RESUMEN
This article reviews the characteristics and weaknesses of the rheumatoid factor (RF) assay compared with anti-citrullinated peptide antibody (ACPA) testing in the work-up of patients with synovitis. This should lead physicians to change their ordering habits and replace RF by ACPA. For RA diagnosis, good clinical judgement based on clinical history, physical examination and routine laboratory work exceeds the value of RF and ACPA assays. In settings of both low and high pretest probability, the added value of each of these assays is low. In cases with intermediate probability, ACPA assays are superior to immunoglobulin (Ig)M-RF because of their higher specificity, and they should be the first choice in a RA diagnostic work-up. Dual testing brings few additional advantages and increases costs significantly. ACPA and IgM-RF are both imperfect tests; around 30% of patients with manifest RA will test negative in both assays and therefore caution needs to be exercised when interpreting negative results. Since 2009, the anti-cyclic citrullinated peptide (anti-CCP) antibody assay has been the only assay available at our institution for RA work-up, with IgM-RF available on a case-by-case basis for non-RA diseases. This has led to a 70% reduction in RF assays performed annually.
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Artritis Reumatoide/diagnóstico , Factor Reumatoide/sangre , Artritis Reumatoide/sangre , Artritis Reumatoide/economía , Autoanticuerpos/sangre , Reacciones Falso Negativas , Humanos , Inmunoglobulina M/inmunología , Péptidos Cíclicos/inmunología , Pautas de la Práctica en Medicina , Valor Predictivo de las Pruebas , Sinovitis/sangre , Sinovitis/diagnósticoRESUMEN
OBJECTIVE: The impetus towards early treatment for patients with rheumatoid arthritis (RA) requires more reliable disease markers than the non-specific immunoglobulin M (IgM) rheumatoid factor (RF). To determine the accuracy of newer biomarkers for RA testing for antibody against cyclic citrullinated peptides (anti-CCP Ab), IgA- and IgG-RF and cartilage oligomeric matrix protein (COMP) levels, measured by enzyme-linked immunosorbent assay (ELISA), were compared with IgM-RF isotyping. METHODS: Serum samples were investigated in patients with an established diagnosis of RA (n = 54), ankylosing spondylitis (AS) (n = 36), and non-inflammatory conditions (n = 18) (cohort A), and in 234 consecutive outpatients in a blinded fashion (cohort B). Non-parametric analysis of areas under the curve (AUC) of receiver operator characteristics were performed. RESULTS: The presence of anti-CCP Ab had the highest accuracy (96%) in distinguishing RA patients in cohort A and cohort B (accuracy 83%), and in both cohorts combined (accuracy 87%). This was related to the high specificity of anti-CCP Ab for RA (95-96%), even though IgM-RF was the most sensitive test (87-96%). Sensitivity (15-48%) and specificity (66-69%) of COMP as a marker for RA was low. Combining results of anti-CCP Ab and IgM-RF or any of the other assays did not increase the diagnostic accuracy for RA. CONCLUSION: The presence of anti-CCP Ab is the most accurate biomarker for RA in both selected and unselected cohorts, while the COMP assay is not very useful in RA diagnosis. Combining assays for anti-CCP Ab and IgM-RF or IgA-RF does not enhance RA diagnosis.
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Artritis Reumatoide/sangre , Proteínas de la Matriz Extracelular/sangre , Glicoproteínas/sangre , Péptidos Cíclicos/sangre , Factor Reumatoide/clasificación , Anciano , Anticuerpos/sangre , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/fisiopatología , Biomarcadores/sangre , Proteína de la Matriz Oligomérica del Cartílago , Femenino , Humanos , Pruebas Inmunológicas/instrumentación , Masculino , Proteínas Matrilinas , Persona de Mediana Edad , Péptidos Cíclicos/inmunología , Factor Reumatoide/sangre , Sensibilidad y EspecificidadRESUMEN
Overexpression of B-lymphocyte activating factor (BAFF) results in arthritis, glomerulonephritis and autoantibody formation in mice, but its role in human autoimmune disease is less obvious. Serum BAFF levels in patients with systemic lupus erythematosus (SLE) (n=42) and rheumatoid arthritis (RA) (n=60) were related to levels of disease activity, anti-dsDNA Ab, anti-ENA Ab, rheumatoid factor (RF) and anti-CCP Ab. BAFF levels were also followed over time in 19 SLE patients. BAFF levels correlated inversely with age, were higher in SLE than RA (median 2.7 versus 1.4 ng/mL, P < 0.01) and more SLE than RA patients had increased BAFF levels (57% versus 10%, P < or = 0.01). In SLE, BAFF levels correlated with SLEDAI scores but not with anti-dsDNA Ab levels. SLE patients with increased BAFF levels had higher SLEDAI and CRP levels. In RA, BAFF levels correlated weakly with anti-CCP levels (Rs 0.27, P = 0.07), but not with joint counts, ESR, CRP or RF levels. Longitudinal BAFF levels remained unaltered in two thirds of SLE patients and changes in BAFF levels were unrelated to disease flares. These findings suggest that BAFF stimulation of B-cells may contribute to SLE by other mechanisms than autoantibody production.
Asunto(s)
Artritis Reumatoide/sangre , Autoanticuerpos/sangre , Factor Activador de Células B/sangre , Lupus Eritematoso Sistémico/sangre , Adulto , Factores de Edad , Anticuerpos Anticardiolipina/sangre , Anticuerpos Antinucleares/sangre , Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Biomarcadores/sangre , Sedimentación Sanguínea , Proteína C-Reactiva/metabolismo , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/patología , Masculino , Persona de Mediana Edad , Factor Reumatoide/biosíntesis , Factor Reumatoide/sangre , Índice de Severidad de la Enfermedad , Factores de TiempoRESUMEN
BACKGROUND: Adult-onset Still's disease (AOSD) is considered a rare disease, but few data exist on the incidence and prevalence of AOSD. This study has analysed the epidemiology, disease presentation, and outcome of AOSD in a stable homogeneous population in Northern Norway. METHODS: A retrospective cohort study of all AOSD patients registered in 1990-2000 at the only hospital in the region with a Rheumatology Service. Clinical diagnosis and exclusion of patients were directed by the Yamaguchi criteria for AOSD. Demographic and clinical data at baseline were extracted from patient records and supplemented with data gathered at control visits. Data were analysed with nonparametric methods. RESULTS: AOSD was ascertained in 13 patients; the estimated annual AOSD incidence was 0.4/100,000 adults (95% CI 0.11-0.97), while point prevalence of AOSD increased from 3.4/100,000 (95% CI 0.8-9.4) in 1990 to 6.9/100,000 in 2000 (95% CI 2.7-14.2). Mean diagnostic delay was 5.2 months (range 0.5-18). Serum ferritin > 5 times the normal upper level had 63% diagnostic sensitivity. During 69 months' follow-up, one patient died, 6/13 patients achieved sustained remission, while six patients developed a chronic progressive (n = 3) or a relapsing/remitting disease course (n = 3). Four of these six patents had to enter social security programmes. CONCLUSION: The annual incidence of AOSD in Northern Norway is at least 0.4/100,000 adults. AOSD in this region is more prevalent than in France or Japan, affects more males, and approximates to the prevalence of juvenile Still's disease. Half of all patients have a monocyclic disease course, while mortality and invalidity occur in patients with chronic disease.
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Enfermedad de Still del Adulto/epidemiología , Adolescente , Adulto , Edad de Inicio , Anciano , Estudios de Cohortes , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Prevalencia , Estudios RetrospectivosRESUMEN
It is unclear whether the destructive lesions of the vertebral bodies in the spondylodiscitis of ankylosing spondylitis (AS) are related to mechanical stress or inflammation. We describe early immunohistopathological findings in an AS patient with severe symptomatic spondylodiscitis that support an inflammatory origin.
Asunto(s)
Discitis/inmunología , Discitis/patología , Espondilitis Anquilosante/inmunología , Espondilitis Anquilosante/patología , Biopsia , Discitis/etiología , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Espondilitis Anquilosante/complicaciones , Vértebras Torácicas/inmunología , Vértebras Torácicas/patologíaRESUMEN
OBJECTIVE: To evaluate the prognostic value of rheumatoid factor (RF), detected in the Waaler-Rose agglutination assay and by nephelometry, in patients with recent-onset rheumatoid arthritis (RA). METHODS: Consecutive patients with new-onset RA between 1993 and 1997 were followed for a median period of 4.7 years. Clinical data at baseline and drug use during the disease course were recorded. Outcome parameters studied were disease process, damage (erosions, joint surgery, extra-articular manifestations, and new co-morbidity), and death. Cut-off levels for RF were >40 IU/mL (nephelometry) and titres 1:160 (Waaler-Rose haemagglutination). RESULTS: RF tests were negative by both methods in 22% of RA patients (RF- group), while 33% were RF positive by nephelometry only (RF+ group) and 45% were positive by Waaler-Rose and nephelometry (RF++ group). Baseline clinical and laboratory findings as well as the number of subsequently used disease-modifying anti-rheumatic drugs (DMARDs), the number of patients starting and the time spent on steroid therapy were similar in the three RF groups. Odd ratios for death (n = 23), erosions (n = 62), and serious extra-articular disease manifestations (EAMs) (n = 13) as well as patient survival, erosion-free or surgery-free survival rates did not differ between the RF groups. Only rheumatoid nodules were more frequent in RF++ patients. CONCLUSION: The baseline presence of RF by either Waaler-Rose or nephelometry was not associated with differences in drug therapy, morbidity other than rheumatoid nodules, or mortality in RA patients in the first 5 years of disease. Being immunoglobulin M (IgM) RF positive thus had little impact on RA patient outcome.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/tratamiento farmacológico , Factor Reumatoide/análisis , Adulto , Anciano , Anciano de 80 o más Años , Pruebas de Aglutinación/métodos , Artritis Reumatoide/mortalidad , Biomarcadores/análisis , Estudios de Cohortes , Intervalos de Confianza , Progresión de la Enfermedad , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Nefelometría y Turbidimetría/métodos , Noruega , Pronóstico , Estudios Retrospectivos , Nódulo Reumatoide/diagnóstico , Nódulo Reumatoide/tratamiento farmacológico , Nódulo Reumatoide/mortalidad , Factores de Riesgo , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Tasa de Supervivencia , Factores de Tiempo , Resultado del TratamientoRESUMEN
OBJECTIVE: Although pulmonary involvement is common in Wegener's granulomatosis (WG), little is known about the pulmonary outcome. We evaluated the relationship between clinical disease characteristics and pulmonary function and high-resolution computed tomography (HRCT) findings after disease duration of 5 years. METHODS: A pulmonary function test (PFT) and pulmonary HRCT were performed in 41 patients from a population-based register of WG. Clinical predictors for abnormal PFT and HRCT were tested by logistic regression. RESULTS: Previous WG-related lung involvement (PLI) had occurred in 80% of patients, but only 24% of patients still reported pulmonary symptoms at the research visit. One-third of patients had abnormal PFT findings, with reduced alveolar diffusion by KCO (transfer coefficient) being most common (24%). The number of PLI episodes was associated with reduced KCO and reduced FEV1% (forced expiratory volume in 1 s as a percentage of forced vital capacity) (overall presence 10%). Reduced KCO was also associated with disease duration. Reduced total lung capacity (TLC) (overall presence 8%) was only related to prior WG-related lung nodules. Pulmonary HRCT was abnormal in 80%, but with more severe abnormalities in only 30%. Pleural thickening and parenchymal bands were associated with PLI. None of the treatment variables was associated with the PFT or HRCT findings. CONCLUSION: Five years after disease onset a quarter of the WG patients reported pulmonary symptoms, had severe abnormalities on HRCT, and abnormal PFT. The correlation between these abnormalities was poor, but the number of pulmonary involvements was a risk factor for reduced gas diffusion, obstructive lung disease, parenchymal bands, and pleural thickening. Treatment variables had no discernible negative pulmonary effects.
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Granulomatosis con Poliangitis/diagnóstico , Granulomatosis con Poliangitis/fisiopatología , Pulmón/fisiopatología , Sistema de Registros , Capacidad Pulmonar Total , Adolescente , Adulto , Edad de Inicio , Anciano , Niño , Diagnóstico Precoz , Femenino , Estudios de Seguimiento , Granulomatosis con Poliangitis/epidemiología , Humanos , Pulmón/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Vigilancia de la Población , Factores de Tiempo , Tomografía Computarizada por Rayos X , Capacidad Pulmonar Total/fisiologíaAsunto(s)
Hipertensión Pulmonar/etiología , Síndrome de Sjögren/complicaciones , Resultado Fatal , Femenino , Humanos , Hipertensión Pulmonar/patología , Hipertensión Pulmonar/fisiopatología , Pulmón/patología , Persona de Mediana Edad , Síndrome de Sjögren/patología , Síndrome de Sjögren/fisiopatologíaRESUMEN
As a consequence of increased insight into the cellular and molecular mechanisms responsible for induction of B cell and T cell autoimmunity to DNA and nucleosomes, there is an obvious need to reconsider the dogma stating that anti-dsDNA antibodies serve as marker antibodies for SLE and also that anti-dsDNA antibodies per se are responsible for the initiation of lupus nephritis. Given that the potential to produce anti-dsDNA antibodies is an inherent property of the normal immune system and that few anti-DNA antibodies have nephritogenic potential, we must try to solve the problem whether it is avidity for DNA, specificity for unique DNA structures or cross-reactivity with non-DNA molecules, that make such antibodies pathogenic and thus potential markers for SLE and lupus nephritis. In this review, we will summarize contemporary problems related to these questions; (1) try to focus on phenotypic differences with respect to the ability to produce anti-dsDNA antibodies between individuals suffering from SLE and those not belonging to this diagnostic group, and (2) to describe differences between pathogenic and non-pathogenic anti-dsDNA antibodies.
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Anticuerpos Antinucleares/inmunología , Nefritis Lúpica/inmunología , Animales , Anticuerpos Antinucleares/genética , Especificidad de Anticuerpos/genética , Variación Genética , Humanos , Glomérulos Renales/inmunología , Nefritis Lúpica/etiología , Nefritis Lúpica/genética , Nucleosomas/inmunologíaAsunto(s)
Antirreumáticos/efectos adversos , Inmunoglobulina G/efectos adversos , Leucemia Mieloide Aguda/complicaciones , Adulto , Etanercept , Femenino , Humanos , Inmunoglobulina G/uso terapéutico , Leucopenia/complicaciones , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Espondilitis Anquilosante/complicaciones , Espondilitis Anquilosante/tratamiento farmacológicoRESUMEN
OBJECTIVE: To determine survival, organ damage and predictors of these outcomes in a population-based, longitudinal cohort study of patients with Wegener's granulomatosis (WG). METHODS: In a retrospective study, 56 WG patients (median age 50 yr) were followed for 56.5 months. Clinical and laboratory data, disease activity, organ involvement and the Vasculitis Damage Index (VDI) were recorded at baseline (start of treatment) and at a research visit after 42.5 months. The Kaplan-Meier method was used to estimate survival and Cox proportional hazards and linear regression models were used to study predictors of outcome. RESULTS: Duration of symptoms before the start of treatment (baseline) was 6 months (1-102 months) and 21 patients (37.5%) had organ damage (VDI > or = 1) at baseline. Baseline organ damage was associated with delay in the start of treatment and an elevated serum creatinine concentration. Fifty-five patients received prednisolone (Pred) and 53 patients received cyclophosphamide by intravenous pulse (CYCiv) or as a daily oral dose (CYCpo). CYCiv patients received lower cumulative doses of CYC and spent less time on Pred >20 mg/day than CYCpo patients. Thirteen patients died during the study period. Ten-year patient survival was 75%. Baseline predictors of reduced survival were higher age, dialysis-dependence and the presence of organ damage. Chronic, end-stage renal failure developed in 10 patients overall and was associated with reduced renal function at baseline. Severe organ damage (VDI > or = 5) developed in 71% of the patients and new damage occurred mainly during the first 6 months. Increased time (months) on Pred >20 mg/day during follow-up increased the last VDI [beta=0.5, 95% confidence interval (CI) 0.3 to 0.8], P<0.001), whereas increased time on CYC during the first 6 months reduced the last VDI (beta=-0.6, 95% CI -1.1 to -0.02, P=0.04). CONCLUSION: Treatment with CYC and corticosteroid led to a 10-yr survival rate of 75% in WG but did not prevent severe organ damage. The presence of baseline organ damage was a marker of poor outcome. There was an association between damage and treatment given.
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Granulomatosis con Poliangitis/mortalidad , Fallo Renal Crónico/mortalidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Ciclofosfamida/uso terapéutico , Progresión de la Enfermedad , Quimioterapia Combinada , Femenino , Granulomatosis con Poliangitis/complicaciones , Granulomatosis con Poliangitis/tratamiento farmacológico , Granulomatosis con Poliangitis/patología , Humanos , Inmunosupresores/uso terapéutico , Fallo Renal Crónico/etiología , Fallo Renal Crónico/patología , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Prednisolona/uso terapéutico , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Tasa de SupervivenciaRESUMEN
ANA testing by immunofluorescence technique (F-ANA) is nowadays still performed in much the same way as 45 years ago when the test was introduced. Due to its low specificity the F-ANA test has a poor predictive value for systemic autoimmune diseases and in addition has proven difficult to standardise. In the meantime, many of the nuclear and cytoplasmatic auto-antigens, related to specific types of autoimmune disease, have been characterised and can be tested for in specific ELISA assays (E-ANA). These assays are in large part automated and enable the large volume testing required, by the current attitude, to use ANA-testing for its high negative predictive value in the exclusion of systemic autoimmune disease. In addition, E-ANA assays give specific results for clinically relevant autoantibodies, while its test repertoire can be altered at any given time to reflect changes in current thinking on relevant auto-antigens. Thus, we suggest that the unspecific F-ANA test should no longer be considered the gold standard for the detection of clinically relevant autoantibodies.
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Anticuerpos Antinucleares/análisis , Enfermedades Autoinmunes/diagnóstico , Ensayo de Inmunoadsorción Enzimática/métodos , Técnica del Anticuerpo Fluorescente , Humanos , Control de Calidad , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: The marked regional variation in the incidence, prevalence, and presentation of systemic lupus erythematosus (SLE) is possibly related to differing spectra of local environmental factors. The aim of this study was to describe such features in a homogenous Caucasian population exposed to an Arctic climate. METHODS: The study area consisted of the 2 northernmost counties of Norway (middle population 222,403) where 4 hospitals (containing only one rheumatology service) provide specialized health care. Retrieval sources were (1) hospital inpatient discharge registries; (2) hospital outpatient registries; (3) mortality database of the National Office for Statistics. Databases were searched with codes for SLE, S ogren's syndrome, unclassified connective tissue disease, and discoid lupus for the period 1978-96. Only patients meeting 1982 American College of Rheumatology criteria for SLE were included in the analysis. Annual incidence rate (AIR), point prevalence (PP), and mortality rates were estimated per 100,000 at risk. RESULTS: Eighty-three incident cases of adult SLE (87% female, mean age 40.6 yrs at diagnosis) were encountered. Crude AIR of SLE in the whole study period was 2.6 (95% CI 1.9-2.9) for adults. Sex-specific AIR was 4.6 for adult women and 0.6 for adult men. AIR in the first (2.4) and second 9-year period (2.7) was similar (p > 0.2). The crude overall PP for SLE at January 1, 1996, was 44.9 and was highest in women aged 3149 (PP 102.5). Mortality in incident cases was 9.6% (after a mean followup of 99 mo) with overall 10-year survival estimated at 75%. CONCLUSION: In a Caucasian population exposed to the Arctic climate incidence of SLE is rather low and stable. Course and presentation of SLE in the Arctic is not different from similar populations in the Western world. Improved outcome now makes SLE a disease present in 1 per 1,000 Norwegian women aged > 30 years.
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Lupus Eritematoso Sistémico/mortalidad , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Regiones Árticas/epidemiología , Niño , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Prevalencia , Distribución por SexoRESUMEN
BACKGROUND: To compare short term efficacy of pulse intravenous (iv) Methylprednisolone (MP) versus Infiximab in flares of polyarthritis. PATIENTS-METHODS: Observational study of consecutive patients admitted with flares of chronic polyarthritis. Treatment consisted of three iv doses of MP 1000mg on alternate days (MP-group, n = 10) or of Infliximab will be 3 mg/kg at baseline, two, and six weeks later (I-group, n=9). DMARD therapy was initiated/continued in all patients. Disease parameters at baseline (t=0), two weeks (t=1) and twelve weeks (t=2) were compared by non-parametric testing. RESULTS: Reductions in disease parameters at both t=1 and t=2, the occurrence of side effects and the proportion of patients reaching ACR 20, 50 or 70% response criteria were similar in both groups. CONCLUSION: Pulse MP resulted in a symptomatic response similar to Infliximab in our patients. The benefit of MP was observed for up to 3 months.
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Anticuerpos Monoclonales/administración & dosificación , Artritis/tratamiento farmacológico , Metilprednisolona/administración & dosificación , Adulto , Anciano , Artritis/diagnóstico , Distribución de Chi-Cuadrado , Enfermedad Crónica , Esquema de Medicación , Femenino , Estudios de Seguimiento , Humanos , Infliximab , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Noruega , Probabilidad , Estudios Prospectivos , Quimioterapia por Pulso , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Resultado del TratamientoAsunto(s)
Vasculitis/epidemiología , Anciano , Femenino , Humanos , Incidencia , Masculino , Noruega/epidemiología , España/epidemiologíaRESUMEN
OBJECTIVE: To determine if changes in the incidence, prevalence, and clinical presentation of Wegener's granulomatosis (WG) have occurred in the stable population of northern Norway during a 15-year period. METHODS: We performed a retrospective cohort study using hospital discharge records from all 11 hospitals in the region and the databases of the 2 pathology departments in the area. Only patients fulfilling the American College of Rheumatology 1990 criteria for WG were included in the study, and demographic and clinical data at diagnosis were recorded. Incidence, point prevalence, and period prevalence rates were estimated for three 5-year periods. RESULTS: Fifty-five patients (62% male) with a median age at diagnosis of 50 years (range 10-84 years) fulfilled the inclusion criteria. The annual incidence/ million population increased from 5.2 (95% confidence interval [95% CI] 2.7-9.0) during 1984-1988 to 12.0 (95% CI 8.0-17.3) during 1994-1998. The point prevalence/million increased from 30.4 (95% CI 16.6-51.0) to 95.1 (95% CI 69.1-129.0). The highest incidence rate occurred in men ages 65-74 years. There were no significant period differences in age, first organ involved, delay of diagnosis, or disease activity, but fewer patients had malaise and renal insufficiency during the earliest time period. No seasonal variation in the onset of WG was present, although we noted a pattern of annual fluctuation. CONCLUSION: The prevalence of WG has tripled in northern Norway over the last 15 years. While more efficacious therapy may explain part of this increase, we also found a significant trend toward increased incidence over that period. The incidence rate over the last 5 years is the highest reported so far, while the clinical presentation has remained unchanged.
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Granulomatosis con Poliangitis/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Anticitoplasma de Neutrófilos/sangre , Niño , Estudios de Cohortes , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Prevalencia , Estaciones del Año , Factores de TiempoRESUMEN
The risk for endstage renal failure in patients with proliferative lupus nephritis (PLN) depends largely on the severity and reversibility of the inflammatory process as determined by light microscopy (LM). As the intrarenal formation of immune complexes is thought to initiate this inflammation, we studied whether renal immunofluorescence microscopy (IFM) provides clinical or prognostic information in addition to LM findings. Clinical data at the time of renal biopsy and during a mean follow-up of 46 months were extracted from the records of 69 SLE patients with proliferative LN (WHO class III/IV). Biopsy specimens were analyzed by LM for AI and CI, while IFM was performed on cryostat sections with the use of antisera against IgG, IgM, IgA, C3, C1q and fibrin. IFM findings were recorded in terms of the localization (glomerular, tubular or vascular) and intensity of fluorescence (score from zero to three). IFM findings were then related to clinical and LM findings and its prognostic value studied by survival analysis. Glomerular immune deposits were present in 99% of patients, tubular deposits in 38% and vascular deposits in 17%. A 'full-house' pattern (all three Ig classes) was found in 67% of biopsies and C3 and C1q deposits in 93% and 74% respectively. Median scores for AI and CI were 6 (1-18) and 3 (0-10); aside from a negative correlation between IgA deposits and CI, we found no other correlation between the amount or type of immune deposits and AI or CI. IgM deposits were associated with high serum levels of anti-dsDNA, while IgG deposits correlated with high ESR and serum creatinin levels. IFM scores were not related to steroid dose at the time of biopsy and neither type of glomerular, tubular or overall renal immune deposits had prognostic value for renal survival. Renal immunofluorescence does not reflect light microscopy findings in patients with PLN and does not contribute prognostic information in patients with PLN. Lupus (2000) 9, 504-510.