Clinical feature analysis of 6 cases of delayed diagnosis of anti-synthetase antibody syndrome / 中华风湿病学杂志

ABSTRACT

Objective:To improve the diagnosis of anti-synthetase antibody syndrome(ASS) by analyzing the clinical features of 6 patients.Methods:Six cases of ASS with complete data were included in this study as they were diagnosed or other CTD during the period of hospitalization in Wuxi People's Hospital from January 2016 to February 2020. Their clinical and laboratory characteristics, and follow-up information were analyzed. Features and changes in the course of disease were analyzed.Results:Four out of 6 patients were females, with age of disease onset as 34-72 years, and an interval of 4-59 months from the first diagnosis to the diagnosis of ASS. The first diagnosis was Sjogren's syndrome (SS) in 2 cases, rheumatoid arthritis (RA) in 1 case, mixed connective tissue disease (MCTD) in 1 case, systemic sclerosis (SSc) in 1 case, and undifferentiated connective tissue disease (UCTD) in 1 case. At the first diagnosis, 5 cases had dry cough and/or dyspnea, followed by fever (4 cases), arthritis and Raynaud's phenomenon (3 cases). Anti-nuclear antibody(ANA), which was more common in cytoplasmic type, and anti-SSA/52 000 antibody were mostly positive(5 cases). The presence of non-specific interstitial pneumonia (NSIP) pattern (6 cases) in high resolution CT(HRCT) was found at the initial diagnosis. During follow-up, patients developed repeated liver function or muscle enzyme abnor-malities (3 cases), mechanic's hand (MH) (3 cases), and lung interstitial disease progression (4 cases). The myositis antibodies were found to be positive.Conclusion:ASS can occur in the course of or at the same time as other CTDs. ASS should be considered in patients with interstitiallung disease (ILD) (especially NSIP pattern) in HRCT, and/or positive of cytoplasmic type ANA and/or anti-SSA/52 000 antibodies At the same time, if repeated liver function or muscle enzyme abnormalities, new onset of MH, and lung interstitial disease progresses during treatment, consideration may be given to the possibility of complicated ASS. Myositis-specific antibodies are helpful in the diagnosis of ASS.