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1.
J Autoimmun ; 107: 102354, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31677965

RESUMO

Mothers giving birth to children with manifestations of neonatal lupus (NL) represent a unique population at risk for the development of clinically evident pathologic autoimmunity since many are asymptomatic and only become aware of anti-SSA/Ro positivity (anti-Ro+) based on heart block in their fetus. Accordingly, we hypothesized that the microbiome in saliva is associated with the development of autoreactivity and in some cases the progression in health status from benign to overt clinical disease including Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE). The study comprised a clinical spectrum of anti-Ro+ mothers, all of whom gave birth to a child with NL: 9 were asymptomatic or had an undifferentiated autoimmune disease (Asym/UAS) and 16 fulfilled criteria for SS and/or SLE. Microbial diversity was reduced across all levels from kingdom to species for the anti-Ro+ mothers vs healthy controls; however, there were no significant differences between Asym/UAS and SS/SLE mothers. Relative abundance of Proteobacteria and more specifically class Betaproteobacteria decreased with clinical severity (healthy controls < Asym/UAS < SS/SLE). These ordered differences were maintained through the taxonomic hierarchy to three genera (Lautropia, Comamonas, and Neisseria) and species within these genera (L. mirabilis, N. flavescens and N. oralis). Biometric analysis comparing von Willebrand Factor domains present in human Ro60 with L. mirabilis proteins support the hypothesis of molecular mimicry. These data position the microbiome in the development of anti-Ro reactivity and subsequent clinical spectrum of disease.


Assuntos
Anticorpos Antinucleares/imunologia , Disbiose , Lúpus Eritematoso Sistêmico/congênito , Efeitos Tardios da Exposição Pré-Natal , Glândulas Salivares/microbiologia , Adulto , Sequência de Aminoácidos , Autoanticorpos/imunologia , Autoimunidade , Biodiversidade , Feminino , Antígenos HLA/imunologia , Humanos , Recém-Nascido , Lúpus Eritematoso Sistêmico/etiologia , Lúpus Eritematoso Sistêmico/metabolismo , Lúpus Eritematoso Sistêmico/terapia , Masculino , Microbiota , Peptídeos/química , Peptídeos/imunologia , Gravidez , Adulto Jovem
2.
Ultrasound Obstet Gynecol ; 54(1): 7-9, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31313868

RESUMO

Linked Comment: Ultrasound Obstet Gynecol 2019; 54: 87-95.


Assuntos
Anticorpos Antinucleares , Bloqueio Cardíaco , Ecocardiografia , Feminino , Bloqueio Cardíaco/congênito , Humanos , Gravidez
3.
Lupus ; 25(2): 116-28, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26762645

RESUMO

Autoimmune congenital heart block (ACHB) is an immune-mediated cardiac disease included among the manifestations collectively referred to as neonatal lupus. The placental transference of maternal Ro/La autoantibodies may damage the conduction tissues during fetal development leading to blocking of signal conduction at the atrioventricular (AV) node in an otherwise structurally normal heart. Irreversible complete AV block is the main cardiac manifestation of ACHB, but some babies may develop endocardial fibroelastosis, valvular insufficiency, and/or frank cardiomyopathies with significantly reduced cardiac function requiring transplant. The severity of ACHB is illustrated by a global mortality rate of 20% and pacemaker rates of at least 64%, often within the first year of life. This review analyses the main complex and/or unusual clinical situations associated with ACHB, including unusual maternal immunological profiles, infrequent maternal autoimmune diseases, cardiac damage unrelated to AV block, fetal invasive management, late complications after birth, risk of congenital heart block (CHB) in ovodonation and in vitro fertilization techniques, the role of maternal features other than autoimmunity, the influence of the birth order or the risk of CHB in twins and triplets.


Assuntos
Bloqueio Cardíaco/congênito , Adulto , Anticorpos Antinucleares/imunologia , Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Feminino , Bloqueio Cardíaco/diagnóstico , Bloqueio Cardíaco/imunologia , Humanos , Recém-Nascido , Masculino , Gravidez , Diagnóstico Pré-Natal/métodos
4.
Ann Rheum Dis ; 75(2): 332-40, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26293163

RESUMO

OBJECTIVES: To evaluate the efficacy and safety of tabalumab, a human IgG4 monoclonal antibody that neutralises membrane and soluble B-cell activating factor (BAFF). METHODS: This randomised, placebo-controlled study enrolled 1124 patients with moderate-to-severe systemic lupus erythematosus (SLE) (Safety of Estrogens in Lupus Erythematosus National Assessment- SLE Disease Activity Index ≥6 at baseline). Patients received standard of care plus subcutaneous study drug, starting with a loading dose (240 mg) at week 0 and followed by 120 mg every 2 weeks (120 Q2W), 120 mg every 4 weeks (120 Q4W) or placebo. Primary endpoint was proportion achieving SLE Responder Index 5 (SRI-5) improvement at week 52. RESULTS: Clinical characteristics were balanced across groups. The primary endpoint was met with 120 Q2W (38.4% vs 27.7%, placebo; p=0.002), but not with the less frequent 120 Q4W regimen (34.8%, p=0.051). Although key secondary endpoints (time to severe flare, corticosteroid sparing and fatigue) were not met, patients treated with tabalumab had greater SRI-5 response rates in a serologically active subset and improvements in more stringent SRI cut-offs, SELENA-SLEDAI, Physician's Global Assessment, anti-double-stranded DNA antibodies, complement, total B cells and immunoglobulins. The incidences of deaths, serious adverse events (AEs), and treatment-emergent AEs were similar in the 120 Q2W, 120 Q4W and placebo groups, but depression and suicidal ideation, albeit rare events, were more commonly reported with tabalumab. CONCLUSION: SRI-5 was met with 120 Q2W and although key secondary endpoints were not met, numerous other secondary endpoints significantly improved in addition to pharmacodynamic evidence of BAFF pathway blockade. The safety profile for tabalumab was similar to placebo, except for depression and suicidality, which were uncommon. TRIAL REGISTRATION NUMBER: NCT01205438.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Fator Ativador de Células B/antagonistas & inibidores , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Adolescente , Adulto , Idoso , Anticorpos Antinucleares/sangue , Anticorpos Monoclonais Humanizados , Autoanticorpos/sangue , Fator Ativador de Células B/administração & dosagem , Linfócitos B/metabolismo , Biomarcadores/sangue , População Negra , Complemento C3/metabolismo , Complemento C4/metabolismo , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Injeções Subcutâneas , Lúpus Eritematoso Sistêmico/etnologia , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto Jovem
5.
Lupus ; 24(1): 42-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25124676

RESUMO

OBJECTIVE: Anti-C1q has been associated with systemic lupus erythematosus (SLE) and lupus nephritis in previous studies. We studied anti-C1q specificity for SLE (vs rheumatic disease controls) and the association with SLE manifestations in an international multicenter study. METHODS: Information and blood samples were obtained in a cross-sectional study from patients with SLE (n = 308) and other rheumatologic diseases (n = 389) from 25 clinical sites (84% female, 68% Caucasian, 17% African descent, 8% Asian, 7% other). IgG anti-C1q against the collagen-like region was measured by ELISA. RESULTS: Prevalence of anti-C1q was 28% (86/308) in patients with SLE and 13% (49/389) in controls (OR = 2.7, 95% CI: 1.8-4, p < 0.001). Anti-C1q was associated with proteinuria (OR = 3.0, 95% CI: 1.7-5.1, p < 0.001), red cell casts (OR = 2.6, 95% CI: 1.2-5.4, p = 0.015), anti-dsDNA (OR = 3.4, 95% CI: 1.9-6.1, p < 0.001) and anti-Smith (OR = 2.8, 95% CI: 1.5-5.0, p = 0.01). Anti-C1q was independently associated with renal involvement after adjustment for demographics, ANA, anti-dsDNA and low complement (OR = 2.3, 95% CI: 1.3-4.2, p < 0.01). Simultaneously positive anti-C1q, anti-dsDNA and low complement was strongly associated with renal involvement (OR = 14.9, 95% CI: 5.8-38.4, p < 0.01). CONCLUSIONS: Anti-C1q was more common in patients with SLE and those of Asian race/ethnicity. We confirmed a significant association of anti-C1q with renal involvement, independent of demographics and other serologies. Anti-C1q in combination with anti-dsDNA and low complement was the strongest serological association with renal involvement. These data support the usefulness of anti-C1q in SLE, especially in lupus nephritis.


Assuntos
Anticorpos Antinucleares/sangue , Complemento C1q/imunologia , DNA/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Adulto , Estudos de Casos e Controles , Proteínas do Sistema Complemento/deficiência , Estudos Transversais , Feminino , Humanos , Lúpus Eritematoso Sistêmico/etnologia , Nefrite Lúpica/etnologia , Nefrite Lúpica/imunologia , Masculino , Pessoa de Meia-Idade , Proteinúria/sangue , Doenças Reumáticas/imunologia , Sensibilidade e Especificidade , Adulto Jovem
6.
Lupus ; 21(5): 559-62, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22140143

RESUMO

Congenital complete heart block associated with transplacental passage of maternal autoantibodies reactive with SSA/Ro and SSB/La is a rare disease with significant fetal, neonatal, and childhood morbidity and mortality. We present the case of dichorionic, diamniotic twins (female twin A and male twin B) exposed to maternal Ro and La autoantibodies with different disease expression. Twin A (female) had Mobitz type I second degree atrioventricular (AV) block (Wenckebach); twin B (male) had normal sinus rhythm. Both twins had structurally normal hearts but demonstrated echocardiographic evidence of endocardial fibroelastosis (EFE). Following maternal dexamethasone 4 mg once daily, twin A reverted to sinus rhythm in utero; twin B remained in sinus rhythm throughout pregnancy. Echocardiograms after delivery demonstrated resolution of EFE in both fetuses, and EKGs confirmed sinus rhythm. However, at five months of age, Holter monitor demonstrated first degree AV block and intermittent Wenckebach in twin A. Twin B remains in sinus rhythm. This case is one of only three in the literature that describes Mobitz type I second degree atrioventricular block presenting in fetuses exposed to maternal SSA and SSB autoantibodies and is the first case that we have seen reported in twins. Importantly, this case also adds to the growing body of literature describing EFE as a presentation of neonatal lupus with or without conduction system abnormalities, emphasizes the spectrum of cardiac conduction abnormalities in neonatal lupus syndrome, and raises interesting questions about discordant disease expression in twins.


Assuntos
Anticorpos Antinucleares/imunologia , Bloqueio Atrioventricular/etiologia , Lúpus Eritematoso Sistêmico/congênito , Complicações na Gravidez/imunologia , Bloqueio Atrioventricular/fisiopatologia , Dexametasona/uso terapêutico , Ecocardiografia , Feminino , Seguimentos , Glucocorticoides/uso terapêutico , Humanos , Lactente , Recém-Nascido , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Gravidez , Gêmeos , Adulto Jovem
7.
Lupus ; 20(5): 453-62, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21148601

RESUMO

The Lupus Foundation of America (LFA) convened an international working group to obtain a consensus definition of disease flare in lupus. With help from the Paediatric Rheumatology International Trials Organization (PRINTO), two web-based Delphi surveys of physicians were conducted. Subsequently, the LFA held a second consensus conference followed by a third Delphi survey to reach a community-wide agreement for flare definition. Sixty-nine of the 120 (57.5%) polled physicians responded to the first survey. Fifty-nine of the responses were available to draft 12 preliminary statements, which were circulated in the second survey. Eighty-seven of 118 (74%) physicians completed the second survey, with an agreement of 70% for 9/12 (75%) statements. During the second conference, three alternative flare definitions were consolidated and sent back to the international community. One hundred and sixteen of 146 (79.5%) responded, with agreement by 71/116 (61%) for the following definition: "A flare is a measurable increase in disease activity in one or more organ systems involving new or worse clinical signs and symptoms and/or laboratory measurements. It must be considered clinically significant by the assessor and usually there would be at least consideration of a change or an increase in treatment." The LFA proposes this definition for lupus flare on the basis of its high face validity.


Assuntos
Lúpus Eritematoso Sistêmico/diagnóstico , Terminologia como Assunto , Doença Aguda , Técnica Delphi , Humanos , Internacionalidade
8.
Lupus ; 19(3): 300-6, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20008445

RESUMO

Neonatal lupus is a model of passively acquired autoimmunity whereby anti-SSA/Ro-SSB/La antibodies target the fetal heart and neonatal skin in a minority of cases. Since neuro-psychiatric impairment has been reported in humans and mice exposed prenatally to a variety of maternal autoantibodies including anti-Ro/La, this study was initiated to evaluate the potential neurotoxic effects of these specific autoantibodies and the overall frequency of autoimmune diseases, general health, and somatic growth of children with neonatal lupus and their unaffected siblings. In addition to the general health questionnaires maintained on family members enrolled in the Research Registry for Neonatal Lupus (RRNL), specific questionnaires related to neuro-psychiatric development were sent to all mothers whose children (both affected and unaffected) were older than 5 years of age. Controls consisted of healthy friends. Of 121 anti-Ro exposed children meeting the inclusion criteria, information was returned on 104 (33 cardiac manifestations of neonatal lupus, 20 rash, and 51 unaffected siblings) and 22 of the friend controls. The mean age of all of the children was 14.5 years (range 5-39). In total, 42 (40%) of the 104 anti-Ro exposed children were reported to have a neuro-psychiatric disorder, compared with 6 (27%) of the friend controls (p = 0.34). For 8 (24%) of the congenital heart block (CHB) children (6 boys, 2 girls) the mothers reported attention problems. Four, all boys, were on stimulants. Of the rash children, 4 (20%) (2 boys, 2 girls) had attention problems with one boy on Ritalin. Of the unaffected siblings, 9 (18%) (8 boys and 1 girl) had attention problems with 3 boys on stimulants. One (5%) of the control children (a girl) had attention problems, not requiring therapy. There was no statistical difference in attention problems between the groups (p = 0.120). Behavioral problems were present in all groups with no statistical differences noted. The prevalence of depression, anxiety, developmental delays, learning, hearing, and speech problems were not significantly different between groups. In the CHB children, one boy has nephrotic syndrome and one girl has psoriasis. In the rash children, one girl has juvenile rheumatoid arthritis. In the unaffected group there are five children with autoimmune diseases, two with inflammatory bowel diseases (one boy and one girl), one boy has a spondyloarthropathy, one girl has alopecia areata and one young woman has Antiphospholipid syndrome. In the control group one boy has Henoch Schonlein purpura. There were four cases of hypothyroidism, possibly secondary to Hashimoto's thyroiditis, three in boys with CHB and one in a girl with rash. None of the unaffected siblings or controls had hypothyroidism. Parental reporting of neuro-psychiatric abnormalities was high in anti-Ro exposed children regardless of the neonatal lupus manifestation. However, medication use was limited and although the frequency of this reporting was greater than friend controls, it did not reach significance.


Assuntos
Anticorpos Antinucleares/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Transtornos Mentais/etiologia , Adolescente , Adulto , Doenças Autoimunes/imunologia , Estudos de Casos e Controles , Criança , Feminino , Humanos , Recém-Nascido , Doenças do Recém-Nascido , Lúpus Eritematoso Sistêmico/fisiopatologia , Masculino , Transtornos Mentais/epidemiologia , Sistema de Registros , Estudos Retrospectivos , Ribonucleoproteínas/imunologia , Síndrome de Sjogren/imunologia , Inquéritos e Questionários , Adulto Jovem
9.
J Intern Med ; 265(6): 653-62, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19493059

RESUMO

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.


Assuntos
Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Coração Fetal/anormalidades , Bloqueio Cardíaco/congênito , Bloqueio Cardíaco/imunologia , Anticorpos Antinucleares , Doenças Autoimunes/congênito , Feminino , Idade Gestacional , Bloqueio Cardíaco/prevenção & controle , Humanos , Masculino , Gravidez , Fatores de Risco , Fatores de Tempo , Ultrassonografia Pré-Natal
10.
Ann Rheum Dis ; 68(6): 828-35, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18625627

RESUMO

OBJECTIVE: To evaluate autoimmune disease progression in asymptomatic and pauci-symptomatic mothers of children with neonatal lupus (NL). METHODS: Clinical information on mothers enrolled in the Research Registry for NL (RRNL) was obtained from medical records. Genotyping was performed for -308A/G tumour necrosis factor (TNF)alpha, 869T/C transforming growth factor (TGF)beta and -889C/T interleukin (IL)1alpha. RESULTS: Of the 321 mothers enrolled, 229 had at least 6 months of follow-up. Of the 51 mothers who were asymptomatic at the NL child's birth, 26 progressed: 12 developed pauci-undifferentiated autoimmune syndrome (pauci-UAS), 2 poly-UAS, 7 SS, 4 SLE and 1 SLE/SS. The median time to develop any symptom was 3.15 years. Of the 37 mothers classified as pauci-UAS at the NL child's birth, 16 progressed: 5 developed poly-UAS, 6 Sjögren syndrome (SS), 4 systemic lupus erythematosus (SLE) and 1 SLE/SS. Of the pauci-UAS mothers enrolled within 1 year, the median time to progression was 6.7 years. Four mothers developed lupus nephritis (two asymptomatic, two pauci-UAS). The probability of an asymptomatic mother developing SLE by 10 years was 18.6%, and developing probable/definite SS was 27.9%. NL manifestations did not predict disease progression in an asymptomatic mother. Mothers with anti-Sjögren syndrome A antigen (SSA/)Ro and anti-Sjögren syndrome B antigen (SSB)/La were nearly twice as likely to develop an autoimmune disease as mothers with anti-SSA/Ro only. Only TGFbetaT/T was significantly higher in SLE mothers compared to asymptomatic mothers (p = 0.03). CONCLUSIONS: Continued follow-up of asymptomatic NL mothers is warranted since nearly half progress, albeit few develop SLE. While the anti-SSB/La antibodies may be a risk factor for progression, further work is needed to determine reliable biomarkers in otherwise healthy women with anti-SSA/Ro antibodies identified solely because of an NL child.


Assuntos
Lúpus Eritematoso Sistêmico/congênito , Mães , Anticorpos Antinucleares/imunologia , Autoanticorpos/sangue , Progressão da Doença , Feminino , Seguimentos , Genótipo , Humanos , Recém-Nascido , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Polimorfismo Genético , Sistema de Registros , Fator de Necrose Tumoral alfa/genética
11.
Clin Exp Immunol ; 154(1): 30-7, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18727629

RESUMO

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.


Assuntos
Autoanticorpos/sangue , Proteínas Ativadoras de GTPase/imunologia , Bloqueio Cardíaco/congênito , Bloqueio Cardíaco/imunologia , Ribonucleoproteínas/química , Adulto , Análise de Variância , Bloqueio Atrioventricular/imunologia , Autoanticorpos/imunologia , Biomarcadores/sangue , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Finlândia , Humanos , Gravidez , Fatores de Risco , Suécia , Estados Unidos
14.
Lupus ; 17(2): 86-90, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18250129

RESUMO

The association of isolated congenital heart block (CHB) with maternal autoantibodies to SSA/Ro and SSB/La ribonucleoproteins is approaching the predictable, even in mothers who are completely asymptomatic. Indeed, this model of passively acquired autoimmunity offers an exceptional opportunity to examine the effector arm of immunity and define the pathogenicity of an autoantibody in mediating tissue injury. The study of CHB exemplifies not only translational research, which inherently draws upon clinical observations and explores them in the laboratory, but "integrational" research which attempts to fit critical clinical and basic observations together, even those seemingly at odds. The spectrum of conduction abnormalities includes second and third-degree block, but injury can extend to the myocardium and endocardium, in rare cases without AV nodal dysfunction. The rarity of disease continues to drive the search for factors (fetal and environmental) that might amplify the effects of the maternal autoantibodies. The identification of exaggerated apoptosis, macrophage/myfibroblast crosstalk, TGF beta expression, and extensive fibrosis in the conducting system and in some cases surrounding myocardium in fetuses dying with CHB, provide in vivo support for several parallel lines of in vitro investigation. Specifically, the consideration of exaggerated apoptosis as the initial link between maternal antibody and tissue injury led to the observation that cardiocytes are capable of phagocytosing autologous apoptotic cardiocytes and anti-Ro/La antibodies inhibit this function. Recognizing that this perturbation of physiologic efferocytosis might divert uptake to professional Fc gamma R-bearing phagocytes fits well with experiments demonstrating macrophage secretion of pro-inflammatory and fibrosing cytokines when coincubated with apoptotic cardiocytes bound by Ro/La antibodies. While CHB is rare, its study should set precedent for defining the role of autoantibodies in driving end organ disease.


Assuntos
Anticorpos Antinucleares/fisiologia , Apoptose/imunologia , Bloqueio Cardíaco/congênito , Bloqueio Cardíaco/imunologia , Anticorpos Antinucleares/imunologia , Autoanticorpos/imunologia , Autoanticorpos/fisiologia , Feminino , Bloqueio Cardíaco/patologia , Humanos , Troca Materno-Fetal/imunologia , Miócitos Cardíacos/imunologia , Miócitos Cardíacos/patologia , Gravidez
15.
Clin Exp Immunol ; 148(1): 153-60, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17286801

RESUMO

Opsonization of apoptotic cardiocytes by maternal anti-Ro/SSA and anti-La/SSB antibodies contributes to tissue injury in the neonatal lupus syndrome. The objective of the current study was to quantify the surface membrane expression of Ro/La components during different phases of apoptosis and map the Ro/La apotopes (epitopes expressed on apoptotic cells) bound by cognate antibodies. Multi-parameter flow cytometry was used to define early and late apoptotic populations and their respective binding by monospecific anti-Ro and anti-La IgGs. Anti-Ro60 bound specifically to early apoptotic Jurkat cells and remained accessible on the cell surface throughout early and late apoptosis. In contrast, anti-La bound exclusively to late apoptotic cells in experiments controlled for non-specific membrane leakage of IgG. Ro52 was not accessible for antibody binding on either apoptotic population. The immunodominant NH2-terminal and RNA recognition motif (RRM) epitopes of La were expressed as apotopes on late apoptotic cells, confirming recent in vivo findings. An immunodominant internal epitope of Ro60 that contains the RRM, and is recognized by a majority of sera from mothers of children with congenital heart block (CHB) and patients with primary Sjögren's syndrome, was also accessible as an apotope on early apoptotic cells. The distinct temporal expression of the immunodominant Ro60 and La apotopes indicates that these intracellular autoantigens translocate independently to the cell surface, and supports a model in which maternal antibody populations against both Ro60 and La apotopes act in an additive fashion to increase the risk of tissue damage in CHB.


Assuntos
Apoptose/imunologia , Autoantígenos/metabolismo , Bloqueio Cardíaco/congênito , Epitopos Imunodominantes/metabolismo , Ribonucleoproteínas/metabolismo , Autoantígenos/imunologia , Células Cultivadas , Ensaio de Imunoadsorção Enzimática/métodos , Mapeamento de Epitopos/métodos , Feminino , Bloqueio Cardíaco/imunologia , Humanos , Epitopos Imunodominantes/imunologia , Imunoglobulina G/imunologia , Troca Materno-Fetal/imunologia , Gravidez , Ribonucleoproteínas/imunologia , Síndrome de Sjogren/imunologia , Antígeno SS-B
17.
Lupus ; 13(9): 705-12, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15485109

RESUMO

The neonatal lupus syndromes (NLS), while quite rare, carry significant mortality and morbidity in cases of cardiac manifestations. Although anti-SSA/Ro-SSB/La antibodies are detected in > 85% of mothers whose fetuses are identified with congenital heart block (CHB) in a structurally normal heart, when clinicians applied this testing to their pregnant patients, the risk for a woman with the candidate antibodies to have a child with CHB was at or below 1 in 50. While the precise pathogenic mechanism of antibody-mediated 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 (e.g., TGFbeta) from the scavenging macrophages and modulation of cardiac fibroblasts to a myofibroflast scarring phenotype. The spectrum of cardiac abnormalities continues to expand, with varying degrees of block identified in utero and reports of late onset cardiomyopathy (some of which display endocardial fibroelastosis). Moreover, there is now clear documentation that incomplete blocks (including those improving in utero with dexamethasone) can progress postnatally, despite the clearance of the maternal antibodies from the neonatal circulation. Better echocardiographic measurements which identify first degree block in utero may be the optimal means of approaching pregnant women at risk. Prophylactic therapies, including treatment with intravenous immunoglobulin, await larger trials. In order to achieve advances at both the bench and bedside, national research registries established in the US and Canada are critical.


Assuntos
Bloqueio Cardíaco/congênito , Lúpus Vulgar/congênito , Autoanticorpos/análise , Feminino , Bloqueio Cardíaco/diagnóstico , Bloqueio Cardíaco/imunologia , Humanos , Recém-Nascido , Lúpus Vulgar/diagnóstico , Gravidez , Diagnóstico Pré-Natal , Prognóstico , Síndrome
18.
Lupus ; 11(3): 145-51, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11999879

RESUMO

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.


Assuntos
Anticorpos Antinucleares/imunologia , Autoantígenos , Bloqueio Cardíaco/imunologia , Bloqueio Cardíaco/fisiopatologia , Cardiopatias Congênitas/imunologia , RNA Citoplasmático Pequeno , Ribonucleoproteínas/imunologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Doenças Autoimunes/fisiopatologia , Pré-Escolar , Eletrocardiografia , Feminino , Fibrose/patologia , Bloqueio Cardíaco/patologia , Cardiopatias Congênitas/patologia , Cardiopatias Congênitas/fisiopatologia , Humanos , Lactente , Recém-Nascido , Masculino , Miocárdio/patologia , Gravidez , Antígeno SS-B
19.
Biochim Biophys Acta ; 1568(2): 155-61, 2001 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-11750763

RESUMO

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.


Assuntos
Autoantígenos/química , Zíper de Leucina , RNA Citoplasmático Pequeno , Ribonucleoproteínas/química , Autoantígenos/genética , Cromatografia em Gel , DNA Complementar/química , Dimerização , Genes Reporter , Células HeLa , Humanos , Luciferases/genética , Proteínas Recombinantes de Fusão/química , Ribonucleoproteínas/genética , Transcrição Gênica , Transfecção , Técnicas do Sistema de Duplo-Híbrido , beta-Galactosidase/análise , Antígeno SS-B
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