Clinical characteristics of systemic lupus erythematosus combined with symptomatic knee osteonecrosis / 西安交通大学学报(医学版)

ABSTRACT

【Objective】 To investigate the clinical characteristics and risk factors of systemic lupus erythematosus （SLE） combined with symptomatic knee osteonecrosis （KON）. 【Methods】 We retrospectively analyzed the clinical data of 26 cases of SLE with KON treated in the Department of Rheumatology and Immunology， The First Affiliated Hospital of Xi’an Jiaotong University， from April 2013 to December 2019. 【Results】 The age of the 26 patients （2 males and 24 females） was （35.3±9.0） years old at the diagnosis of KON， and the course of SLE was （48.7±35.1） months. The time from glucocorticoids initiation to the development of KON was （37.8±42.7） months， the maximum dosage of methylprednisolone was （197.7±290.7）mg and the cumulative dosage was （6.02±6.66）g. Six of the patients had a history of large-dose glucocorticoids impulse therapy. All of them had a history of immunosuppressant treatment. SLEDAI score was （11.23±5.46） at the onset of SLE and （4.46±4.81） at the onset of KON. The most common initial symptoms were edema and arthritis. The most common systemic damages were blood system damage and lupus nephritis. The most common immunological abnormalities were positive antinuclear antibody （25/26）， positive anti-SSA/Ro52kD antibody （16/26）， and positive anti-SmD1 antibody （15/26）. There were 4 patients with positive anticardiolipin antibody （ACA）. Bone metabolism was characterized by vitamin D3 （Vit-D3） deficiency， insufficient N-terminal osteocalcin （N-OST）， and increased β-C-terminal telopeptide of type I collagen （β-CTx）. In 9 out of the 26 patients， SLE was combined with aseptic necrosis of the femoral head. Multifocal bone necrosis （at least 3 lesions） was common （12/26）. Longer disease course and glucocorticoids using time， larger cumulative dose and ACA positive were seen in patients with multifocal bone necrosis compared with those who had one lesion site. 【Conclusion】 KON most possibly occurs 3 to 4 years after the diagnosis of SLE， which is associated with high disease activity， large hormone dose， and long duration in the treatment process. Multifocal bone necrosis is easily seen in patients with severe disease， large initial hormone dose and high cumulative dose， as well as in ACA positive patients.