RESUMO
Introduction: Evidence-based data suggest that under inflammatory conditions, classical monocytes are the main source of osteoclasts and might be involved in bone erosion pathophysiology. Here, we analyze the transcriptomic profile of classical monocytes in erosive and non-erosive rheumatoid arthritis patients in order to better understand their contribution to bone erosion. Methods: Thirty-nine premenopausal RA patients were consecutively enrolled and divided into two groups based on the presence of bone erosions on hand joints. Classical monocytes were isolated from peripheral blood through negative selection, and RNA-seq was performed using a poly-A enrichment kit and Illumina® platform. Classical monocytes transcriptome from healthy age-matched women were also included to identify differentially expressed genes (DEGs). Therefore, gene sets analysis was performed to identify the enriched biological pathways. Results: RNA-seq analysis resulted in the identification of 1,140 DEGs of which 89 were up-regulated and 1,051 down-regulated in RA patients with bone erosion compared to those without bone erosions. Among up-regulated genes, there was a highlighted expression of IL18RAP and KLF14 related to the production of pro-inflammatory cytokines, innate and adaptive immune response. Genes related to collagen metabolism (LARP6) and bone formation process (PAPPA) were down-regulated in RA patients with erosions. Enriched pathways in patients with erosions were associated with greater activation of immune activation, and inflammation. Interestingly, pathways associated with osteoblast differentiation and regulation of Wnt signaling were less activated in RA patients with erosions. Conclusion: These findings suggest that alterations in expression of monocyte genes related to the inflammatory process and impairment of bone formation might have an important role in the pathophysiology of bone erosions in RA patients.
Assuntos
Artrite Reumatoide , Monócitos , Humanos , Feminino , Monócitos/metabolismo , Transcriptoma , Inflamação/genética , Inflamação/metabolismo , Perfilação da Expressão GênicaRESUMO
OBJECTIVES: To analyze longstanding polyarticular juvenile idiopathic arthritis (pJIA) for possible associations between localized bone damage (erosions), and systemic bone loss. Besides, to compare the systemic bone mass of pJIA with healthy controls. METHODS: Thirty-four pJIA women and 99 healthy controls (HC) were included. Radius and tibia of all subjects were scanned by HR-pQCT. Volumetric bone mineral density (vBMD), bone microarchitecture, and -finite element parameters were analyzed. Patients underwent HR-pQCT of 2nd and 3rd metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of the dominant hand, for bone erosions quantification. RESULTS: The mean age of patients was 31.5 ± 7.4yrs with a mean disease duration of 21.7 ± 9.2yrs. Bone erosions were detectable in 79% of patients. The number of bone erosions was positively correlated with cortical porosity (Ct.Po) at tibia (r = 0.575, p = 0.001), and radius (r = 0.423, p = 0.018); and negatively correlated with cortical vBMD at tibia (r=-0.420, p = 0.015). In a logistic regression analysis, adjusted for anti-CCP, the presence of bone erosions was independently associated with Ct.Po at radius (p = 0.018) and cortical vBMD at tibia (p = 0.020). Moreover, cortical and trabecular vBMD, trabecular number, and µ-finite element parameters were decreased in patients compared to HC (p < 0.05). CONCLUSION: Bone erosions in longstanding pJIA women were associated with decreased cortical bone parameters, and these patients showed systemic bone impairment at peripheral sites compared with healthy controls.
Assuntos
Artrite Juvenil , Osteoporose , Humanos , Feminino , Adulto Jovem , Adulto , Artrite Juvenil/complicações , Artrite Juvenil/diagnóstico por imagem , Densidade Óssea , Rádio (Anatomia) , Tomografia Computadorizada por Raios X , Tíbia/diagnóstico por imagem , Absorciometria de FótonRESUMO
BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disease depicted by synovial inflammation leading to local and systemic bone loss. The aim of this study was to evaluate by a HR-pQCT (High Resolution Peripheral Quantitative Computed Tomography) study which parameters are associated with volume of bone erosions including bone mineral density (BMD) around erosions (VOI 1 to 4 = volume of interest), BMD of metacarpophalangeal (MCP) head, BMD of radius, presence of osteophytes and joint space width (JSW). METHODS: Fifty female RA patients (18-50 years) were enrolled in this study. Demographic and disease-specific data, laboratory inflammatory parameters and handgrip test were performed. All patients underwent HR-pQCT of 2nd and 3rd MCP joints and distal radius, according to established protocols. The volume of bone erosions was evaluated by MIAF (Medical Image Analysis Framework) software. Osteophytes were analyzed by manual method. RESULTS: The mean of age and disease duration were 40.0 ± 6.0 yrs. and 10.8 ± 4.8 yrs., respectively. According to DAS-28 (Disease Activity Score), 54% (27) of the sample were in remission. However, when SDAI (Simplified Disease Activity Index) was used, only 18% (9) were under remission. The mean of HAQ (Health Assessment Questionnaire), ESR (Erythrocyte sedimentation rate) and CRP (C reactive protein) were 0.9 ± 0.7, 13.9 ± 12.2 mm and 5.6 ± 7.5 mg/mL, respectively. Forty-six bone erosions (0.9 ± 1.2 erosion/patient) and 14 osteophytes (0.3 ± 0.7 osteophyte/patient) were found in 2nd MCP head. The median (IQR-Interquartile range) of volume of erosion and volume of osteophytes were 14.9 (5.7;35.9)mm3 and 3.1 (2.1, 4.3)mm3, respectively. The mean of JSW was 80.5 ± 34.2 mm3. The volume of bone erosions was negatively correlated with BMD of 2nd MCP head, VOI-4 and JSW; and it was positively correlated with osteophytes number. Regarding absence or presence of erosion in 2nd MCP head, a significant difference was found between BMD of MCP head, osteophyte number and JSW. Multiple linear regression analysis showed that only BMD of 2nd MCP head was independently associated with volume of bone erosions. CONCLUSION: BMD of MCP head was independently associated with volume of bone erosion, suggesting that this parameter should be used to analyze and monitoring bone destruction, as well as to evaluate treatment response in RA patients.