Introduction: Rheumatoid arthritis (RA) is biologically marked by a positive serum rate of rheumatoid factor (RA) and/or anti-citrullinated protein antibodies (ACPA). Nevertheless, 20% of RA cases remain seronegative. Objective: The main purpose of this study, is to bring out the clinical, biological, imaging, therapeutic, and evolutionary distinctions between seropositive RA and seronegative one. Methods: This is an observational cross-sectional study that involves patients with RA admitted in the rheumatology department, from the period between January 2012 and January 2018. RA seronegativity is described as the absence of both RF and ACPA, while seropositivity is recognized by the presence of at least one of the two antibodies. Results: 294 patients were included, of which 90% were seropositive and 10% seronegative. Therefore, RA in this study is seropositive most often. The bivariate analysis underscored plenty of differences, statistically notable, according to the RA immune status. In fact, patients with seropositive RA had more synovitis (p=0.049), more deformities (p=0.01), and more bone destruction on radiographs (p=0.04). Furthermore, RA in this Moroccan study was quite severe (p=0.006) and got more complicated by systemic manifestations (p=0.02). Whereas, no distinction was brought up between the two groups, concerning the use of biotherapy. As for the multivariate study, seropositive RA in these patients, had greater severity (p=0.009, OR=4.53) and was more deforming (p=0.03 OR=2.45). Conclusion: RA in our Moroccan context is dominated by the seropositive form. This seropositivity is often coupled with clinical severity and joint destruction, resulting in more deformities.

Introduction: Magnetic resonance imaging of sacroiliac joints (MRI SI) is the gold standard imaging tool for axial spondyloarthritis (ax SpA) diagnosis, when the pelvic radiograph is normal or non-conclusive. In fact, subchondral bone marrow edema (BME) is the primary MRI feature of early ax SpA. The associated factors with active sacroiliitis on MRI are still not properly elucidate. The main objective of this study is to identify the relationship between active sacroiliitis on MRI, biomarkers of inflammation and Disease Activity Scores.Materials and methods: Our work could be categorized as a cross sectional study that enrolls all patients with non-radiographic axial spondyloarthritis (nr axSpA), meeting each; the assessment of SpondyloArthritis international Society axSpA criteria (ASAS 2009), and who were admitted in our Rheumatology Department, in the university hospital Hassan II of Fez (Morocco), all along the period laying between January 2012 and March 2018. The relationship between MRI-SI, Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), C reactive protein and erythrocyte sedimentation rate was investigated. Results: 105 patients were involved in the study. The average age was [44years ± 13.5]. The Sex ratio was about [1.4]. 29 % of patients were smokers. 76% of cases had active sacroiliitis on MRI, while only 28% had inactive sacroiliitis. The average CRP serum level was roughly [23.5 ± 36mg / l]. On the other side, the ESR blood level was almost [25.9±24mm/h]. 94.2% of patients used non-steroidal antiinflammatory drugs (NSAIDs). The average ASDAS value was about [2.3 ± 1]. Whereas the BASDAI one was [4.2± 1], and the BASFI one was about [4± 1.5]. Actually, No significant relationship was found between active sacroiliitis and inflammation’s biomarkers. Indeed, men had 5.6 times more active sacroiliitis, of which smokers had even 3 times more the risk to develop active sacroiliitis, while treatment with NSAIDs was proved to be a protective factor. Conclusion: Biomarkers of inflammation cannot be used as a marker of objective inflammation of sacroiliac joints on MRI; hence, the necessity of MRI screening, and more additional studies with larger number of patients, should be conducted, to identify this association even better.