RESUMEN
OBJECTIVES: Interleukin (IL) 34 is a new cytokine implicated in macrophage differentiation and osteoclastogenesis. This study assessed IL-34 expression in the tissue of patients with rheumatoid arthritis (RA). METHODS: Immunohistochemistry was performed in synovial biopsies from patients with RA (n=20), osteoarthritis (n=3) or other inflammatory arthritis (n=4). IL-34 was detected in the synovial fluid by ELISA and its messenger RNA expression was studied by quantitative PCR in rheumatoid synovial fibroblasts after stimulation by tumour necrosis factor α (TNFα) and IL-1ß. Wild-type, jnk1(-/-)-jnk2(-/-) and nemo(-/-) murine fibroblasts and pharmacological inhibition were used to determine the involvement of nuclear factor kappa B (NF-κB) and JNK in that effect. RESULTS: IL-34 was expressed in 24/27 biopsies, with three samples from RA patients being negative. A significant association was found between IL-34 expression and synovitis severity. Levels of IL-34 and the total leucocyte count in synovial fluid were correlated. TNFα and IL-1ß stimulated IL-34 expression by synovial fibroblasts in a dose/time-dependent manner through the NF-κB and JNK pathway. CONCLUSION: This work for the first time identifies IL-34 expression in the synovial tissue of patients with arthritis. This cytokine, as a downstream effector of TNFα and IL-1ß, may contribute to inflammation and bone erosions in RA.
Asunto(s)
Artritis Reumatoide/metabolismo , Interleucinas/metabolismo , Sinovitis/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/complicaciones , Artritis Reumatoide/genética , Células Cultivadas , Relación Dosis-Respuesta a Droga , Femenino , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-1beta/farmacología , Interleucinas/genética , Sistema de Señalización de MAP Quinasas/fisiología , Masculino , Persona de Mediana Edad , FN-kappa B/fisiología , Osteoartritis/genética , Osteoartritis/metabolismo , ARN Mensajero/genética , Líquido Sinovial/metabolismo , Sinovitis/etiología , Sinovitis/genética , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
OBJECTIVE: Septic arthritis of the facet joint is a rare clinical entity. We report 11 cases of facet joint infections diagnosed in our institution. PATIENTS AND METHOD: Patients were identified via the computerized patients record (PMSI). Their features were collected and compared with published data. RESULTS: The clinical symptoms are similar to those of infectious spondylodiscitis: back pain with stiffness (11/11), fever (9/11), radicular pain (5/11), and asthenia. Ten patients presented with lumbar infection and 1 with dorsal infection. An inflammatory syndrome was observed in every case. A rapid access to spine MRI allowed making the diagnosis in every case, and assessing a potential extension of infection (epidural extension 5/11, paraspinal extension 5/11). Blood culture (8/11) or culture of spinal samples allowed identifying the causative bacterium in every case and adapting the antibiotic treatment. The bacteria identified in our series were different from previously reported ones, with less staphylococci. The origin of the infection was found in 4 cases. Another localization of infection was observed in 4 cases. The outcome was favorable with medical treatment in 10 cases. An abscess was surgically drained in 1 case. None of our patients presented with neurological complications, probably because of the rapid diagnosis. CONCLUSION: Assessing the facet joint is essential in case of inflammatory back pain, and the radiologist must be asked to perform this examination.