OBJECTIVE: To investigate the clinical and immunological characteristics of anti-synthetase syndrome (ASS) patients overlap with rheumatoid arthritis (RA). METHODS: A retrospective analysis was conducted on ASS patients with arthritis who were treated at Peking University People' s Hospital. Data collected included demographic information, clinical manifestations, laboratory features, lymphocyte subsets in peripheral blood, and treatments. The patients with ASS were divided into two groups based on the presence or absence of RA for comparative analysis. RESULTS: A total of 104 ASS patients with arthritis were included, among whom 23.1% (24/104) were diagnosed with RA. The ASS with RA group had a significantly higher incidence of rapidly progressive interstitial lung disease (RP-ILD) (41.7% vs. 17.6%, P=0.032), number of tender joints [10 (7, 14) vs. 4 (0, 8), P < 0.001], number of swollen joints [4 (2, 8) vs. 2 (0, 4), P=0.012], and rate of bone erosion (47.8% vs. 2.5%, P < 0.001) compared with the non-RA group. Levels of platelets [(289.57±68.74)×10³/μL vs. (247.94±77.04)×10³/μL, P=0.022], erythrocyte sedimentation rate (ESR) [43 (19, 59) mm/h vs. 18 (10, 44) mm/h, P=0.019], and C-reactive protein (CRP) [19.20 (4.80, 55.36) mg/L vs. 5.68 (1.10, 14.96) mg/L, P=0.006] were found significantly higher in the ASS with RA group than those in non-RA group. Analysis of immune cells in peripheral blood mononuclear cell (PBMC) showed that significantly decreased proportions of CLA⁺ Treg cells [(11.12±4.10)% vs. (17.22±8.49)%, P=0.003], B cells [8.56% (4.80%, 11.90%) vs. 14.55% (8.75%, 20.29%), P=0.025], and natural killer (NK) cells [7.56% (4.65%, 13.20%) vs. 13.25% (7.46%, 19.25%), P=0.045] in the overlap group compared with non-RA group. Proportion of Naïve Th cells [(52.66±17.66)% vs. (40.76±14.96)%, P=0.033)] was significantly increased in overlap group compared with non-RA group. Overlap group had lower rate of complete clinical response than non-RA group (16.7% vs. 43.8%, P=0.031). CONCLUSION Among ASS patients with arthritis, those with RA have more severe lung and joint involvement and a lower treatment response rate, highlighting the need for early recognition and aggressive intervention.
Humans ; Arthritis, Rheumatoid/immunology* ; Retrospective Studies ; Lung Diseases, Interstitial/immunology* ; Male ; Myositis/blood* ; Female ; Middle Aged ; Autoantibodies/blood*

This article reported the clinical features of a rare patient with anti-metabotropic glutamate receptor 5 （mGluR5） encephalitis with mental disorders as the initial symptom， so as to provide references for clinical diagnosis and treatment. The patient was a 38-year-old male， developed pharyngeal pain as prodromal symptoms， and the main clinical manifestations included rapidly progressive memory loss， anxiety and depression， and psychomotor excitement symptoms including irritability and impulsive behaviors. The disease had a progressive deterioration. In the most severe state， the patient became unconscious in a shallow coma， with further cognitive decline， hallucinations and delusions， and lack of self-awareness. Both cerebrospinal fluid and serum anti-mGluR5 antibody were strongly positive （1∶100）. After two sessions of hormone shock therapy， the patient showed significantly improvement in consciousness， cognitive， emotional and psychiatric dimensions.