Objective To re-evaluate the diagnoses of ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis (nr-axSpA) and analyze the incidence and reason of misdiagnosis.Methods Patients who were previously diagnosed as AS and nr-axSpA before referrals to Peking Union Medical College Hospital (PUMCH) were re-evaluated by three rheumatologists of PUMCH according to the modified New York criteria for AS and Assessment of SpondyloArthritis international Society (ASAS) axial SpA classification criteria for nr-axSpA.Results Totally 87 prior AS patients and 53 prior nr-axSpA patients were enrolled in this study.After re-evaluation,57 patients were still diagnosed as AS and 16 patients were still diagnosed as nr-axSpA.The misdiagnosis incidences were 34.48％ and 69.81％,respectively.The misdiagnosis incidence of nr-axSpA was higher than that of AS (P ＜ 0.01).Conclusions The misdiagnosis of AS were mainly due to the misjudgment of sacroiliac joints by CT.The misdiagnosis of nr-axSpA were mainly due to the misjudgment of sacroiliac joints by magnetic resonance imaging.Moreover,the misuse of ASAS axial SpA classification criteria contributed to the misdiagnosis also.

Objective To investigate the prevalence of HBV infection and the risk of hepatitis B virus (HBV) reactivation in patients with inflammatory arthritis receiving tumour hecrosis factor alpha (TNFα) inhibitors.Methods The liver function,serology of HBV and viral loads (HBV DNA) were tested before using TNFα inhibitors,at 3 months and 6 months.Patients with chronic hepatitis B (CHB) infection (HBV DNA ＞ 1 × 103copies/ml) were eliminated.Results A total of 162 patients were investigated including 156 patients who finished the study.Eleven (7.05％) patients were HBsAg-positive.Two patients with HBV DNA ＞ 1 × 103copies/ml were eliminated before starting anti-TNFα therapy.Among HBsAgpositive patients,HBV reactivation was documented in only one of the 11 patients.This patient with rheumatoid arthritis developed elevation of glutamic-pyruvic transaminase (ALT) and HBV DNA copies three months after infliximab therapy.Therefore lamivudine was given for three months,which translated into the fall of ALT and HBV DNA copies back to normal level.After follow-up for six months,the virology and serology remained stable.In contrast,none of the other 155 patients had demonstrated evidence of HBV infection or HBV reactivation.Conclusion The kinetics of HBV viral loads should be carefully monitored in patients with inflammatory arthritis and HBsAg-positive during anti-TNFα therapy.HBV reactivation should be treated with antiviral medicine through out the period of anti-TNFα therapy.