Analysis of four serum biomarkers in rheumatoid arthritis: association with extra articular manifestations in patients and arthralgia in relatives / Análise de quatro marcadores sorológicos na artrite reumatoide: associação com manifestações extra-articulares no paciente e artralgia em familiares

ABSTRACT Objectives: To evaluate the frequency of four serum biomarkers in RA patients and their relatives and identify possible associations with clinical findings of the disease. Methods: This was a transversal analytical study. Anti-cyclic citrullinated peptide (anti-CCP), anti-mutated citrullinated vimentin (anti-MCV) and IgA-rheumatoid factor (RF) were determined by ELISA and IgM-RF by latex agglutination in 210 RA patients, 198 relatives and 92 healthy controls from Southern Brazil. Clinical and demographic data were obtained through charts review and questionnaires. Results: A higher positivity for all antibodies was observed in RA patients when compared to relatives and controls (p < 0.0001). IgA-RF was more frequent in relatives compared to controls (14.6% vs. 5.4%, p = 0.03, OR = 2.98; 95% CI = 1.11-7.98) whereas anti-CCP was the most common biomarker among RA patients (75.6%). Concomitant positivity for the four biomarkers was more common in patients (46.2%, p < 0.0001). Relatives and controls were mostly positive for just one biomarker (20.2%, p < 0.0001 and 15.2%, p = 0.016, respectively). No association was observed between the number of positive biomarkers and age of disease onset, functional class or tobacco exposure. In seronegative patients predominate absence of extra articular manifestations (EAMs) (p = 0.01; OR = 3.25; 95% CI = 1.16-10.66). Arthralgia was present in positive relatives, regardless the type of biomarker. Conclusions: A higher number of biomarkers was present in RA patients with EAMs. Positivity of biomarkers was related to arthralgia in relatives. These findings reinforce the link between distinct biomarkers and the pathophysiologic mechanisms of AR.

RESUMO Objetivos: Avaliar a frequência de quatro marcadores sorológicos em pacientes com AR e seus familiares e identificar possíveis associações com achados clínicos da doença. Métodos: Estudo analítico transversal. Determinaram-se os níveis de anticorpos antipeptídeo citrulinado cíclico (anti-CCP), anticorpos antivimentina citrulinada-mutada (anti-MCV) e fator reumatoide (FR) IgA por Elisa e de FR-IgM por aglutinação em látex em 210 pacientes com AR, 198 familiares e 92 controles saudáveis do sul do Brasil. Coletaram-se dados clínicos e demográficos por meio da revisão de prontuários e questionários. Resultados: Observou-se maior positividade para todos os anticorpos em pacientes com AR em comparação com os familiares e controles (p < 0,0001). O FR-IgA era mais frequente em familiares quando comparados com os controles (14,6% versus 5,4%, p = 0,03, OR = 2,98; IC95% = 1,11 a 7,98). O anti-CCP foi o biomarcador mais comum entre pacientes com AR (75,6%). A positividade concomitante para os quatro biomarcadores foi mais comum nos pacientes (46,2%, p < 0,0001). Familiares e controles eram positivos em sua maioria para apenas um biomarcador (20,2%, p < 0,0001 e 15,2%, p = 0,016, respectivamente). Não foi observada associação entre o número de biomarcadores positivos e a idade de início da doença, classe funcional ou exposição ao fumo. Em pacientes soronegativos, predominou a ausência de manifestações extra-articulares (MEA) (p = 0,01; OR = 3,25; IC95% = 1,16 a 10,66). A artralgia estava presente em familiares positivos, independentemente do tipo de biomarcador. Conclusões: Um maior número de biomarcadores estava presente em pacientes com AR com MEA. A positividade dos biomarcadores estava relacionada com a artralgia em familiares. Esses achados reforçam a ligação entre os diferentes biomarcadores e os mecanismos fisiopatológicos da AR.

Analysis of four serum biomarkers in rheumatoid arthritis: association with extra articular manifestations in patients and arthralgia in relatives.

OBJECTIVES: To evaluate the frequency of four serum biomarkers in RA patients and their relatives and identify possible associations with clinical findings of the disease. METHODS: This was a transversal analytical study. Anti-cyclic citrullinated peptide (anti-CCP), anti-mutated citrullinated vimentin (anti-MCV) and IgA-rheumatoid factor (RF) were determined by ELISA and IgM-RF by latex agglutination in 210 RA patients, 198 relatives and 92 healthy controls from Southern Brazil. Clinical and demographic data were obtained through charts review and questionnaires. RESULTS: A higher positivity for all antibodies was observed in RA patients when compared to relatives and controls (p<0.0001). IgA-RF was more frequent in relatives compared to controls (14.6% vs. 5.4%, p=0.03, OR=2.98; 95% CI=1.11-7.98) whereas anti-CCP was the most common biomarker among RA patients (75.6%). Concomitant positivity for the four biomarkers was more common in patients (46.2%, p<0.0001). Relatives and controls were mostly positive for just one biomarker (20.2%, p<0.0001 and 15.2%, p=0.016, respectively). No association was observed between the number of positive biomarkers and age of disease onset, functional class or tobacco exposure. In seronegative patients predominate absence of extra articular manifestations (EAMs) (p=0.01; OR=3.25; 95% CI=1.16-10.66). Arthralgia was present in positive relatives, regardless the type of biomarker. CONCLUSIONS: A higher number of biomarkers was present in RA patients with EAMs. Positivity of biomarkers was related to arthralgia in relatives. These findings reinforce the link between distinct biomarkers and the pathophysiologic mechanisms of AR.

Association of anticyclic citrullinated peptide antibodies with extra-articular manifestations, gender, and tabagism in rheumatoid arthritis patients from southern Brazil.

Gender and environmental factors are known to influence the clinical heterogeneity and outcome of rheumatoid arthritis (RA). Some variables have been suggested to be associated with the severity of the disease, which can be of great value in the correct management of RA patients. The purpose of this study was to investigate the associations among anticyclic citrullinated antibody (anti-CCP2) positivity, extra-articular manifestations (EAM), gender, and tobacco exposure in a Brazilian RA population. We performed a transversal study comprising 156 RA patients which were investigated for EAM, functional class, presence of anti-CCP2, and IgM rheumatoid factor (IgM-RF). The determination of anti-CCP2 was performed using enzyme immunoassay (ELISA) kits and IgM-RF by latex agglutination test. Clinical and demographical data were obtained through review of charts. Anti-CCP positivity intensity was directly correlated with tobacco smoking, sex, and the development of rheumatoid nodules. Intense anti-CCP2 reaction was 19.8-fold higher in females vs. males, 2.7-fold higher in tobacco vs. non-tobacco users, 7.7-fold higher in female vs. male tobacco users, and 5.15-fold higher in patients with rheumatoid nodules. Tobacco smoking, gender, and rheumatoid nodules are significantly correlated with anti-CCP2 positivity in Brazilian RA patients.

Autoantibodies for gastrointestinal organ-specific autoimmune diseases in rheumatoid arthritis patients and their relatives.

BACKGROUND: Clustering of autoimmune diseases is common and may be due to genetic background and exposition to environmental triggers. OBJECTIVE: The aim is to carry out a laboratory and clinical study of the prevalence of gastrointestinal organ-specific autoantibodies in rheumatoid arthritis (RA) patients and their relatives. METHODS: Serum samples of 156 RA patients, 200 relatives, and 100 healthy controls were studied for anti-smooth muscle antibody (ASMA), anti-mitochondrial (AMA), anti-parietal cell (APCA), anti-liver-kidney microsome (LKM), and anti-endomysium antibodies (IgA-EmA) by indirect immunofluorescence. RESULTS: A total of eight out of the 156 (5.1%) RA patients were positive for the autoantibodies (ASMA = 1; AMA = 2, APCA = 5). In the relative group, 12/200 (6%) had at least one positive autoantibody (ASMA = 1; AMA = 2, APCA = 7, IgA-EmA = 2). In the control group, two out of the 100 (2%) healthy controls were positive (ASMA = 1, APCA = 1). No statistical difference was found between RA patients, their relatives, and controls in relation to the frequency of autoantibodies evaluated. CONCLUSION: Although RA patients and their relatives have positivity of AMA, ASMA, and APCA without statistical difference in relation to healthy individuals, the findings may be of value for adequate clinical approach of these subjects.

Anti-cyclic citrullinated peptide antibodies and rheumatoid factor in rheumatoid arthritis patients and relatives from Brazil.

OBJECTIVES: To evaluate the prevalence of anti-cyclic citrullinated peptide (anti-CCP) antibodies and RF in RA patients and their relatives from Southern Brazil. METHODS: Anti-CCP2 and IgM-RF were evaluated in 156 RA patients and 200 relatives. Sera from 100 healthy unrelated individuals were used as control. The anti-CCP2 was detected by ELISA and the IgM-RF using the latex agglutination test. RESULTS: We identified 117 anti-CCP2 (75%)-positive and 106 RF (67.9%)-positive patients. Anti-CCP2 was increased in relatives (5.5%; 11/200) when compared with unrelated individuals (1%; P = 0.050). Titre of anti-CCP2 in RA patients did not differ from relatives [140.4 (75.7) vs 115.6 (84.2) U, respectively; P = 0.30]. Positive relatives were younger than patients for anti-CCP2 (P = 0.0081), RF (P < 0.001) and both concomitantly (P = 0.012), and although there was no difference for anti-CCP2 positivity according to gender, increased RF positivity and concomitant anti-CCP2/RF were observed in the female relatives (P = 0.067 and 0.082, respectively). No difference regarding the relative degree of tobacco use in relatives was detected. Among the 11 anti-CCP2-positive relatives, 2 females had RA diagnosis established and 6 individuals presented with joint symptoms suggestive of RA. CONCLUSION: The results demonstrate a significant positivity of anti-CCP2 in relatives of RA patients from Brazil and reinforce the importance of serological tools to identify undiagnosed RA.

High positivity of anti-CCP antibodies in patients with Down syndrome.

The aim of the present study was to evaluate the prevalence of anti-cyclic citrullinated peptide (CCP) antibodies in patients with Down's syndrome (DS) previously tested for IgM rheumatoid factor (RF) and to correlate the results with clinical findings. Eighty-eight patients with DS previously tested for IgM-RF were divided into two groups matched for sex and age. Group A consists of 42 RF positive patients and group B of 44 RF negative patients. The presence of anti-CCP antibody was determined using a second-generation enzyme-linked immunosorbent assay. A total of 52.3% (45/86) of DS patients were positive for anti-CCP antibodies. Twenty-four patients (57.1%) of the RF positive group and 21 (47.7%) of the RF negative group presented anti-CCP circulating antibodies. The concordance between both tests was 54.6%. None of the patients had clinical evidence of rheumatoid arthritis or juvenile idiopathic arthritis. Although a high prevalence of anti-CCP antibodies was observed in DS patients, no association has been found presently with clinical disease. Careful follow-up of these patients will be necessary to clarify the real significance of these findings.

Celiac disease in children and adolescents with Down syndrome.

OBJECTIVES: High prevalence rates of celiac disease in patients with Down syndrome have been reported in several countries. However, in Brazil there is no data regarding this association. In this study we report the prevalence of celiac disease in Down syndrome children and adolescents from southern Brazil. METHODS: Seventy-one patients (32 female and 39 male, 2-18 years) from Curitiba, Brazil, were studied. Eighty young people (42 male and 38 female, 2-19 years) were used as controls. All subjects were screened for the IgA-antiendomysium antibody (EmA) and IgA anti-tecidual transglutaminase (anti-tTG). EmA was measured by an immunofluorescence assay using umbilical cord as the substrate and anti-tTG by ELISA with tecidual transglutaminase as the antigen. The total IgA serum level was determined by turbidimetry. RESULTS: Five DS patients (7%) were positive for EmA-IgA, with titers from 1/5 to 1/80 and 14 (17.5%) for anti-tTG (21-340 units). All EmA positive patients also presented anti-tTG antibodies simultaneously. Clinical and histological findings of the intestinal mucosa confirmed celiac disease diagnoses in four patients. The other EmA positive patient was asymptomatic and was not submitted to duodenal biopsy. Patients only positive for anti-tTG presented borderline values (< 25 units) and were asymptomatic. None of the controls were positive for EmA or anti-tTG. No Down syndrome patients or controls presented IgA deficiency. CONCLUSIONS: These data indicates a high prevalence (5.6%) of confirmed celiac disease in Down syndrome patients from southern Brazil.

Doença celíaca em crianças e adolescentes com síndrome de Down / Celiac disease in children and adolescents with Down syndrome

OBJETIVOS: Alta prevalência de doença celíaca em pacientes com síndrome de Down tem sido descrita em vários países. No entanto, no Brasil ainda não há relatos mostrando essa associação. O presente estudo teve como objetivo avaliar a prevalência de doença celíaca em crianças e adolescentes com síndrome de Down no sul do Brasil. MÉTODOS: Setenta e um pacientes (32 do sexo feminino e 39 masculino, 2-18 anos) provenientes de Curitiba, Brasil, foram estudados. Oitenta indivíduos (42 do sexo masculino e 38 feminino, 2-19 anos) foram utilizados como controles do estudo. Todas as amostras foram investigadas para anticorpo anti-endomísio (EmA) e anti-transglutaminase tecidual (anti-tTG). O EmA foi pesquisado através de imunofluorescência indireta usando cordão umbilical como substrato e o anti-tTG através da técnica de ELISA, utilizando transglutaminase tecidual como antígeno. As dosagens de IgA foram realizadas por turbidimetria. RESULTADOS: Cinco pacientes com síndrome de Down (7 por cento) foram positivos para EmA-IgA, com títulos entre 1/5 e 1/80 e catorze (17,5 por cento) para anti-tTG (21-340 unidades). Todos os pacientes positivos para EmA apresentaram simultaneamente positividade para o anti-tTG. Os achados clínicos e histológicos na mucosa intestinal confirmaram doença celíaca em quatro pacientes. O outro paciente EmA positivo não foi submetido a biópsia duodenal. Os pacientes positivos apenas para anti-tTG apresentaram valores limítrofes (< 25 unidades) e eram assintomáticos. Nenhum indivíduo do grupo controle foi positivo para EmA ou anti-tTG. Nenhuma amostra do estudo foi deficiente para IgA. CONCLUSÕES: Os dados do presente estudo mostram alta prevalência (5,6 por cento) de doença celíaca confirmada em crianças e adolescentes com síndrome de Down da região sul do Brasil.