RESUMEN
OBJECTIVE: We aim to examine changes in usage of nonbiologic, disease-modifying antirheumatic drugs (DMARDs) and evaluate their continuation rates in Japan. METHODS: We analyzed DMARD treatment data for 3,734 patients with rheumatoid arthritis (RA) from 1998 to 2009 at Juntendo Hospital in Tokyo, Japan. The DMARD usage rate per month was determined to evaluate RA treatment history in the last decade. We also evaluated continuation rates of nonbiologic DMARDs in single and combination therapies and number of nonbiologic DMARD combination therapies used in each patient. RESULTS: We found that nonbiologic DMARD usage has dramatically changed in the last decade, with the most commonly used DMARD shifting from bucillamine to methotrexate (MTX). MTX showed the highest continuation rate; however, much lower continuation rate was observed when used alone rather than in combination treatments. Further, MTX was also used in the highest number of different combination therapies for a particular patient. CONCLUSIONS: These findings indicate that single MTX treatment may be unable to keep patients in clinical remission or lower disease activity compared with several combination therapies. Recent change in permitted maximum dosage of MTX from 8 to 16 mg/week may improve its efficacy and continuation rate in treating Japanese RA patients.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Pautas de la Práctica en Medicina/tendencias , Adulto , Cisteína/análogos & derivados , Cisteína/uso terapéutico , Quimioterapia Combinada , Femenino , Humanos , Japón , Masculino , Metotrexato/uso terapéutico , Índice de Severidad de la Enfermedad , Sulfasalazina/uso terapéutico , Resultado del TratamientoRESUMEN
BACKGROUND: Elderly patients with rheumatoid arthritis (RA) have more aging-related complications than nonelderly patients with RA. OBJECTIVES: The objective of the study was to investigate the treatment status of elderly patients with RA. METHODS: Between January and March 2008, 969 patients with RA were enrolled in this observational cross-sectional study. Prescription of disease-modifying antirheumatic drugs (DMARDs) and corticosteroids and laboratory data related to RA, including matrix metalloproteinase 3, rheumatoid factor, and anti-cyclic citrullinated peptide antibody levels, were compared between the elderly and the nonelderly patients. RESULTS: Fewer DMARDs were prescribed to the elderly patients (1.40 [SD, 0.57] vs. 1.51 [SD, 0.61]; P = 0.029). Furthermore, a lower percentage of patients received methotrexate (MTX) (47.2% vs. 56.9%; P = 0.0001), a lower average dosage of MTX was administered (5.46 [SD, 1.66] mg/wk vs. 5.96 [SD, 1.77] mg/wk; P = 0.0001), and fewer biologic DMARDs were used (1.46% vs. 5.59% for infliximab, P = 0.0008; 0.58% vs. 3.19% for etanercept, P = 0.0038) in the elderly group. The laboratory data suggested that the disease status was uncontrolled to a greater extent, and complications were more common in the elderly group. CONCLUSION: Elderly patients with RA receive less aggressive treatment than nonelderly patients with RA, despite laboratory evidence for poorly controlled disease status among the elderly. The use of a less aggressive regimen could be attributed to the higher prevalence of complications and problems. Therefore, the elderly with RA should be considered a different patient population from the viewpoint of treatment and be administered specialized medical care.
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Corticoesteroides/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Factores de Edad , Anciano , Anticuerpos Antiidiotipos/sangre , Anticuerpos Monoclonales/uso terapéutico , Artritis Reumatoide/sangre , Estudios Transversales , Relación Dosis-Respuesta a Droga , Etanercept , Femenino , Humanos , Inmunoglobulina G/uso terapéutico , Infliximab , Masculino , Metaloproteinasa 3 de la Matriz/sangre , Metotrexato/uso terapéutico , Persona de Mediana Edad , Péptidos Cíclicos/inmunología , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Factor Reumatoide/sangreRESUMEN
We evaluated the extent to which anti-proteasome activator (PA) 28alpha antibodies act as anti-cytoplasmic antibodies in systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS). Sera from 46 SLE patients without SS, 11 SLE patients with SS, and 45 primary SS patients were tested. Using anti-PA28alpha and anti-PA28gamma (Ki) antibodies purified from nitrocellulose membranes onto which recombinant PA28alpha and Ki had been transferred, the cellular distributions of the targeted antigens were analyzed immunohistochemically. In addition, the incidence of anti-PA28alpha antibodies was compared with those of other anti-cytoplasmic antibodies. Immunofluorescent staining showed that purified anti-PA28alpha antibodies reacted with the cytoplasm of HEp-2 cells, whereas purified anti-Ki antibodies reacted with nucleoplasm. Among the 15 SLE patients without SS, the six SLE patients with SS, and the 30 primary SS patients who were anti-cytoplasmic-antibody positive, anti-SS-A/Ro antibodies were the most frequently detected (53, 67, and 70%, respectively); anti-PA28alpha antibodies were, respectively, detected in 33, 50, and 40% of those patient groups, incidences that were higher than those of anti-ribosomal P, anti-smooth muscle and anti-mitochondrial M2 antibodies. These results show that anti-PA28alpha antibodies are major anti-cytoplasmic antibodies in patients with SLE and SS, and the distinct cellular distributions of PA28alpha and Ki suggest these proteins are associated with different cellular functions.
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Autoanticuerpos/inmunología , Lupus Eritematoso Sistémico/inmunología , Proteínas Musculares/inmunología , Complejo de la Endopetidasa Proteasomal/inmunología , Síndrome de Sjögren/inmunología , Autoanticuerpos/sangre , Autoantígenos/inmunología , Western Blotting , Células Cultivadas , Distribución de Chi-Cuadrado , Clonación de Organismos , Citoplasma/inmunología , Ensayo de Inmunoadsorción Enzimática , Técnica del Anticuerpo Fluorescente , HumanosRESUMEN
OBJECTIVE: To investigate the autoimmune responses against SS-A/B antigens by double immunodiffusion (DID) and western blotting (WB) in primary and secondary Sjögren's syndrome (SS). PATIENTS: Forty-nine patients with primary SS (PSS), 28 patients with secondary SS (SSS) and control group that couldn't be diagnosed as SS were included in this study. RESULTS: In DID analysis, Anti-SS-A antibody was detected in 69% of PSS and 86% of SSS, and anti-SS-B antibody was found in 22% of PSS and 39% of SSS. No significant difference could be demonstrated between PSS and SSS concerning anti-SS-A/B antibodies. Conversely, WB studies disclosed evidences that 18% of PSS and no SSS reacted only with the 52 kD protein, and there was significantly increased in PSS. Sera reacting with the 60 kD antigen were found in 37% of PSS, 71% of SSS, and 75% of SSS with SLE, 63% of SSS with RA. The ratio of SSS, and SSS with SLE were particularly significantly higher than PSS. CONCLUSION: Our results revealed data that there are the difference of reactivity against SS-A/B antigens in WB between PSS and SSS.
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Anticuerpos Antinucleares/sangre , Western Blotting , Inmunodifusión , Síndrome de Sjögren/inmunología , HumanosRESUMEN
BACKGROUND: Rheumatoid arthritis (RA) increases the mortality and morbidity of cardiovascular disease (CVD). However, the relationship between RA and the risk of CVD in the Japanese population remains unclear. METHODS AND RESULTS: This study comprised 571 RA patients who were admitted to Juntendo University Hospital from January 1990 to December 2000. Cardiovascular events (CVEs) were defined as cardiac death, acute coronary syndrome (ACS), symptomatic stroke, and congestive heart failure. During follow-up (mean 11.7 ± 5.8 years), 7.5% of the patients died from all causes and 11.0% experienced CVEs. The morbidity of stroke and ACS was 3.6 and 2.5 per 1000 person-years, respectively. The mean RA disease duration at enrolment was significantly longer in patients who experienced CVEs than in those who did not experience CVEs (15.0 ± 12.7 years vs. 10. 8 ± 9.7 years; p = 0.01). Physical disabilities due to RA were more severe in patients who experienced CVEs than in those who did not experience CVEs. Patients with a long RA disease duration showed significantly higher event rates (p = 0.033). Cox proportional hazards analysis identified a longer RA duration as an independent risk factor for CVD (hazard ratio 1.57, 95% CI 1.09-2.30, p = 0.02). CONCLUSION: Japanese RA patients showed a relatively high incidence of CVD, despite the fact that they had few coronary risk factors. The RA disease duration was an independent risk factor for CVEs.
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Artritis Reumatoide/complicaciones , Enfermedades Cardiovasculares/etiología , Anciano , Pueblo Asiatico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/mortalidad , Personas con Discapacidad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de TiempoAsunto(s)
Anticuerpos Monoclonales/uso terapéutico , Granulomatosis con Poliangitis/tratamiento farmacológico , Factores Inmunológicos/uso terapéutico , Meningitis/tratamiento farmacológico , Enfermedades Orbitales/tratamiento farmacológico , Adulto , Anticuerpos Monoclonales de Origen Murino , Femenino , Humanos , RituximabAsunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Hepcidinas/sangre , Fragmentos de Péptidos/sangre , Adulto , Anciano , Anemia/sangre , Artritis Reumatoide/complicaciones , Factores Biológicos , Biomarcadores/sangre , Progresión de la Enfermedad , Femenino , Hepcidinas/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/efectos adversosRESUMEN
To retrospectively evaluate the efficacy and safety of combination therapy with tacrolimus (TAC) and other disease-modifying antirheumatic drugs (DMARDs). One hundred fifteen rheumatoid arthritis (RA) patients treated with tacrolimus were enrolled in this retrospective analysis. We collected clinical information, including patient background, treatment efficacy (evaluated using the DAS score), and adverse events observed. Multiple logistic regression analysis was conducted to analyze factors contributing to clinical response and adverse effects. The disease activity score of 28 joints (DAS28) improved significantly at 24 weeks, and continuation rate at 1 year was 57.9%. There was no difference in continuation rate between different DMARD combinations, and not only methotrexate (MTX) but also bucillamine (BUC) and salazosulfapyridine (SSZ) were effective combination partners with TAC. No serious adverse events were observed, and no different inefficacy or safety was observed between non-elderly (<65 years old) and elderly (≥65 years old) RA patients. By conducting multiple logistic regression analysis, combination therapy with MTX and TAC, the number of baseline DMARDs (specifically, ≥3), and old age were identified as risk factors for adverse events. Our findings indicate that TAC is a valuable DMARD for second-line combination therapy in RA.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Tacrolimus/uso terapéutico , Adulto , Anciano , Antirreumáticos/efectos adversos , Cisteína/efectos adversos , Cisteína/análogos & derivados , Cisteína/uso terapéutico , Progresión de la Enfermedad , Quimioterapia Combinada , Femenino , Humanos , Masculino , Metotrexato/efectos adversos , Metotrexato/uso terapéutico , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Sulfasalazina/efectos adversos , Sulfasalazina/uso terapéutico , Tacrolimus/efectos adversos , Resultado del TratamientoRESUMEN
OBJECTIVE: Joint swelling, an important factor in the classification criteria and disease activity assessment in rheumatoid arthritis (RA), renders joint palpation a necessary skill for physicians. Ultrasound (US) examination that visualizes soft tissue abnormalities is now used to assess musculoskeletal disease. We assessed the usefulness of US assessments in enhancing physical joint examination skills. METHODS: We examined 1944 joints (bilateral shoulder, elbow, wrist, metacarpophalangeal joints 1-5, and knee joints) in 108 patients with RA during April-July 2011. We first physically examined and confirmed joint swelling; subsequently, the same rheumatologist conducted US examinations and multiple assessors graded the joint swelling. When the 2 results differed, we received autofeedback from the US results to improve the physical examination skills. RESULTS: The sensitivities and specificities of physical examination for US-detected swollen joint, the correlation coefficient (CC) of the swollen joint counts, and the concordance rate in each patient for joint swelling sites and power Doppler (PD)-positive sites with the κ coefficients between the physical and US examinations were compared over time. We found that the sensitivity of physical examination increased by 42 percentage points (pp), while the specificity decreased by 18 pp. The average CC in June-July was greater than that in April-May. The percentage of κ coefficients > 0.8 increased from 8.8% to 17% for joint swelling and from 8.3% to 14% for PD-positive sites. CONCLUSION: Our results suggest that autofeedback from US assessment provides quick improvement in palpation skills for identifying joint swelling in patients with RA.
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Artritis Reumatoide/diagnóstico , Edema/diagnóstico , Retroalimentación Sensorial , Articulaciones/patología , Palpación/métodos , Sinovitis/diagnóstico , Ultrasonografía/métodos , Adulto , Anciano , Artritis Reumatoide/complicaciones , Artritis Reumatoide/diagnóstico por imagen , Edema/diagnóstico por imagen , Edema/etiología , Femenino , Humanos , Articulaciones/diagnóstico por imagen , Articulaciones/fisiopatología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Sinovitis/diagnóstico por imagen , Sinovitis/etiología , Adulto JovenRESUMEN
OBJECTIVE: To study the significance of anti-Ro/SSA antibodies (anti-Ro) in the clinical response to tumor necrosis factor (TNF) inhibitors in patients with rheumatoid arthritis (RA). METHODS: The clinical responses of a cohort of 190 patients with RA who were treated with infliximab, etanercept, or adalimumab (n = 112, 64, and 14, respectively) as the first biologics were examined using the Disease Activity Score in 28 joints (DAS28) at 24 weeks and the discontinuation rate at 56 weeks. The baseline characteristics of responders and the nonresponders were compared. The clinical response was compared between anti-Ro-negative and -positive patients. The factors associated with the inefficiency of TNF inhibitors were estimated with a multivariable logistic regression analysis. RESULTS: The positive rate of anti-Ro was significantly higher in patients with no European League Against Rheumatism (EULAR) response at 24 weeks (OR 3.64, 95% CI 1.45-9.01, p = 0.003). In anti-Ro-positive patients, a moderate or good EULAR response rate was significantly lower with a sustaining higher median DAS28 (p = 0.006), and this difference was greater among infliximab-treated patients. The discontinuation rate for TNF inhibitors due to inefficacy at 56 weeks was also higher in anti-Ro-positive patients (OR 4.68, 95% CI 1.82-11.99, p = 0.0005), and 75% of these patients received infliximab. The presence of anti-Ro was strongly associated with no EULAR response at 24 weeks and a higher discontinuation rate of TNF inhibitors by 56 weeks (OR 5.22, 95% CI 1.75-15.57, p = 0.003 and OR 10.18, 95% CI 2.18-49.56, p = 0.003). CONCLUSION: The presence of anti-Ro might be related to the lesser clinical response to infliximab compared to other TNF inhibitors, suggesting that the presence of anti-Ro should be considered when choosing the appropriate biologics for patients with RA.
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Anticuerpos Antinucleares/sangre , Antirreumáticos/uso terapéutico , Artritis Reumatoide/sangre , Artritis Reumatoide/tratamiento farmacológico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adalimumab , Adulto , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Biomarcadores/sangre , Etanercept , Femenino , Estudios de Seguimiento , Humanos , Inmunoglobulina G/uso terapéutico , Infliximab , Modelos Logísticos , Masculino , Persona de Mediana Edad , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Conventional therapy for Wegener's granulomatosis, steroid and cyclophosphamide, fails to control disease activity in some refractory patients and has treatment-related toxicity. B cell depletion therapy using rituximab, a chimeric anti-CD20 monoclonal antibody, has been shown to be effective for certain autoimmune diseases including antineutrophil cytoplasmic antibody (ANCA) -associated systemic vasculitis. We report two refractory cases of Wegener's granulomatosis: one with bronchial and pulmonary involvement and retroorbital granuloma, the other with retroorbital granuloma and hypertrophic pachymeningitis causing severe headache. Rituximab was effective in both cases, with diminished granuloma and reduced ANCA titers, allowing steroids to be tapered. No adverse effects were detected.
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Anticuerpos Monoclonales/uso terapéutico , Granulomatosis con Poliangitis/tratamiento farmacológico , Adolescente , Adulto , Anticuerpos Monoclonales de Origen Murino , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Estudios de Seguimiento , Granulomatosis con Poliangitis/diagnóstico , Humanos , Imagen por Resonancia Magnética , Prednisona/uso terapéutico , Inducción de Remisión/métodos , Medición de Riesgo , Rituximab , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
OBJECTIVE: To determine the autoimmune response against proteasome activator 28alpha (PA28alpha) in patients with various connective tissue diseases, and to compare the immunoreactivity between anti-PA28alpha and anti-Ki antibodies. METHODS: Serum samples were obtained from 219 patients with various connective tissue diseases. cDNA encoding full-length human PA28alpha and Ki were produced by polymerase chain reaction. Antigens were expressed as glutathione S-transferase (GST) fusion proteins. The immunoreactivity of serum for PA28alpha and Ki was studied by Western blotting. An inhibition test was performed by ELISA using purified Ki antigen. RESULTS: Anti-PA28alpha> antibody was detected in serum from 23% of patients with systemic lupus erythematosus (SLE) and 24% with Sjögren's syndrome (SS). These rates were significantly higher than those for the other rheumatic diseases. Since both PA28alpha and Ki are elements of the PA28 complex and their amino acid sequences share 40.2% homology, immunoreactivity to PA28alpha was studied further. Among 27 anti-Ki positive serum samples, 13 samples (48%) also reacted with PA28alpha, suggesting a relationship between anti-PA28alpha and anti-Ki antibodies. To investigate whether this finding was due to the presence of cross-reacting epitopes for PA28alpha and Ki antigens, an inhibition test was performed by ELISA. The reactivity to purified Ki antigen was not inhibited by preincubation with recombinant PA28alpha. CONCLUSION: Detection of anti-PA28alpha antibody was significantly higher in serum from patients with SLE and SS. The relationship between anti-PA28alpha and Ki antibodies suggests the importance of an antigen-driven system in the induction of an autoimmune response to PA28 complex.
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Cisteína Endopeptidasas/inmunología , Lupus Eritematoso Sistémico/inmunología , Complejos Multienzimáticos/inmunología , Proteínas Musculares/inmunología , Proteínas/inmunología , Síndrome de Sjögren/inmunología , Especificidad de Anticuerpos , Autoanticuerpos/sangre , Autoantígenos/inmunología , Humanos , Proteínas Nucleares/inmunología , Complejo de la Endopetidasa Proteasomal , Proteínas Recombinantes/inmunologíaRESUMEN
OBJECTIVE: To determine the relationships between subtypes of anti-Ki antibodies and clinical manifestations of systemic lupus erythematosus. METHODS: The cDNA encoding full-length bovine Ki antigens or N- or C-terminal fragments were produced by polymerase chain reaction, and the fragments of Ki antigen were expressed as GST fusion proteins. Immunoreactivities of anti-Ki antibodies were tested by Western blotting. RESULTS: Of 60 sera reactive with full-length Ki antigen (KiF), 21 sera recognized only KiF. KiC5, a fragment containing the last 69 C-terminal amino acids, was recognized by 23 sera. Since no significant difference was observed in prevalence of reactivities between fragments from KiC2 to KiC5, a domain within the last 69 C-terminal amino acids was suggested to be the most common antigenic domain expressed among the GST fusion proteins. All 11 sera reacting with a fragment containing the initial 81 N-terminal amino acids also recognized all other fragments. A domain homologous to SV40 nuclear localization signal was required for N-terminal recognition by 8 sera. Reactivity to the last 69 C-terminal amino acids and the initial 81 N-terminal amino acids showed specificities to systemic lupus erythematosus without and with Sjögren's syndrome, respectively. Sicca was significantly more prevalent in patients whose sera reacted with both N- and C-terminal fragments, while prevalence of anti-SSA/Ro antibody was low. CONCLUSION: Ki antigen contains multiple epitopes recognized by autoimmune sera. Autoantibody profiles revealed distinctive immune responses, associated with certain clinical subtypes.
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Autoanticuerpos/inmunología , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Proteínas Musculares , Proteínas Nucleares/genética , Proteínas Nucleares/inmunología , Autoanticuerpos/sangre , Autoantígenos , Western Blotting , Epítopos/inmunología , Eliminación de Gen , Humanos , Lupus Eritematoso Sistémico/diagnóstico , Mutagénesis , Proteínas Nucleares/química , Complejo de la Endopetidasa Proteasomal , Estructura Terciaria de Proteína , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Síndrome de Sjögren/diagnóstico , Síndrome de Sjögren/genética , Síndrome de Sjögren/inmunologíaRESUMEN
OBJECTIVE: To analyze the autoimmune response to the proliferating cell nuclear antigen (PCNA) multiprotein complex in patients with connective tissue diseases (CTD). METHODS: The PCNA complex was purified by affinity chromatography using anti-PCNA monoclonal antibodies. Then 196 serum samples from patients with systemic lupus erythematosus (SLE) and 82 from patients with other CTD were tested for reactivity with the complex by immunoblotting. RESULTS: Of 196 SLE sera, 61 (31%) reacted with at least one component of the PCNA complex, and most reactive sera contained autoantibodies to several components of the complex. Autoantibodies to PCNA complex were less common in patients with other CTD, and most of their sera reacted only with one or a few proteins in the complex. Two out of 20 scleroderma sera reactive with 100, 85, and 70 kDa proteins in the PCNA complex also had autoantibodies to topoisomerase I (topo I) antibodies, which is an element of the complex. These findings suggest that the autoimmune response to the PCNA complex was specific for SLE. Anti-PCNA complex antibodies were associated with an increased serum level of PCNA detected by ELISA. The spreading of the autoimmune response to the elements of the complex was observed in parallel with the increased serum PCNA level when a series of sera from a lupus patient were tested longitudinally. In addition, anti-PCNA complex antibodies were significantly correlated with lupus erythematosus cells. CONCLUSION: The "antigen-drive" system may play a crucial role in inducing the autoimmune response to the PCNA complex in patients with SLE.
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Autoinmunidad , Enfermedades del Tejido Conjuntivo/inmunología , Complejos Multiproteicos/inmunología , Antígeno Nuclear de Célula en Proliferación/inmunología , Cromatografía de Afinidad , Enfermedades del Tejido Conjuntivo/fisiopatología , Humanos , Lupus Eritematoso Sistémico/inmunología , Antígeno Nuclear de Célula en Proliferación/químicaRESUMEN
The clinical significance of anticyclic citrullinated peptide (CCP) antibodies in patients with mixed connective tissue disease (MCTD) was assessed. Altogether, 86 sera from MCTD patients, 96 from rheumatoid arthritis (RA) patients, 42 from systemic lupus erythematosus (SLE) patients, 23 from systemic sclerosis (SSc) patients, 21 from polymyositis/dermatomyositis (PM/DM) patients, and 17 from those with Sjögren's syndrome (SjS) were tested for anti-CCP antibodies using an enzyme-lined immunosorbent assay. Among the 96 RA patients, anti-CCP antibodies were detected in 85%, with the frequency being significantly higher than in MCTD, SLE, SSc, PM/DM, and SjS patients (9%, 14%, 13%, 14%, and 18%, respectively; P < 0.001). Among eight MCTD patients who fulfilled the diagnostic criteria for RA, only 50% had anti-CCP antibodies, and the prevalence was significantly lower than for all RA patients (p < 0.01). All eight patients who fulfilled the criteria for RA had overlap of SLE and SSc, except one patient, whereas the four anti-CCP-positive patients who did not fulfill the criteria for RA had SjS without overlapping features of SLE and SSc; moreover, most of their antibody titers were low. These results suggested that anti-CCP antibodies are associated with RA in MCTD patients, but careful diagnosis of RA is required if patients with low titers of anti-CCP antibodies lack overlapping SLE and SSc.
RESUMEN
OBJECTIVE: To analyze the reaction of lupus sera with proliferating cell nuclear antigen (PCNA) multiprotein complexes (PCNA complexes), which are part of the protein machinery involved in cell proliferation. METHODS: PCNA complexes were purified from rabbit thymus extract by affinity chromatography using anti-PCNA monoclonal antibodies (TOB7, TO17, and TO30); monomeric and trimeric PCNA forms (AK-PCNA) were purified using anti-PCNA serum AK. The reactions to these antigens of 10 anti-PCNA-positive and 40 anti-PCNA-negative sera selected from 560 lupus patients were tested by immunoblotting, immunoprecipitation, and enzyme-linked immunosorbent assays (ELISAs). RESULTS: With one exception (serum OK), anti-PCNA-positive sera reacted exclusively with only the 34-kd polypeptide. In contrast, 14 of 40 anti-PCNA-negative sera reacted with multiple proteins within PCNA complexes. Most anti-PCNA-positive sera probably recognize as epitopes the binding sites for other proteins on PCNA, which are likely hidden when PCNA is complexed with other proteins. As a consequence, only serum OK reacted with the PCNA complex in a series of ELISAs. Using AK-PCNA as a competitive inhibitor, it was determined that serum OK reacts with both the 58-kd polypeptide and the 34-kd PCNA within complexes. Together with the results of a longitudinal analysis, these results suggest that the immune system of patient OK likely recognized the complexed PCNA protein, after which the autoimmune response spread to other elements of the complexes. CONCLUSION: Intermolecular-intrastructural help, leading to the spread of autoimmune response from PCNA to other proteins associated with its biologic function, plays a crucial role in the induction of the autoimmune response seen in lupus patients.
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Autoinmunidad/inmunología , Lupus Eritematoso Sistémico/inmunología , Antígeno Nuclear de Célula en Proliferación/inmunología , Anticuerpos Monoclonales , Ensayo de Inmunoadsorción Enzimática , Mapeo Epitopo , Humanos , Immunoblotting , Pruebas de PrecipitinaRESUMEN
Using 2-dimensional electrophoresis and ion-pair chromatography, we have identified elements of proliferating cell nuclear antigen (PCNA) multiprotein complexes that are reactive to antibodies in sera from patients with systemic lupus erythematosus. Among the various elements of the complexes, a 37 kDa protein (PI 8.5) that specifically reacted with SLE sera, but not with sera from patients with other connective tissue diseases, was identified as glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Immunoblot analysis showed that SLE sera reactive with the 37 kDa protein specifically reacted with GAPDH, as did anti-GAPDH mAbs. The purified autoantibodies to GAPDH from lupus serum showed both nuclear speckled and cytoplasmic staining patterns in immunofluorescence on Hep-2 cells. In addition, enzyme-linked immunosorbent assay (ELISA) revealed the presence of anti-GAPDH autoantibodies in 47% of lupus patients. Longitudinal analysis of the reactivity of lupus sera to PCNA complexes showed the autoimmune response to spread from GAPDH to other elements of PCNA complexes, and the presence of anti-GAPDH antibodies was significantly correlated with increased levels of serum PCNA. Taken together, these findings suggest that GAPDH interacting with PCNA in association with its cellular function is a novel autoantigen recognized by lupus sera, and that GAPDH thus plays an important role in the induction of autoimmune responses against the PCNA complex.