RESUMEN
OBJECTIVES: To analyse demographic and clinical variables in patients with disease onset before and after 40, 45 and 50 years in a large series of Brazilian SpA patients. METHODS: A common protocol of investigation was prospectively applied to 1424 SpA patients in 29 centres distributed through the main geographical regions in Brazil. The mean age at disease onset was 28.56 ± 12.34 years, with 259 patients (18.2%) referring disease onset after 40 years, 151 (10.6%) after 45 years and 81 (5.8%) after 50 years. Clinical and demographic variables and disease indices (BASDAI, BASFI, BASRI, MASES, ASQoL) were investigated. Ankylosing spondylitis was the most frequent disease (66.3%), followed by psoriatic arthritis (18%), undifferentiated SpA (6.7%), reactive arthritis (5.5%), and enteropathic arthritis (3.5%). RESULTS: Comparing the groups according to age of disease onset, those patients with later onset presented statistical association with female gender, peripheral arthritis, dactylitis, nail involvement and psoriasis, as well as negative statistical association with inflammatory low back pain, alternating buttock pain, radiographic sacroiliitis, hip involvement, positive familial history, HLA-B27 and uveitis. BASDAI, BASFI and quality of life, as well as physicians and patient's global assessment, were similar in all the groups. Radiographic indices showed worse results in the younger age groups. CONCLUSIONS: There are two different clinical patterns in SpA defined by age at disease onset: one with predominance of axial symptoms in the group with disease onset ≤ 40 years and another favouring the peripheral manifestations in those with later disease onset.
Asunto(s)
Índice de Severidad de la Enfermedad , Espondiloartritis/epidemiología , Espondiloartritis/fisiopatología , Espondilitis Anquilosante/epidemiología , Espondilitis Anquilosante/fisiopatología , Adolescente , Adulto , Distribución por Edad , Edad de Inicio , Anciano , Brasil/epidemiología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto JovenRESUMEN
Neutrophils participate in the initiation and progression of rheumatoid arthritis (RA) although the exact mechanisms responsible for neutrophil accumulation in rheumatoid joints are not understood. This study compared the adhesive and chemotactic functions of neutrophils from RA patients in activity (DAS28 > 3.2) and not in activity (DAS28 < 2.6) and observed the effects of different treatment approaches on these functions. Neutrophils were isolated from healthy controls (CON), and patients with active or inactive RA in use of therapy not specific for RA (NSAIDs), in use of DMARDs and in use of anti-TNF-α therapy. Adhesive and chemotactic properties were evaluated using in vitro assays; adhesion molecule expression was assessed by flow cytometry and real-time PCR and circulating chemokines were determined by ELISA. No significant alterations in the adhesive and chemotactic properties of neutrophils from active RA were observed when compared to CON neutrophils, independently of treatment regimen. In contrast, neutrophils from RA patients in disease remission presented reduced adhesive properties and a lower spontaneous chemotactic capacity, in association with decreased adhesion molecule expression, although profiles of alterations differed for those patients on DMARDs and those on anti-TNF-α therapy. Circulating levels of the major neutrophilic chemokines, IL-8 and epithelial neutrophil activating peptide-78, were also significantly decreased in those patients demonstrating a clinical response. Remission of RA appears to be associated with ameliorations in aspects important for neutrophil adhesion and chemotaxis; whether these alterations contribute to decrease neutrophil migration to the synovial fluid, with consequent improvements in the clinical manifestations of RA, remains to be determined.
Asunto(s)
Artritis Reumatoide/tratamiento farmacológico , Quimiocinas/sangre , Quimiotaxis de Leucocito/efectos de los fármacos , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adulto , Anciano , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Antirreumáticos/farmacología , Antirreumáticos/uso terapéutico , Artritis Reumatoide/sangre , Artritis Reumatoide/diagnóstico , Estudios de Casos y Controles , Adhesión Celular/efectos de los fármacos , Moléculas de Adhesión Celular/genética , Moléculas de Adhesión Celular/metabolismo , Femenino , Expresión Génica/efectos de los fármacos , Humanos , Infliximab , Interleucina-8/sangre , Interleucina-8/farmacología , Selectina L/sangre , Masculino , Persona de Mediana Edad , Neutrófilos/metabolismo , Inducción de Remisión , Adulto JovenRESUMEN
Paracoccidioidomycosis is a systemic fungal infection endemic to Central and South America. It is associated with a broad spectrum of clinical manifestations and has been classified into acute and chronic forms. The latter is the most common type and usually affects male agricultural workers in rural communities. The disease typically begins in the lungs producing varying degrees of parenchymal damage, and in a significant number of cases the organism spreads through bronchogenic, lymphatic, or hematogenous routes to involve 1 or more organs. Bone and joint infection is relatively uncommon and has not been well described in the English literature. Much of the information on this form of the disease has been derived from radiographic and autopsy studies on patients with severe or fatal infections in whom skeletal involvement was a minor or incidental finding. We describe our experience with 9 cases in which osteoarticular manifestations were the sole or 1 of the few major complications of the disease. All 9 patients were male, from 9 to 49 years of age (mean, 36.6 yr). Six were farmers. Evidence of visceral infection was present in 6 patients, in all of whom the lungs were considered the primary site of disease. The osteoarticular lesions were symptomatic in all cases, with the duration of symptoms ranging from 1 week to 2 years. The lesions were centered in bone in 2 cases: they manifested radiographically as circumscribed areas of lysis with or without a rim of sclerosis. The disease was centered in joints in 7 cases; the associated radiographic changes included evidence of joint effusion, periarticular bony erosions, and narrowing of the joint space. Biopsy of the involved skeletal site revealed compact or loose granulomas containing variable numbers of fungi. Although follow-up information was not available for all patients, those treated with TMP-SMX (and 1 patient who also received amphotericin B) and who were followed had prompt resolution of their signs and symptoms. Our findings substantiate some of what is known about the epidemiology of bone and joint involvement in chronic paracoccidioidomycosis. Our patients exhibited features of skeletal infection that have not been emphasized previously, however, including 1) frequent involvement of large joints or long bones of the extremities, 2) presentation with relatively rapidly developing musculoskeletal symptoms, and 3) manifestation as a solitary joint or bone lesion with or without concurrent clinically detectable pulmonary disease. Bone and joint paracoccidioidomycosis should be considered in the differential diagnosis in patients who have skeletal lesions with or without pulmonary involvement and have either lived in or traveled through endemic areas. Early diagnosis and treatment with antifungal medications can achieve an excellent outcome with limited local sequelae.
Asunto(s)
Enfermedades Óseas/diagnóstico , Artropatías/diagnóstico , Paracoccidioidomicosis/diagnóstico , Adulto , Enfermedades Óseas/diagnóstico por imagen , Enfermedades Óseas/patología , Huesos/diagnóstico por imagen , Huesos/patología , Niño , Humanos , Artropatías/diagnóstico por imagen , Artropatías/patología , Enfermedades Pulmonares Fúngicas/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Paracoccidioidomicosis/diagnóstico por imagen , Paracoccidioidomicosis/patología , Tomografía Computarizada por Rayos XRESUMEN
The aim of the study was to analyse the 2-year follow-up of a series of patients with the diagnosis of undifferentiated spondyloarthropathy (uSpA). A prospective study was carried out analysing 68 patients with symptomatic uSpA who fulfilled the European Spondylarthropathy Study Group (ESSG) criteria for seronegative spondyloarthropathies (SpA) and were aged between 18 and 50 years. Inclusion criteria included inflammatory low back pain (ILBP) (without radiographic sacroiliitis), asymmetric oligoarthritis (predominantly affecting large joints in the lower limbs) and heel enthesopathies (Achilles tendinitis and/or plantar fasciitis). Imaging methods included pelvic radiography (at study entry and after 2 years) and calcaneal radiography (at study entry). There was a predominance of male gender (78%), caucasoid race (72%) and positive HLA-B27 (54%), with a mean age of 31 years and mean disease duration of 5 years. The first disease manifestations were ILBP (49%), asymmetric oligoarthritis (35%) and heel enthesopathies (16%). A positive family history of a definite SpA was mentioned by 9% of the patients. Seventeen patients (25%) scored 5 points in the Amor set of SpA criteria; logistic regression analysis showed that HLA-B27, heel enthesopathy and asymmetric oligoarthritis were significantly associated with Amor criteria > or = 6, whereas ILBP was associated with Amor criteria <6. Male sex was associated with heel enthesopathies (p = 0.041) and ankle involvement (p = 0.015). Caucasoid race was associated with ILBP (p=0.015) and buttock pain (p = 0.047). Positive HLA-B27 was associated with wrist involvement (p=0.019) and Amor criteria > or = 6 (p=0.001). After a 2-year follow-up the following outcomes were observed: uSpA 75%; disease remission 13%; ankylosing spondylitis 10%; psoriatic arthritis 2%. Logistic regression analysis showed that buttock pain and positive HLA-B27 (trend) were statistically associated with progression to a definite SpA. In conclusion, uSpA can represent a provisional diagnosis in the group of SpA and a systematic follow-up is necessary in order to better establish the different patterns of the disease.
Asunto(s)
Artritis/diagnóstico , Enfermedades de la Columna Vertebral/diagnóstico , Adulto , Artritis/clasificación , Artritis/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedades de la Columna Vertebral/clasificación , Enfermedades de la Columna Vertebral/fisiopatologíaRESUMEN
We investigated the occurrence of an active cytomegalovirus (CMV) infection in patients with polyarteritis nodosa (PAN). Eleven patients with PAN were screened for the presence of CMV-DNA in their blood using the polymerase chain reaction (PCR). Serum anti-CMV IgG and anti-CMV IgM antibodies were determined by enzyme-linked immunosorbent assays (ELISA). The ELISA for IgM was negative in all cases whereas that for IgG was positive in eight cases. Only one patient was positive for CMV-DNA by PCR. He presented with myalgia, polyarthralgia, fever and weight loss, suggesting PAN activity. CMV infection was uncommon in our series of patients with PAN, despite disease activity and immunosuppressor therapy. The finding of a transient CMV infection in one case at the beginning of PAN activity suggests that CMV may be involved in the pathogenesis of PAN.
Asunto(s)
Infecciones por Citomegalovirus/diagnóstico , Citomegalovirus/genética , Poliarteritis Nudosa/diagnóstico , Adolescente , Adulto , Anticuerpos Antivirales/sangre , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/complicaciones , Cartilla de ADN/química , ADN Viral/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Poliarteritis Nudosa/etiología , Reacción en Cadena de la PolimerasaRESUMEN
The objective of this study was to determine the frequency of cognitive impairment in patients with rheumatoid arthritis (RA). A cross-sectional study of 40 patients with RA and 40 healthy controls was performed. To assess cognitive impairment, anxiety and depression, the following standardized psychiatric and clinical research methods were used: the Mini-Mental State Examination (MMSE), logic memory tests, short and long memory tests, verbal fluency tests, attention tests, the Brief Psychiatric Rating Scale (BPRS), the Hospital Anxiety and Depression (HAD)/CAGE scale and the Beck Depression Inventory (BDI). Patients and controls with incomplete primary education were excluded from the study. Statistics were performed by chi-square test and by Fisher's exact test. Cognitive impairment was observed in 30% of patients with RA and in 7.5% (p < 0.05) of healthy controls. Patients with RA had a significantly worse outcome in verbal fluency (p < 0.05), logic memory (p < 0.05) and short memory (p < 0.05). No statistical difference was observed among the results obtained in the MMSE, BPRS, HAD/CAGE and BDI. There was no significant relation to the duration of the illness, use of corticotherapy or disability. We observed a high prevalence of cognitive impairment in RA patients. Cognitive impairment was not related to clinical and treatment features or disability. More studies are necessary to determine clinical impact of cognitive impairment in RA.
Asunto(s)
Artritis Reumatoide/complicaciones , Trastornos del Conocimiento/etiología , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración PsiquiátricaRESUMEN
In the present study, we evaluated 42 wrists using the semi-quantitative scales power Doppler ultrasound (PDUS) and gray scale ultrasound (GSUS) with scores ranging from 0 to 3 and correlated the results with clinical, laboratory and radiographic data. Twenty-one patients (17 women and 4 men) with rheumatoid arthritis according to criteria of the American College of Rheumatology were enrolled in the study from September 2008 to July 2009 at Universidade Estadual de Campinas (UNICAMP). The average disease duration was 14 months. The patients were 66.6% Caucasians and 33.3% non-Caucasians, with a mean age of 42 and 41 years, respectively. A dorsal longitudinal scan was performed by ultrasound on the radiocarpal and midcarpal joints using GE LOGIQ XP-linear ultrasound and a high frequency (8-10 MHz) transducer. All patients were X-rayed, and the Larsen score was determined for the joints, with grades ranging from 0 to V. This study showed significant correlations between clinical, sonographic and laboratory data: GSUS and swollen right wrist (r = 0.546), GSUS of right wrist and swelling of left wrist (r = 0.511), PDUS of right wrist and pain in left wrist (r = 0.436), PDUS of right wrist and C-reactive protein (r = 0.466). Ultrasound can be considered a useful tool in the diagnosis of synovitis in early rheumatoid arthritis mainly when the anti-cyclic citrullinated peptide and rheumatoid factor are negative, and can lead to an early change in the therapeutic decision.
Asunto(s)
Artritis Reumatoide/diagnóstico por imagen , Sinovitis/diagnóstico por imagen , Articulación de la Muñeca/diagnóstico por imagen , Adulto , Artritis Reumatoide/complicaciones , Diagnóstico Precoz , Femenino , Humanos , Masculino , Sensibilidad y Especificidad , Sinovitis/etiología , Ultrasonografía DopplerRESUMEN
The objective of the present study was to evaluate the contribution of the shared epitope (SE), the rheumatoid arthritis (RA) protection model, and the occurrence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA patients from a genetically diverse population. One hundred and forty Brazilian RA patients and 161 matched controls were typed for HLA-DRB1 alleles using amplified DNA hybridized with sequence-specific oligonucleotide probes or primers. Patients were stratified according to the presence or absence of SE (DRB1*0401, *0404, *0405, *0101, *1001, and *1402), of the DERAA alleles (DRB1*0103, *0402, *1102, *1103, *1301, *1302, and *1304), and X (all other alleles). Anti-CCP antibodies were measured by ELISA. The combined frequency of SE-positive alleles was significantly greater (76.4 vs 23.6%, P < 0.0001) than the controls. The SE/SE and SE/X genotypes were over-represented (P < 0.0001, OR = 6.02) and DERAA/X was under-represented in RA patients (P < 0.001, OR = 0.49), whereas the frequencies of the SE/DERAA, X/X and X/DERAA genotypes were not significantly different from controls. The frequency of anti-CCP antibodies was higher in SE-positive patients than in SE-negative patients (64.6 vs 44.7%, P = 0.03; OR = 2.25). Although the Brazilian population is highly miscegenated, the results of this study support the findings observed in most genetically homogeneous populations with RA; however, they are not mutually exclusive but rather complementary. The participation of DRB1-DERAA alleles in protection against RA was also observed (OR = 0.4; 95%CI = 0.23-0.68).
Asunto(s)
Alelos , Artritis Reumatoide/genética , Autoanticuerpos/inmunología , Epítopos/genética , Antígenos HLA-DR/genética , Péptidos Cíclicos/genética , Adulto , Anciano , Artritis Reumatoide/inmunología , Brasil , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Epítopos/inmunología , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Antígenos HLA-DR/inmunología , Cadenas HLA-DRB1 , Humanos , Masculino , Persona de Mediana Edad , Péptidos Cíclicos/inmunología , Reacción en Cadena de la Polimerasa , Adulto JovenRESUMEN
OBJECTIVE: To evaluate the effectiveness of foot orthoses using the foot function index (FFI) in a group of patients with rheumatoid arthritis (RA) during a period of 6 months. METHODS: Thirty-six rheumatoid subjects with foot pain were examined and appropriate foot orthoses were prescribed according to each patient's needs. All the patients were evaluated 30, 90 and 180 days after the baseline visit. FFI values, daily time of wearing the orthoses and adverse effects were noted at each appointment. The Stanford Health Assessment Questionnaire (HAQ) was used at the initial visit to evaluate the influence of physical condition on FFI response. RESULTS: With the use of foot orthoses, FFI values decreased in all subscales (pain, disability and activity limitation). This reduction was noted in the first month and was maintained throughout the trial. Those using EVA (ethyl-vinyl acetate; n = 28) orthoses presented results similar to those for the total group. Patients wearing made-to-measure orthoses (n = 8) exhibited higher initial FFI values and worse evolution during the trial, significant for pain and disability but not for activity limitation. Minor adverse reactions were noted; none required interruption of treatment. There was no relation between HAQ and FFI evolution. CONCLUSIONS: Foot orthoses were effective as an adjuvant in the management of rheumatoid foot. They significantly reduced pain, disability and activity limitation, as measured by the FFI, with minor adverse effects.
Asunto(s)
Artritis Reumatoide/fisiopatología , Enfermedades del Pie/fisiopatología , Pie/fisiopatología , Aparatos Ortopédicos , Actividades Cotidianas , Adulto , Anciano , Artritis Reumatoide/complicaciones , Artritis Reumatoide/rehabilitación , Evaluación de la Discapacidad , Diseño de Equipo , Femenino , Deformidades Adquiridas del Pie/rehabilitación , Enfermedades del Pie/complicaciones , Enfermedades del Pie/rehabilitación , Humanos , Masculino , Metatarsalgia/etiología , Metatarsalgia/fisiopatología , Metatarsalgia/rehabilitación , Persona de Mediana Edad , Aparatos Ortopédicos/efectos adversos , Dolor/etiología , Dolor/fisiopatología , Dolor/rehabilitación , Dimensión del Dolor/métodos , Resultado del TratamientoRESUMEN
In the present study, we evaluated 42 wrists using the semi-quantitative scales power Doppler ultrasound (PDUS) and gray scale ultrasound (GSUS) with scores ranging from 0 to 3 and correlated the results with clinical, laboratory and radiographic data. Twenty-one patients (17 women and 4 men) with rheumatoid arthritis according to criteria of the American College of Rheumatology were enrolled in the study from September 2008 to July 2009 at Universidade Estadual de Campinas (UNICAMP). The average disease duration was 14 months. The patients were 66.6 percent Caucasians and 33.3 percent non-Caucasians, with a mean age of 42 and 41 years, respectively. A dorsal longitudinal scan was performed by ultrasound on the radiocarpal and midcarpal joints using GE LOGIQ XP-linear ultrasound and a high frequency (8-10 MHz) transducer. All patients were X-rayed, and the Larsen score was determined for the joints, with grades ranging from 0 to V. This study showed significant correlations between clinical, sonographic and laboratory data: GSUS and swollen right wrist (r = 0.546), GSUS of right wrist and swelling of left wrist (r = 0.511), PDUS of right wrist and pain in left wrist (r = 0.436), PDUS of right wrist and C-reactive protein (r = 0.466). Ultrasound can be considered a useful tool in the diagnosis of synovitis in early rheumatoid arthritis mainly when the anti-cyclic citrullinated peptide and rheumatoid factor are negative, and can lead to an early change in the therapeutic decision.
Asunto(s)
Adulto , Femenino , Humanos , Masculino , Artritis Reumatoide , Sinovitis , Articulación de la Muñeca , Artritis Reumatoide/complicaciones , Diagnóstico Precoz , Sensibilidad y Especificidad , Sinovitis/etiología , Ultrasonografía DopplerRESUMEN
The authors carried out an open prospective study analyzing methotrexate (MTX) efficacy and toxicity in 34 patients with ankylosing spondylitis (AS) for a period of one year. All the patients presented with active axial disease, characterized by inflammatory spinal pain, prolonged morning stiffness, erythrocyte sedimentation rate (ESR) > or = 25 mm, and failure on treatment with non-steroidal anti-inflammatory drugs for a period of more than two years. MTX was taken at a single weekly intramuscular dose of 12.5 mg. Thirty-one patients (91%) concluded treatment. Eighteen patients (53%) were considered responders to MTX; most of them presented peripheral arthritis. Despite clinical improvement, axial measures were unaltered at the end of the study. The mean value of ESR decreased significantly at the end of the treatment (p=0.0001), predominantly in the responders group. Side effects were observed in 23 patients (68%) and included dyspeptic syndrome, transient elevation of liver enzymes, and dizziness. The results of this one year open study suggest that MTX can be an efficient drug in the treatment of AS.
Asunto(s)
Antirreumáticos/uso terapéutico , Metotrexato/uso terapéutico , Espondilitis Anquilosante/tratamiento farmacológico , Adulto , Fosfatasa Alcalina/sangre , Antirreumáticos/administración & dosificación , Antirreumáticos/efectos adversos , Aspartato Aminotransferasas/sangre , Sedimentación Sanguínea/efectos de los fármacos , Dispepsia/inducido químicamente , Humanos , Inyecciones Intramusculares , Masculino , Metotrexato/administración & dosificación , Metotrexato/efectos adversos , Estudios Prospectivos , Espondilitis Anquilosante/sangre , Síndrome , Resultado del TratamientoRESUMEN
OBJECTIVE: To analyze patterns of disease in a population of Brazilian patients with primary ankylosing spondylitis (AS). METHODS: Retrospective study (1988-98) analyzing 147 patients with a diagnosis of primary AS according to the modified New York criteria. Selected patients had complete clinical (initial symptom, axial and peripheral involvement, heel enthesitis, extraarticular manifestations) and radiological (sacroiliac, lumbar, thoracic, and cervical spine) investigations, and these data were compared with sex, race, age at onset, and HLA-B27. RESULTS: There was a predominance of men (84.4%), Caucasian race (75.5%), adult onset (> 16 years, 85%), and positive HLA-B27 (78.2%). Family history of AS was noted in 14.3% of the patients. Pure axial AS was observed in 37 patients (25.2%). The predominant initial symptoms were inflammatory low back pain (61.9%) and peripheral arthritis (22.4%). Thoracic and cervical spine involvement was noted in 70.1% of the patients; radiological findings included syndesmophytes in 46.9% and "bamboo spine" in 20.4% of patients. The extraaxial joints most frequently involved were: ankles (39.5%), hips (36.1%), knees (29.3%), shoulders (19%), and sternoclaviculars (14.3%); heel enthesitis was present in 22.4%. Acute anterior uveitis was noted in 14.3% of patients. Male sex was associated with involvement of thoracic spine (p = 0.002), cervical spine (p = 0.002), and hips (p = 0.042), whereas female sex was associated with sternoclavicular (p = 0.024) involvement. Caucasian race presented higher frequency of positive family history (p = 0.023); there was no statistical significance of clinical and radiological variables compared with African-Brazilians. Juvenile onset AS presented higher frequency of ankle (p = 0.012) and knee (p = 0.001) involvement, heel enthesitis (p = 0.001), and total hip replacement (p = 0.038), whereas adult onset was associated with thoracic (p = 0.026) and cervical spine (p = 0.026) involvement and positive family history (p = 0.044). Positive HLA-B27 was associated with ankle involvement (p = 0.007) and heel enthesitis (p = 0.013). CONCLUSION: In this population women showed a milder axial involvement, Caucasian race presented axial and peripheral involvement similar to African-Brazilians, juvenile onset AS was associated with articular involvement of the lower limbs, and positive HLA-B27 was associated with ankle involvement.
Asunto(s)
Espondilitis Anquilosante/etnología , Adolescente , Adulto , Edad de Inicio , Anciano , Articulación del Tobillo , Brasil/epidemiología , Femenino , Predisposición Genética a la Enfermedad , Antígeno HLA-B27/genética , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Articulación Sacroiliaca , Distribución por Sexo , Espondilitis Anquilosante/genética , Uveítis Anterior/etnología , Uveítis Anterior/genéticaRESUMEN
The objective of the present study was to evaluate the contribution of the shared epitope (SE), the rheumatoid arthritis (RA) protection model, and the occurrence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA patients from a genetically diverse population. One hundred and forty Brazilian RA patients and 161 matched controls were typed for HLA-DRB1 alleles using amplified DNA hybridized with sequence-specific oligonucleotide probes or primers. Patients were stratified according to the presence or absence of SE (DRB1*0401, *0404, *0405, *0101, *1001, and *1402), of the DERAA alleles (DRB1*0103, *0402, *1102, *1103, *1301, *1302, and *1304), and X (all other alleles). Anti-CCP antibodies were measured by ELISA. The combined frequency of SE-positive alleles was significantly greater (76.4 vs 23.6 percent, P < 0.0001) than the controls. The SE/SE and SE/X genotypes were over-represented (P < 0.0001, OR = 6.02) and DERAA/X was under-represented in RA patients (P < 0.001, OR = 0.49), whereas the frequencies of the SE/DERAA, X/X and X/DERAA genotypes were not significantly different from controls. The frequency of anti-CCP antibodies was higher in SE-positive patients than in SE-negative patients (64.6 vs 44.7 percent, P = 0.03; OR = 2.25). Although the Brazilian population is highly miscegenated, the results of this study support the findings observed in most genetically homogeneous populations with RA; however, they are not mutually exclusive but rather complementary. The participation of DRB1-DERAA alleles in protection against RA was also observed (OR = 0.4; 95 percentCI = 0.23-0.68).