Objective：To investigate the pathogenic factors and clinical and laboratory features of patients with ankylosing spondylitis （AS） and rheumatoid arthritis（RA）. Methods：A retrospective analysis was performed for the clinical data of two patients with AS and RA who were diagnosed in Department of Rheumatology，People’s Hospital Affiliated to Fujian University of Traditional Chinese Medicine，and a literature review was performed to summarize the clinical，laboratory，and imaging features of such patients. Results：The pathogenesis of AS with RA was associated with genetic factors，pathogen infection，smoking，and immune abnormalities，with the involvement of common cytokines. AS with RA was commonly seen in young and middle-aged women，with a disease onset in youth and low back pain or lumbosacral pain as initial symptoms. Radiological examination showed sacroiliitis in all patients，peripheral arthritis in most patients，and bamboo spine in some patients. The patients with AS and RA had a lower positive rate of human leuko－cyte antigen-B27 than those with AS alone and similar positive rates of rheumatoid factor and anti-cyclic citrullinated peptide anti－body as those with RA alone. The patients with AS and RA had a high degree of disease activity and poorer treatment response than those with AS or RA alone；early，active，and combined medication could be given，and glucocorticoids and/or biological agents could be used in patients with a severe refractory disease. Conclusion：The pathogenesis of AS with RA is associated with multiple factors. AS with RA is commonly seen in young and middle-aged women and has complex initial symptoms. There is a high degree of disease activity and severe bone destruction on imaging. Early diagnosis and active treatment should be performed.
