Inmunopatología de la brucelosis osteoarticular / Immunopathology of osteoarticular brucelosis

La brucelosis es una de las enfermedades zoonóticas más importantes a nivel mundial capaz de producir enfermedad crónica en los seres humanos. La localización osteoarticular es la presentación más común de la enfermedad activa en el hombre. Sin embargo, algunos de los mecanismos moleculares implicados en la enfermedad osteoarticular han comenzado a dilucidarse recientemente. Brucella abortus induce daño óseo a través de diversos mecanismos en los cuales están implicados TNF-α y RANKL. En estos procesos participan células inflamatorias que incluyen monocitos/macrófagos, neutrófilos, linfocitos T del tipo Th17 y linfocitos B. Además, B. abortus puede afectar directamente las células osteoarticulares. La bacteria inhibe la deposición de la matriz ósea por los osteoblastos y modifica el fenotipo de estas células para producir metaloproteinasas de matriz (MMPs) y la secreción de citoquinas que contribuyen a la degradación del hueso. Por otro lado, la infección por B. abortus induce un aumento en la osteoclastogénesis, lo que aumenta la resorción de la matriz ósea orgánica y mineral y contribuye al daño óseo. Dado que la patología inducida por Brucella afecta el tejido articular, se estudió el efecto de la infección sobre los sinoviocitos. Estos estudios revelaron que, además de inducir la activación de estas células para secretar quemoquinas, citoquinas proinflamatorias y MMPs, la infección inhibe la muerte por apoptosis de los sinoviocitos. Brucella es una bacteria intracelular que se replica en el retículo endoplásmico de los macrófagos. El análisis de los sinoviocitos infectados con B. abortus indicó que las bacterias también se multiplican en el retículo endoplasmático, lo que sugiere que la bacteria podría usar este tipo celular para la multiplicación intracelular durante la localización osteoarticular de la enfermedad. Los hallazgos presentados en esta revisión intentan responder a preguntas sobre los mediadores inflamatorios implicados en el daño osteoarticular causado por Brucella. (AU)

Brucellosis is one of the most important zoonotic diseases that can produce chronic disease in humans worldwide. Osteoarticular involvement is the most common presentation of human active disease. The molecular mechanisms implicated in bone damage have started to be elucidated. B. abortus induces bone damage through diverse mechanisms in which TNF-α and RANKL are implicated. These processes are driven by inflammatory cells, including monocytes/macrophages, neutrophils, Th17 lymphocytes and B cells. Also, Brucella abortus (B. abortus) can directly affect osteoarticular cells. The bacterium inhibits bone matrix deposition by osteoblast and modifies the phenotype of these cells to produce matrix methalloproteinases (MMPs) and cytokine secretion that contribute to bone matrix degradation. B. abortus also affects osteoclast increasing mineral and organic bone matrix resorption and contributing to bone damage. Since the pathology induced by Brucella species involves joint tissue, experiments conducted in sinoviocytes revealed that besides inducing the activation of these cells to secrete chemokines, proinflammatory cytokines and MMPS, the infection also inhibits sinoviocyte apoptosis. Brucella is an intracellular bacterium that replicate in the endoplasmic reticulum of macrophages. The analysis of B. abortus infected sinoviocytes indicated that bacteria also replicate in their reticulum suggesting that the bacterium could use this cell type for intracellular replication during the osteoarticular localization of the disease. The findings presented in this review try to answer key questions about the inflammatory mediators involved in osteoarticular damage caused by Brucella. (AU)

Anti-CCP2 and anti-keratin antibodies in rheumatoid and osteoarthritis patients

The use of the autoantibodies family directed to Citrulline-containing peptides including antibodies to cyclic citrullinated peptides2 [Anti CCP2] and Anti Keratin Antibodies [AKA] test is growing worldwide in the diagnosis of rheumatoid arthritis [RA]. To determine the frequency of Anti CCP2 and AKA and their relation to activity and severity in patients with RA and Osteoarthritis [OA]. 60 patients were recruited for the study; they were equally divided into two groups according to their diagnosis [RA and OA groups]. The thirty patients with RA were diagnosed according to the Revised Criteria for Classification of Rheumatoid Arthritis by the ACR [Arnett et al, 1988]. The thirty Patients with OA were fulfilling the criteria for classification of OA proposed by Altman [1991]. Patients' charts were reviewed for demographic information, clinical diagnosis, and radiographic information. They all had their peripheral blood sampled for CRP, CBC, ESR, IgM RF titre, Anti CCP2 and AKA. The comparison between both studied groups showed significant difference between disease duration and patient's assessment of pain by Visual analog scale [VAS] [p<0.05], while there was no significant difference between both diseases as regard patient's and physician's global assessment of disease activity [p>0.05]. The comparison between both studied groups showed also highly significant differences regarding age, duration, as well as CRP, ESR, Anti CCP2, AKA and IgM RF [p<0.01]. The relation between Activity of RA and severity of OA showed significant relation between both, as regard to Patient's Assessment Of Physical Function [Pt Ass Ph F] in RA patients and OA severity assessed according to Lequesne and Samson, 1991 [p<0.05]. In RA patients, there were significant correlations between each of IgM RF and Anti CCP2 with joint erosions [p<0.05], while there was no significant correlation as regard AKA with joint erosions [p>0.05]. the correlation between each of the IgM RF, Anti-CCP2 and AKA with the clinical assessment items in RA patients [age, disease duration, TJC, SJC, patient's assessment of pain, patient's global assessment of disease activity and physician's global assessment of disease activity showed no significant correlation except for disease duration with AKA [p<0.05]. None of the laboratory assessment items [ESR, CRP, IgMRF, Anti CCP2, and AKA] showed any significant correlation, except for CRP, with both IgM RF and Anti CCP2 [p<0.05]. Also there was a significant correlation between IgM RF and Anti CCP2 [p<0.05]. We concluded that anti-CCP2 could be a very useful serological assay for the diagnosis of RA, because anti-CCP2 revealed higher diagnostic specificity than RF and AKA and could be performed with an easy technique. It also has an independent role in predicting disease activity and has a prognostic value as a marker of erosive disease in RA

Detection of antibodies against glucose 6-phosphate isomerase in synovial fluid of rheumatoid arthritis using surface plasmon resonance (BIAcore)

We have used a surface plasmon resonance biosensor (SPR, BIACORE 2000) to detect antibodies against glucose 6-phosphate isomerase (GPI) in synovial fluids of rheumatoid arthritis (RA) and osteoarthritis (OA). Recombinant human GPI proteins fused with or without NusA were expressed in E. coli, purified to homogeneity and immobilized in flow cells of CM5 sensor chips. The flow cells immobilized with NusA protein or bovine serum albumin were used to monitor non-specific binding. Synovial fluid samples from RA patients showed a significantly higher level of binding to recombinant GPI proteins than samples from OA patients. Proteins which bound to the recombinant GPI proteins were confirmed to be immunoglobulin through the administration of anti-human immunoglobulin. NusA fusion protein was excellent for this assay because of a low background binding activity in the SPR analysis and its advantage of increased solubility in recombinant protein production. These results suggested a useful utilization of recombinant NusA-GPI fusion protein for the detection of autoantibodies against GPI in RA patients.

Anticuerpos contra citoplasma de neutrófilo (ANCAs) en lupus eritomatoso sistémico y artritis reumatoidea

Los ANCAs con positividad para proteinasa-3 se han asociado con granulomatosis de Wegener y los dirigidos contra mieloperoxidasa se han descrito en enfermedades caracterizadas por inflamación como la colitis ulcerativa, enfermedad hepática autoinmune y artritis reumatoidea. El objeto de este estudio fue determinar la prevalencia de ANCAs en pacientes con AR, LES Y OA y su posible relación con actividad de la enfermedad o vasculitis Material y métodos: Estudiamos 50 pacientes, 20 de LES, 20 de AR y 10 de OA. Los ANCAs se determinaron por técnicas de IFI y ELISA para mieloperoxidasa (MPO) y proteinasa-3 (PR-3). En los pacientes con LES se les determinó la actividad por criterios de Liang y cols, en los de AR por el índice de Ritchie y en los de OA por parámetros clínicos. Además se evaluó la presencia de vasculitis clínicamente. Resultados: De los pacientes con AR, 12 estabna activos, 8 inactivos. Los ANCAs fueron positivos por IFI (O-ANCA) en 3 casos (15 por ciento) y ELISA para MPO, todos con enfermedad activa. En LES 13 estaban activos y 7 inactivos. Los ANCAs fueron positivos en 9 pacientes (45 por ciento), 6 activos, 3 inactivos todos con patrón P-ANCA y positividad para MPO. Los pacientes con OA fueron negativos tanto para IFI como para ELISA. Ninguno de los pacientes con AR y LES tenian vasculitis. Conclusión: la prevalencia de ANCAs en AR y LES, prototipos de enfermedad inflamatoria crónica es alta: 15 por ciento en AR y 45 por ciento en LES. Aun cuando en LES hubo positividad de ellos en enfermedad inactiva, la mayor incidencia se observó en pacientes con enfermedad activa. Consideramos que el patrón P-ANCA es inespecífico y podría ser un marcador de inflamación crónica