti-Ro/SS-A, has been proposed as prophylactic therapy in patients who had one or more child with CHB. Transplacental passage of antiplatelet antibodies, in about 10% of mothers with SLE, can induce thrombocytopenia in the fetus or the neonate. Patients with RD have a higher incidence of anxiety and depression compared to the general population, interfering with parenthood and the upbringing of children.

Systemic lupus erythematosus and pregnancy

Women with systemic lupus erythematosus (SLE) face significant risks when embarking on a pregnancy, but attending a multidisciplinary clinic staffed by an experienced team can improve pregnancy outcome for women and their babies. Pregnancy in SLE should be planned and a management strategy should be agreed in full consultation with the patient, prior to conception. Pregnancy increases the likelihood of a lupus flare. It is not possible to predict when, or if, an individual patient will flare, although flare is more likely if disease has been active within 6 months of conception. Worsening of proteinuria in pregnancy could herald a lupus flare, but the differential diagnosis also includes the physiological response to pregnancy and pre-eclampsia. Corticosteroids, hydroxychloroquine and azathioprine are safe to use in pregnancy, with no adverse fetal effects reported despite many years of experience with their use. Correct identification of patients with antiphospholipid syndrome is important because treatment of affected women during pregnancy can improve fetal and maternal outcome. Neonatal SLE, although rare, carries a significant mortality and morbidity when the fetal heart is the targeted organ. Prophylaxis therapies, including treatment with intravenous immunoglobulin, await larger trials.

Doppler echocardiographic and electrocardiographic atrioventricular time intervals in newborn infants: evaluation of techniques for surveillance of fetuses at risk for congenital heart block

OBJECTIVE

To evaluate one novel and two previously reported Doppler flow velocimetric techniques to estimate atrioventricular (AV) time intervals, suggested to be useful for early identification of fetuses at risk for congenital heart block.

METHODS

In 22 newborn infants, Doppler tracings were obtained from the mitral valve/aortic outflow and the superior vena cava/ascending aorta, as an ECG was recorded simultaneously. AV time intervals were measured using the onsets of the mitral A-wave/aortic outflow (MV-Ao), superior vena cava a-wave/aortic flow (SVC-Ao), and mitral A-wave/mitral valve closure (MV) as indirect markers of electrical atrial/ventricular activation.

RESULTS

Close positive linear relationships to the electrocardiographic PR interval were demonstrated for the MV-Ao (r = 0.82, S(y/x) = 7.4 ms), SVC-Ao (r = 0.85, S(y/x) = 6.8 ms), and MV (r = 0.92, S(y/x) = 3.8 ms) approaches. Both techniques using the aortic flow to indicate ventricular activation overestimated the PR interval: the MV-Ao by + 32 +/- 7.7 ms (mean +/- SD) and the SVC-Ao approach by + 22 +/- 7.0 ms. The new MV approach using mitral closure for the same purpose did not overestimate the PR interval, but there was a trend towards underestimation of the PR intervals as time intervals increased.

CONCLUSIONS

When systematic differences between echocardiographic and electrocardiographic AV time intervals are compensated for, all three techniques are useful to get indirect estimates of the PR interval. As MV recordings only need insonation of a single valve, and are thus easier to obtain, this technique may be of value as a first screening method to identify fetuses in need for further surveillance. In cases with AV time prolongation the SVC-Ao method seems superior.

Assessment of fetal atrioventricular time intervals by tissue Doppler and pulse Doppler echocardiography: normal values and correlation with fetal electrocardiography

OBJECTIVE

To establish gestational age-specific reference values of normal fetal atrioventricular (AV) time interval by spectral tissue Doppler imaging (TDI) and pulse-wave Doppler (PD) methods, and to assess their correlation with signal-averaged fetal PR intervals (ECG).

DESIGN

Cohort study.

SETTING

Tertiary centre for fetal cardiology. PATIENTS AND MEASURES: 131 pregnant women between 14 and 42 weeks' gestation underwent 196 fetal echocardiograms and 158 fetal ECG studies. TDI-derived AV intervals were measured as the intervals from atrial contraction (Aa) to isovolumic contraction (IV) and from Aa to ventricular systole (Sa) at the right ventricular free wall. PD-derived AV intervals were measured from simultaneous left ventricular inflow/outflow (in/out) and superior vena cava/aorta (V/AO) recordings.

RESULTS

Measurements were possible by ECG in 61%, by TDI in 100%, by in/out in 100% and by V/AO in 97% of examinations. Aa-IV correlated significantly better with PR intervals (y = 0.67x + 38.29, R(2) = 0.15, p < 0.0001, mean bias 8.0 ms) than did in/out (R(2) = 0.10, p = 0.002, bias 18.7 ms) and V/AO (R(2) = 0.06, p = 0.02, bias 12.4 ms). Gestational age and AV intervals were positively correlated with all imaging modalities (R(2) = 0.19-0.31, p < 0.0001).

CONCLUSION

This study showed the feasibility of fetal AV interval measurements by TDI, and established gestational age-specific reference data. TDI-derived Aa-IV intervals track ECG PR intervals more closely than PD-derived AV intervals and thus should be used as the ultrasound method of choice in assessing fetal AV conduction.

[Systematic lupus erythematosus and antiphospholipid syndrome during pregnancy]

Women with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) are subject to several complications during pregnancy, including reactivation of SLE, thrombosis, miscarriage, neonatal lupus, pregnancy-induced hypertension, pulmonary hypertension and drug toxicity. Correct management of these patients requires combined medical-obstetric care, close surveillance of baby's growth and well-being, control of SLE activity and correct thromboprophylaxis. With good care, most pregnancies in women with SLE and APS end successfully.

Doppler tissue imaging in the assessment of atrioventricular conduction time: validation of a novel technique and comparison with electrophysiologic and pulsed wave Doppler-derived equivalents in an animal model

Accurate assessment of atrioventricular conduction time (AVCT) is crucial for early detection of evolving fetal heart block. Simultaneous pulsed wave Doppler (PD) interrogation of left ventricular inflow and outflow is mainly used to study fetal AVCT. Limitations of this modality include its dependency on loading conditions and merging early and late diastolic inflow waves at faster heart rate (HR). Sequential analysis of atrioventricular myocardial motion by Doppler tissue imaging (DTI) might be more useful in this regard. In 15 open-chest pigs, AVCT was measured by PD, DTI, and electrocardiogram at baseline HR and during incremental atrial pacing up to 200 beats/min. Electromechanical delay and pre-ejection period were assessed at baseline and maximal HR. DTI-derived AVCT correlated better with PR intervals and allowed measurements at faster HRs than did PD (P < .05). Pre-ejection period prolonged with faster HR (P < .001), unlike electromechanical delay. In conclusion, DTI allows more accurate measurement of AVCT over a wider HR range than does PD.

Le lupus néonatal

Children born from mothers positive for autoantibodies against SSA/Ro and/or anti-SSB/La ribonucleoproteins may develop heart conduction tissue damage resulting in atrioventricular block and/or transient skin rash, liver enzyme abnormalities and anaemia/thrombocytopenia. Additional transient electrocardiographic abnormalities (sinus bradycardia, QT interval prolongation) have been reported. Such clinical and laboratory manifestations are included in the so-called neonatal lupus syndromes, independently whether the mother is suffering from a systemic autoimmune disease or is totally asymptomatic. The prevalence of the congenital heart block is around 2%, of neonatal rash around 20%, while laboratory abnormalities in asymptomatic babies can be detected in up to 40% of cases. The risk of recurrence of complete heart block is almost 10 times higher in the following pregnancies. Most of the mothers are asymptomatic at delivery and are identified only by the birth of an affected child. Their long-term outcome is generally more reassuring than previously assumed. Serial echocardiograms and obstetric sonograms, performed at least every 2 weeks, starting from 16 weeks gestation, are recommended in anti-Ro/SSA positive pregnant women: the goal is to detect early fetal abnormalities, that might precede complete atrioventricular block and that might be a target for preventive therapy. Transplacental passage of maternal anti-SSA/Ro -SSB/La IgG is thought to be pivotal in inducing tissue damage. However, the discordant appearance of the syndrome in twins does suggest a role also for fetal or environmental factors.

Prise en charge obstétricale des patientes à risque de « lupus néonatal »

Fetuses and infants of women with anti-SSA/Ro and anti-SSB/La antibodies are at risk of neonatal lupus syndrome, featuring skin lesions, hematological and hepatic disorders, and congenital heart block (CHB) in the absence of severe cardiac malformation. The prevalence of CHB in newborns of anti-SSA/Ro positive women with known connective tissue disease is 1 to 2% and the risk of recurrence ranges from 10 to 17%. CHB is definitive and is associated with significant morbidity (pacemaker must be implanted in 2/3 of cases) and mortality (16 to 19%). Myocardial involvement may either be associated or appear subsequently. Other manifestations are discussed. For anti-SSA/Ro positive pregnant women, echocardiograms should be performed every 2 weeks from 16 to 24 weeks of gestation, and every week in case of past history of CHB. Electrocardiogram should be performed in the first days of life for all children to detect incomplete CHB. Therapy for CHB detected in utero is based on fluorinated steroids, especially betamethasone. Its efficiency is variable.

Syndrome de Gougerot-Sjögren en gynécologie obstétrique

Sjogren syndrome (SS) is an immune disease characterized by a progressive degeneration of exocrine glands. It leads to dryness of mucosa and conjunctivitis. Gynecologists and obstetricians may encounter this disease in women at any age, including during pregnancy. Knowledge of the main characteristics is required for early diagnosis and multidisciplinary program. In the event of secondary Sjögren syndrome occurring during pregnancy, treatment focuses on the associated disease, mainly systemic lupus erythematosus. In primary Sjögren syndrome, pregnancy does not appear to influence disease course. However, patients with both primary and secondary Sjögren syndrome must be monitored carefully. There is a risk of neonatal lupus and congenital atrioventricular bloc associated with high morbidity and mortality. These patients should benefit from multidisciplinary care in a hospital with a neonatal intensive care unit.

Normal neuropsychological development in children with congenital complete heart block who may or may not be exposed to high-dose dexamethasone in utero

BACKGROUND

Antenatal and postnatal treatment with dexamethasone (DEX) may negatively affect the neuropsychological development in children. Maternal anti-Ro/Sjögren's syndrome A (SSA) antibodies may also be associated with learning disabilities in offspring.

OBJECTIVE

To assess neuropsychological development in babies exposed to very high dosages of DEX in utero, whose mothers were anti-Ro/SSA positive.

METHODS

13 children with congenital complete heart block (CHB) (11 exposed and 2 not exposed to DEX) and 3 healthy siblings, all of anti-Ro/SSA-positive women, were evaluated. 11 preschool-aged children (5 boys) were assessed using Griffiths Mental Development Scales. 5 school-aged children (2 boys) were examined using Wechsler Intelligence Scale for Children-Revised to check IQ and reading tests to explore the existence of learning disabilities or dyslexia. None of the children had had major neonatal complications, although those with CHB had to be paced at different intervals from birth.

RESULTS

The children had been exposed in utero to a mean total dose of 186.6 mg DEX. IQ levels were always normal (mean IQ 105.1, standard deviation (SD) 9.5). Only one child had a learning disability, of borderline clinical significance, but this child had never been exposed to DEX.

CONCLUSION

No negative effects were found on the neuropsychological development in this cohort of children, even if they had been exposed to maternal anti-Ro/SSA antibodies and to very high dosages of DEX (much higher than those used to improve fetal lung maturity). These findings might be of interest in view of the large number of infants exposed in the past to repeated antenatal courses of steroids.

Neonatal lupus erythematosus: a review of the racial differences and similarities in clinical, serological and immunogenetic features of Japanese versus Caucasian patients

There has been tremendous interest in neonatal lupus erythematosus (NLE) since the reports of anti-Ro/SSA antibodies as a diagnostic marker. Recent studies, including ours, have revealed racial differences as well as similarities in the clinical features and immunogenetic backgrounds of Japanese and Caucasian patients with NLE. The frequency of photosensitivity and subacute cutaneous LE lesions is not high in Japanese infants with NLE, which is in sharp contrast to their Caucasian American counterparts. The majority of Japanese infants with NLE develop annular, erythematous or edematous lesions which have also been reported in association with Sjögren's syndrome. The frequency of isolated congenital heart block (CHB) is about 50% in Japanese anti-Ro/SSA positive neonatal lupus infants; this is similar to the frequency among Caucasians. The HLA-DR3 phenotype, which is found in the great majority of Caucasian mothers of NLE infants, is absent in Japanese mothers. Finally, both Japanese and Caucasian children with CHB are often identical to their mothers in their alleles of HLA-DRB1, DQA1 and DQB1 loci.

Identification and management of fetuses at risk for, or affected by, congenital heart block associated with autoantibodies to SSA (Ro), SSB (La), or an HsEg5-like autoantigen

The congenital heart block (CHB), diagnosed in structurally normal hearts, is strongly associated with, if not caused by, maternal SSA/SSB antibodies (Abs). It develops between 16 and 24 weeks' gestation, coincidentally with the increased transplacental IgG passage, and a window of unique cardiac vulnerability. Less is known about rare CHB cases in which neither cardiac malformations nor SSA/SSB Abs are detectable. We report on four pregnant women: patient 1 at high CHB risk (owing to Sjögren's syndrome (SS) and recurrent pregnancy losses), and patients 2-4 with already established CHB (aggravated by hydrops in patient 2). Abs were found directed to SSA/SSB (patients 1-3) or to an HsEg5-like autoantigen instead (patient 4). During preventive immunoadsorption (IA) from week 19 throughout (patient 1), or therapeutic IA (plus dexamethasone), commenced at week 25 (patient 2), SSA Ab levels decreased per session by 47+/-7 or 80+/-16%, respectively, and hydropic changes resolved. Patient 1 delivered a healthy boy, while patients 2-4 gave birth to CHB-affected children at need for permanent pacing. The irreversibility of complete CHB may justify (a) early ANA screening in all pregnancies (thereby also considering specificities as anti-HsEg5), and (b) preventive immmunoadsorption in high-risk pregnancies (before/during the critical cardiac development phase). This implies controversy, because factors converting risk to disease (in only approximately 2%) are unknown, and prospective randomized treatment studies are not available, given the rarity of CHB.

Conduction system disease in fetuses evaluated for irregular cardiac rhythm

OBJECTIVES

To determine the prevalence of 1st and 2nd degree AV block in fetuses with an irregular cardiac rhythm, and to summarize outcome of these pregnancies.

BACKGROUND

The diagnosis of irregular cardiac rhythm or 'skipped beats' includes isolated ectopy that resolves spontaneously. Recently, Doppler measurements of the 'mechanical' PR interval have been shown to identify AV conduction disease prenatally. Prenatal therapy of these conduction abnormalities may limit the progression to more advanced disease either in utero or after birth.

METHODS

A retrospective review was performed of fetuses evaluated between 1996 and 2004 with the findings of irregular cardiac rhythm. 1st or 2nd degree AV block was diagnosed on Doppler and M-mode recordings, and confirmed using either fetal magnetocardiography (fMCG) or postnatal 12-lead ECG. Dexamethasone was administered to 4 mothers with abnormal fetal AV conduction in the setting of anti-Ro/anti-La antibodies.

RESULTS

Of 702 fetuses initially referred for arrhythmia, 306 had an irregular rhythm. Eight (2.6%) had intermittent 1st or 2nd degree AV block confirmed by fMCG and/or postnatal 12-lead ECG. AV block was presumed idiopathic in 2, associated with congenital long QT syndrome in 2 or with clinically unsuspected maternal anti-Ro or anti-La antibodies in 4. During the intrauterine period there was no progression to complete AV block and all were born alive at 34-40 weeks of gestation.

CONCLUSION

A small but clinically significant population of fetuses with irregular rhythm will have 1st or 2nd degree AV block. Transplacental therapy may limit the intrauterine progression to more advanced disease.

Fetal brady- and tachyarrhythmias: new and accepted diagnostic and treatment methods

Sustained bradyarrhythmias are typically the result of symptomatic sinus bradycardia, atrial bigeminy or complete atrioventricular (AV) block. Fetal tachyarrhythmias relate to sinus tachycardia, atrial flutter and supraventricular tachycardia as the main aetiology. Ultrasound is essential to understand the underlying arrhythmia mechanism, to study the impact on cardiac function, to exclude cardiac defects or tumours, and to survey the fetal heart rate and well-being, e.g. during anti-arrhythmic treatment. Based on retrospective studies, several more or less safe, effective and well-tolerated anti-arrhythmic agents are currently available for the treatment of atrial and supraventricular tachycardia. Isolated congenital complete AV block is mainly related to maternal anti-Ro/La auto-antibodies. The rationale to treat a fetus at this irreversible stage of AV nodal damage is primarily to mitigate or prevent concomitant myocardial inflammation and to augment cardiac output. A recently published study demonstrated a significant improved outcome with transmaternal dexamethasone and beta-stimulation.

Maternal antibody responses to the 52-kd SSA/RO p200 peptide and the development of fetal conduction defects

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.

Neonatal lupus: basic research and clinical perspectives

Neonatal lupus, although quite rare, carries a significant mortality and morbidity when the fetal heart is the targeted organ. Anti-SSA/Ro-SSB/La antibodies are present in more than 85% of mothers whose fetuses are identified with congenital heart block (CHB) in a structurally normal heart, but the risk for a woman who has the candidate antibodies to have a child who has CHB is approximately 2%. Although the precise pathogenic mechanism of injury remains unknown, it is clear that the antibodies alone are insufficient to cause disease, and fetal factors are likely contributory. In vivo and in vitro evidence supports a pathologic cascade, involving apoptosis of cardiocytes, surface translocation of Ro and La antigens, binding of maternal autoantibodies, secretion of profibrosing factors (eg, tumor growth factor ) from the scavenging macrophages, and modulation of cardiac fibroblasts to a myofibroblast-scarring phenotype. The spectrum of cardiac abnormalities encompasses varying degrees of block identified in utero and late-onset cardiomyopathy. Better echocardiographic measurements that identify first-degree block in utero may be the optimal approach for pregnant women at risk; prophylactic therapies, including treatment with intravenous immunoglobulin, await larger trials.